Efficacy and safety of adjuvant targeted immunotherapy for hepatocellular carcinoma with high recurrence risks after hepatectomy

Abstract

BACKGROUND

Postoperative recurrence of hepatocellular carcinoma (HCC) is an important factor affecting long-term patient survival, and there is a lack of effective methods to reduce the chance of recurrence and metastasis after hepatectomy.

AIM

To study the efficacy and safety of targeted and/or immunotherapy for HCC with high recurrence risks after hepatectomy, and to explore the target population that would benefit from receiving adjuvant therapy after hepatectomy.

METHODS

A retrospective analysis of 1708 patients for hepatic resection for HCC from January 2019 to August 2022. According to whether or not they received postoperative immunotherapy and/or molecular-targeted therapy, they were divided into the adjuvant therapy group and the surgery-only group. The primary study endpoint was relapse-free survival, and secondary outcomes were overall survival (OS) and treatment-related adverse events. Cox analyzes were applied to find risk factors affecting recurrence-free survival. Subgroup analyzes were performed to further compare the targeted therapy, immunotherapy and targeted therapy combined with immunotherapy groups in the adjuvant therapy group in order to explore the safety and efficacy of adjuvant therapy.

RESULTS

Postoperative tumor recurrence was observed in 230 cases (61.8%), of which 122 cases (32.7%) had tumor recurrence within one year after surgery. The OS rate was 95.9% (357/372). Analysis of prognosis yielded a statistically significant difference in recurrence free survival (RFS) between the two groups (median RFS, 26.0 months vs 14.0 months, P = 0.028), while OS was not statistically significant (P = 0.620). Multifactorial Cox regression analysis in the entire cohort identified independent prognostic factors for RFS including receipt of adjuvant therapy (P = 0.005, hazard ratio = 0.657) and maximum tumor diameter (P = 0.039, hazard ratio = 1.006). In the subgroup analysis, the targeted therapy group had the highest 1-year RFS rate (88.6%) among all subgroups. In terms of safety, the most common adverse reactions were elevated alanine aminotransferase/aspartate aminotransferase (28.41%), hypertension (26.13%), rash or dermatitis (25.00%), and diarrhea (22.73%), and there were 4 cases of grade 3-4 adverse reactions (4.55%), and most of the adverse reactions were reversible.

CONCLUSION

Targeted and/or immunotherapy has shown better efficacy and safety in HCC patients at high risk of recurrence after hepatectomy.

Key Words: Hepatocellular carcinoma; Hepatectomy; Recurrence; Adjuvant therapy; Tyrosine kinase inhibitors; Immune-checkpoint inhibitors; Cohort study

Core Tip: This retrospective cohort study demonstrates that adjuvant targeted and/or immunotherapy can significantly improve recurrence-free survival in hepatocellular carcinoma patients at high risk of recurrence after hepatectomy, compared to surgery alone. The therapy was identified as an independent protective factor against recurrence. While a clear overall survival benefit was not observed in this analysis, the treatment regimen showed a manageable safety profile, with most adverse events being reversible. These findings support the potential role of this adjuvant strategy in improving outcomes for this patient population.

INTRODUCTION

Hepatocellular carcinoma (HCC) is the sixth most common malignant tumor globally and the fourth leading cause of cancer-related deaths[1]. Hepatic resection has long been the standard treatment for HCC, with a 5-year survival rate of 70%-80%[1,2]. However, the 5-year recurrence rate remains as high as 70%, presenting a significant challenge to long-term survival[3]. Postoperative adjuvant therapies are potential treatments aimed at reducing recurrence and improving prognosis. Local therapies such as transcatheter arterial chemoembolization[4], hepatic artery perfusion chemotherapy[5], portal vein perfusion chemotherapy[6], and radiation therapy have been widely used as adjuvant treatments following hepatic resection[7]. However, their effectiveness in reducing recurrence and improving survival is still uncertain, and there are no established recommendations in clinical guidelines[8]. The STORM trial confirmed that sorafenib, when used as an adjuvant therapy after hepatic resection, does not provide significant benefits in terms of disease recurrence or survival[9]. Nevertheless, several randomized controlled trials have demonstrated survival benefits with both local and systemic adjuvant therapies in patients at high risk of recurrence, such as those with microvascular invasion (MVI), satellite nodules, multiple tumors, alpha-fetoprotein (AFP) levels > 400 μg/L, and tumors larger than 5 cm[10-12]. Identifying the patient populations that would benefit most from adjuvant therapy is therefore crucial.

In recent years, targeted therapies and immunotherapy have significantly improved the prognosis of patients with HCC. The development of various anti-angiogenesis-targeted tyrosine kinase inhibitors and anti-vascular endothelial growth factor and anti- programmed death-1 (PD-1) antibodies has led to a paradigm shift in the clinical treatment of HCC[12,13]. Radical interventions for HCC comprise hepatectomy, liver transplantation, and ablation therapy, with hepatectomy being the most widely employed modality. Postoperative recurrence is categorized as early (typically within 2 years) or late (beyond 2 years)[14,15]. Established risk factors for early recurrence include multiple tumors, maximum tumor diameter > 5 cm, poor differentiation (Edmondson grade III-IV), microvascular or macrovascular invasion, lymph node metastasis, surgical margin ≤ 1 cm, and persistently elevated tumor markers such as AFP and/or des-gamma-carboxyprothrombin. In contrast, risk factors associated with late recurrence encompass age > 60 years, active chronic viral hepatitis, high hepatitis B virus (HBV) DNA levels (10⁶ copies/mL), hepatitis B surface antigen positivity, advanced liver cirrhosis (Ishak score > 6 or Scheuer score > 4), hypoalbuminemia, and multiple tumors[16-20]. Patients with identified risk factors for early recurrence, adjuvant therapy should be considered on an individualized basis. To date, no universally accepted adjuvant regimen has been established to effectively prevent recurrence or metastasis of HCC. Current investigations are actively exploring adjuvant strategies that integrate systemic anticancer therapies - including targeted agents and immune checkpoint inhibitors - with local treatments, either as monotherapy or in combination.

In the domain of postoperative adjuvant therapy for HCC, the multicenter, randomized, phase III IMbrave050 trial represents one of the most internationally recognized studies[21]. This trial demonstrated that adjuvant atezolizumab plus bevacizumab significantly improved recurrence-free survival in high-risk HCC patients after curative resection or ablation, with a manageable safety profile. IMbrave050 is the first phase III study to report positive outcomes for adjuvant systemic therapy in HCC. Nonetheless, while recurrence-free survival was significantly improved, overall survival (OS) data remain immature and subject to future analysis. Consequently, the adoption of this regimen as a standard adjuvant therapy remains debated, warranting further evaluation of its risk-benefit ratio and cost-effectiveness. Presently, evidence supporting other targeted or immunotherapeutic agents in the adjuvant setting remains limited.

Informed by conventional adjuvant approaches and the IMbrave050 findings, targeted and/or immunotherapy may represent potential postoperative strategies for high-risk HCC patients. However, clinical data supporting this approach are still scarce. This retrospective study aims to analyze clinical outcomes in high-risk HCC patients who underwent liver resection, comparing the safety and efficacy of surgery alone vs surgery followed by adjuvant targeted and/or immunotherapy. The objective is to evaluate the impact of such adjuvant treatments on short-term outcomes and long-term survival in this patient population.

MATERIALS AND METHODS

Data sources and recruitment

This study was approved by the Ethics Committee of the First Affiliated Hospital of Sun Yat-sen University. It retrospectively collected data from patients diagnosed with HCC who underwent hepatic resection at the First Affiliated Hospital of Sun Yat-sen University between January 2019 and August 2022. The cut-off date for follow-up was December 31, 2023. The inclusion criteria were as follows: (1) Age ≥ 18 years; (2) Postoperative histopathological confirmation of R0 surgical resection of HCC and comprehensive clinical judgment in line with R0 surgical resection (no signs of tumor residue or recurrence in radiological examination within 1-2 months after hepatectomy; preoperative AFP abnormalities reduced to normal within 2 months after surgery); (3) Eastern Cooperative Oncology Group Performance Status score ≤ 1; (4) Child-Pugh A or Child-Pugh B; (5) Hepatectomy performed at our hospital; and (6) Presence of one or more high-risk factors for recurrence: MVI, AFP > 400 μg/L, preoperative tumor rupture, vascular invasion, tumor envelope invasion or absence, poor tumor differentiation (Edmondson grade III-IV), lymph node metastasis, multiple tumors or the presence of satellite foci, and the largest tumor diameter ≥ 5 cm. The exclusion criteria were as follows: (1) Serious postoperative complications; (2) Complicated cardiac, pulmonary, cerebral, or renal dysfunction; (3) History of active autoimmune or immunodeficiency diseases; (4) Pathological diagnosis of cholangiocarcinoma or other types of cancers; (5) History of other malignant tumors; (6) Follow-up period of less than 6 months; (7) Incomplete clinical or follow-up data; (8) Age > 75 years; (9) Received local and/or systemic treatments prior to surgery; and (10) Received local treatments after surgery.

Data collection

Data collection encompassed demographic characteristics, preoperative and postoperative laboratory parameters, operative details, imaging features, and histopathological findings. Specific variables analyzed included: Laboratory indices - white blood cell count, neutrophil count and percentage, lymphocyte count and percentage, platelet count, alanine aminotransferase (ALT), aspartate aminotransferase (AST), γ-glutamyl transpeptidase, AFP, prothrombin time, prothrombin activity, international normalized ratio, activated partial thromboplastin time, hemoglobin, creatinine, hepatitis B surface antigen, hepatitis C virus antibody, quantitative HBV DNA, albumin, total protein, total bilirubin, direct bilirubin, and indirect bilirubin; surgical variables - type of resection, operative duration, intraoperative blood loss and transfusion volume, portal vein ligation status, resection margin width, tumor clinical classification, and length of hospital stay; and imaging characteristics - tumor size, number, presence of cirrhosis or ascites, vascular invasion, tumor rupture, satellite nodules, tumor encapsulation, and examination date. Additionally, among patients receiving adjuvant therapy, detailed records were obtained regarding targeted therapy regimens (including drug types and dosages) and immunotherapy protocols (including types and doses of PD-1/programmed death ligand-1 inhibitors, number of cycles, and administration dates). Clinical assessments included Child-Pugh score, Eastern Cooperative Oncology Group performance status, Barcelona Clinic Liver Cancer (BCLC) staging, China Liver Cancer (CNLC) staging, and postoperative pathology reports.

Study design and measurements

This retrospective cohort study analyzed patients diagnosed with HCC who underwent liver resection at the First Affiliated Hospital of Sun Yat-sen University between January 2019 and August 2022. After applying predefined inclusion and exclusion criteria, 372 patients were enrolled and stratified into two groups based on postoperative treatment: An adjuvant therapy group (n = 88), who received immunotherapy and/or molecular targeted therapy after surgery, and a surgery-alone group (n = 284). The study aimed to compare recurrence-free survival (RFS) and OS between the two groups, including 1-year RFS and OS rates. The primary endpoint was RFS; secondary endpoints included OS and treatment-related adverse events. Univariate and multivariate Cox regression analyzes were conducted to identify risk factors associated with RFS. Furthermore, subgroup analyzes were performed within the adjuvant therapy cohort to evaluate the safety and efficacy of different regimens - targeted therapy, immunotherapy, and their combination. The study design is shown in Figure 1.

Figure 1 Schematic description of the study design. ATG: Adjuvant therapy group; PSM: Propensity score matching; SG: Surgery-alone group.

Statistical analysis

Data management and statistical analyzes were performed using SPSS Statistics version 26.0 (IBM Corp., Armonk, NY, United States) and R software version 4.0 (R Foundation for Statistical Computing, Vienna, Austria). Graphical presentations were generated with GraphPad Prism version 9.0.0 (GraphPad Software, San Diego, CA, United States).

Continuous variables were tested for normality using the Kolmogorov-Smirnov test, Shapiro-Wilk test, and visual inspection of Q-Q plots. Normally distributed data are presented as mean ± SD and were compared using the Student’s t-test. Non-normally distributed data are expressed as median (interquartile range) and were compared using the Mann-Whitney U test. Categorical variables are summarized as n (%). Comparisons for unordered categorical variables were performed using the χ² test or Fisher’s exact test, as appropriate, while the Wilcoxon rank-sum test was applied for ordered categorical variables.

Survival analysis was conducted using Kaplan-Meier curves, and between-group differences in RFS and OS were assessed with the log-rank test. Univariate and multivariate Cox proportional hazards regression models were employed to identify independent prognostic factors associated with RFS. A two-sided P value of less than 0.05 was considered statistically significant for all tests.

RESULTS

Comparative analysis of recurrence sites and subsequent therapies

During follow-up, disease recurrence was observed in 47 patients (53.4%) in the adjuvant therapy group and in 62 patients (70.5%) in the surgery-alone group. The predominant pattern of first recurrence in both cohorts was intrahepatic-only recurrence, accounting for 42 patients (89.4%) in the adjuvant therapy group and 56 patients (90.3%) in the surgery-alone group. Extrahepatic metastasis alone was observed in 3 (6.4%) and 2 (3.2%) patients, while combined intra- and extrahepatic recurrence occurred in 2 (4.3%) and 4 (6.5%) patients in the adjuvant and surgery-only groups, respectively. No statistically significant difference was found in the patterns of first recurrence between the two groups (P = 0.790, Table 1).

Table 1 Patterns of initial recurrence and subsequent management strategies following surgery, n (%).

	Total (n = 109)	ATG (n = 47)	SG (n = 62)	P value
Recurrence site				0.790
Intrahepatic	98 (89.9)	42 (89.4)	56 (90.3)
Extrahepatic	5 (4.6)	3 (6.4)	2 (3.2)
Intrahepatic + extrahepatic	6 (5.5)	2 (4.3)	4 (6.5)
Post relapse treatment				0.475
Re-hepatectomy	30 (27.5)	11 (23.4)	19 (30.6)
Local + systemic treatment	18 (16.5)	7 (14.9)	11 (17.7)
Local therapy + radiofrequency ablation + systemic therapy	18 (16.5)	8 (17.0)	10 (16.1)
Radiofrequency ablation + systemic therapy	14 (12.8)	7 (14.9)	7 (11.3)
Local treatment	9 (8.3)	2 (4.3)	7 (11.3)
Radiofrequency ablation	8 (7.3)	6 (12.8)	2 (3.2)
Systemic therapy	6 (5.5)	4 (8.5)	2 (3.2)
Resection of extrahepatic metastases	5 (4.6)	2 (4.3)	3 (4.8)
Liver transplant	1 (0.9)	0 (0.0)	1 (1.6)

ATG: Adjuvant therapy group; SG: Surgery-alone group.

Characteristics of adjuvant therapy regimens in the study cohort

Among the 88 patients in the adjuvant therapy cohort, the distribution of treatment modalities was as follows: Targeted monotherapy in 44 patients (50.0%), combination targeted and immunotherapy in 27 patients (30.7%), and immunotherapy alone in 17 patients (19.3%; Table 2). Lenvatinib was the most frequently administered targeted agent, used in 58 patients (65.9%). The predominant immune checkpoint inhibitors were camrelizumab (22 patients, 25.0%) and tislelizumab (20 patients, 22.7%). The median time to initiation of adjuvant therapy was 2.0 months, with a median treatment duration of 12.0 months (3.0-29.0 months; Figure 2).

Figure 2 Adjuvant therapy regimen details. Cam: Camrelizumab; Pem: Pembrolizumab; Tis: Tislelizumab; Tor: Toripalimab; Anl: Anlotinib; Apa: Apatinib; Len: Lenvatinib; Sor: Sorafenib.

Table 2 Adjuvant therapy regimen details, n (%)/mean ± SD.

Adjunctive treatment modalities	Adjuvant therapy group (n = 88)
Targeted therapy only
No	44 (50.0)
Yes	44 (50.0)
Immunotherapy only
No	71 (80.7)
Yes	17 (19.3)
Combination of targeted and immunotherapy
No	61 (69.3)
Yes	27 (30.7)
Time to initiation of adjuvant therapy, mouths	2.2 ± 1.2
Treatment duration, mouths	12.7 ± 7.0

Prognosis analysis

RFS, a short-term prognostic endpoint, was defined as the time from postoperative day 1 to radiologically confirmed tumor recurrence or the last recurrence-free follow-up. After propensity score matching, the median RFS was significantly longer in the adjuvant therapy group [26.00 months; 95% confidence interval (CI): 22.14-29.87] than in the surgery-alone group (14.00 months; 95%CI: 10.22-17.76), with a log-rank P value of 0.028. The 1-year RFS rate was also higher in the adjuvant therapy group (79.5% vs 62.5%; P = 0.013, χ² test), indicating a beneficial effect of postoperative adjuvant therapy on short-term prognosis (Figure 3A and B; Table 3).

Figure 3 Kaplan-Meier survival curves before and after propensity score matching. A and B: Recurrence-free survival curves comparing the adjuvant therapy group vs the surgery-only group before (A) and after 1:1 propensity score matching (B); C and D: Overall survival curves for the same groups before (C) and after matching (D). P values were calculated using the log-rank test.

Table 3 Recurrence-free and overall survival rates before and after propensity score matching.

	PSM before			PSM after
	ATG (n = 88)	SG (n = 284)	P value	ATG (n = 88)	SG (n = 88)	P value
Median recurrence-free survival (months)	26.0	16.0	0.038	26.0	14.0	0.028
1-year recurrence-free survival rate (%)	79.5	63.7	0.006	79.5	62.3	0.013
Number of deaths (n)	3	12		3	6
Median overall survival, months			1.000			1.000
1-year overall survival rate (%)	100.0	100.0	1.000	100.0	100.0	1.000
Overall survival rate (%)	96.6	95.8	0.976	96.6	93.3	0.494

PSM: Propensity score matching; ATG: Adjuvant therapy group; SG: Surgery-alone group.

OS, the long-term endpoint, was defined as the time from postoperative day 1 to death or last follow-up. After matching, the median follow-up duration was 35.0 months (95%CI: 32.9-37.1) in the adjuvant therapy group and 37.0 months (95%CI: 33.5-40.5) in the surgery-alone group. Due to the relatively short follow-up period, the median OS was not reached in either group before or after matching. The log-rank test showed no significant difference in OS between groups (P = 0.084 before matching; P = 0.620 after matching). The 1-year OS rate was 100% in both groups, while the OS rate at the last follow-up was 96.6% in the adjuvant therapy group and 93.3% in the surgery-alone group (Figure 3C and D; Table 3).

Safety analysis

Adverse reactions were observed in 65.9% of the patients receiving adjuvant therapy. The most commonly reported adverse reactions included elevated ALT/AST levels (28.41%), hypertension (26.13%), rash or dermatitis (25.00%), and diarrhea (22.73%). Of these, 4 (4.55%) patients experienced grade 3-4 adverse reactions: 3 (3.41%) cases of elevated ALT/AST and 1 (1.41%) case of thrombocytopenia. The majority of the adverse reactions were reversible, with symptoms resolving after appropriate management (Table 4).

Table 4 Overview of treatment-related adverse event, n (%).

	0	1-2	3-4
Hypertensive	65 (73.80)	23 (26.13)	0 (0.00)
ALT/AST elevated	60 (68.18)	25 (28.41)	3 (3.41)
Leukopenia	86 (97.73)	2 (2.27)	0 (0.00)
Thrombocytopenia	84 (95.45)	3 (3.41)	1 (1.14)
Neutropenia	86 (97.73)	2 (2.27)	0 (0.00)
Anemic	86 (97.73)	2 (2.27)	0 (0.00)
Elevated creatinine	85 (96.59)	3 (3.41)	0 (0.00)
TSH elevated	84 (95.45)	4 (4.55)	0 (0.00)
Vomiting	86 (97.73)	2 (2.27)	0 (0.00)
Constipation	68 (77.27)	20 (22.73)	0 (0.00)
Anorexia	84 (95.45)	4 (4.55)	0 (0.00)
Dermatitis or rash	66 (75.00)	22 (25.00)	0 (0.00)
Fatigue	85 (96.59)	3 (3.41)	0 (0.00)

ALT: Alanine aminotransferase; AST: Aspartate aminotransferase; TSH: Thyroid-stimulating hormone.

Baseline characteristics of follow-up participants

A retrospective analysis was conducted on 372 patients with HCC at high risk of recurrence following liver resection. To mitigate potential confounding factors, a 1:1 propensity score matching was performed, resulting in 88 well-matched patients in each group for comparative analysis.

Prior to propensity score matching, baseline characteristics were compared between the adjuvant therapy and surgery-only groups (Table 5). Significant imbalances were observed in several high-risk pathological features. Specifically, the adjuvant therapy group had a significantly higher proportion of patients with preoperative AFP levels > 400 μg/L (36.4% vs 21.8%) and poorly differentiated tumors (Edmondson grade III-IV) (25.0% vs 14.8%) compared to the surgery-only group (both P < 0.05). Although a higher prevalence of multiple high-risk recurrence factors (75.0% vs 69.0%, P = 0.282) and MVI (60.0% vs 51.0%, P = 0.107) was noted in the adjuvant therapy group, these differences were not statistically significant. The overall cohort was predominantly young adult (62.9%), male (89.5%), with preserved liver function (Child-Pugh A: 93.2%), good performance status (Eastern Cooperative Oncology Group 0: 72.5%), and a high hepatitis B surface antigen positivity rate (69.8%). Regarding tumor staging, the CNLC classification was primarily stage Ib (39.5%) and stage Ia (26.3%), while the BCLC classification was predominantly stage A (60.2%) and stage B (19.2%). Most patients (64.5%) had a maximum tumor diameter ≥ 5 cm, with solitary lesions being predominant (72.3%). Vascular invasion was confined to patients within CNLC stage III and BCLC stage C, with no cases of extrahepatic metastasis. The adjuvant therapy group demonstrated a significantly lower rate of anatomic resection compared to the surgery-only group (52.8% vs 66.5%, P < 0.05; Table 6).

Table 5 Baseline characteristics of 372 participants on follow-up, n (%)/mean ± SD.

	PSM before (n = 372)			PSM after (n = 176)
	ATG (n = 88)	SG (n = 284)	P value	ATG (n = 88)	SG (n = 88)	P value
Diabetes			0.111			0.294
No	82 (93.2)	247 (87.0)		82 (93.2)	78 (88.6)
Yes	6 (6.8)	37 (13.0)		6 (6.8)	10 (11.4)
ECOG PS			0.089			0.064
0	69 (78.4)	196 (69.0)		69 (78.4)	58 (65.9)
1	19 (21.6)	88 (31.0)		19 (21.6)	30 (34.1)
BMI (kg/m2)	22.5 ± 2.7	22.8 ± 2.7	0.386	22.5 ± 2.7	22.8 ± 2.7	0.520
Age (years)			0.678			0.639
> 60	31 (35.2)	107 (37.7)		31 (35.2)	34 (38.6)
≤ 60	57 (64.8)	177 (62.3)		57 (64.8)	54 (61.4)
Sex			0.625			0.799
Female	8 (9.1)	31 (10.9)		8 (9.1)	9 (10.2)
Male	80 (90.9)	253 (89.1)		80 (90.9)	79 (89.8)
HBsAg			0.505			0.245
Negative	29 (33.0)	83 (29.2)		29 (33.0)	22 (25.0)
Positive	59 (67.0)	201 (70.8)		59 (67.0)	66 (75.0)
HBsAb			0.882			0.528
Negative	33 (37.5)	109 (38.4)		33 (37.5)	29 (33.0)
Positive	55 (62.5)	175 (61.6)		55 (62.5)	59 (67.0)
HCV			0.536			1.000
Negative	86 (97.7)	271 (95.4)		86 (97.7)	87 (98.9)
Positive	2 (2.3)	13 (4.6)		2 (2.3)	1 (1.1)
HBV-DNA (IU/mL)			0.777			0.546
> 2000	39 (44.3)	121 (42.6)		39 (44.3)	43 (48.9)
≤ 2000	49 (55.7)	163 (57.4)		49 (55.7)	45 (51.1)
AFP (μg/L)			0.006			0.525
> 400	32 (36.4)	62 (21.8)		32 (36.4)	28 (31.8)
≤ 400	56 (63.6)	222 (78.2)		56 (63.6)	60 (68.2)
ALBI score			0.589			1.000
1	25 (28.4)	97 (34.2)		25 (28.4)	25 (28.4)
2	61 (69.3)	182 (64.1)		61 (69.3)	62 (70.5)
3	2 (2.3)	5 (1.8)		2 (2.3)	1 (1.1)
WBC (× 109/L)	6.7 ± 2.4	6.4 ± 2.4	0.255	6.7 ± 2.4	6.7 ± 3.1	0.924
RBC (× 1012/L)	4.6 ± 0.7	4.6 ± 0.6	0.539	4.6 ± 0.7	4.6 ± 0.6	0.882
Hb (g/L)	135.0 ± 20.6	137.9 ± 18.9	0.214	135.0 ± 20.6	138.9 ± 16.5	0.173
PLT (× 109/L)	216.0 ± 80.6	199.0 ± 83.7	0.095	216.0 ± 80.6	207.2 ± 80.6	0.471
ALP (umol/L)	102.0 ± 68.5	100.9 ± 60.8	0.888	102.0 ± 68.5	99.5 ± 45.0	0.772
AST (U/L)	52.7 ± 59.8	61.8 ± 95.8	0.405	52.7 ± 59.8	59.6 ± 82.6	0.527
ALT (U/L)	53.3 ± 75.0	59.4 ± 87.6	0.558	53.3 ± 75.0	59.4 ± 79.7	0.601
Hydroperitoneum			0.257			0.353
No	57 (64.8)	202 (71.1)		57 (64.8)	51 (58.0)
Yes	31 (35.2)	82 (28.9)		31 (35.2)	37 (42.0)
Child-Pugh grade			0.656			0.755
A	83 (94.3)	264 (93.0)		83 (94.3)	82 (93.2)
B	5 (5.7)	20 (7.0)		5 (5.7)	6 (6.8)
Number of tumors			0.710			0.479
≥ 2	23 (26.1)	80 (28.2)		23 (26.1)	19 (21.6)
1	65 (73.9)	204 (71.8)		65 (73.9)	69 (78.4)
Maximum tumor diameter (mm)	72.6 ± 37.9	64.6 ± 35.0	0.067	72.6 ± 37.9	63.9 ± 35.9	0.119
Cirrhosis			0.070			0.226
No	44 (50.0)	111 (39.1)		44 (50.0)	36 (40.9)
Yes	44 (50.0)	173 (60.9)		44 (50.0)	52 (59.1)
PVTT			0.601			0.245
0	71 (80.7)	243 (85.6)		71 (80.7)	80 (90.9)
1	5 (5.7)	14 (4.9)		5 (5.7)	3 (3.4)
2	8 (9.1)	16 (5.6)		8 (9.1)	3 (3.4)
3	4 (4.5)	11 (3.9)		4 (4.5)	2 (2.3)
HVTT			1.000			1.000
No	84 (95.5)	272 (95.8)		84 (95.5)	83 (94.3)
Yes	4 (4.5)	12 (4.2)		4 (4.5)	5 (5.7)

ECOG PS: Eastern Cooperative Oncology Group Performance Status; BMI: Body mass index; HBsAg: Hepatitis B surface antigen; HBsAb: Hepatitis B surface antibody; HCV: Hepatitis C virus; HBV: Hepatitis B virus; AFP: Alpha-fetoprotein; ALBI: Albumin-bilirubin score; WBC: White blood cell; RBC: Red blood cell; Hb: Hemoglobin; PLT: Platelet; ALP: Alkaline phosphatase; AST: Aspartate aminotransferase; ALT: Alanine aminotransferase; PVTT: Portal vein tumor thrombus; HVTT: Hepatic vein tumor thrombus; PSM: Propensity score matching; ATG: Adjuvant therapy group; SG: Surgery-alone group.

Table 6 Surgical and perioperative data of 372 participants on follow-up, n (%)/mean ± SD/median (interquartile rage).

	PSM before (n = 372)			PSM after (n = 176)
	ATG (n = 88)	SG (n = 284)	P value	ATG (n = 88)	SG (n = 88)	P value
Surgical methods			0.544			0.114
Laparoscopy	16 (18.2)	58 (20.4)		16 (18.2)	23 (26.1)
Open	68 (77.3)	205 (72.2)		68 (77.3)	56 (63.6)
Anatomic resection			0.013			0.88
No	42 (47.7)	95 (33.5)		42 (47.7)	41 (46.6)
Yes	46 (52.3)	189 (66.5)		46 (52.3)	47 (53.4)
Tumor clinical typing			0.273			0.393
Nodular fusion	7 (8)	16 (5.6)		7 (8)	5 (5.7)
Nodular	48 (54.5)	179 (63)		48 (54.5)	58 (65.9)
Chunky	19 (21.6)	39 (13.7)		19 (21.6)	13 (14.8)
Lumpy	12 (13.6)	46 (16.2)		12 (13.6)	12 (13.6)
Diffuse	2 (2.3)	4 (1.4)		2 (2.3)	0 (0)
Tumor margin (cm)			0.339			0.344
< 1	34 (38.6)	94 (33.1)		34 (38.6)	28 (31.8)
≥ 1	54 (61.4)	190 (66.9)		54 (61.4)	60 (68.2)
Transfusion			0.112			0.202
No	72 (81.8)	251 (88.4)		72 (81.8)	78 (88.6)
Yes	16 (18.2)	33 (11.6)		16 (18.2)	10 (11.4)
Pringle maneuver application			0.945			0.289
No	52 (59.1)	169 (59.5)		52 (59.1)	45 (51.1)
Yes	36 (40.9)	115 (40.5)		36 (40.9)	43 (48.9)
Surgical time (minutes)	254.5 ± 110.2	265.3 ± 113.5	0.43	254.5 ± 110.2	276.8 ± 128.4	0.218
Day of hospitalization (days)	15.4 ± 4.7	15.7 ± 4.5	0.659	15.4 ± 4.5	15.7 ± 4.8	0.661
Blood loss (mL)	275.0 (200.0-500.0)	300.0 (187.5-500.0)	0.148	300.0 (187.5-500.0)	200.0 (100.0-425.0)	0.127
Red blood cell transfusion (mL)	0.0 (0.0-0.0)	0.0 (0.0-0.0)	0.055	0.0 (0.0-0.0)	0.0 (0.0-0.0)	0.176
Plasma transfusion (mL)	0.0 (0.0-0.0)	0.0 (0.0-0.0)	0.253	0.0 (0.0-0.0)	0.0 (0.0-0.0)	0.374
Number of Pringle maneuver time	0.0 (0.0-1.0)	0.0 (0.0-1.0)	0.828	0.0 (0.0-1.0)	0.0 (0.0-1.0)	0.42
Pringle maneuver time (minutes)	0.0 (0.0-20.0)	0.0 (0.0-15.0)	0.933	0.0 (0.0-20.0)	0.0 (0.0-20.2)	0.21

PSM: Propensity score matching; ATG: Adjuvant therapy group; SG: Surgery-alone group.

Following propensity score matching, the baseline characteristics between the two groups were well-balanced, with no statistically significant differences observed in demographics, tumor burden, or staging criteria (all P > 0.05), indicating effective reduction of selection bias (Table 6).

Univariable and multivariable Cox regression analyzes for RFS before and after propensity score matching

Cox proportional hazards regression models were employed to identify factors associated with RFS in the overall cohort and in the propensity score-matched cohort (Table 7). In the pre-matching univariable analysis, a comprehensive set of clinicopathological and treatment variables were assessed. Variables yielding a P < 0.10 were included in the subsequent multivariable model. This final model identified receipt of adjuvant therapy [hazard ratio (HR) = 0.659, 95%CI: 0.450-0.964, P = 0.032] and larger maximum tumor diameter (HR = 1.006, 95%CI: 1.002-1.011, P = 0.007) as independent prognostic factors for poorer RFS.

Table 7 Univariate and multivariate Cox regression analysis of factors associated with recurrence-free survival.

Cluster	PSM before				PSM after
	Univariate		Multifactor		Univariate		Multifactor
	P value	HR	95%CI	P value	P value	HR	95%CI	P value
Receiving adjuvant therapy (yes vs no)	0.042	0.717	0.521-0.988	0.01	0.031	0.659	0.450-0.964	0.005
diabetes (yes vs no)	0.758	0.94	0.633-1.395		0.315	0.761	0.447-1.295
ECOG score (0 vs 1)	0.891	0.98	0.740-1.299		0.9	0.975	0.653-1.454
Age (≤ 60 vs > 60)	0.401	0.893	0.685-1.164		0.632	0.91	0.618-1.339
Sex (male vs female)	0.681	0.914	0.594-1.405		0.721	1.12	0.600-2.090
HBsAg (positive vs negative)	0.603	0.928	0.700-1.230		0.077	0.679	0.441-1.043	0.13
HBsAb (positive vs negative)	0.662	1.06	0.815-1.379		0.949	1.013	0.686-1.495
AST, U/L (≤ 37 vs > 37)	0.005	0.686	0.527-0.893	0.23	0.035	0.655	0.443-0.970	0.13
ALT, U/L (≤ 40 vs > 40)	0.012	0.719	0.556-0.930	0.416	0.033	0.665	0.456-0.968	0.489
HCV DNA (positive vs negative)	0.274	0.723	0.404-1.293		0.697	0.757	0.187-3.072
HBV DNA, IU/mL (≤ 2000 vs > 2000)	0.677	1.057	0.814-1.373		0.225	0.792	0.543-1.154
AFP, μg/L (≤ 400 vs > 400)	0.058	1.358	0.990-1.862	0.026	0.206	1.309	0.863-1.985
ALBI score (1 vs 2/3)	0.021	0.714	0.537-0.950	0.119	0.077	0.668	0.427-1.045	0.155
Hydroperitoneum (yes vs no)	0.43	1.12	0.846-1.482		0.509	1.139	0.774-1.678
Child-Pugh grade (A vs B)	0.675	0.902	0.558-1.460		0.76	1.127	0.523-2.426
Number of tumors (1 vs ≥ 2)	0.208	0.833	0.627-1.107		0.094	0.692	0.450-1.065	0.07
Maximum tumor diameter (mm)	0.001	1.005	1.002-1.009	0.053	0.01	1.006	1.002-1.011	0.039
Cirrhosis (yes vs no)	0.588	1.075	0.828-1.395		0.21	1.276	0.872-1.867
PVTT (yes vs no)	0.156	0.779	0.552-1.100		0.518	1.46	0.463-4.607
HVTT (yes vs no)	0.077	0.614	0.358-1.055	0.126	0.615	0.822	0.382-1.768
Satellite node (yes vs no)	0.4	1.229	0.760-1.989		0.702	1.136	0.592-2.177
Peritoneal invasion or absence (yes vs no)	0.587	0.925	0.697-1.227		0.487	0.866	0.576-1.300
Tumor rupture (yes vs no)	0.885	1.029	0.697-1.519		0.894	0.966	0.583-1.602
CNLC staging (Ⅲ vs I/II)	0.132	0.769	0.547-1.082		0.323	1.354	0.743-2.469
Edmonson tumor grade (Ⅲ-IV vs I-II)	0.709	1.054	0.798-1.393		0.623	0.91	0.625-1.325
MVI (M1/M2 vs M0)	0.075	0.79	0.610-1.024	0.193	0.448	0.863	0.590-1.263
High recurrence risk factors (multiple vs single)	0.038	0.736	0.551-0.984	0.32	0.674	0.915	0.606-1.383
Surgical methods (open vs laparoscopy/robot)	0.469	0.896	0.666-1.206		0.337	0.81	0.527-1.245
Anatomic resection (yes vs no)	0.585	1.078	0.824-1.410		0.932	1.017	0.698-1.481
Tumor margin (< 1 cm vs ≥ 1 cm)	0.786	0.963	0.733-1.265		0.764	1.062	0.717-1.572
Blocking the hepatic portal (yes vs no)	0.925	1.013	0.779-1.317		0.63	0.911	0.625-1.330
Transfusion (yes vs no)	0.57	0.898	0.618-1.304		0.367	1.295	0.738-2.273

ECOG: Eastern Cooperative Oncology Group; HBsAg: Hepatitis B surface antigen; HBsAb: Hepatitis B surface antibody; AST: Aspartate aminotransferase; ALT: Alanine aminotransferase; HCV: Hepatitis C virus; HBV: Hepatitis B virus; AFP: Alpha-fetoprotein; ALBI: Albumin-bilirubin score; PVTT: Portal vein tumor thrombus; HVTT: Hepatic vein tumor thrombus; CNLC: China Liver Cancer; MVI: Microvascular invasion; PSM: Propensity score matching; HR: Hazard ratio; CI: Confidence interval.

Following 1:1 propensity score matching, which balanced baseline characteristics between the adjuvant therapy and surgery-alone groups, the Cox regression analysis was repeated on the matched cohort. Consistent with the pre-matching findings, receipt of adjuvant therapy remained a significant independent protective factor for RFS in the multivariable analysis of the matched pairs (HR = 0.670, 95%CI: 0.452-0.994, P = 0.046). Maximum tumor diameter also retained its independent prognostic significance in this balanced cohort.

Subgroup analysis of adjuvant treatment modalities

To further evaluate the differential impact of adjuvant regimens, a subgroup analysis was conducted within the adjuvant therapy cohort, stratified by treatment modality: Targeted therapy alone, immunotherapy alone, or their combination. Comparative survival analysis revealed that the RFS and OS outcomes for patients receiving targeted monotherapy or immunotherapy alone were not significantly different from those observed in patients receiving combined targeted-immunotherapy (all inter-group log-rank P > 0.05; Figure 4).

Figure 4 Comparison of recurrence-free survival among adjuvant therapy subgroups. Kaplan-Meier curves for recurrence-free survival were compared between different adjuvant therapy regimens within the cohort. A: Targeted therapy group vs immunotherapy group (log-rank P = 0.26); B: Targeted therapy group vs combination therapy group (log-rank P = 0.57); C: Immunotherapy group vs combination therapy group (log-rank P = 0.49).

DISCUSSION

Hepatectomy is the primary curative treatment for HCC; however, postoperative recurrence rates remain substantial, approaching 70% at 5 years and approximately 30% among patients who meet the Milan criteria[3,14]. Therefore, minimizing recurrence is crucial for improving long-term outcomes. Although postoperative adjuvant therapy has emerged as a promising strategy, the optimal regimen and patient selection criteria are still under investigation.

Our findings indicate that adjuvant targeted therapy and/or immunotherapy significantly improves RFS and has an acceptable safety profile, supporting its viability as a postoperative strategy. These results are consistent with recent advances in the adjuvant treatment landscape. The landmark IMbrave050 phase III trial showed that, compared with active surveillance, the combination of atezolizumab plus bevacizumab improved RFS for patients with high-risk resected HCC (12-month RFS: 78% vs 65%, P = 0.012)[21]. Similarly, Li et al[22] reported that adjuvant folinic acid, fluorouracil, and oxaliplatin-based hepatic arterial infusion chemotherapy improved disease-free survival (median disease-free survival: 20.3 months) among patients with MVI. Moreover, Li et al[23] observed a median RFS of 25.2 months for patients with resected HCC who received immune checkpoint inhibitors with or without tyrosine kinase inhibitors. Other studies by Chen et al[24] and Li et al[25] also revealed significant improvements in 1-year RFS with adjuvant PD-1 inhibitors or tyrosine kinase inhibitors/PD-1 combinations.

Consistent with these reports, our study, which was conducted in a cohort predominantly characterized by a hepatitis B background and preserved liver function, showed that adjuvant therapy was associated with a 17.0% increase in 1-year RFS and a median RFS of 26 months after propensity score matching. It is important to contextualize our findings regarding the predominantly HBV-related etiology in our cohort. This specific etiological background may limit the direct extrapolation of our conclusions to Western populations, where HCC more commonly arises from hepatitis C virus infection, alcohol-related liver disease, or metabolic dysfunction-associated steatotic liver disease. These different etiologies are associated with distinct tumor immune microenvironments and genomic profiles, which could potentially influence responses to adjuvant therapies, particularly immunotherapies[26,27]. Multivariate Cox regression analyzes further confirmed that, along with tumor diameter and preoperative AFP level, adjuvant therapy was an independent protective factor for RFS both before and after matching. These findings underscore the prognostic value of tumor-related features such as AFP level, MVI, and tumor burden[19,26-30] and collectively suggest that adjuvant targeted therapy and/or immunotherapy reduces recurrence risk in patients with high-risk HCC.

Moreover, subgroup analyzes indicated that patients receiving targeted therapy alone achieved the most favorable outcomes, with a 1-year RFS of 88.6%. This outcome may be attributed to this subgroup's comparatively lower baseline risk profile, characterized by fewer patients with large tumors, advanced BCLC stage, poor differentiation, or vascular invasion. While the heterogeneity of treatment regimens (targeted, immunotherapy, combination) within our adjuvant group reflects real-world clinical pragmatism, it complicates direct comparisons of efficacy between modalities. Nevertheless, the observed variation in outcomes invites consideration of potential underlying biological mechanisms. For instance, tumors with specific molecular or microenvironmental features - such as high angiogenic signaling without a profoundly immunosuppressive milieu - might derive optimal benefit from targeted anti-angiogenic therapy alone[31]. In contrast, combination therapy might be more critical for overcoming resistance in tumors with a complex, immunosuppressive tumor microenvironment[32]. These hypotheses, while requiring validation in prospective studies with integrated biomarker analyses, highlight the importance of understanding tumor biology for treatment selection. In contrast, the combination therapy subgroup, which had a higher burden of risk factors, had a 1-year RFS of 70.4% and a median RFS of 28 months. These results are in line with previous studies by Zhang et al[33] and Ouyang et al[34], emphasizing the efficacy of adjuvant sorafenib in patients with MVI and the potential benefit associated with combining immune checkpoint inhibitors and tyrosine kinase inhibitors in high-risk settings.

Notably, we did not find a significant OS benefit from adjuvant therapy, contradicting some previous reports[11,24,25]. This discrepancy warrants a nuanced interpretation. The relatively short follow-up duration in our study is a primary factor, as OS benefits often require longer observation to manifest, especially when RFS is improved[35]. More importantly, the natural history of HCC and the effectiveness of subsequent therapies must be considered. In contemporary practice, patients who experience recurrence often have access to multiple lines of effective salvage therapies. The efficacy of these post-recurrence treatments can potentially mitigate an early survival advantage conferred by adjuvant therapy, thereby diluting observable differences in OS between groups - a well-recognized phenomenon in oncology trials for cancers with an evolving multi-line therapeutic landscape[36]. This discrepancy may be due to the relatively short follow-up in our study, highlighting the need for longer-term evaluation.

The safety profile of adjuvant therapy in our cohort was consistent with established patterns of targeted therapy and immunotherapy. Hypertension and elevated transaminase levels were the most common adverse events, similar to those observed in the SHR-1210-III-310 trial[37]. Most toxicities were grade 1-2 (63.6%), with only 4.5% of the patients experiencing grade 3 events, and all of which resolved following appropriate intervention.

Nonetheless, our study has several limitations that should be acknowledged. First, its retrospective design may have introduced potential selection bias, which we sought to address through propensity score matching; however, residual confounding cannot be excluded. A primary limitation stems from the inclusion of heterogeneous treatment strategies within the adjuvant group. While propensity score matching balanced baseline characteristics, it cannot fully account for unmeasured confounders or the specific biological effects of different drug classes. This inherent heterogeneity, while reflective of real-world practice, limits the granularity of conclusions we can draw regarding the comparative efficacy of any single therapeutic modality from our pooled analysis. Second, the modest sample size after matching (n = 88 per group) may have further limited the statistical power of our analysis. Third, the high prevalence of hepatitis virus-related HCC in our cohort may limit the generalizability of our findings to HCCs arising from other etiologies. Fourth, the assessment of symptomatic adverse events, such as anorexia and fatigue, partly relied on patient self-report, which is susceptible to recall and reporting bias, particularly among those followed at local institutions. Finally, the relatively short follow-up time may have hindered the detection of long-term survival differences and late toxicities. Therefore, while our real-world data provide supportive evidence for the feasibility and activity of adjuvant therapy in high-risk HCC, they underscore an urgent need for prospective validation. Future large-scale, prospective, randomized controlled trials are required to definitively establish the efficacy of adjuvant therapy in a more uniformly treated patient population. Furthermore, embedding translational research within such trials is paramount to identify predictive biomarkers from tumor tissue or blood samples, thereby precisely identifying patient subgroups most likely to benefit from specific treatment modalities and advancing towards personalized adjuvant care[38].

CONCLUSION

Targeted and/or immunotherapy has shown promising efficacy and safety in HCC patients at high risk of recurrence after radical hepatectomy, but the optimal treatment strategy needs to be determined by further studies. We look forward to further randomized controlled trials to support our results.

ACKNOWLEDGEMENTS

The authors would like to sincerely thank the colleagues from the Department of Hepatobiliary Surgery, Department of Radiology, and Department of Pathology for their professional support throughout the diagnosis and treatment process, particularly in clinical evaluation, imaging interpretation, and pathological analysis.