Radiofrequency ablation of liver metastases in a patient with pancreatic cancer and long-term survival: A case report

Abstract

BACKGROUND

According to the GLOBCAN2022 database, pancreatic cancer has become the 6th leading cause of cancer-related death worldwide. The latest statistics suggest that the incidence of pancreatic cancer is increasing at a rate of 0.5% to 1.0% per year, and it is expected to become the 2nd leading cause of tumor-related deaths in the United States by 2030. More than 50% of pancreatic cancer patients have already developed distant metastases at the time of diagnosis, with the liver being the most common site. Patients with pancreatic cancer with liver metastasis (PCLM) have a worse prognosis than those with locally progressed pancreatic cancer, with a median survival of less than six months. Therefore, the outcome of liver metastases is often a vital determinant of the prognosis of patients with PCLM. There are few successful cases of localized treatment for PCLM patients. Our department recently performed local radiofrequency ablation (RFA) treatment for a PCLM patient through an evidence-based medicine approach, with remarkable therapeutic effects.

CASE SUMMARY

The patient was admitted to the hospital on May 03, 2018, 3 weeks after pancreatic cancer surgery. In October 2017, the patient presented with lower back pain. No abnormalities were detected via computed tomography (CT), colonoscopy, or gastroscopy. However, on March 18, 2018, the patient was investigated in a foreign hospital via CT, which suggested occupational lesions in the descending part of the duodenum, and magnetic resonance imaging suggested pancreatic occupancy. He was considered to be suffering from pancreatic cancer. He underwent laparoscopic-assisted pancreatic + duodenum + superior mesenteric vein partial resection and reconstruction under general anesthesia on March 26, 2018 at The Affiliated Hospital of Xuzhou Medical University. The pancreas and duodenum were partially resected. Postoperative pathology showed adenocarcinoma of the pancreas (moderately differentiated), partly mucinous carcinoma, invading the mucosal layer of the duodenum; the tumor size was 4.5 cm × 4 cm × 4 cm. There was no apparent nerve or vascular invasion. There was no cancer or involvement of the pancreas section or expected hepatic duct margins. There was no cancer involvement in the gastric and duodenal sections. There was no cancer metastasis to the peripheral lymph nodes of the pancreas (0/9). No metastasis to the gastric lesser curvature or more significant curvature lymph nodes (0/1, 0/5) was detected, and the peri-intestinal lymph nodes showed no cancer metastasis (0/4). Although the gallbladder showed signs of chronic cholecystitis, there was no cancer involvement, and the lymph nodes in Groups 12 and 13 also showed no cancer metastasis (0/6, 0/1). His postoperative recovery was acceptable. CT was performed on May 2018 at our hospital and found the following: (1) Double lung bronchial vascular bundles slightly heavier than normal; (2) Postoperative changes in the pancreas and a retention tube shadow in front of the head of the pancreas; (3) Small cysts in the right lobe of the liver; (4) Abdominopelvic effusion; and (5) Para splenic enlargement. pTNM stage: PT3N0M0. The patient was in the second stage of postoperative pancreatic cancer, with a potential risk of recurrence considering the patient's postoperative body quality deviation. The patient was unable to tolerate the standard multidrug combination and underwent six cycles of single-agent gemcitabine chemotherapy from May 10, 2018 to August 31, 2018 (the specific drug dosage was 1.4 g/d1/d8 gemcitabine injection, which was repeated every 21 days). Efficacy was determined to be stable disease after 2, 4, and 6 cycles. The side effects during treatment were tolerable.

CONCLUSION

This case suggests that RFA can serve as a viable local treatment modality for selected patients with PCLM, offering a chance for long-term survival. Such localized interventions, when carefully tailored, may complement systemic therapies in controlling metastatic pancreatic cancer.

Key Words: Radiofrequency ablation; Pancreatic cancer; Liver metastasis; Case report

Core Tip: Patients with pancreatic cancer liver metastases have a worse prognosis than locally advanced pancreatic cancer patients do, with a median survival of less than 6 months; however, patients are now surviving for more than 6 years after radiofrequency ablation.

INTRODUCTION

According to the GLOBCAN2022 database, pancreatic cancer has become the 6th leading cause of cancer-related deaths worldwide[1]. The latest statistics suggest that the incidence of pancreatic cancer is increasing at a rate of 0.5% to 1.0% per year, and it is expected to become the 2^nd leading cause of tumor-related deaths in the United States by 2030[2]. More than 50% of pancreatic cancer patients have already developed systemic distant metastases at the time of diagnosis, with the liver being the most common site of metastasis for pancreatic cancer. Patients with pancreatic cancer with liver metastasis (PCLM) have a worse prognosis than those with locally progressed pancreatic cancer, with a median survival of less than six months[3]. Therefore, the outcome of liver metastases is often a vital determinant of the prognosis of patients with PCLM. There are few successful cases of localized treatment for PCLM patients; however, our department recently performed local radiofrequency ablation (RFA) treatment for a PCLM patient through an evidence-based medicine approach, with remarkable therapeutic effects, which are reported herein.

CASE PRESENTATION

Chief complaints

The patient was admitted to the hospital on March 03, 2018, 3 weeks after pancreatic cancer surgery.

History of present illness

There was no significant past medical history. There were no chronic diseases, previous surgeries, hospitalizations, or known allergies. The patient was not on any current or past medications and had no notable significant illnesses. The patient’s family medical history was unremarkable.

History of past illness

In October 2017, the patient experienced lower back pain. No abnormalities were detected via computed tomography (CT), colonoscopy, or gastroscopy. On March 18, 2018, the patient was investigated in a foreign hospital via CT, which suggested occupational lesions in the descending part of the duodenum, and magnetic resonance imaging (MRI) suggested pancreatic occupancy. The patient was considered to be suffering from pancreatic cancer. He underwent laparoscopic-assisted pancreatic + duodenum + superior mesenteric vein partial resection and reconstruction under general anesthesia on March 26, 2018 at the Affiliated Hospital of Xuzhou Medical University. The pancreas and duodenum were partially resected. Postoperative pathology revealed adenocarcinoma of the pancreas (moderately differentiated), partly mucinous carcinoma, invading the mucosal layer of the duodenum.

Personal and family history

The individual has a healthy lifestyle with no significant occupational or social issues and no relevant travel history or hobbies that could have impacted his health. No significant genetic disorders or chronic illnesses were reported in the family.

Physical examination

RFA of liver metastases was performed on the patient (Figure 1).

Figure 1 Radiofrequency ablation of liver metastases was performed on the patient. A: Radiofrequency ablation of the left outer lobe, the right anterior lobe, and the right upper lobe of the liver was performed under computed tomography guidance, and the procedure went smoothly; B: On March 20, 2020, the patient underwent radiofrequency ablation of liver metastases.

Laboratory examinations

Resected tumor, 4.5 cm × 4 cm × 4 cm; no apparent nerve or vascular invasion, no cancer or involvement of the pancreas section and expected hepatic duct margins, no cancer involvement in the gastric or duodenal sections, no cancer metastasis to the peripheral lymph nodes of the pancreas (0/9), and no metastasis to the gastric lesser curvature or more significant curvature lymph nodes (0/1, 0/5), and the peri-intestinal lymph nodes show no cancer metastasis (0/4); the gallbladder shows chronic cholecystitis but no cancer involvement, and the lymph nodes in Groups 12 and 13 have no cancer metastasis (0/6, 0/1; Figure 2).

Figure 2  The postoperative pathological report of the patient.

Imaging examinations

MRI testing was conducted on the patient (Figures 3 and 4).

Figure 3 Original pancreatic cancer after surgery and chemotherapy. Postoperative changes in the head of the pancreas: no clear abnormal enhancement foci are observed in the operation area. Follow-up combined with the examination of tumor markers is recommended. Abnormal enhancement signals in the left outer lobe of the liver and metastatic foci are visible. Speckled and abnormal enhancement foci in the upper part of the right anterior lobe of the liver, a possible hemangioma. Metastatic tumors were not excluded for the time being. Small cyst in the right lobe of the liver. Gallbladder agenesis. Parasplenic incidental observation: small adenoma of the left adrenal gland. Small adenoma of the left adrenal gland. Small adenoma of the left adrenal gland.

Figure 4 Original pancreatic cancer liver metastases after radiofrequency ablation. A: Postoperative changes in the head of the pancreas: no clear abnormal enhancement foci are observed in the operated area, but the central pancreatic duct is mildly dilated. It is recommended to follow up for review in combination with tumor markers. Minor nodular enhancement in the arterial stage of the left inner and outer lobes of the liver and iso-signals in the hepatic and biliary stages; pseudoenhancement was considered. No enhancement signals in the left inner lobe of the liver or in the right posterior lobe of the liver, which was false enhancement. Absence of the gallbladder; Parasplenic incidental observations: Small left adrenal adenoids. Postradiofrequency changes, compared with those in the July 07, 2020 slices: Part of the lesion was slightly reduced. The gallbladder is missing. Parasplenic incidental observations: small adenoma of the left adrenal gland; B: Pancreatic head postoperative changes: no clear abnormal enhancement foci in the operated area. Abnormal enhancement foci in the upper part of the right posterior lobe of the liver, which is a newly-emerged lesion, and it is recommended to follow up and review the disease. The left inner and outer lobes of the liver and the right posterior lobe have no enhancement signals, which is a postoperative change of the radiofrequency operation; compared with the January 12, 2019.13 slices, the lesion has shrunk. The left inner lobe lesion has no significant change in comparison with the previous slices. The gallbladder is absent. Parasplenic incidental observations: small adenoma of the left adrenal gland.

FINAL DIAGNOSIS

A diagnosis of PCLM was made.

TREATMENT

Metastatic pancreatic cancer has historically been considered a disease with an inferior prognosis, with a survival of less than one year, even with the most effective combination chemotherapy. This patient has experienced prolonged survival of 6 years postoperatively to date, thanks to RFA treatment applied as soon as the liver metastasis was detected (Figure 5).

Figure 5  Return to the hospital for review in March 2024 showing stabilization.

OUTCOME AND FOLLOW-UP

After completing two rounds of RFA, the patient achieved scomplete remission of the liver metastasis. Remarkably, no recurrence of the metastatic liver tumor was observed over a six-year follow-up period since the initial treatment, indicating a favorable long-term outcome.

DISCUSSION

Pancreatic cancer is a common malignant tumor of the digestive tract, which has the highest morbidity and mortality rate and the lowest survival rate among all digestive tract tumors, and the 5-year survival rate of patients is only 7%-9%. Due to its deep location and lack of early diagnostic methods, 70%-80% of pancreatic cancer patients are diagnosed with locally advanced or distant metastases, and only 10% of patients are suitable for surgical resection[4]. Among operable patients, surgical resection is still the most effective treatment for pancreatic cancer. Still, postoperative distant metastasis and local recurrence are common, and the median survival of patients with postoperative combined adjuvant therapy is primarily located in 24-28 months[5,6]. The conventional treatment process for resectable pancreatic cancer is radical (R0) resection followed by postoperative adjuvant chemotherapy, and the recommended regimen is combination chemotherapy based on gemcitabine or fluorouracil analogs[7]. The patient was found in time, with no organ metastasis before surgery, and no invasion of lymph nodes, vasculature, nerves, or surrounding organs and tissues was seen in the pathology sent for examination after surgical resection. To reduce the risk of recurrence and metastasis in the postoperative period, the patient's progression-free survival reached nearly one year after the administration of cyclic chemotherapy. The patient developed multiple liver metastases one year after chemotherapy. In patients with PCLM, the treatment has limited segmentation and poor outcome. The current first-line chemotherapy regimens are the AG regimen and the FOLFIRINOX regimen, whose median overall survival times reached 8.5 months and 11.1 months, respectively[8,9]. However, there is still a significant gap compared with surgically resectable patients (median overall survival time of up to 22 months in R0 surgically resected patients[10]). A current study found that for patients with pancreatic cancer with oligometastatic liver metastases, surgical resection of the primary site and liver metastases can improve the overall survival of patients[11]. Not all patients with liver metastases can benefit from surgery, and for those who are in poor health and cannot tolerate the vigorous intensity of treatment, local interventional therapy is less invasive, and recovery is possible; RFA has become a safe and effective local treatment modality for many unresectable and metastatic solid tumors, and in colorectal cancers accompanied by liver metastases, RFA has a 5-year survival rate similar to that of surgical resection of liver metastases[12]. However, its effectiveness in treating pancreatic cancer liver metastases is unclear. Hua et al[12] reviewed 102 patients with concurrent pancreatic cancer with liver metastases who underwent RFA of liver metastases, with a median OS of 11.4 months and a complete tumor ablation rate of 94.5%. And the complication rate was relatively low. Yan et al[13] reviewed 104 patients with hepatic oligometastases from pancreatic cancer, 74 with RFA of metastatic foci in combination with chemotherapy, and 30 with chemotherapy alone, and found that the ablation-combination-chemotherapy group had a longer median overall survival than the chemotherapy-alone group (10.8 vs 5.8 months). The subgroup analyses suggested that the number of tumors, complete ablations, and multiple ablations were proved to be independent prognostic factors. Metastatic pancreatic cancer has historically been considered a disease with an inferior prognosis, with a survival of less than one year, even with the most effective combination chemotherapy. This patient has had a prolonged survival of 6 years postoperatively to date, thanks to RFA treatment as soon as it was detected, and Faraoni et al[14] found that RFA increased the number of dendritic cells in RFA-treated tumors and promoted significant CD4⁺ and CD8⁺ T-cell distant responses. Furthermore, in the context of RFA, RFA increased programmed death ligand 1 (PD-L1) levels, and checkpoint blockade inhibition targeting PD-L1 consistently reduced tumor growth. This study suggests that RFA therapy has increased tumor antigen shedding, promoting antitumor immunity. It is also possible that the activation of immune function after RFA results in an “immune tail” effect. Ablation can effectively control local tumor progression in patients with PCLM and has the advantages of high safety, low trauma, and low economic cost of treatment, which may be the most critical factor in the long-term survival of patients with PCLM and other metastatic hepatocellular carcinomas.

CONCLUSION

This case suggests that RFA can serve as a viable local treatment modality for select patients with PCLM, offering a chance for long-term survival. Such localized interventions, when carefully tailored, may complement systemic therapies in controlling metastatic pancreatic cancer.