Adjuvant chemoradiotherapy vs adjuvant chemotherapy in locally advanced Siewert type II/III adenocarcinoma of gastroesophageal junction after D2/R0 resection

Table 1 Clinicopathological features of all patients

Variable	Overall	Adjuvant chemoradiotherapy group	Adjuvant chemotherapy group
	316	57	259
Age, n (%)
< 40 yr	6 (1.9)	2 (3.5)	4 (1.5)
≥ 40 yr	310 (98.1)	55 (96.5)	255 (98.5)
Sex, n (%)
Male	268 (84.8)	46 (80.7)	222 (85.7)
Female	48 (15.2)	11 (19.3)	37 (14.3)
BMI, n (%)
< 18.5 or > 23.9	169 (53.5)	27 (47.4)	142 (54.8)
18.5-23.9	147 (46.5)	30 (52.6)	117 (45.2)
The degree of differentiation, n (%)
Poorly differentiated	233 (73.7)	45 (78.9)	188 (72.6)
Moderately-highly differentiated	83 (26.3)	12 (21.1)	71 (27.4)
Nerve invasion, n (%)
Yes	269 (85.1)	43 (75.4)	226 (87.3)
No	47 (14.9)	14 (24.6)	33 (12.7)
Vascular invasion, n (%)
Yes	263 (83.2)	40 (70.2)	223 (86.1)
No	53 (16.8)	17 (29.8)	36 (13.9)
Pathologic T stage, n (%)
pT1-3	179 (56.6)	34 (59.6)	145 (56.0)
pT4a-4b	137 (43.4)	23 (40.4)	114 (44.0)
Pathologic N stage, n (%)
pN1-2	73 (23.1)	10 (17.5)	63 (24.3)
PN3	243 (76.9)	47 (82.5)	196 (75.7)
Pathological stage, Siewert type II	148 (46.8)	25 (43.9)	123 (47.5)
IIIB stage	30 (9.5)	6 (10.5)	24 (9.3)
IVA stage	118 (37.3)	19 (33.3)	99 (38.2)
Pathological stage, Siewert type III	168 (53.2)	32 (56.1)	136 (52.5)
IIIA	32 (10.1)	1 (1.8)	31 (12.0)
IIIB	80 (25.3)	22 (38.6)	58 (22.4)
IIIC	56 (17.7)	9 (15.8)	47 (18.1)

BMI: Body mass index.

Table 2 5-year survival rate in adjuvant chemoradiotherapy group and adjuvant chemotherapy group

	Group	N	5-yr survival rate (%)	Log rank test
OS	All patietnts			P = 0.010
	Adjuvant chemoradiotherapy group	57	66.7
	Adjuvant chemotherapy group	295	41.9
RFS	All patietnts			P = 0.254
	Adjuvant chemoradiotherapy group	52	64.5
	Adjuvant chemotherapy group	128	55.3
OS	Siewert type II			P = 0.063
	Adjuvant chemoradiotherapy group	25	59.3
	Adjuvant chemotherapy group	123	39.4
RFS	Siewert type II			P = 0.995
	Adjuvant chemoradiotherapy group	22	60.5
	Adjuvant chemotherapy group	58	55.9
OS	Siewert type III			P = 0.006
	Adjuvant chemoradiotherapy group	32	65.7
	Adjuvant chemotherapy group	136	43.9
RFS	Siewert type III			P = 0.082
	Adjuvant chemoradiotherapy group	30	72.6
	Adjuvant chemotherapy group	70	56.8

OS: Overall survival; RFS: Relapse-free survival.

Table 3 Distributions of recurrence in Adjuvant chemoradiotherapy group and adjuvant chemotherapy group

Recurrence site	Adjuvant chemoradiotherapy group		Adjuvant chemotherapy group
	No. of patients	% of recurrence patients (n = 18)	No. of patients	% of recurrence patients (n = 61)
Local recurrence, n (%)
Remnant stomach	1	5.6	1	1.6
Anastomosis site	3	16.7	14	23.0
Regional recurrence	5	27.8	24	39.3
Distant metastasis, n (%)
One site
Peritoneum	5	27.8	8	13.1
Pleura	2	11.1	4	6.6
Solid organ	4	22.2	16	26.2
Distant LNs	2	11.1	5	8.2
Bone metastases	2	11.1	3	4.9
≥ 2 sites
Peritoneum + solid organ	2	11.1	3	4.9
Solid organs	1	5.6	2	3.3
Peritoneum + distant LNs	0	0	1	1.6
Solid organs + distant LNs	0	0	1	1.6

LNs: Lymph nodes.

Table 4 Univariate and multivariable cox proportional hazards modeling for overall survival in Siewert type II gastroesophageal junction

Clinicopathological features	Univariate analysis		Multivariable analysis
	HR (95%CI)	P value	HR (95%CI)	P value
Sex
Male	Ref.
Female	0.683 (0.389-1.199)	P = 0.185
BMI
18.5-23.9	Ref.
< 18.5 or > 23.9	1.019 (0.657-1.581)	P = 0.931
The degree of differentiation
Poorly differentiated	Ref.
Moderately-highly differentiated	0.733 (0.437-1.227)	P = 0.237
Nerve invasion
Yes	Ref.		Ref.
No	0.083 (0.020-0.339)	P = 0.001	0.117 (0.028-0.500)	P = 0.004
Vascular invasion
Yes	Ref.		Ref.
No	0.215 (0.093-0.496)	P < 0.001	0.425 (0.178-1.014)	P = 0.054
Pathologic T stage
Group 1-3	Ref.		Ref.
Group 4a-4b	1.404 (0.899-2.194)	P = 0.136	1.271 (0.777-2.080)	P = 0.340
Pathologic N stage
Group 1-2	Ref.		Ref.
Group 3a-b	2.089 (1.137-3.721)	P = 0.012	1.027 (0.385-2.739)	P = 0.958
Pathologic TNM stage
IIIB stage	Ref.		Ref.
IVA stage	2.540 (1.267-5.091)	P = 0.009	2.081 (0.629-6.885)	P = 0.230
Adjuvant chemoradiotherapy
Yes	Ref.		Ref.
No	1.859 (0.956-3.614)	P = 0.068	1.877 (0.943-3.738)	P = 0.073

BMI: Body mass index; HR: Hazard ratio; CI: Confidence interval.

Table 5 Univariate and multivariable cox proportional hazards modeling for overall survival in Siewert type III gastroesophageal junction

Clinicopathological features	Univariate analysis		Multivariable analysis
	HR (95%CI)	P value	HR (95%CI)	P value
Sex
Male	Ref.
Female	0.573 (0.277-1.186)	P = 0.134
BMI
18.5-23.9	Ref.
< 18.5 or > 23.9	1.142 (0.755-1.728)	P = 0.530
The degree of differentiation
Poorly differentiated	Ref.
Moderately-highly differentiated	0.945 (0.592-1.509)	P = 0.813
Nerve invasion
Yes	Ref.		Ref.
No	0.086 (0.021-0.349)	P = 0.001	0.169 (0.037-0.774)	P = 0.022
Vascular invasion
Yes	Ref.		Ref.
No	0.041 (0.006-0.295)	P = 0.002	0.092 (0.012-0.689)	P = 0.020
Pathologic T stage
Group 1-3	Ref.		Ref.
Group 4a-4b	1.479 (0.975-2.242)	P = 0.065	1.151 (0.751-1.763)	P = 0.518
Pathologic N stage
Group 1-2	Ref.		Ref.
Group 3	1.983 (1.099-3.580)	P = 0.023	3.621 (0.380-34.469)	P = 0.263
Pathologic TNM stage
IIIA stage	Ref.		Ref.
IIIB stage	1.420 (0.759-2.656)	P = 0.273	1.801 (0.180-18.037)	P = 0.617
IIIC stage	2.783 (1.472-5.261)	P = 0.002	0.681 (0.434-1.069)	P = 0.095
Adjuvant chemoradiotherapy
Yes	Ref.		Ref.
No	2.465 (1.270-4.782)	P = 0.008	2.258 (1.145-4.453)	P = 0.019

BMI: Body mass index; HR: Hazard ratio; CI: Confidence interval.