Background The postoperative recurrence rate of stage Ⅲ gastric cancer is high. Postoperative adjuvant chemotherapy can improve survival, but some individuals cannot tolerate multiple cycles of chemotherapy. The breast cancer adjuvant therapy models show that different drugs of sequential chemotherapy can reduce the adverse reaction of chemotherapy and does not affect curative effect, however, this treatment approach has not yet been validated for gastric cancer.

Objective To compare the efficacy of postoperative adjuvant chemotherapy with an 8-cycle CAPOX regimen versus adjuvant chemotherapy with a 4-cycle CAPOX sequential 4-cycle docetaxel (CAPOX→D) regimen in patients with stage Ⅲ gastric cancer.

Methods Clinical data about 141 patients with stage Ⅲ gastric cancer who underwent postoperative adjuvant chemotherapy in Chinese PLA General Hospital from January 1, 2009 to December 30, 2020 were retrospectively collected. Patients in the CAPOX regimen group completed 8 cycles of adjuvant chemotherapy, and patients in the CAPOX→D regimen group completed 4 cycles of CAPOX chemotherapy followed by 4 cycles of docetaxel adjuvant chemotherapy. The disease-free survival (DFS), overall survival (OS) and adverse effects of chemotherapy in patients treated with two different regimens of chemotherapy, CAPOX and CAPOX→D, were compared, and univariate and multivariate analyses were performed to analyze different prognostic factors.

Results  The CAPOX group consisted of 95 cases, including 75 males and 20 females, with 36 cases aged ≥60 years and 59 cases aged <60 years. The CAPOX→D group consisted of 46 cases, including 39 males and 7 females, with 16 cases aged ≥60 years and 30 cases aged <60 years. There was no statistically significant difference in gender and age between the two groups (P>0.05). The median DFS of the CAPOX group was 23.2 months (95% CI: 15.6-30.8 months), and it was 23.0 months in the CAPOX→D group (95% CI: 11.7-34.3 months), with no statistically significant difference (P=0.074). The median OS was 38.2 months (95% CI: 27.8-48.6 months) in the CAPOX group and 46.2 months (95% CI: 30.6-61.8 months) in the CAPOX→D group, and the difference was statistically significant (P=0.026). Cox regression results demonstrateed, compared to male, female had a higher risk of disease of progression (HR=1.649, 95% CI: 1.066-2.552, P=0.025); female (HR=1.645, 95% CI: 1,094-2.607, P=0.030), tumor located in the gastric body (HR=1.751, 95% CI: 1.110-2.761, P=0.016) or pyloric area (HR=1.889, 95% CI: 1.129-2.960, P=0.005) showed higher mortality risk. Compared with CAPOX regimen, CAPOX→D regimen decreased the risk of death (HR=0.663, 95% CI: 0.445-0.989, P=0.044). The incidences of adverse reactions in CAPOX group, including bone marrow suppression (41.3% vs 76.8%, P=0.005), digestive tract reaction (60.7% vs 84.2%, P=0.010) and peripheral nerve toxicity (51.6% vs 32.6%, P=0.030), were higher than those of CAPOX→D group.

Conclusion Postoperative choice of adjuvant chemotherapy with CAPOX→D regimen is safe and beneficial to patients with stage Ⅲ gastric cancer.