The added value of capecitabine to adjuvant gemcitabine monotherapy (GEM) in pancreatic ductal adenocarcinoma (PDAC) was shown by the ESPAC-4 trial. Real-world data on the effectiveness of gemcitabine plus capecitabine (GEMCAP), in patients inelegible for mFOLFIRINOX, are lacking. This study assessed whether adjuvant GEMCAP is superior to GEM in a nationwide cohort.

Patients treated with adjuvant GEMCAP or GEM after resection of PDAC without preoperative treatment were identified from the Netherlands Cancer Registry (2015-2019). The primary outcome was overall survival (OS), measured from start of chemotherapy. The treatment effect of GEMCAP vs. GEM was adjusted for sex, age, performance status, tumor size, lymph node involvement, resection margin, and tumor differentiation in a multivariable Cox regression analysis. Secondary outcome was the percentage of patients who completed the planned six adjuvant treatment cycles.

Overall, 778 patients were included, of whom 21.1% received GEMCAP and 78.9% received GEM. The median OS was 31.4 months (95% CI 26.8-40.7) for GEMCAP and 22.1 months (95% CI 20.6-25.0) for GEM (HR 0.71, 95% CI 0.56-0.90; logrank p=0.004). After adjustment for prognostic factors, survival remained superior for patients treated with GEMCAP (HR:0.73, 95% CI 0.57-0.92, logrank p=0.009). Survival with GEMCAP was superior to GEM in most subgroups of prognostic factors. Adjuvant chemotherapy was completed in 69.5% of the patients treated with GEMCAP and 62.7% with GEM (p=0.11).

In this nationwide cohort of patients with PDAC, adjuvant GEMCAP was associated with superior survival as compared to GEM monotherapy and number of cycles was similar.