Maintenance therapy with capecitabine in patients with resected pancreatic adenocarcinoma after adjuvant therapy: a retrospective cohort study.

Abstract

Background: The 5-year survival of pancreatic adenocarcinoma with surgery and adjuvant chemotherapy is below 25%. The original Gastrointestinal Tumor Study Group (GITSG) adjuvant study demonstrated a survival benefit attributed to weekly intravenous boluses of 5-fluorouracil (5-FU) for 2 years in addition to chemoradiation compared to surgery alone. In theory, the prolonged exposure to therapy could maintain pressure on dormant cancer cells that remain in G0 arrest and kill them as they infrequently enter the G1/S phase. We retrospectively evaluated outcomes in patients who were treated with adjuvant chemotherapy and maintenance capecitabine compared with those who received only adjuvant chemotherapy.

Methods: Patients who had undergone surgical resection with curative intent and received adjuvant chemotherapy were analyzed. Those who subsequently received maintenance capecitabine therapy were compared to those who received adjuvant chemotherapy only. The primary end points were disease recurrence and all-cause mortality.

Results: The median overall survival (OS) of patients receiving maintenance capecitabine was greater than 48.4 months (the exact estimate was not available, since the survival probability curve does not cross 0.5). It was 22.0 months (95% confidence interval [CI], 16.6-29.2) in patients who received adjuvant chemotherapy only (P < .001 by log-rank test). The median recurrence-free survival (RFS) was also longer in the maintenance capecitabine group: 54.3 (95% CI, 22.2-Inf) compared to 14.1 (95% CI, 11.6-16.7) months (P < .001, by log-rank test).

Conclusions: In this retrospective study, patients with resected pancreatic adenocarcinoma who received adjuvant chemotherapy had improved OS and RFS with additional maintenance therapy with capecitabine. These findings should be confirmed with a randomized, controlled trial.