Survival analysis of maintenance therapy with capecitabine (Cape) in patients with resected pancreatic adenocarcinoma (PAC) after adjuvant therapy: A retrospective cohort study.

Abstract

e14658 Background: The 5-year survival of PAC with surgery alone is below 10%, and with adjuvant chemotherapy increases to about 20%. The original GITSG adjuvant study demonstrating a survival benefit compared to surgery could be attributed to the use of 2-years of weekly IV bolus 5FU, and not only chemoradiation. In theory, the prolonged exposure to therapy could maintain pressure on dormant cancer cells that may remain in G0 arrest, by attacking them as they infrequently enter G1/S phase. To evaluate this hypothesis, we retrospectively evaluated our pts who were treated with or without maintenance Cape. Methods: Pts in the Georgetown/Lombardi Cancer Center EMR since Oct 2007 were sought for PAC that was resected with curative intent, received standard adjuvant chemotherapy with or without chemoradiation. The study group received maintenance cape for at least 2 months, and the control group was monitored until disease recurrence. Only pts with complete follow-up survival data were analyzed. Results: 20 pts met the criteria as study group, and 58 pts as the control group. In the study group, cape was usually given 1000mg orally twice a day, Monday through Friday following adjuvant therapy, for an indefinite period, up to 2 years. Pts received cape for median duration of 12.5 months (2 to 24 months), and the median follow-up duration was 33 months (16 to 78 months). The median overall survival (OS) for the study group was 48 months. The 2 year OS was 94%, and 5 year OS was 40%. The median recurrence free survival (RFS) was 39 months. The 2 year RFS was 67%, and the 5 year RFS was 25%. Common toxicities were mild hand-and-foot syndrome and fatigue. 4 pts discontinued cape due to toxicities: febrile neutropenia, severe fatigue, weight loss and diarrhea. The control group was of comparable staging, and the median OS was 22 months, 5 year OS rate was 16%, median RFS was 13 months, 2 year RFS was 19%. Conclusions: In this single institute retrospective controlled cohort study, Cape maintenance therapy following adjuvant therapy in resected PAC is associated with a significantly (p<0.05) higher OS and PFS compared to the control group. This approach should be studied in a RCT.