(S)-1(Duquesne University)

Relationship between timing of initiating adjuvant chemotherapy (AC) and clinical outcomes after surgery for pancreatic cancer remains controversial.

In this ancillary analysis of the JASPAC 01 trial, 187 patients were classified according to the interval between surgery and chemotherapy initiation to Early (< 6 weeks, n  = 45), Standard (6–8 weeks, n  = 70), and Delayed (> 8 weeks, n  = 72). Overall survival (OS) and relapse‐free survival (RFS) were analyzed.

Baseline characteristics were comparable among three groups. The Standard group showed significantly longer OS than the Early group (median, 66 vs. 37 months; HR 0.61, 95% CI 0.38–0.99; p  = 0.041), and relatively longer OS compared with the Delayed group (median, 45 months; HR 0.68, 95% CI 0.44–1.05; p  = 0.077). RFS was longer in the Standard group (median, 46 months) compared with the Early group (20 months; HR 0.61, 95% CI 0.38–0.99; p  = 0.040) and the Delayed group (20 months; HR 0.59, 95% CI 0.39–0.89; p  = 0.011). Multivariate analysis identified operative procedure, R1 resection, lymph node metastasis, and nonstandard initiation (< 6 or > 8 weeks) as independent adverse prognostic factors.

Initiation of S‐1 AC at 6–8 weeks after pancreatectomy was associated with favorable survival outcomes.