Analysis of Predictors of Resection and Survival in Locally Advanced Stage III Pancreatic Cancer: Does the Nature of Chemotherapy Regimen Influence Outcomes?

Background: Locally advanced unresectable pancreatic cancer (LAPC) historically portends a poor prognosis. FOLFIRINOX and gemcitabine/nab-paclitaxel have proven effective in the metastatic setting. We sought to evaluate the outcomes of these regimens compared with older regimens in LAPC. Methods: A retrospective, single institutional review of all consecutive LAPC treated with “new” (FOLFIRINOX and/or gemcitabine/nab-paclitaxel) and “old” (gemcitabine or 5-FU) chemotherapy from 2010 to 2014 was performed. Univariate and multivariate predictors of resection and survival were determined. Results: A total of 92 patients (new chemotherapy = 61, old chemotherapy = 31) were analyzed, of which 19 (21%) underwent eventual resection (median overall survival [OS] = 32 vs. 14.3 months for unresected patients, P = 0.0002). For the overall cohort, resection (hazard ratio [HR] 0.261, P = 0.014), radiation therapy (HR 0.458, P = 0.004), number of lines of chemotherapy (HR 0.486, P = 0.012), and new chemotherapy (HR 0.593 vs. old regimens, P = 0.065) were independent predictors of OS on multivariate analyses (MVA). On MVA, predictors of eventual resection were head and neck tumors (OR 0.307, P = 0.033) or SMA involvement (OR 0.285, P = 0.023). In nonresected patients (73), MVA showed treatment with new chemotherapy (HR 0.452, P = 0.006), radiation (HR 0.459, P = 0.006), and number of lines of CT (HR 0.705, P = 0.013) to be predictors of survival. Conclusions: In LAPC, use of FOLFIRNOX and/or gemcitabine/nab-paclitaxel is associated with improved survival compared with older chemotherapy regimens, regardless of eventual resection. Tumor location and relationship to certain vasculature are important determinants of resection in this cohort.