Association of total neoadjuvant therapy with major pathologic response and survival in localized pancreatic cancer: A multi-institutional analysis of 504 patients.

Abstract

4145 Background: Despite increased utilization of neoadjuvant therapy for pancreatic cancer (PC), a substantial proportion of patients never receive adjuvant therapy. We examined if total neoadjuvant therapy (TNT) would facilitate delivery of all prescribed (≥6 months) non-surgical therapy (NST: chemotherapy ± radiation) to improve oncologic outcomes. Methods: Patients receiving neoadjuvant FOLFIRINOX or gemcitabine/nab-paclitaxel ±radiation followed by pancreatectomy at 7 centers were reviewed. Patients receiving TNT (≥6 months NST pre-resection) were compared to those receiving < 6 months ( < TNT). Primary outcomes were major (complete/near-complete) pathologic response (MPR) and overall survival (OS). Results: Of 504 patients, 105 (21%) were selected for TNT. TNT and < TNT patients had similar performance status and rates of borderline resectable/locally advanced disease (82% vs. 80%). TNT patients were significantly more likely to receive ≥6 months NST (100% vs. 31%; p < 0.001) vs. < TNT. While selection of chemotherapy regimen (FOLFIRINOX or gemcitabine/nab-paclitaxel) did not differ between TNT and < TNT cohorts, TNT patients were more likely to receive neoadjuvant radiation (44% vs. 25%, p < 0.001). Rates of vascular resection, postoperative complications, and mortality were similar between groups. TNT was associated with decreased rates of lymphovascular/perineural invasion (p = 0.002) and nodal positivity (p = 0.001), and increased rates of MPR (41% vs. 23%; p = 0.001) and pathologic complete response (13% vs. 6%; p = 0.02). TNT was associated with improved OS compared with < TNT (median 38 vs. 30 months; p = 0.039). Both MPR (median 38 [MPR] vs. 28 [limited response] months; p = 0.002) and ≥6 months NST (TNT or peri-operative) (median 38 [≥6m] vs. 26 [ < 6m] months; p = 0.001) were associated with improved OS. Addition of radiation was not associated with MPR or OS. Conclusions: The TNT approach allows more patients with localized PC to receive ≥6 months NST and is associated with improved rates of MPR and OS. TNT should be considered for all patients with operable PC when possible.