Systemic Therapy for Resected Pancreatic Adenocarcinoma: How Much is Enough?

Background Systemic therapy is an essential part of treatment for pancreatic ductal adenocarcinoma (PDAC). However, not all patients receive every cycle of chemotherapy and even if they do, the impact of reduced dose density (DD) on survival is not known. Patients and Methods A single institutional prospective database was queried for patients with PDAC who underwent curative resection between 2009 and 2018. The primary outcome was DD, defined as the percentage of total planned chemotherapy actually received and associated survival. Results Of the 126 patients included, 38.9% underwent a neoadjuvant approach, which was associated with a greater median number of completed chemotherapy cycles (5 cycles versus 4 cycles, p < 0.01) and a higher median total DD (93.0% versus 65.0%, p < 0.01), compared with an adjuvant treatment approach. In both groups, adjuvant chemotherapy completion rates were low, with only 55 patients completing all adjuvant cycles. After sequential survival analysis, patients who received a DD ≥ 80% had improved median overall survival (OS) (27.1 months versus 18.6 months, p = 0.01), compared with patients who achieved a DD < 80%. On multivariate Cox proportional-hazards modeling, only the presence of lymphovascular invasion (HR: 1.77, 95% CI: 1.04–2.99, p = 0.04) and DD < 80% (HR: 1.91, 95% CI: 1.23–3.00, p = 0.01) were associated with decreased OS. Conclusions In this cohort study, patients who received ≥ 80% DD had significantly better OS. DD should be considered an important prognostic metric in pancreatic cancer, and strategies are needed to improve chemotherapy tolerance to improve patient outcomes.