Chemotherapy dose intensity and outcomes in resected pancreatic cancer

Background Optimal treatment of locoregional pancreatic cancer includes chemotherapy and surgical resection. Chemotherapy can be difficult to tolerate, requiring dose reductions or missed cycles. This study aimed to evaluate the rates of dose reduction and outcomes based on the relative dose intensity (RDI) of chemotherapy received. Methods This was a single-institution retrospective study (2020–2024) of patients who underwent curative-intent treatment of pancreatic malignancy with modified fluorouracil, leucovorin, irinotecan, and oxaliplatin (mFOLFIRINOX) or gemcitabine/nab-paclitaxel (Gem-Nab) and surgical resection. The total chemotherapy dose administered was recorded, and the outcomes were compared between patients who received <70% RDI and those who received ≥70% RDI of the standard dosing regimens. Results A total of 46 patients had complete dosing information (33 in the mFOLFIRINOX group and 13 in the Gem-Nab group). In addition, 56.5% of patients met the 70% threshold (60.6% in the mFOLFIRINOX group and 46.2% in the Gem-Nab group). Compared with patients who received ≥70% RDI, those who received <70% RDI were significantly older (65.7 ± 11.4 vs 73.0 ± 7.1, respectively; P =.01) and had a higher Charlson Comorbidity Index (4.5 ± 2.1 vs 5.9 ± 1.4, respectively; P =.02). Dose reduction was required in 59.0% of patients during treatment. Of note, 20% of patients who completed >5 months of treatment still received <70% RDI and had significantly worse survival (15.5 months in patients who received <70% RDI vs 40.5 months in patients who received ≥70% RDI; P =.05). Conclusion Dose reduction is common when treating resectable pancreatic cancer with mFOLFIRINOX or Gem-Nab. Just over half the cohort achieved the ≥70% RDI threshold. Time in months or cycles may not adequately define chemotherapy completion, as one-fifth of patients completed treatment by duration but failed to achieve the ≥70% RDI threshold, which affected survival.