Abstract
IntroductionNanoliposomal irinotecan (nal-IRI) plus 5-fluorouracil and leucovorin (5-FU/LV) is an established second-line therapy for metastatic pancreatic ductal adenocarcinoma (PDAC). We previously developed a prognostic model (CGMH nomogram) to predict overall survival (OS) in patients receiving second-line chemotherapy before the nal-IRI + 5-FU/LV era. Herein, we aimed to validate the CGMH nomogram in a real-world cohort treated with nal-IRI plus 5-FU/LV, the current standard second-line treatment for metastatic PDAC.MethodsA retrospective cohort of 148 patients with metastatic PDAC treated with second-line nal-IRI + 5-FU/LV was analyzed. Prognostic scores were assigned using the CGMH nomogram, with patients stratified into tertiles as good, intermediate, and poor prognostic groups. Predictive performance was assessed using the concordance index (c-index) and calibration plots.ResultsOur cohort had a median OS of 6.1 months. Patients in the good, intermediate, and poor prognostic groups had median OS of 8.7 (95% confidence interval [CI], 6.7-10.7), 5.7 (95% CI, 5.3-6.3), and 4.0 (95% CI, 2.8-5.2) months, respectively. Compared with the good group, intermediate and poor groups had hazard ratios of 1.99 (95% CI, 1.29-3.07, P = .002) and 3.18 (95% CI, 1.87-5.40, P < .001), respectively. The nomogram demonstrated strong predictive ability, with c-indices of 0.73 and 0.70 for 6- and 12-month OS predictions, respectively. Calibration plots displayed excellent agreement between predicted and observed survival.ConclusionThe CGMH nomogram reliably predicted survival outcomes in nal-IRI + 5-FU/LV-treated patients with metastatic PDAC, and validation supported its use in clinical decision-making and personalized treatment planning.