Efficacy of the third-line chemotherapy in patients with advanced pancreatic cancer.

711 Background: First-line FOLFIRINOX or gemcitabine plus nab-paclitaxel (GNP) have improved the survival outcomes of patients with advanced pancreatic cancer (APC) and nano-liposomal irinotecan (nal-IRI) plus 5-FU/leucovorin is proven as the second-line agents. The current study aims to assess the efficacy of the third-line palliative chemotherapy in APC. Methods: Medical records were retrospectively reviewed in a single tertiary hospital between 2012 and 2020. The enrolled patients have APC who received the first and second-line chemotherapy. To fine the efficacy of the third-line chemotherapy, Kaplan Meier curve with cox-regression analysis was performed. Results: Of total 1,152 patients with pancreatic cancer, 362 patients were enrolled. Of these, 125 received the third-line chemotherapy and 238 received only supportive care after progression of the second-line chemotherapy. Median age at diagnosis was 60.3 years (range 36.0 – 86.0) and males were 52.0%. The first-line chemotherapy regimen was FOLFIRINOX (85, 68.0%), GNP (33, 26.4%), and others (7, 5.6%). The second-line chemotherapy regimen was GNP (55, 44.0%), FOLFIRINOX (34, 27.2%). As the third-line regimen, TS-1 and nal-IRI plus 5-FU/leucovorin were 73 (58.4%) and 20 (16.0%). The median overall survival (OS) from diagnosis was 18.0 months in all patients (95% CI, 14.6 – 21.4). The median OS after progression of the second-line therapy were 15.1 (95% CI, 12.8 – 17.5) and 8.5 weeks (95% CI, 7.7 – 9.4, p=0.007) between the patients with the third-line chemotherapy and supportive care only. Of the patients with the third-line chemotherapy, female showed the significant longer OS than male (12.4 (95% CI 10.2-14.6) vs. 6.6 weeks (95% CI 13.4-19.7), p=0.042). Conclusions: The current study suggested that proceeding with the third-line chemotherapy could be recommended in some patients. Females showed significantly more benefit than males. Further research on the selection for patient who will get the benefit from the third-line therapy is necessary.