First-line chemotherapy regimens associated with survival in advanced pancreatic cancer: A Mexican single-center, real-world study.

683 Background: Effectiveness of FOLFIRINOX and Gemcitabine – Nabpaclitaxel as first-line chemotherapy regimens in advanced pancreatic cancer has been demonstrated in phase III clinical trials. However, prospective studies directly comparing both interventions are lacking. Gemcitabine has proved effective when combined with other drugs such as Oxaliplatin. Despite GEMOX has not proved overall survival benefit over Gemcitabine and it is unclear if its effectiveness could be similar to FOLFIRINOX or Gemcitabine-Nabpaclitaxel, it is broadly used as first line chemotherapy in our center due to safety concerns and higher costs associated to FOLFIRINOX and Nabpaclitaxel. Methods: We retrospectively analyzed data of patients with stage IV Pancreatic Adenocarcinoma treated at Instituto Nacional de Cancerología from 2014 to 2021. Our aim was to compare Overall Survival (OS) in patients treated with GEMOX, FOLFIRINOX, Gemcitabine-Nabpaclitaxel, or Gemcitabine in the front-line setting. Progression Free Survival (PFS), Overall Response Rate (ORR) and Adverse Effects (AEs) were also assessed. Results: A total of 141 patients were analyzed, 72 (51.0%) were treated with GEMOX, 13 (9.2%) with FOLFIRINOX, 9 (6.4%) with Gemcitabine-Nabpaclitaxel and 47 (33.3%) with Gemcitabine. Median Overall Survival for each regimen was: 11.0, 10.7, 6.7 and 4.7 months; (p = 0.078), and median PFS was 9.2, 6.5, 5.7 and 4.0 months, respectively (p = 0.026).ORR was 21.6%, 20.0%, 11.1%, 4.8% with GEMOX, FOLFIRINOX, Gemcitabine-Nabpaclitaxel and Gemcitabine, respectively. The percentage of patients who received a second line chemotherapy after progression was 43.1%, 61.5%, 55.6% and 23.4%, (p = 0.031). Regarding AEs, G3/4 most common effects ( > 5%) were Neutropenia (9.8%, 30.0%, 55.6%, 4.8%; p = 0.001), Diarrhea (2.0%, 10.0%, 11.1%, 0.0%; p = 0.247), and Increased Liver Enzymes (7.8%, 20.0%, 0.0%, 4.8%; p = 0.371). Grade 1/2 Neuropathy was found in 43.1%, 60.0%, 44.4% and 9.5%, p = 0.018. The percentage of patients who required GCSF was 9.8%, 60.0%, 22.2% and 9.5%, P = 0.001. Conclusions: In patients with advanced pancreatic cancer treated with different chemotherapy regimens, median OS was similar in this real-world analysis. Though PFS was higher in the group of patients treated with GEMOX, a higher percentage of patients initially treated with FOLFIRINOX or Gemcitabine – Nabpaclitaxel reached 2nd line chemotherapy after progression. Percentage G3/4 Neutropenia, G1/2 Neuropathy and use of GCSF were significantly higher in patients treated with FOLFIRINOX.