IMPACT OF THE USE OF GRANULOCYTE COLONY-STIMULATING FACTOR (G-CSF) ON THE OUTCOME OF PATIENTS WITH METASTATIC PANCREATIC ADENOCARCINOMA TREATED WITH FOLFIRINOX: A RETROSPECTIVE ANALYSIS

Introduction: FOLFIRINOX stands as a major breakthrough in the management of metastatic pancreatic ductal adenocarcinoma (PDAC). However, this protocol is associated with a high frequency of neutropenia. Despite its frequent use in clinical practice, the role of granulocyte colony-stimulating factor (G-CSF) prophylaxis during the treatment with FOLFIRINOX is unclear. Objective: We aimed to compare the frequency of grade 3-4 neutropenia and febrile neutropenia (FN), and survival outcomes of patients who received primary G-CSF or no primary G-CSF prophylaxis. Methods: We included patients aged ≥18 years-old, with pathologically confirmed metastatic PDAC, treated with FOLFIRINOX in the first-line setting. Patients who received primary prophylaxis (PP) were compared to patients who received secondary or no G-CSF. Categorical variables were compared using Fisher’s exact test. Survival curves were estimated using the Kaplan-Meier method and compared using log-rank test. We looked for putative prognostic factors using univariate and multivariate Cox proportional hazard models for progression-free survival and overall survival. Results: Results: From January 2011 to December 2019, 123 subjects were included. Primary prophylaxis was used in 75 patients (65%); most common G-CSF was peg-filgastrim. The median first-line therapy durations was higher in this group compared to no-PP (7.9 vs. 5.6 months; P=0.02). Grade 3-4 neutropenia occurred more frequently among patients without PP (10.7 vs. 41.7%; P < 0.001). Eight patients had FN (four on each group). All patients with FN were hospitalized and two patients died. The majority of grade 3-4 neutropenia and FN occurred before cycle 8. Regarding survival analysis, PP patients had better overall survival (OS) (15,2 vs. 10,8 months; P=0,01); there was no differences in progression free survival (PFS). In univariate Cox analysis, PP was associated with 39% reduction risk of death; in multivariate analysis, liver metastasis was associated with 1.79 fold increased risk of death. PP was not associated with better prognosis. Conclusion: Conclusion: Despite reducing the frequency of grade 3-4 neutropenia in metastatic PDAC patients receiving FOLFIRINOX, PP was not an independent predictor of survival. Its use should be individualized to high-risk patients and cost-effectiveness issues should be discussed.