Comparison of fluoropyrimidine based (FP)and taxane based platinum doublets (TP) in frontline treatment of patients with metastatic gastroesophageal adenocarcinomas (mGEAC): A retrospective analysis.

Abstract

e15604 Background: Although, fluoropyrimidine (FP) and taxane based platinum doublet (TP) chemotherapy have demonstrated efficacy against advanced gastroesophageal cancer, these two regimens have not been compared in prospective trials. We retrospectively compared fluoropyrimidine based (FP)and taxane based platinum doublet (TP)chemotherapy in the frontline setting in patients with mGEAC. Methods: Patients with mGEAC treated at Karmanos Cancer Institute between 2000-2014 were reviewed. We compared progression free survival (PFS), Response rate (RR), and toxicity profile of the two regimens. Outcomes were analyzed using weighted estimates. Fisher’s exact tests and Kruskal-Wallis tests were used for categorical and continuous variables, respectively. Survival differences were assessed by a log-rank test. Results: Of the total136 patients, 39% (53) received FP and 61% (83) received TP chemotherapy. Males were 68% (94) of the patients. Gastric, esophageal and gastroesophageal adenocarcinomas contributed to 47% (64), 26.5% (36) and 26.5% (36) of the cases respectively. FOLFOX was the main regimen in FP (62%), followed by 5FU cisplatin (38%). Carboplatin paclitaxel was the main regimen in the TP group. There was no statistically significant difference between the FP and TP arms in terms of PFS, RR, and median OS. The estimated median PFS was 6.39 (95% CI, 5.54-11.15) for the FP group vs 6.92 months (95% CI, 6.13-9.02) for the TP group, (p = 0.90). Objective response rate was (48% for FP group Vs 56% for TP group, p = 0.70). There was more significant grade 4-5 toxicity in FP vs TP based regimen (79 % vs 55 % respectively, p = 0.004). Conclusions: The efficacy of fluoropyrimidine platinum doublet chemotherapy appears to be as comparable to taxane based platinum doublet in the frontline treatment of mGEC. However, the fluorpyrimidine based regimen appears to have more toxicity. Consideration of treatment adverse effects ought to be a key factor in determining the choice of either regimen in mGEAC.