PET-directed chemoradiation (CRT) with induction FOLFOX compared to induction carboplatin/paclitaxel (CP) in patients with locally advanced esophageal adenocarcinoma (EA)

4554 Background: Induction chemotherapy with PET-directed CRT and surgery is the standard treatment for locally advanced EA at our institution. Following results of the CALGB 80803 trial, FOLFOX has recently replaced CP as the preferred induction regimen. Methods: We retrospectively evaluated patients with locally advanced EA treated with induction CP vs FOLFOX, followed by trimodality therapy between January 2010 and June 2019. Patients treated with CP with RT followed by surgery without induction chemo were also included. We compared pathological complete response (pCR) and near pCR (ypN0 with ≥90% response) rates in the induction FOLFOX group to the induction CP and no-induction groups. Univariable and multivariable analyses were used to adjust for confounding factors. Disease-free survival (DFS) was estimated by the Kaplan-Meier method and compared between groups using max-combo weighted log rank test. Results: 445 patients were included. Patients in the induction FOLFOX group had significantly higher pCR and near pCR rates vs induction CP patients. Notably, pCR rate was 38% among FOLFOX PET responders vs 19% in non-responders. In multivariable analysis, compared to induction CP, induction FOLFOX administration was an independent predictor of near pCR (OR: 2.22, 95%CI: 1.20-4.20, p = 0.012). Compared to 24% pCR rate among no-induction patients, induction FOLFOX pCR rate was slightly higher at 32%. DFS by 2-years was higher in induction FOLFOX compared to no-induction-treated patients (62% vs. 42%, p = 0.05). Postoperative complication rates were similar among the three groups. Conclusions: PET-directed CRT with FOLFOX instead of CP improves pCR and near pCR rates. Improved DFS was observed in the FOLFOX vs no-induction patients. Longer follow-up is needed to confirm any survival benefits. [Table: see text]