Comparison of chemoradiotherapy (CRT) with carboplatin/paclitaxel (CP) versus cisplatin/5-FU (CF) for esophageal or junctional cancer: Experience from the Princess Margaret Cancer Centre.

Abstract

126 Background: The optimal CRT regimen for neoadjuvant or definitive treatment of locoregional esophageal or gastroesophageal junctional (GEJ) cancer is uncertain. There has been no direct comparison between concurrent Cisplatin/5-FU (CF) as per the CALGB 9781 trial (50.4 Gy) or Carboplatin/Paclitaxel (CP) as per the CROSS trial (41.4 Gy). Methods: A retrospective analysis comparing CF and CP was performed in all patients (pts) with locoregional esophageal or GEJ cancer treated in 2012-2014. Overall survival (OS) and disease-free survival (DFS) were assessed via uni- and multivariable Cox proportional hazards regression, adjusting for age, performance status and Charlson comorbidity index. Pathological complete response (pCR) rates were compared using Fisher’s exact test. Results: 64/86 (74%) pts were male. Median age was 64 years (range: 34-84). Primary sites were esophageal (56%, with 60% squamous histology) and GEJ (44%, with 11% squamous). 22 pts received CRT in 2012 (100% CF), 33 pts in 2013 (58% CF, 42% CP) and 31 pts in 2014 (16% CF, 84% CP). Surgery was undertaken in 19 (41%) CF and 27 (68%) CP pts. Median follow-up was 38 months. We found no significant OS difference between CF and CP overall (HR 0.82, 95% CI: 0.43-1.56, p = 0.55) or in the subgroup having surgery (n = 46; HR 2.01, 95% CI: 0.62-6.55, p = 0.25). However, in the subgroup without surgery (n = 40), CF (n = 27) was superior to CP (n = 13)(HR 0.11, 95% CI: 0.03-0.38, p < 0.001). OS was similar by histology (adenocarcinoma/squamous) in all-comers (p = 0.96), and in CF (p = 0.66) and CP subgroups (p = 0.66). DFS results were similar to OS. There was a non-significant numerical difference in pCR rates between CF (31%) and CP (18%) (p = 0.45). Conclusions: Survival is similar for CF and CP CRT regimens in patients undergoing trimodality therapy. pCR rates were comparable but lower than previously reported. In contrast, in the absence of surgical resection, CP given for CRT results in significantly inferior outcomes. Clinicians may prefer CP for surgical candidates given its toxicity profile. However, when treating with definitive CRT, CF may be preferable to CP as a standard regimen.