Real-world Scenario: CROSS Regimen as Preoperative Therapy for Oesophageal Squamous Cell Carcinoma.

Background: Preoperative chemoradiation (CROSS regimen) has been widely adopted worldwide. The survival advantage imparted is especially impressive for oesophageal squamous cell carcinoma (OSCC). This study aimed at investigating the efficacy of the CROSS regimen in real-world scenario.

Methods: This is a retrospective study of all patients with OSCC intended for preoperative treatment using the CROSS regimen during 2012-2017. Patients were divided into two groups: those within the selection criteria in the CROSS trial and those beyond criteria, namely age > 75 years old, tumour length > 8 cm or clinical M1 stage of lymph node involvement (AJCC 6th edition). Clinical outcome and survival data were compared.

Results: Eighty-eight patients were included. There were 46 patients in the "CROSS eligible" group and 42 in the "CROSS ineligible" group. By intention-to-treat, the estimated median survival was 24.2 months vs. 12.7 months, respectively (p = 0.047). The results were much inferior compared to that published in the original CROSS trial. Univariable and multivariable analyses showed tumour length and resectability as independent variables affecting survival.

Discussion: In a real-world scenario, the clinical outcome remains suboptimal and the excellent results in the trial setting were not reproducible in this Asian cohort. Patient selection is one key element accountable for the difference. The efficacy of the CROSS regimen may not be adequate for patients with more advanced disease. The optimal multimodal therapy for this group of patients remains undefined.