Feasibility, Safety, and Factors Predicting Completion of CROSS Protocol-Based Neoadjuvant Chemoradiotherapy for...

Neoadjuvant chemoradiotherapy (NACRT) using the ChemoRadiotherapy for Oesophageal cancer followed by Surgery Study (CROSS) protocol has improved esophageal cancer outcomes. This study reports the real-world experience of the CROSS regimen for esophageal squamous cell carcinoma (ESCC) regarding its feasibility, safety, and predictors of treatment completion from an Indian tertiary center.

A retrospective review was conducted for patients with ESCC receiving CROSS (radiation dose: 41.4 Gy) or a modified CROSS (mCROSS; radiation dose: 45 Gy) protocol NACRT between 2015 and 2022. We studied the treatment tolerability, factors predicting NACRT completion, and the effect of completion of its chemotherapy component on the pathological outcomes.

Of the109 patients (68.8% males; mean age, 56 ± 9 years; Charlson's comorbidity index [CCI] >2, 19.3%; stage III-IVA, 58%; mean tumor length, 5.5 ± 2.1cm; CROSS, 70.6%; mCROSS, 29.4%), all except 4 completed radiotherapy but only 58 (53.2%) patients completed ≥4 cycles of chemotherapy. Forty-nine patients belonged to the "extended" CROSS trial inclusion criteria. Among the 60 patients who fulfilled the CROSS inclusion criteria, only 51.7% were able to complete ≥4 chemotherapy cycles. The commonest reason for noncompletion of chemotherapy was the occurrence of neutropenia (60.8%). Pretreatment hemoglobin (≥12 vs. <12 g%; odds ratio [OR]: 2.76; 95% confidence interval [CI]: 1.10-6.96; p  = 0.031), a low CCI (≤2 vs. >2; OR: 2.98; 95% CI: 1.02-8.73; p  = 0.047), and radiation therapy techniques (conformal vs. conventional; OR: 3.29; 95% CI: 1.14-9.50; p  = 0.028) were associated with completion of chemotherapy (≥4 cycles). Although there was a trend toward improved R0 resection (95.7 vs. 91.4%), reduced node positivity (17.0 vs. 31.4%), and a high pCR (57.4 vs. 48.6%) in patients completing chemotherapy (≥4 cycles) compared with those not completing chemotherapy (<4 cycles), these differences were statistically nonsignificant.

In this study, ESCC patients receiving the CROSS protocol NACRT could complete their radiotherapy component, but a significant proportion exhibited poor chemotherapy tolerance. Neutropenia was a major factor limiting chemotherapy delivery, but anemia, high CCI, and conventional radiation techniques were also associated with noncompletion of chemotherapy. The omission of a few chemotherapy cycles had no significant effect on the pathological response; however, its impact on cancer survival requires further evaluation.