Factors associated with local-regional failure after definitive chemoradiation for locally advanced esophageal cancer

Background: Locally advanced esophageal cancer is often treated with a trimodality approach. While a substantial proportion of such patients initially achieve a clinical complete response (cCR) after chemoradiation, only a small proportion achieve durable control. We analyzed patients who reached cCR after definitive chemoradiation for esophageal cancer to identify clinical predictors of local disease recurrence. Methods: We identified 141 patients who obtained initial cCR after definitive chemoradiation without surgery for esophageal cancer from 2002 through 2009. The initial response to treatment was assessed by endoscopic evaluation and biopsy results, with cCR defined as having no evidence of disease present. Patterns of failure were categorized as in-field (within the planned treatment volume [PTV]), outside the radiation treatment field, or both. Results: At a median follow-up of 22 months (range, 6-87 months), 77 patients (55 %) had experienced disease recurrence (local or both). Of first failures, 32 (23 %) were outside the radiation field, followed by 30 (21 %) within the field, and 15 (11 %) were both. By multivariate analysis, in-field failure after cCR was associated with a pretreatment standardized uptake value on positron emission tomography of >10 (subhazard ratio [SHR] 3.31, p = 0.023) and poorly differentiated tumors (SHR 3.69, p = 0.031). All failures, in-field and out-of-field, correlated with non-Caucasian ethnicity (SHR 2.55, p = 0.001), N1 disease (SHR 2.05, p = 0.034), T3/T4 disease (SHR 3.56, p = 0.011), and older age (SHR 0.96, p = 0.008). Conclusions: Our data suggest that selected clinical characteristics can be used to predict failure patterns after definitive chemoradiation. Such risk-assessment strategies can help individualize therapy.