Distant nodal metastases from intrathoracic esophageal squamous cell carcinoma: Characteristics of long-term survivors after chemoradiotherapy

Background: Non-regional lymph node metastasis in intrathoracic esophageal cancer is classified as M1 lesion with poor prognosis following surgery alone. We studied the controversial question of whether chemoradiotherapy (CRT) improves survival of these patients. Methods: A cohort of patients with clinically overt nodal M1 disease, which could be encompassed by a tolerable radiation therapy port, was selected from the database of the Chang Gung Memorial Hospital. Results: From 1994 to 2005, 54 nodal stage IV intrathoracic esophageal squamous cell carcinoma (SCC) patients received neoadjuvant CRT. Significant response occurred in 24 patients. Scheduled esophagectomy was performed in 26 patients. The 3-year overall survival (OS) and disease-free survival (DFS) for the whole group were 27% (median: 14.2 months) and 22% (median: 14.7 months), respectively. Multivariate analysis identified pretherapy lymph nodes classified as M1a and R0 resection after CRT as independent favorable prognosticators. Median survival reached 36.9 months in the pretherapy M1a subgroup as opposed to 12.5 months in the M1b subgroup (3-year-DFS: 40% vs. 10%, P=0.0117). Scheduled surgery after CRT benefits only after R0 resection (3-year-DFS: 36%, median survival: 45 months). The group with incomplete resection had a high surgical risk and dismal survival compared to the non-surgery group (3-year-DFS: 0% vs. 9%, 9.5 vs. 10.5 months). Conclusions: Pretherapy M1a disease had a significantly better survival than nodal M1b disease after CRT in SCC. Aggressive surgical treatment after CRT is reserved for cases when complete resection is anticipated.