Prognosis After Surgical Resection of M1a/M1b Esophageal Squamous Cell Carcinoma

This study was undertaken to examine prognosis after resection for M1 disease in squamous cell esophageal carcinoma. Fifty-six patients with M1 esophageal cancer underwent esophageal resection with two or three-field nodal dissection from 1994 to 2001. Operative mortality occurred in 3 patients. Primary tumor sites were as follows; 10 upper, 23 middle, and 20 lower thoracic esophagus. They were found to have M1 disease by pathologic examination of dissected nodes, 24 M1a and 29 M1b. Forty-two patients (79%) were considered to have undergone curative resection. Chemotherapy and/or radiation therapy was given to 38 patients perioperatively. Recurrence was identified in 35 patients (66%) during a mean follow-up of 23 months. Overall median and 5-yr survivals were 19 months and 12.7%. Five-year survivals for M1a and M1b disease were 23.9% and 6.1%, respectively (p=0.0488). Curative resection tended to show better survival (p=0.3846). Chemotherapy and/or radiation therapy provided no advantage (p=0.5370). Multivariate analysis showed that M1b was significant risk factor over M1a disease. Our conclusion is that surgical resection can provide acceptable survival in thoracic squamous esophageal cancer with M1a disease. Survival differences between M1a and M1b disease support the current subclassification staging system.