[Is adjuvant chemotherapy necessary for the peripherally located stage I adenocarcinoma of the lung?]

This study was done for the purpose of picking out the cases of poor prognosis from the peripherally located stage I adenocarcinoma of the lung.

Between January 1989 and December 2004, 235 patients with peripherally located stage I adenocarcinoma of the lung were resected curatively in our hospital. Relation between the 5-year survival rate and lymphatic and/or blood vessel invasion (from now on ductal invasion) was examined in these cases.

The 5-year survival rate was 99% in ly0v0 cases, 86% in ly0v1 cases, 85% in ly1v0 cases, 72% in ly1v1 cases, and 80% in ly2, 3 and/or v2, 3 (lyv 2-3) cases, respectively. Obviously the outcome of the cases without ductal invasion was good. The ratio of the cases without ductal invasion was 61% in stage IA, and 31% in stage IB. The 5-year survival rate was 99% in the cases without ductal invasion in stage IA, 100% in the cases without ductal invasion in stage IB, 90% in the cases with ductal invasion in stage IA, and 65% in the cases with ductal invasion in stage IB, respectively. And the 5-year survival rate without recurrence was 94% in the cases without ductal invasion in stage IA, 76% in the cases without ductal invasion in stage IB, 76% in the cases with ductal invasion in stage IA, and 54% in the cases with ductal invasion in stage IB, respectively.

Ductal invasion is significant prognostic factor in stage I adenocarcinoma of the lung. Adjuvant chemotherapy is unnecessary for the case without ductal invasion in stage IA. But we think that adjuvant chemotherapy is necessary for the case with ductal invasion in stage IA and for the case in stage IB, because there is much recurrence.