Patient subsets benefiting from adjuvant therapy following surgical resection of non-small cell lung cancer.

Adjuvant chemotherapy is the standard of therapy for some patients with stages I, II, and III breast and colon cancer. The therapeutic efficacy of adjuvant chemotherapy following surgical resection of early stage non-small cell lung cancer (NSCLC) has been less clear. A meta-analysis was reported in 1995 of patients who underwent surgical resection for early stage NSCLC and were then randomized to either observation or chemotherapy. This meta-analysis showed a 13% reduction in the hazard ratio of death, leading to a 5% absolute improvement in survival 5 years after the start of adjuvant cisplatin-based chemotherapy treatment compared with observation only. Multiple prospective randomized trials for patients with NSCLC were planned and undertaken to attempt to validate the observations of the meta-analysis. Six trials with > or =150 patients with early stage NSCLC (stages I-IIIA) on each arm have been reported in the last 2 years. Four of the six trials show a survival advantage for the patients with early stage NSCLC treated with adjuvant chemotherapy compared with those who underwent observation. The survival benefit in these four studies varies from a 4% to a 16% survival advantage at 4 to 5 years after the start of chemotherapy. The hazard ratio of death for the patients treated with chemotherapy ranged from 0.61 to 0.86 compared with patients on observation. Thus, the information available at the current time supports the administration of chemotherapy for patients with stages IB and II NSCLC. Further research will be needed to define the role of adjuvant chemotherapy and its use in conjunction with chest radiotherapy for the treatment of patients with resected stages IA and IIIA NSCLC.