Long-term intermittent adjuvant chemotherapy for primary, resected lung cancer

Adjuvant chemotherapy for lung cancer has previously been unsuccessful in improving the results of pulmonary resections. During a 12 year period, we tested long-term intermittent chemotherapy (LTIC) with mitomycin C and chromomycin A3 adjuvant to resections. LTIC was begun before the operations and the first course was completed postoperatively. Additional courses of 4 weeks each were scheduled at 3 month intervals during the first postoperative year and at 6 month intervals during the next 2 years. LTIC was defined as three or more full courses, and short-term chemotherapy (STC) was defined as a single course of adjuvant treatment. Resections for cancer in 425 patients over a 22 year period included 117 operations during a 10 year control period in which LTIC was not used and 308 during the LTIC test period. Results from adjuvant LTIC in 85 patients were compared with lesser adjuvant chemotherapy in 155 synchronously treated patients who included 77 STC recipients. Further comparison was made between LTIC and asynchronously treated, comparable control subjects. Although there were side effects and occasional deaths from chemotherapy, they did not alter the operative mortality rate. The over-all 5 year survival rate of the adjuvant LTIC patients was 50.9 per cent, as compared to 22.6 per cent in the asynchronous control subjects (p less than 0.01). For patients who were given LTIC adjuvant to palliative resections the 5 year survival rate was 35.6 per cent, as compared to 4.3 per cent for STC patients or 5.2 per cent for asychronous control subjects (p less than 0.01). Strikingly promising results were obtained from adjuvant LTIC in 10 of 33 patients with undifferentiated cancers. We conclude that LTIC prolonged life among lung cancer patients who were not cured by resection alone. Dual-agent LTIC is safe, apparently beneficial, and worthy of further clinical trials in a research setting.