Initial chemotherapeutic doses and survival in patients with limited small-cell lung cancer.

Background: Moderate increases in the initial doses of certain chemotherapeutic drugs, such as cisplatin and cyclophosphamide, may prolong overall survival in patients with limited small-cell lung cancer.

Methods: We conducted a prospective study of 105 patients with limited small-cell lung cancer. The patients were randomly assigned to receive higher or lower initial doses of cisplatin (100 or 80 mg per square meter of body-surface area) and cyclophosphamide (300 or 225 mg per square meter daily for four days); all patients received the same doses of doxorubicin and etoposide. The first course of chemotherapy was followed by five additional courses and by three courses of radiotherapy. All patients received the lower doses of cisplatin and cyclophosphamide and the same doses of doxorubicin and etoposide from the second through the sixth cycle of chemotherapy.

Results: The median follow-up was 33 months. The two-year survival rate for the 55 patients who received the higher doses of chemotherapy was 43 percent, as compared with 26 percent for the 50 patients who received the lower doses (P = 0.02). The rates of complete response at six months were 67 percent in the higher-dose group and 54 percent in the lower-dose group (P = 0.16). Disease-free survival at two years was 28 percent in the higher-dose group, as compared with 8 percent in the lower-dose group (P = 0.02). Side effects from treatment were not increased in the higher-dose group.

Conclusions: Higher initial doses of cyclophosphamide and cisplatin improve disease-free and overall survival in patients with limited small-cell lung cancer.