Combination chemotherapy using high or low dose methotrexate for small cell carcinoma of the lung--a randomised trial

Eighty-three patients with histologically proven small cell carcinoma of the lung were entered into a prospective randomised clinical trial to evaluate two induction regimes. A 'low' dose methotrexate regime which employed three cycles of etoposide, adriamycin and methotrexate given at conventional dosage was compared with a regime which employed three cycles of etoposide and adriamycin together with five courses of high dose methotrexate and folinic acid rescue. All patients achieving a complete response (CR) received prophylactic cranial irradiation. Patients with limited disease who achieved a CR received additional radiotherapy to the primary site. An alternative four drug regime (procarbazine, vincristine, cyclophosphamide and CCNU) was evaluated in patients failing to achieve or subsequently relapsing from a complete response. Response rates for the low dose and high dose methotrexate arms were 54 and 55% respectively with median survivals of 8.6 and 9.7 months. Median survival for complete and partial responders was 20.2 and 11 months respectively. The alternative four drug regime showed limited activity in patients failing to achieve a complete response after primary therapy. We conclude that high dose methotrexate as used in this study has no role in small cell lung cancer. The 'low' dose regime was well tolerated by outpatients, is effective and is suitable for generalised use in the palliation of small cell lung cancer.