Multiagent chemotherapy, prophylactic neuraxis irradiation, and consolidative irradiation for small cell carcinoma of the lung.

Between 6/81 and 6/83, 73 patients with small cell carcinoma of the lung were treated according to a prospective protocol in which cyclophosphamide, doxorubicin, and vincristine (CAV) were given concurrently with prophylactic craniocervical irradiation to the level of C5. Both limited and extensive disease patients with normal computed tomography of the brain received 25 Gy in 10 fractions in 2 weeks. Complete responders to CAV received consolidative thoracic irradiation (CTI) to the local-regional primary (37.5 Gy in 15 fractions in 3 weeks), the first 25 Gy in 10 fractions serving as prophylaxis of the C6 to T12 spinal cord. The neuraxis from L1 to S2 then received 25 Gy in 10 fractions in 2 weeks. Consolidative irradiation of localizable metastatic sites was given in extensive disease patients. Partial and nonresponders to CAV received 50-60 Gy in 5-6 weeks to local-regional disease. With a median followup of 29 months, survival was significantly better (p less than .01) in patients receiving CTI to the chest after complete response to CAV (both limited disease and extensive disease) than without CTI. Of 41 patients completing the protocol and without central nervous system (CNS) involvement at presentation, four (9%) failed initially in the CNS (two brain, two spinal axis); CNS failure was the cause of death in all four patients with no other sites of metastases at death in two of these. Failure to complete protocol treatment was due to disease progression during chemotherapy in 25/73 (34%) and chemotherapy related complications (three sepsis, one gastrointestinal bleed) in four of 73 (5.5%) patients. CTI and prophylactic neuraxis irradiation did not increase morbidity or result in mortality in the sequence utilized; prophylactic neuraxis irradiation appears to reduce the CNS relapse rate, and CTI benefits survival.