The role of radiation therapy in the treatment of small cell undifferentiated bronchogenic cancer.

The current enthusiasm for polychemotherapy in small cell undifferentiated bronchogenic carcinoma obscures the necessity for primary control by radiation therapy. One hundred and sixty-three patients with this diagnosis were treated in the periods 1965-67 (56) and 1974-76 (107). In the earlier period patients received radiation alone or radiation plus single-agent chemotherapy. In the latter period, all patients were treated with multiple-agent chemotherapy in addition to radiation therapy. Median survival time was extended approx. 4 weeks for the latter group of patients at the cost of much morbidity and occasional lethality. In the patients that were autopsied from both series, only 5/30 were free of disease within the treatment portals and all had received more than 4000 rad tumor dose regardless of adjuvant therapy. A total of 14 autopsies were performed on patients treated by chemo-immunotherapy alone during the 1974-76 period. All of these revealed disease in the primary site and mediastinum although some had no evidence of distant metastasis. Tumor volume is sufficiently large within the primary site and regional lymphatics that presently available chemoimmunotherapy without high dose irradiation is unlikely to sterilize loco-regional disease. Elective radiation to the whole brain was administered to 25 patients and only 3 developed cerebral metastases. Of the remaining 82 patients who were treated concurrently, 25 developed cerebral metastasis and then received radiation therapy to the whole brain, 10 of these patients subsequently died.