Multiple Primary Bronchogenic Carcinoma with a Review of the Literature

Five patients with bilateral primary bronchogenic carcinomas of different cell types were identified in a review of 926 patients with lung cancer, an incidence of 0.5 per cent. In a review of the literature 155 patients with multiple primary bronchogenic carcinoma were reported. In several large series the incidence of multiple lung cancers ranged from 0.2 to 1.8 per cent. These figures are not strikingly different from the 2.0 to 4.0 per cent of multiple cancers found in other organs. Epidermoid carcinomas predominated, representing 57 per cent of all multiple tumors and 87 per cent of multiple neoplasms having identical histology. Among multiple primary neoplasms with dissimilar histology the combination of epidermoid and oat cell carcinoma constituted 47 per cent. Cigarette smoking as a common etiologic factor might explain the frequency of these cell types among multiple lung cancers. With few exceptions, concomitant pulmonary disease and exposure to environmental carcinogens were not recognized as playing significant etiologic roles in the de· velopment of multiple neoplasms. Reoperation for a second primary lung cancer was performed in 46 patients; although the number of cases was small and the patients were carefully selected, 23 per cent survived a second operation 2 years or longer. No significant difference in survival was found between the group reoperated for a second primary carcinoma within 2 years and the group having a second resection after an interval of 3 to 15 years. This is the first report of the association of oat cell carcinoma and large cell carcinoma in a single patient; the differential response seen when these tumors were treated with cyclophosphamide is unique among reports or multiple bron· chogenic carcinoma.