The effect of CNS metastases on the survival of patients with small cell cancer of the lung

Abstract

The records of 227 patients with small cell lung cancer (SMCLC) treated between January 1974 and July 1978 in a series of randomized trials were reviewed to determine the influence of central nervous system (CNS) metastases on survival. Sixteen patients were excluded because of single agent chemotherapy (11), lack of CNS irradiation despite proven metastases (2), prior chemotherapy (2), and concomitant metastatic second primary (1). Of 211 evaluable patients, 100 presented with limited disease and 111 with extensive disease, 25 of whom had CNS metastases at presentation, 21 ("CNS-limited") as the only site of metastases. Treatment of limited patients consisted of chemotherapy and thoracic radiation, while chemotherapy alone was used for extensive patients. No prophylactic brain irradiation was used, but CNS radiation was given to almost all patients when CNS metastases developed. Median survivals were: limited, 13.8 months; CNS-limited, 15.1 months; and extensive 8.6 months (P less than 0.0001). There was no significant difference in the survival experience of limited and CNS-limited patients, although none of the CNS-limited patients experienced long-term remissions. Thirty-five of the limited patients and 21 of the extensive patients subsequently developed CNS metastases. Their median survivals following CNS metastases were 3.7 months and 1.6 months, respectively. In conclusion, CNS metastases as the sole site of metastatic disease at diagnosis of SMCLC is not necessarily a bad prognostic sign, while the subsequent development of CNS metastases may be.