Adverse prognostic effect of N2 disease in treated small cell carcinoma of the lung

We reviewed survival of patients with clinically localized small cell carcinoma of the lung treated by surgical resection, combination chemotherapy, and prophylactic cranial irradiation. Long-term survival was defined as continuing complete remission 30 months after the start of treatment. Initial TNM staging determined the course of treatment. Ten patients with disease in Stages I and II were treated over 30 months ago by initial resection followed by the full course of chemotherapy. Only one has had a relapse, whereas 80% remained disease-free at 30 months. Five of these patients have passed 5 years. Four patients with T3 N1 disease were treated by two cycles of chemotherapy, surgical resection, and cranial irradiation plus resumption of chemotherapy thereafter; two remained in remission at 30 months. Sixteen patients initially with N2 disease were treated according to the same schedule; 10 of the 16 underwent successful resection. All 16 patients have had a relapse, but the relapse occurred very late in three--at 27, 30, and 37 months. The reasons for the apparently poor prognosis of N2 disease are not clear. Considerations of tumor response kinetics and somatic mutation suggest that these biologic factors are fundamentally responsible. Other studies may find disease control achieved in a very few patients with N2 disease.