Studies on chemotherapy for small cell lung cancer Part 2. Patterns of relapse in patients with small cell lung cancer receiving chemotherapy with or without Radiotherapy

Between 1976 and 1987, a total of 180 patients with small cell lung cancer who were entered into three protocol studies of an intensive chemotherapy with or without radiotherapy was fully evaluated for tumor response and survival. Of them, 74 patients achieved a complete response (CR) : 47 out of 91 patients with limited disease (LD) and 27 out of 89 patients with extensive disease (ED). The author analysed the pattern of relapse among the 74 patients in an attempt to clarify the role of chest irradiation and/or prophylactic cranial irradiation. Of 47 patients with LD achieving a CR, 20 patients (43%) developed initial relapse in the chest and seven (15%) developed it in the brain. Of the 27 patients with extensive disease, the chest was also the most frequent site of initial relapse (44%) followed by the brain (19%). In patients with LD receiving chemotherapy plus chest irradiation, the rate of initial relapse in the chest and the cumulative actuarial probability for initial chest relapse 2 years later were 29% and 37%, respectively. These figures were siginificantly lower than the rate of 69% and the probability of 69% for patients receiving chemotherapy alone (p<0.05). The patient survival was improved by the addition of chest irradiation substantially, but not significantly. However, long-term disease-free survivors predominated in the group of patients receiving chemotherapy plus chest irradiation. Prophylactic cranial irradiation exerted no significant advantage for prolonging survival. However, it showed a trend for reducing the brain relapse in complete responders. These findings indicate that chest irradiation concomitant with intensive chemotherapy may be effective for prolonging suvival in patients with LD through preventing relapse from the chest.

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