Concurrent cisplatin-etoposide chemotherapy plus thoracic radiotherapy for limited-stage small cell lung cancer. Japanese Lung Cancer Chemotherapy Group in Japanese Clinical Oncology Group.

A recent approach in the treatment of limited-stage small cell lung cancer (LDSCLC) has involved a combined modality of chemotherapy and chest irradiation. In using the modality, the study of scheduling methods for combining chemotherapy and radiotherapy should lead to other trials of combined modalities against LDSCLC since it is the most basic issue to be evaluated. We have thus conducted a multicenter phase II trial of concurrent cisplatin-etoposide (PVP) chemotherapy and radiotherapy for LDSCLC to determine the effects of the concurrent administration of a PVP regimen and chest irradiation on response rate, relapse, survival and treatment toxicity. The chemotherapy regimen consisted of a four-week cycle: cisplatin (80 mg/m2, given intravenously on day 1) and etoposide (100 mg/m2, given intravenously on days 1-3). This cycle was given four to six times within six months. Chest irradiation to the primary tumors at both the hili and the mediastinum was administered in standard fractions on days 2-12 in the first cycle of chemotherapy and on days 29-47 in the second cycle, with a total dose of 40-50 Gy. Prophylactic cranial irradiation was performed among complete remission (CR) or good partial remission (PR) patients after completion of the concurrent therapy. A total of 66 patients were entered into the trial and 59 were evaluated. The concurrent therapy induced an overall response rate of 94.9% in 59 patients: 24 patients, 40.7% CR, 32 patients, 54.2% PR. The median response duration was 8.7 months, and the median survival time for all eligible patients was 14.8 months. The percentage of patients with two-year survival periods was 20. A local relapse within the irradiated area was seen in only 22% of relapse patients. Brain metastases occurred in 24% of patients. Four of 32 patients treated with prophylactic cranial irradiation had brain metastases. Toxic effects, chiefly grades 3 and 4 leukopenia, as established by the World Health Organization, were detected in all treated patients. Other toxicities, including radiation-induced esophagitis and pneumonitis, were deemed almost acceptable. We concluded concurrent treatment of a PVP regimen with chest irradiation to be a feasible and beneficial therapy with an efficacy compatible to that of other published reports. The outcome of this protocol warrants further investigation to determine the optimal type of schedule for concurrent chemoradiotherapy against LDSCLC.