[Localized small-cell lung cancers: prospects of concomitant radiochemotherapy]

Concurrent chemoradiotherapy in the treatment of small-cell lung cancer: current results and future prospects. The prognosis of small cell carcinoma of the lung is reportedly poor, even in limited disease. However, new modalities of combined chemotherapy and radiotherapy may actually result in improved survival in these patients. First-line chemotherapy regimens with cisplatin and etoposide are effective and allow early and concurrent administration of thoracic radiotherapy, without overwhelming toxicity. Radiosensitizing properties of cisplatin and etoposide have been demonstrated, and concurrent delivery of radiotherapy results in a high complete response rate on the primary tumor, and improved long-term local control, which is a prerequisite for cure. In addition, a reduction of the irradiated volume, restricted to the macroscopic tumor, appears feasible without compromising local control and results in a reduced long-term complication rate of the combined treatment. Acute toxicities of these concurrent regimens are mainly hematological and esophageal, but are reversible and without late effect in the majority of the patients. The potential benefit of a twice-daily over standard once-daily irradiation has not been conclusively demonstrated in recent trials. However, these trials have demonstrated excellent outcome after short duration chemotherapy (four courses) with early concurrent radiotherapy (45 Gy), resulting in a 40% survival at 2 years, which appears substantially higher than that obtained with the sequential or alternating regimens. The benefit of prophylactic cranial irradiation has also been confirmed in a large trial in terms of reduction of brain relapses, but with only marginal benefit upon survival. Further improvement of the prognosis of these patients may result form an early intensification of chemotherapy with the support of hematopoietic growth factors and from a dose escalation of radiotherapy with the support of three dimensional computerized dosimetry.