CONCURRENT CHEMORADIOTHERAPY IN THE TREAT MENT 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 chemother apy and radiotherapy may actually result in improved survival in these patients. First-line chemotherapy regimens with cisplatin and etoposi de are effective and allow early and concurrent administration of thor acic radiotherapy, without overwhelming toxicity. Radiosensitizing pro perties of cisplatin and etoposide have been demonstrated, and concurr ent 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 vol ume, restricted to the macroscopic tumor, appears feasible without com promising local control and results in a reduced long-term complicatio n rate of the combined treatment Acute toxicities of these concurrent regimens are mainly hematological and esophageal, but are reversible a nd 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 larg e trial in terms of reduction of brain relapses, bur with only margina l benefit upon survival. Further improvement of the prognosis of these patients may result form an early intensification of chemotherapy wit h the support of hematopoietic growth factors and from a dose escalati on of radiotherapy with the support of three dimensional computerized dosimetry.