Radiation therapy and chemotherapy in the treatment of limited-disease small cell lung cancer

The standard treatment for most patients with LD SCLC is a combination of TRT and PE given concurrently, with TRT being started early. Although most institutions worldwide use four cycles of PE, numerous TRT and CHT issues remain unresolved. Ongoing studies will help clarify these important issues in optimizing the treatment approach and outcome in this disease. The lessons learned from optimization of the treatment approach in LD SCLC also have contributed to the attempt to optimize the treatment in ED SCLC. As the author and colleagues [69] recently showed in a prospective randomized trial, TRT can play an important role in ED SCLC, providing that suitable patients are identified. The author and colleagues focused on those patients who had the most favorable prognosis after induction CHT (ie, those who achieved CR at distant sites accompanied by either CR or PR intrathoracically). These patients were chosen for this study because they most closely resembled LD SCLC patients. After three initial cycles of PE, accelerated hyperfractionated TRT offered a survival advantage over that achieved with CHT alone (mean survival time, 17 versus 11 months; 5-year survival rate, 9.1% versus 3.7%; P = 0.041) due to an improvement in the local recurrence-free survival (P = 0.062). Patients treated with TRT achieved better results than those treated with CHT only, regarding both median time to first relapse (13 versus 9 months) and 1- to 5-year first relapse-free survival (P = 0.045). After the initial three cycles of PE, TRT offered a higher response rate than additional PE. When further response was evaluated, additional PE (in both groups) only offered a few percentage points of additional response, which was indirect evidence of the necessity of limiting the number of CHT cycles to four to six. Results of this study await further verification, an important task for future endeavors in SCLC.