Concurrent or Sequential Chemoradiotherapy after 3-4 Cycles Induction Chemotherapy for LS-SCLC with Bulky Tumor.

The current study was to compare the efficacy and safety between concurrent and sequential chemoradiotherapy after 3-4 cycles of induction chemotherapy for limited-stage small-cell lung cancer (LS-SCLC) with bulky tumor. From July 2012 to September 2015, a total of 68 patients with stage IIIA and IIIB SCLC who had completed 3-4 cycles of etoposide plus cisplatin/carboplatin and achieved clinical complete response (cCR) or clinical partial response (cPR) were randomized into the two groups equally. The concurrent group received radiotherapy combined with oral etoposide and cisplatin and the sequential group received sequential chemoradiotherapy. Thoracic radiotherapy was performed using intensity-modulated radiation therapy (IMRT) with 95% PTV 60Gy/30 times. After completing chemoradiotherapy, patients received prophylactic cranial irradiation. The primary endpoint was progression-free survival (PFS), and secondary endpoints included overall survival (OS) and toxicity. The median follow-up time was 63.3 months (95% confidence interval [CI], 50.8-75.8). Better PFS and OS were observed in concurrent group (median PFS, 26.0 months [95% CI, 9.0-43.0] versus 13.1 months [95%CI, 9.7-16.6], p=0.023; median OS, 35.0 months [95% CI, 25.4-44.6] versus 22.0 months [95% CI, 17.0-27.1], p=0.015). There was no significant difference in the incidence of radiation esophagitis and radiation pneumonitis between the two groups (p=0.795, p=0.525). This study demonstrated that after the completion of 3-4 cycles of chemotherapy with a remission, concurrent chemoradiotherapy with oral etoposide and cisplatin improved survival compared with sequential chemoradiotherapy in LS-SCLC with bulky tumor.