The effect of dose fractionation on overall survival in patients with limited-stage small cell lung cancer / 中华放射肿瘤学杂志

ABSTRACT

Objective To study the effect of different dose fractionation on overall survival in patients with limited-stage small cell lung cancer (LS-SCLC). Methods LS-SCLC patients treated with radical combined chemotherapy and radiotherapy (RT) between January 2001 and Dec 2007 were analyzed retrospectively. According to the dose fractionation schemes, patients were divided into three groupsconventional fractionated RT (1. 8 -2.0 Gy,once daily), hyperfractionated RT (1.4 Gy, twice daily) and hypofractionated RT (2. 5 Gy,once daily). Overall survival, disease free survival and pattern of failures of the three groups were compared. A total of 177 patients were enrolled, including 63 patients in conventional fractionated RT group, 79 in hyperfractionated RT group and 35 in hypofractionated RT group. Results The overall follow-up rate was 96. 6%. The patient numbers with follow-up of more than 2 and 5 years were 153 and 92, respectively. The median survival time of the entire group was 22. 4 months, and the 2-and 5-year survival rates were 43.4% and 23. 5%, respectively. The 2-year survival rates for three groups were 31%, 46% and 59% (x2 =7.94,P=0.019), respectively. The 2-year disease free survival for three groups were 20%, 31% and 40% ( x2 = 4. 86, P = 0. 088 ), respectively. In the pairwise comparisons,patients in hypofractionated RT group have better survival than those in conventional fractionated RT group ( x2 = 7. 81, P = 0. 005 ), the effect of hyperfractionated RT group lies between the hypo-and the conventional fractionated RT groups, but no significant differences were detected ( x2 = 2. 31, P = 0. 128; x2 = 2. 95, P =0. 086). The mildest side effect was found in the hypofractionated RT group. No statistically significant differences were found in the patterns of first failure. Conclusion The hypofractionated RT scheme showed potential survival benefits for patients with LS-SCLC and should be considered in the setting of randomized clinical trials.