Role of granulocyte and granulocyte-macrophage colony-stimulating factors in the treatment of small-cell lung cancer: a systematic review of the literature with methodological assessment and meta-analysis

In order to clarify the role of haematological colony-stimulating factors (CSF) in the treatment of small-cell lung cancer, we performed a systematic review of the randomised trials published on this topic. Since 1991, 12 studies were eligible, including a total of 2107 randomised patients. They were divided into three groups: (1) maintenance of dose-intensity when chemotherapy was given at conventional doses and time intervals (seven trials); (2) accelerated chemotherapy with increased dose-intensity by reducing the delay between chemotherapy cycles (five trials); (3) concentration of chemotherapy on an overall shorter duration time with a lower number of cycles (one trial). Before quantitative aggregation, we performed a methodological assessment using two previously published quality scales (Chalmers and ELCWP). The median quality scores for the pooled 12 trials was 59.9% (range: 42.2-82.0%) for the ELCWP scale and 55.8% (range: 38.0-76.8%) for the Chalmers scale. No statistically significant difference was observed between positive (significant) and negative (non-significant) studies allowing us to perform a meta-analysis. A detrimental effect on response rate was associated with CSF administration in the maintenance group (RR 0.92; 95% confidence interval [CI] 0.87-0.97) without significant effect on survival (HR 1.004; 95% CI, 0.89-1.13). In the accelerated group, no significant impact on response rate (RR 1.02; 95% CI, 0.94-1.09) or survival (HR 0.82; 95% CI, 0.67-1.00) was found. Although no difference in response rate was observed, a reduced survival was associated with concentrated chemotherapy. In conclusion, the published data do not support the routine use of haematological colony-stimulating factors in the treatment of small-cell lung cancer (SCLC).