Gomes F, Faivre-Finn C, Mistry H, et al. - Given that the American Society of Clinical Oncology does not advise use of granulocyte colony-stimulating factors (G-CSF) during concurrent chemo-radiotherapy (cCTRT) for small cell lung cancer because of safety concerns, researchers examined the safety as well as the role of prophylactic G-CSF (proG-CSF) in the delivery of cCTRT in this secondary analysis. Participants were managed according to protocol in the phase 3 CONVERT trial, which randomized patients between once- or twice-daily RT. There were 487 eligible patients, and of those, 180 (37%) were administered proG-CSF, 60 (33%) as primary preventive and 120 (67%) as secondary preventive after myelotoxic events. Experts found no evidence that myelotoxicity was directly induced by G-CSF, instead higher myelotoxicity risk was the reason to initiate G-CSF in most patients. The planned dose intensity was maintained by G-CSF and no detrimental impact on survival was identified. In this setting, G-CSF may be regarded as a supportive measure.