In our limited series of patients, severe neutropenia G3/4 and FN were observed in unexpectedly high portion of patients not receiving primary G-CSF prophylaxis already in the first cycle of platinum/etoposide chemotherapy; neutropenia G 3/4 developed in more than half patients (53.3%) and FN developed in 2 out of 15 patients. Here, CSF3 is linked to neutropenia.