Can first cycle CBCs predict older patients at very low risk of neutropenia during further chemotherapy?

Elderly cancer patients with normal complete blood cell counts (CBCs) during the first course of (some types of) chemotherapy might be unlikely to experience grade 4 neutropenia during subsequent cycles. In this case, further weekly CBCs might be avoided.We used data of 223 cancer patients aged 70+ who were included in the CRASH (Chemotherapy Risk Assessment Score for High-age patients) trial between 2003 and 2007 in 7 cancer practices in the US. First cycle CBC values were compared to subsequent cycles. MAX2-score was used as a measure for toxicity of the chemotherapy regimen.Sixty-two patients (28%) experienced grade 4 neutropenia during subsequent cycles. Among patients who received chemotherapy with a MAX2-score lower than 0.20, only 4.6% of those without neutropenia during the first cycle experienced grade 4 neutropenia during subsequent cycles. Weekly CBC might be avoided in these patients receiving chemotherapy. Future prospective studies should confirm these results.