Prediction of docetaxel monotherapy-induced neutropenia based on the monocyte percentage

Abstract

We retrospectively reviewed the medical records of 32chemonaïve patients with either breast, lung or prostate cancer, who were treated with docetaxel (DOC) monotherapy, and evaluated whether the proportion of peripheral blood monocytes was capable of predicting the occurrence of neutropenia following chemotherapy. In the granulocyte-colony stimulating factor (G-CSF) non‑administration group, the monocyte percentage was inversely correlated with the decrease in neutrophils (P=0.01; corrected correlation coefficient, -0.71). The neutrophil count decreased by ≥30% in 7 of 8patients with <5%monocytes, whereas it decreased by >30% in 1of 6patients with ≥5% monocytes (P=0.01). Three of 8patients with <5% monocytes experienced grade4 neutropenia, while in the group with ≥5% monocytes, 1 of 6patients experienced grade4 neutropenia. The frequency of grade3 or 4 neutropenia was lower in patients with ≥5% monocytes than in patients with <5% monocytes, but the difference was not significant (P=0.41). Following G-CSF administration, grade3 or 4 neutropenia had the tendency of lasting longer in patients with <5% monocytes than in those with ≥5% monocytes; however, the monocyte percentage was not correlated with the grade of neutropenia (P=0.34). The monocyte percentage following chemotherapy was inversely correlated with the decrease in neutrophils. The percentage of monocytes that are available in clinical practice may be predictive of neutropenia following chemotherapy. Our findings suggest that patients with <5% monocytes following DOC monotherapy are at risk of severe neutropenia and should be carefully monitored.