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

Abstract

We retrospectively reviewed the medical records of 32 chemonaïve 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 8 patients with <5% monocytes, whereas it decreased by >30% in 1 of 6 patients with ≥5% monocytes (P=0.01). Three of 8 patients with <5% monocytes experienced grade 4 neutropenia, while in the group with ≥5% monocytes, 1 of 6 patients experienced grade 4 neutropenia. The frequency of grade 3 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, grade 3 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.

Table I

The background of the patients in the G-CSF non-administration group (group A).

Table II

The background of the patients in the G-CSF administration group (group B).

Table III

Status of G-CSF administration.

Figure 1

Correlation between the monocyte percentage and decrease in the neutrophil count in the G-CSF non-administration group. G-CSF, granulocyte-colony stimulating factor.

Table IV

Change in neutrophils in the G-CSF non-administration group.

Table V

Correlation between the monocyte percentage and the grade of neutropenia.

Figure 2

Correlation between the fraction of monocytes and the grade of neutropenia following G-CSF administration. G-CSF, granulocyte-colony stimulating factor.

Table VI

Change in neutrophils in the G-CSF administration group.