Monitoring of Leukocyte Counts to Help Ensure Proper Use of Anticancer Drugs in Patients with Solid Tumors

During cancer chemotherapy,myelosuppression is a frequently observed toxicity manifestation which may sometimes cause severe infections.In this regard,though leukopenia-induced infections are more closely related to neutrophil counts than leukocyte counts,it is important to evaluate both leukocyte counts and neutrophil counts as markers of myelosuppression.Neutrophil counts,however,are sometimes estimated to be half leukocyte counts without conducting differential leukocyte counts.In the present study,the authors evaluated the necessity of differential leukocyte counts during cancer chemotherapy using pooled laboratory data at the University of Fukui Hospital.Variation in the percentage of neutrophils in leukocytes was observed in each leukocyte range,with the neutrophil count decreasing in pace with decreases in the leukocyte count.As an alternative index to the neutrophil count,the utility of the leukocyte count is thus considered to be low in cancer chemotherapy.There was also a divergence between adverse event grade between neutrophil and leukocyte numbers.In addition,neutrophil counts in 14.8% of the patients (26)were less than 1000/μL in spite of the fact that their leukocyte counts were higher than 3000/μL,and it was noted that 23 of them had undergone a paclitaxel-containing regimen.These results suggested that leukocyte differential counts should be measured during cancer chemotherapy,especially during the nadir period and when receiving chemotherapy containing paclitaxel.