title: Monocyte nadir is a possible indicator for neutrophil nadir during lung cancer chemotherapy.
abstract: BACKGROUND
  No previous study clearly demonstrated the association between the absolute neutrophil count (ANC) nadir and the absolute monocyte count (AMC) nadir among patients undergoing chemotherapy.
  
  
  METHODS
  We retrospectively reviewed patients with an incurable lung cancer in two university hospital who were treated with platinum doublet or triplet. In this study, the nadir was defined as the lowest value during days 1-22.
  
  
  RESULTS
  We observed 75 patients: 61 men (81%) and 14 women (19%), median age of 69 years. The number of days that elapsed between the first day of chemotherapy and the median ANC nadir of 12 days was longer than that for AMC nadir of 6 (Wilcoxon signed rank test: P < 0.001). The number of days that elapsed between the first day of chemotherapy and the AMC nadir was the only factor that had a significant correlation with that for ANC nadir (Spearman's rank correlation: r = 0.34, P = 0.003). Among 75 patients, 23 (31%) had an ANC at nadir <1000/μL. AMC at nadir of 100/μL predicted an ANC at nadir <1000/μL with a sensitivity of 83% and a specificity of 56%.
  
  
  CONCLUSIONS
  Both neutrophils and monocytes are differentiated from a common progenitor, a granulocyte macrophage colony forming cell, which can provide good explanation for the association between ANC and AMC nadirs. We would like to recommend physicians to observe the AMC nadir to predict the timing and severity of the ANC nadir.
authors.affiliation: Department of Pulmonology, Yokohama City University Graduate School of Medicine, Yokohama, Japan.
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Moriyama
authors.affiliation: Department of Pulmonology, Yokohama City University Graduate School of Medicine, Yokohama, Japan.
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Horita
authors.affiliation: Department of Pulmonology, Yokohama City University Graduate School of Medicine, Yokohama, Japan.
authors.forename: Makoto
authors.initials: M
authors.lastname: Kudo
authors.affiliation: Department of Pulmonology, Yokohama City University Graduate School of Medicine, Yokohama, Japan.
authors.forename: Masaharu
authors.initials: M
authors.lastname: Shinkai
authors.affiliation: Department of Hematology, Saiseikai Yokohamashi Nanbu Hospital, Yokohama, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Fujita
authors.affiliation: Department of Biostatistics and Epidemiology, Yokohama City University Graduate School of Medicine, Yokohama Japan.
authors.forename: Takeharu
authors.initials: T
authors.lastname: Yamanaka
authors.affiliation: Department of Internal Medicine and Clinical Immunology, Yokohama City University Graduate School of Medicine, Yokohama, Japan.
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Ishigatsubo
authors.affiliation: Department of Pulmonology, Yokohama City University Graduate School of Medicine, Yokohama, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Kaneko
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D004358:Drug Therapy; D005260:Female; D006801:Humans; D007958:Leukocyte Count / Q000379:methods; D008175:Lung Neoplasms / Q000188:drug therapy* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009000:Monocytes / Q000166:cytology* / Q000187:drug effects / Q000473:pathology; D009367:Neoplasm Staging; D009504:Neutrophils / Q000166:cytology* / Q000187:drug effects / Q000473:pathology; D064887:Observational Studies as Topic; D017063:Outcome Assessment, Health Care; D010984:Platinum / Q000627:therapeutic use / Q000633:toxicity*; D012189:Retrospective Studies
chemical_list: D010984:Platinum
keywords: leukocytes - myelosuppression - neoplasms - platinum - toxicity