title: Prognostic impact of preoperative monocyte counts in patients with resected lung adenocarcinoma.
abstract: OBJECTIVE
  Increasing evidence suggests that an elevated peripheral monocyte count at presentation predicts a poor prognosis in various types of malignancy, including malignant lymphoma. In lung adenocarcinoma, tumor-associated macrophages (TAMs) were reported to be associated with a poor prognosis. However, it is unknown if an elevated peripheral monocyte count is associated with a poor prognosis in lung adenocarcinoma. This study assessed the prognostic impact of the preoperative peripheral monocyte count in lung adenocarcinoma.
  
  
  METHODS
  We retrospectively analyzed 302 consecutive patients with lung adenocarcinoma who received curative resection at Kitano Hospital. The receiver operating characteristic (ROC) curve for the peripheral monocyte count was used to determine the cut-off value. The relations between peripheral monocyte counts and clinicopathological factors were assessed. We also evaluated the impacts of possible prognostic factors including the preoperative peripheral monocyte count on survival, using the two-tailed log-rank test and Cox proportional hazards model. In addition, immunohistochemical staining for CD68 was performed to evaluate the monocytes in primary tumors.
  
  
  RESULTS
  A peripheral monocyte count of 430mm(-3) was the optimal cut-off value for prognosis. An elevated peripheral monocyte count was significantly associated with sex, performance status, smoking history, chronic obstructive pulmonary disease and interstitial lung disease. The two-tailed log-rank test demonstrated that patients with an elevated peripheral monocyte count experienced a poorer recurrence-free survival (RFS) and overall survival (OS) (P=0.0063, P<0.0001, respectively). In the multivariate analysis an elevated peripheral monocyte count was shown to be an independent prognostic factor for the RFS and OS (HR: 1.765; 95% CI: 1.071-2.910; P=0.0258, HR: 4.339; 95% CI: 2.032-9.263; P=0.0001, respectively). Furthermore, numbers of the monocytes in primary tumors significantly correlated with peripheral monocyte counts (r=0.627, P<0.0001).
  
  
  CONCLUSIONS
  The preoperative peripheral monocyte count is an important prognostic factor for patients with lung adenocarcinoma after curative resection.
authors.affiliation: Respiratory Disease Center, Tazuke Kofukai Medical Research Institute, Kitano Hospital, Osaka, Japan.
authors.forename: Shogo
authors.initials: S
authors.lastname: Kumagai
authors.affiliation: Respiratory Disease Center, Tazuke Kofukai Medical Research Institute, Kitano Hospital, Osaka, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Marumo
authors.affiliation: Respiratory Disease Center, Tazuke Kofukai Medical Research Institute, Kitano Hospital, Osaka, Japan.
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Shoji
authors.affiliation: Respiratory Disease Center, Tazuke Kofukai Medical Research Institute, Kitano Hospital, Osaka, Japan.
authors.forename: Minoru
authors.initials: M
authors.lastname: Sakuramoto
authors.affiliation: Respiratory Disease Center, Tazuke Kofukai Medical Research Institute, Kitano Hospital, Osaka, Japan.
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Hirai
authors.affiliation: Department of Clinical Oncology, Tazuke Kofukai Medical Research Institute, Kitano Hospital, Osaka, Japan.
authors.forename: Takafumi
authors.initials: T
authors.lastname: Nishimura
authors.affiliation: Department of Hematology, Tazuke Kofukai Medical Research Institute, Kitano Hospital, Osaka, Japan.
authors.forename: Nobuyoshi
authors.initials: N
authors.lastname: Arima
authors.affiliation: Respiratory Disease Center, Tazuke Kofukai Medical Research Institute, Kitano Hospital, Osaka, Japan.
authors.forename: Motonari
authors.initials: M
authors.lastname: Fukui
authors.affiliation: Respiratory Disease Center, Tazuke Kofukai Medical Research Institute, Kitano Hospital, Osaka, Japan. Electronic address: chuang@kitano-hp.or.jp.
authors.forename: Cheng-Long
authors.initials: CL
authors.lastname: Huang
mesh_terms: D000230:Adenocarcinoma / Q000097:blood* / Q000188:drug therapy / Q000401:mortality* / Q000473:pathology / Q000601:surgery; D000077192:Adenocarcinoma of Lung; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003131:Combined Modality Therapy; D015897:Comorbidity; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007958:Leukocyte Count; D008175:Lung Neoplasms / Q000097:blood* / Q000188:drug therapy / Q000401:mortality* / Q000473:pathology / Q000601:surgery; D018655:Lymphocyte Count; D008297:Male; D008875:Middle Aged; D009000:Monocytes; D009362:Neoplasm Metastasis; D009364:Neoplasm Recurrence, Local; D009367:Neoplasm Staging; D009504:Neutrophils; D057234:Preoperative Period; D011379:Prognosis; D012372:ROC Curve; D012189:Retrospective Studies; D012307:Risk Factors; D016896:Treatment Outcome
keywords: Curative resection; Lung adenocarcinoma; Overall survival; Peripheral monocyte counts; Prognostic factor; Recurrence-free survival