title: Postoperative follow-up strategy based on recurrence dynamics for non-small-cell lung cancer.
abstract: OBJECTIVE
  Our study was designed to visually represent recurrence patterns after surgery for non-small-cell lung cancer (NSCLC) with the use of event dynamics and to clarify postoperative follow-up methods based on the times of recurrence.
  
  
  METHODS
  A total of 829 patients with NSCLC who underwent complete pulmonary resection from 2005 to 2007 in 9 hospitals affiliated with the Yokohama Consortium of Thoracic Surgeons were studied. Event dynamics, based on the hazard rate, were evaluated. Only first events involving the development of distant metastases, local recurrence or both were considered. The effects of sex, histological type, pathological stage and age were studied.
  
  
  RESULTS
  The hazard rate curve displayed an initial surge that peaked about 6-8 months after surgery. The next distinct peak was noted at the end of the second year of follow-up. On non-parametric kernel smoothing, the maximum peak was found 6-8 months after surgery in men. In women, the highest peak occurred 22-24 months after surgery, which was about 16 months later than the peak in men. The peak timing of the hazard curve was not affected by histological type, pathological stage or age in either sex.
  
  
  CONCLUSIONS
  Our results suggest that the timing of recurrence after surgery for lung cancer is characterized by a bimodal pattern, and the times with the highest risk of recurrence were suggested to differ between men and women. Postoperative follow-up strategies should be based on currently recommended follow-up programmes, take into account the recurrence patterns of lung cancer, and be modified as required to meet the needs of individual patients.
authors.affiliation: Department of Surgery, Yokohama City University, Yokohama, Japan katsuyawatanabe@kantoh.rofuku.go.jp.
authors.forename: Katsuya
authors.initials: K
authors.lastname: Watanabe
authors.affiliation: Division of Thoracic Surgery, National Cancer Center Hospital East, Kashiwa, Japan.
authors.forename: Masahiro
authors.initials: M
authors.lastname: Tsuboi
authors.affiliation: Department of Biostatistics and Epidemiology, Yokohama City University, Yokohama, Japan.
authors.forename: Kentaro
authors.initials: K
authors.lastname: Sakamaki
authors.affiliation: Department of Surgery, Yokohama City University, Yokohama, Japan.
authors.forename: Teppei
authors.initials: T
authors.lastname: Nishii
authors.affiliation: Department of Surgery, Yokohama City University, Yokohama, Japan.
authors.forename: Taketsugu
authors.initials: T
authors.lastname: Yamamoto
authors.affiliation: Department of Surgery, Yokohama City University, Yokohama, Japan.
authors.forename: Takuya
authors.initials: T
authors.lastname: Nagashima
authors.affiliation: Department of Surgery, Yokohama City University, Yokohama, Japan.
authors.forename: Kohei
authors.initials: K
authors.lastname: Ando
authors.affiliation: Department of Surgery, Yokohama City University, Yokohama, Japan.
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Ishikawa
authors.affiliation: Department of Surgery, Yokohama City University, Yokohama, Japan.
authors.forename: Tekkan
authors.initials: T
authors.lastname: Woo
authors.affiliation: Department of Surgery, Yokohama City University, Yokohama, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Adachi
authors.affiliation: Department of Surgery, Yokohama City University, Yokohama, Japan.
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Kumakiri
authors.affiliation: Department of Surgery, Yokohama City University, Yokohama, Japan.
authors.forename: Takamitsu
authors.initials: T
authors.lastname: Maehara
authors.affiliation: Department of Surgery, Yokohama City University, Yokohama, Japan.
authors.forename: Haruhiko
authors.initials: H
authors.lastname: Nakayama
authors.affiliation: Department of Surgery, Yokohama City University, Yokohama, Japan.
authors.forename: Munetaka
authors.initials: M
authors.lastname: Masuda
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D002289:Carcinoma, Non-Small-Cell Lung / Q000473:pathology / Q000556:secondary / Q000601:surgery*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008175:Lung Neoplasms / Q000473:pathology / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000175:diagnosis*; D009367:Neoplasm Staging; D011013:Pneumonectomy / Q000379:methods; D011159:Population Surveillance / Q000379:methods; D011182:Postoperative Care / Q000379:methods; D011184:Postoperative Period; D012737:Sex Factors; D020775:Thoracic Surgery, Video-Assisted / Q000379:methods; D055815:Young Adult
keywords: Follow-up; Non-small-cell lung cancer; Postoperative; Recurrence dynamics