title: Factors Affecting Use and Delay (≥8 Weeks) of Adjuvant Chemotherapy after Colorectal Cancer Surgery and the Impact of Chemotherapy-Use and Delay on Oncologic Outcomes.
abstract: OBJECTIVE
  To evaluate factors affecting the use and delay ≥8 weeks of adjuvant chemotherapy and the impact of chemotherapy use and delay on survival.
  
  
  METHODS
  Between 2005 and 2012, consecutive patients with stage II and III colorectal cancer who were treated with major curative resection were enrolled.
  
  
  RESULTS
  Among 750 patients with stage II (n = 318) and III (n = 432) disease, 153 (20.4%) did not receive chemotherapy. Among 597 patients with adjuvant chemotherapy, 31 (5.2%) began chemotherapy 8 weeks or more after surgery. Factors associated with not receiving chemotherapy were: age ≥80 years (hazard ratio [HR] = 5.2), American Society of Anesthesiologists score ≥3 (HR = 1.9), underlying cerebrovascular disease (HR = 1.7), stage II disease (HR = 2.0), presence of postoperative complications (HR = 2.2), or intensive care unit admission (HR = 2.4). Factors associated with chemotherapy delay ≥8 weeks were: male sex (HR = 4.2), rectal primary cancer (HR = 5.4), or presence of postoperative complications (HR = 2.5). Independent prognostic factors for overall survival included TNM III stage (HR = 2.04) and chemotherapy delay ≥8 weeks (HR = 0.39) or <8 weeks (HR = 0.22). Independent prognostic factors for recurrence-free survival were TNM III stage (HR = 2.26) and chemotherapy delay <8 weeks (HR = 0.35).
  
  
  CONCLUSIONS
  Postoperative complications were associated with both lack of and delayed chemotherapy. Timely initiation of chemotherapy, defined as <8 weeks, was a favorable prognostic factor for overall and recurrence-free survival. To increase the proportion of patients receiving chemotherapy and timely initiation of chemotherapy, surgical complications should be minimized after curative resection.
authors.affiliation: Department of Surgery, Division of Colorectal Surgery, Yonsei University Wonju College of Medicine, Wonju, Korea.
authors.forename: Ik Yong
authors.initials: IY
authors.lastname: Kim
authors.affiliation: Department of Internal Medicine, Division of Gastroenterology, Yonsei University Wonju College of Medicine, Wonju, Korea.
authors.forename: Bo Ra
authors.initials: BR
authors.lastname: Kim
authors.affiliation: Department of Surgery, Division of Colorectal Surgery, Yonsei University Wonju College of Medicine, Wonju, Korea.
authors.forename: Young Wan
authors.initials: YW
authors.lastname: Kim
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D017024:Chemotherapy, Adjuvant; D015179:Colorectal Neoplasms / Q000188:drug therapy* / Q000401:mortality / Q000601:surgery; D003131:Combined Modality Therapy; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D012737:Sex Factors; D015996:Survival Rate; D013997:Time Factors; D061665:Time-to-Treatment; D016896:Treatment Outcome