title: Outcomes of multimodality therapies for patients with stage II or III rectal cancer in California, 1994-2009.
abstract: BACKGROUND
  Perioperative chemoradiotherapy is being used for the treatment of locally advanced rectal cancer to improve survival and reduce recurrence. Although several studies have prompted these changes, the survival benefits of additional chemoradiotherapy have not been adequately tested in a large-scale, population-based setting.
  
  
  OBJECTIVE
  The purpose of this study was to evaluate survival differences between perioperative chemoradiotherapy and surgery alone for the treatment of rectal cancer.
  
  
  METHODS
  : This was a nonconcurrent cohort study of patients treated for rectal cancer stages II and III between 1994 and 2009.
  
  
  METHODS
  The study was conducted through the California Cancer Registry.
  
  
  METHODS
  Eligible patients were those with rectal cancer stage II or III who received either radical surgery alone (N = 2988) or perioperative chemoradiotherapy (N = 8852) during the study period.
  
  
  METHODS
  Cox proportional hazards regression was used to assess the risk of mortality associated with perioperative chemoradiotherapy versus surgery alone, adjusting for age, sex, race/ethnicity, socioeconomic status, tumor stage, month/year of surgery, and hospital factors.
  
  
  RESULTS
  In multivariable binomial log-linear regression, the adjusted prevalence ratio (PR) for receiving perioperative chemoradiotherapy was lower among patients in the older age groups, especially among those ≥75 years of age (PR = 0.52 [95% CI, 0.49-0.55]), and increased monotonically from lowest (PR = 0.92 [95% CI, 0.89-0.95]) to highest socioeconomic status group (referent). Multivariable Cox proportional hazards regression analysis, adjusting for demographic factors, tumor stage, and hospital identification number, showed that perioperative chemoradiotherapy, relative to surgery alone, was associated with lower mortality during the entire study period, with survival benefit increasing over time (1994-1997: HR = 0.76 [95% CI, 0.66-0.88]; 1998-2001: HR = 0.71 [95% CI, 0.64-0.79]; 2002-2005: HR = 0.63 [95% CI, 0.55-0.71]; 2006-2008: HR = 0.47 [95% CI, 0.39-0.56]).
  
  
  CONCLUSIONS
  No information was available on comorbidities or specific surgeon factors, which could contribute to survival differences.
  
  
  CONCLUSIONS
  Perioperative chemoradiotherapy, compared with surgery alone, was associated with significantly improved survival during the entire study period, with increasing benefit among those treated during the latter years of our studied time period. (see Video, Supplemental Digital Content 1, http://links.lww.com/DCR/A120).
authors.affiliation: 1Department of Epidemiology, Biostatistics, and Population Medicine, School of Public Health, Loma Linda University, Loma Linda, California 2Department of Surgery, Mutual Aid Association of Public School Teachers, Kinki Central Hospital, Hyogo, Japan 3Region 5 of the California Cancer Registry, Desert Sierra Cancer Surveillance Program, Loma Linda, California 4Department of Surgery, School of Medicine, Loma Linda University, Loma Linda, California.
authors.forename: Myung Mi
authors.initials: MM
authors.lastname: Cho
authors.forename: John W
authors.initials: JW
authors.lastname: Morgan
authors.forename: Raymond
authors.initials: R
authors.lastname: Knutsen
authors.forename: Keiji
authors.initials: K
authors.lastname: Oda
authors.forename: David
authors.initials: D
authors.lastname: Shavlik
authors.forename: Synnove
authors.initials: S
authors.lastname: Knutsen
authors.forename: Kevork
authors.initials: K
authors.lastname: Kazanjian
mesh_terms: D000230:Adenocarcinoma / Q000401:mortality / Q000473:pathology / Q000628:therapy*; D000368:Aged; D002140:California; D059186:Chemoradiotherapy, Adjuvant / Q000379:methods / Q000401:mortality / Q000706:statistics & numerical data; D015331:Cohort Studies; D003131:Combined Modality Therapy / Q000379:methods / Q000401:mortality; D013505:Digestive System Surgical Procedures / Q000379:methods; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D016016:Proportional Hazards Models; D012004:Rectal Neoplasms / Q000401:mortality / Q000473:pathology / Q000628:therapy*; D016896:Treatment Outcome