title: Radiation Therapy Noncompliance and Clinical Outcomes in an Urban Academic Cancer Center.
abstract: To examine associations between radiation therapy (RT) noncompliance and clinical outcomes.
  
  
  
  We reviewed all patients who completed courses of external beam RT with curative intent in our department from the years 2007 to 2012 for cancers of the head and neck, breast, lung, cervix, uterus, or rectum. Patients who missed 2 or more scheduled RT appointments (excluding planned treatment breaks) were deemed noncompliant. Univariate, multivariable, and propensity-matched analyses were performed to examine associations between RT noncompliance and clinical outcomes.
  
  
  
  Of 1227 patients, 266 (21.7%) were noncompliant. With median follow-up of 50.9 months, 108 recurrences (8.8%) and 228 deaths (18.6%) occurred. In univariate analyses, RT noncompliance was associated with increased recurrence risk (5-year cumulative incidence 16% vs 7%, P<.001), inferior recurrence-free survival (5-year actuarial rate 63% vs 79%, P<.001), and inferior overall survival (5-year actuarial rate 72% vs 83%, P<.001). In multivariable analyses that were adjusted for disease site and stage, comorbidity score, gender, ethnicity, race, and socioeconomic status (SES), RT noncompliance was associated with inferior recurrence, recurrence-free survival, and overall survival rates. Propensity score-matched models yielded results nearly identical to those seen in univariate analyses. Low SES was associated with RT noncompliance and was associated with inferior clinical outcomes in univariate analyses, but SES was not associated with inferior outcomes in multivariable models.
  
  
  
  For cancer patients being treated with curative intent, RT noncompliance is associated with inferior clinical outcomes. The magnitudes of these effects demonstrate that RT noncompliance can serve as a behavioral biomarker to identify high-risk patients who require additional interventions. Treatment compliance may mediate the associations that have been observed linking SES and clinical outcomes.
authors.affiliation: Department of Radiation Oncology, Montefiore Medical Center, Albert Einstein College of Medicine, Bronx, New York.
authors.forename: Nitin
authors.initials: N
authors.lastname: Ohri
authors.affiliation: Department of Epidemiology and Population Health, Montefiore Medical Center, Albert Einstein College of Medicine, Bronx, New York.
authors.forename: Bruce D
authors.initials: BD
authors.lastname: Rapkin
authors.affiliation: Department of Radiation Oncology, Montefiore Medical Center, Albert Einstein College of Medicine, Bronx, New York.
authors.forename: Chandan
authors.initials: C
authors.lastname: Guha
authors.affiliation: Department of Radiation Oncology, Montefiore Medical Center, Albert Einstein College of Medicine, Bronx, New York.
authors.forename: Shalom
authors.initials: S
authors.lastname: Kalnicki
authors.affiliation: Department of Radiation Oncology, Montefiore Medical Center, Albert Einstein College of Medicine, Bronx, New York. Electronic address: mgarg@montefiore.org.
authors.forename: Madhur
authors.initials: M
authors.lastname: Garg
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local; D009369:Neoplasms / Q000401:mortality / Q000532:radiotherapy*; D010349:Patient Compliance; D057216:Propensity Score; D016016:Proportional Hazards Models; D012923:Social Class