title: Symptoms and QOL as Predictors of Chemoprevention Adherence in NRG Oncology/NSABP Trial P-1.
abstract: BACKGROUND
  Tamoxifen provides a 50% reduction in the incidence of breast cancer (BC) among high-risk women, yet many do not adhere to the five-year course of therapy. Using the prospective double-blind National Surgical Adjuvant Breast and Bowel Project P-1 study, we evaluated whether participant-reported outcomes were associated with drug adherence and whether baseline behavioral risk factors modified those associations.
  
  
  METHODS
  P-1 participants were randomly assigned to placebo vs tamoxifen (20mg/day). Mixed effects logistic regression was used to evaluate whether baseline or three-month SF-36 quality of life (QOL) mental and physical component summaries (MCS, PCS), and participant-reported symptoms (gynecologic, vasomotor, sexual, and other) predicted 12-month drug adherence (76-100% of assigned medication). The evaluation accounted for age, treatment, estimated breast cancer risk, education, baseline smoking, alcohol consumption, and obesity. All statistical tests were two-sided.
  
  
  RESULTS
  Participants enrolled at least three years before trial unblinding and without medically indicated discontinuation before 12 months were eligible for the present analyses (n = 10 576). At 12 months, 84.3% were adherent. Statistically significant predictors of adherence were: three-month MCS (odds ratio [OR] = 1.15 per 10 points, 95% confidence interval [CI] = 1.06 to 1.25); three-month gynecologic symptoms among moderate alcohol drinkers (OR = .79, 95% CI = 0.72 to 0.88); baseline vasomotor symptoms among participants assigned tamoxifen (OR = .88, 95% CI = 0.80 to 0.97); and three-month sexual symptoms among younger participants (OR = .89 at age 41 years, 95% CI = 0.80 to 0.99). The strongest association was with three-month other symptoms (OR = .77, 95% CI = 0.63 to 0.93). PCS was not associated with adherence. Symptom and QOL associations were not modified by smoking or obesity.
  
  
  CONCLUSIONS
  Promoting QOL and managing symptoms early in therapy may be important strategies to improve adherence.
authors.affiliation: National Surgical Adjuvant Breast and Bowel Project (now a part of NRG Oncology), Pittsburgh, PA (SRL, DLW, PAG); Division of Cancer Control and Population Sciences (SRL) and Division of Cancer Prevention (FLW), National Cancer Institute, Rockville, MD; NRG Oncology, Pittsburgh, PA and Department of Biostatistics, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, PA (QL, JPC); Allegheny Cancer Center at Allegheny General Hospital, Pittsburgh, PA (DLW); UCLA Schools of Medicine and Public Health, and Jonsson Comprehensive Cancer Center, Division of Cancer Prevention & Control Research, Department of Health Services, Los Angeles, CA (PAG). stephanie.land@nih.gov.
authors.forename: Stephanie R
authors.initials: SR
authors.lastname: Land
authors.affiliation: National Surgical Adjuvant Breast and Bowel Project (now a part of NRG Oncology), Pittsburgh, PA (SRL, DLW, PAG); Division of Cancer Control and Population Sciences (SRL) and Division of Cancer Prevention (FLW), National Cancer Institute, Rockville, MD; NRG Oncology, Pittsburgh, PA and Department of Biostatistics, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, PA (QL, JPC); Allegheny Cancer Center at Allegheny General Hospital, Pittsburgh, PA (DLW); UCLA Schools of Medicine and Public Health, and Jonsson Comprehensive Cancer Center, Division of Cancer Prevention & Control Research, Department of Health Services, Los Angeles, CA (PAG).
authors.forename: Farzana L
authors.initials: FL
authors.lastname: Walcott
authors.affiliation: National Surgical Adjuvant Breast and Bowel Project (now a part of NRG Oncology), Pittsburgh, PA (SRL, DLW, PAG); Division of Cancer Control and Population Sciences (SRL) and Division of Cancer Prevention (FLW), National Cancer Institute, Rockville, MD; NRG Oncology, Pittsburgh, PA and Department of Biostatistics, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, PA (QL, JPC); Allegheny Cancer Center at Allegheny General Hospital, Pittsburgh, PA (DLW); UCLA Schools of Medicine and Public Health, and Jonsson Comprehensive Cancer Center, Division of Cancer Prevention & Control Research, Department of Health Services, Los Angeles, CA (PAG).
authors.forename: Qing
authors.initials: Q
authors.lastname: Liu
authors.affiliation: National Surgical Adjuvant Breast and Bowel Project (now a part of NRG Oncology), Pittsburgh, PA (SRL, DLW, PAG); Division of Cancer Control and Population Sciences (SRL) and Division of Cancer Prevention (FLW), National Cancer Institute, Rockville, MD; NRG Oncology, Pittsburgh, PA and Department of Biostatistics, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, PA (QL, JPC); Allegheny Cancer Center at Allegheny General Hospital, Pittsburgh, PA (DLW); UCLA Schools of Medicine and Public Health, and Jonsson Comprehensive Cancer Center, Division of Cancer Prevention & Control Research, Department of Health Services, Los Angeles, CA (PAG).
authors.forename: D Lawrence
authors.initials: DL
authors.lastname: Wickerham
authors.affiliation: National Surgical Adjuvant Breast and Bowel Project (now a part of NRG Oncology), Pittsburgh, PA (SRL, DLW, PAG); Division of Cancer Control and Population Sciences (SRL) and Division of Cancer Prevention (FLW), National Cancer Institute, Rockville, MD; NRG Oncology, Pittsburgh, PA and Department of Biostatistics, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, PA (QL, JPC); Allegheny Cancer Center at Allegheny General Hospital, Pittsburgh, PA (DLW); UCLA Schools of Medicine and Public Health, and Jonsson Comprehensive Cancer Center, Division of Cancer Prevention & Control Research, Department of Health Services, Los Angeles, CA (PAG).
authors.forename: Joseph P
authors.initials: JP
authors.lastname: Costantino
authors.affiliation: National Surgical Adjuvant Breast and Bowel Project (now a part of NRG Oncology), Pittsburgh, PA (SRL, DLW, PAG); Division of Cancer Control and Population Sciences (SRL) and Division of Cancer Prevention (FLW), National Cancer Institute, Rockville, MD; NRG Oncology, Pittsburgh, PA and Department of Biostatistics, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, PA (QL, JPC); Allegheny Cancer Center at Allegheny General Hospital, Pittsburgh, PA (DLW); UCLA Schools of Medicine and Public Health, and Jonsson Comprehensive Cancer Center, Division of Cancer Prevention & Control Research, Department of Health Services, Los Angeles, CA (PAG).
authors.forename: Patricia A
authors.initials: PA
authors.lastname: Ganz
mesh_terms: D000328:Adult; D000368:Aged; D000428:Alcohol Drinking / Q000453:epidemiology; D018931:Antineoplastic Agents, Hormonal / Q000008:administration & dosage* / Q000009:adverse effects*; D001943:Breast Neoplasms / Q000517:prevention & control*; D018890:Chemoprevention / Q000379:methods; D004311:Double-Blind Method; D004334:Drug Administration Schedule; D005260:Female; D005836:Genitalia, Female / Q000187:drug effects*; D006801:Humans; D055118:Medication Adherence / Q000523:psychology; D008875:Middle Aged; D009765:Obesity / Q000453:epidemiology; D016017:Odds Ratio; D011322:Primary Prevention / Q000379:methods*; D011446:Prospective Studies; D011788:Quality of Life; D018570:Risk Assessment; D012307:Risk Factors; D057566:Self Report; D012907:Smoking / Q000453:epidemiology; D013629:Tamoxifen / Q000008:administration & dosage* / Q000009:adverse effects*; D014666:Vasomotor System / Q000187:drug effects*; D016903:Drug Monitoring
chemical_list: D018931:Antineoplastic Agents, Hormonal; D013629:Tamoxifen