title: Predictors of adverse cosmetic outcome in the RAPID trial: an exploratory analysis.
abstract: OBJECTIVE
  To evaluate factors associated with adverse cosmesis outcome in breast cancer patients randomized to accelerated partial breast irradiation (APBI) using 3-dimensional conformal radiation therapy or whole-breast irradiation in the RAPID (Randomized Trial of Accelerated Partial Breast Irradiation) trial.
  
  
  METHODS
  Subjects were trial participants with nurse-assessed global cosmetic scores at baseline and at 3 years. Adverse cosmesis was defined as a score of fair or poor. Cosmetic deterioration was defined as any adverse change in score from baseline to 3 years. The analysis is based on data from the previously reported interim analysis. Logistic regression models were used to assess the association of risk factors for these outcomes among all patients and those treated with APBI only.
  
  
  RESULTS
  Clinicopathologic characteristics were similar between subjects randomized to APBI (n=569) or whole-breast irradiation (n=539). For all subjects, factors associated with adverse cosmesis at 3 years were older age, central/inner tumor location, breast infection, smoking, seroma volume, breast volume, and use of APBI; factors associated with cosmetic deterioration were smoking, seroma volume, and use of APBI (P<.05). For APBI subjects, tumor location, smoking, age, and seroma volume were associated with adverse cosmesis (P<.05), and smoking was associated with cosmetic deterioration (P=.02). An independent association between the V95/whole-breast volume ratio and adverse cosmesis (P=.28) or cosmetic deterioration (P=.07) was not detected. On further exploration a V95/whole-breast volume ratio <0.15 was associated with a lower risk of cosmetic deterioration (p=.04), but this accounted for only 11% of patients.
  
  
  CONCLUSIONS
  In the RAPID trial, a number of patient tumor and treatment-related factors, including the use of APBI, were associated with adverse cosmesis and cosmetic deterioration. For patients treated with APBI alone, the high-dose treatment volume was not independently associated with an adverse cosmetic outcome, and a useful clinical threshold could not be identified.
authors.affiliation: Vancouver Island Centre, British Columbia Cancer Agency, Victoria, British Columbia, Canada.
authors.forename: David
authors.initials: D
authors.lastname: Peterson
authors.affiliation: Vancouver Island Centre, British Columbia Cancer Agency, Victoria, British Columbia, Canada.
authors.forename: Pauline T
authors.initials: PT
authors.lastname: Truong
authors.affiliation: Ontario Clinical Oncology Group, McMaster University, Hamilton, Ontario, Canada.
authors.forename: Sameer
authors.initials: S
authors.lastname: Parpia
authors.affiliation: Tom Baker Cancer Centre, University of Calgary, Calgary, Alberta, Canada.
authors.forename: Ivo A
authors.initials: IA
authors.lastname: Olivotto
authors.affiliation: Vancouver Island Centre, British Columbia Cancer Agency, Victoria, British Columbia, Canada.
authors.forename: Tanya
authors.initials: T
authors.lastname: Berrang
authors.affiliation: Juravinski Cancer Centre at Hamilton Health Sciences, McMaster University, Hamilton, Ontario, Canada.
authors.forename: Do-Hoon
authors.initials: DH
authors.lastname: Kim
authors.affiliation: Juravinski Cancer Centre at Hamilton Health Sciences, McMaster University, Hamilton, Ontario, Canada.
authors.forename: Iwa
authors.initials: I
authors.lastname: Kong
authors.affiliation: Centre Hospitalier Universitaire de Québec, Pavillon Hôtel-Dieu de Quebec, Quebec City, Québec, Canada.
authors.forename: Isabelle
authors.initials: I
authors.lastname: Germain
authors.affiliation: Vancouver Centre, British Columbia Cancer Agency, Vancouver, British Columbia, Canada.
authors.forename: Alan
authors.initials: A
authors.lastname: Nichol
authors.affiliation: CancerCare Manitoba, Winnipeg, Manitoba, Canada.
authors.forename: Mohamed
authors.initials: M
authors.lastname: Akra
authors.affiliation: Centre intégré de cancérologie de Laval, Laval, Québec, Canada.
authors.forename: Isabelle
authors.initials: I
authors.lastname: Roy
authors.affiliation: Center for the Southern Interior, British Columbia Cancer Agency, Kelowna, British Columbia, Canada.
authors.forename: Melanie
authors.initials: M
authors.lastname: Reed
authors.affiliation: University Health Network, Princess Margaret Hospital, Toronto, Ontario, Canada.
authors.forename: Anthony
authors.initials: A
authors.lastname: Fyles
authors.affiliation: Tom Baker Cancer Centre, University of Calgary, Calgary, Alberta, Canada.
authors.forename: Theresa
authors.initials: T
authors.lastname: Trotter
authors.affiliation: London Regional Cancer Centre, London, Ontario, Canada.
authors.forename: Francisco
authors.initials: F
authors.lastname: Perera
authors.affiliation: Fraser Valley Centre, British Columbia Cancer Agency, Surrey, British Columbia, Canada.
authors.forename: Susan
authors.initials: S
authors.lastname: Balkwill
authors.affiliation: Centre Hospitalier de l'Université de Montréal, Hôpital Notre-Dame, Montreal, Québec, Canada.
authors.forename: Sophie
authors.initials: S
authors.lastname: Lavertu
authors.affiliation: Juravinski Cancer Centre at Hamilton Health Sciences, McMaster University, Hamilton, Ontario, Canada.
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Elliott
authors.affiliation: Ontario Clinical Oncology Group, McMaster University, Hamilton, Ontario, Canada.
authors.forename: Jim A
authors.initials: JA
authors.lastname: Julian
authors.affiliation: Ontario Clinical Oncology Group, McMaster University, Hamilton, Ontario, Canada.
authors.forename: Mark N
authors.initials: MN
authors.lastname: Levine
authors.affiliation: Ontario Clinical Oncology Group, Juravinski Cancer Centre at Hamilton Health Sciences, McMaster University, Hamilton, Ontario, Canada. Electronic address: twhelan@hhsc.ca.
authors.forename: Timothy J
authors.initials: TJ
authors.lastname: Whelan
mesh_terms: D000367:Age Factors; D000368:Aged; D001940:Breast / Q000528:radiation effects*; D001941:Breast Diseases / Q000150:complications; D001943:Breast Neoplasms / Q000451:nursing / Q000473:pathology / Q000532:radiotherapy*; D018270:Carcinoma, Ductal, Breast / Q000451:nursing / Q000473:pathology / Q000532:radiotherapy*; D004954:Esthetics; D005260:Female; D006801:Humans; D007239:Infections / Q000150:complications; D016015:Logistic Models; D008875:Middle Aged; D011832:Radiation Injuries / Q000150:complications / Q000451:nursing / Q000473:pathology; D011878:Radiotherapy / Q000379:methods; D011879:Radiotherapy Dosage; D020266:Radiotherapy, Conformal / Q000009:adverse effects* / Q000379:methods; D012307:Risk Factors; D049291:Seroma / Q000150:complications / Q000473:pathology; D013997:Time Factors; D016896:Treatment Outcome; D047368:Tumor Burden