title: The influence of gene expression profiling on decisional conflict in decision making for early-stage breast cancer chemotherapy.
abstract: Women with early-stage breast cancer, of whom only 15% will experience a recurrence, are often conflicted or uncertain about taking chemotherapy. Gene expression profiling (GEP) of tumours informs risk prediction, potentially affecting treatment decisions. We examined whether receiving a GEP test score reduces decisional conflict in chemotherapy treatment decision making.
  
  
  
  A general population sample of 200 women completed the decisional conflict scale (DCS) at baseline (no GEP test score scenario) and after (scenario with GEP test score added) completing a discrete choice experiment survey for early-stage breast cancer chemotherapy. We scaled the 16-item DCS total scores and subscores from 0 to 100 and calculated means, standard deviations and change in scores, with significance (p < 0.05) based on matched pairs t-tests.
  
  
  
  We identified five respondent subgroups based on preferred treatment option; almost 40% did not change their chemotherapy decision after receiving GEP testing information. Total score and all subscores (uncertainty, informed, values clarity, support, and effective decision) decreased significantly in the respondent subgroup who were unsure about taking chemotherapy initially but changed to no chemotherapy (n =33). In the subgroup of respondents (n = 25) who chose chemotherapy initially but changed to unsure, effective decision subscore increased significantly. In the overall sample, changes in total and all subscores were non-significant.
  
  
  
  GEP testing adds value for women initially unsure about chemotherapy treatment with a decrease in decisional conflict. However, for women who are confident about their treatment decisions, GEP testing may not add value. Decisions to request GEP testing should be personalised based on patient preferences.
authors.affiliation: Department of Community Health Sciences, University of Calgary, Room 3C62, Health Research Innovation Centre, 3280 Hospital Drive NW, Calgary, Alberta T2N 4Z6, Canada.
authors.forename: Karen V
authors.initials: KV
authors.lastname: MacDonald
authors.affiliation: Li Ka Shing Knowledge Institute of St. Michael's Hospital, 209 Victoria Street, Room 312, Toronto, Ontario M5B 1T8, Canada; Institute of Health Policy, Management and Evaluation, University of Toronto, 209 Victoria Street, Room 312, Toronto, Ontario M5B 1T8, Canada.
authors.forename: Yvonne
authors.initials: Y
authors.lastname: Bombard
authors.affiliation: DeGroote School of Business, McMaster University, 1280 Main Street West, Hamilton, Ontario L8S 4M4, Canada.
authors.forename: Ken
authors.initials: K
authors.lastname: Deal
authors.affiliation: University of Toronto, Sunnybrook Health Sciences Centre, 2075 Bayview Avenue, Toronto, Ontario M4N 3M5, Canada.
authors.forename: Maureen
authors.initials: M
authors.lastname: Trudeau
authors.affiliation: Department of Medicine, University of Toronto, 610 University Avenue, Toronto, Ontario M5G 2M9, Canada; Princess Margaret Cancer Centre, 610 University Avenue, Toronto, Ontario M5G 2M9, Canada.
authors.forename: Natasha
authors.initials: N
authors.lastname: Leighl
authors.affiliation: Department of Community Health Sciences, University of Calgary, McMaster University, Room 3C56, Health Research Innovation Centre, 3280 Hospital Drive NW, Calgary, Alberta T2N 4Z6, Canada. Electronic address: damarsha@ucalgary.ca.
authors.forename: Deborah A
authors.initials: DA
authors.lastname: Marshall
mesh_terms: D000328:Adult; D000368:Aged; D000970:Antineoplastic Agents / Q000627:therapeutic use*; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000235:genetics* / Q000473:pathology; D017024:Chemotherapy, Adjuvant; D003657:Decision Making; D003661:Decision Support Techniques; D005260:Female; D020869:Gene Expression Profiling; D006801:Humans; D046228:Microarray Analysis; D008875:Middle Aged
chemical_list: D000970:Antineoplastic Agents
keywords: Breast cancer; Choice behaviour; Decision making; Decisional conflict; Gene expression profiling