Prophylactic Mastectomy or Screening in Women Suspected to Have the BRCA1/2 Mutation

Abstract

Background. Women suspected to have the BRCA1/2 mutation may choose between two management options: breast cancer screening and prophylactic mastectomy (PM). Objectives. To compare women's treatment choices with medical and decision-analytic recommendations and to explore variables related to the women's choices. Methods. After provision of information, individual time-tradeoff values for the health outcome "living after PM" were assessed and incorporated into a decision-analytic model, which compared the management options PM and screening with respect to their effects on quality-adjusted life expectancy. Results. Of the 54 women suspected to have the mutation, 51 completed the shared-decision-making procedure. Quality-adjusted life expectancy after PM management was longer for 67% of proven carriers and for 58% of women awaiting the DNA-test result. Twelve proven carriers made definitive treatment choices: eight (67%) chose PM and four (33%) chose screening. All carriers' treatment choices agreed with the normative decision-analytic recommendations. Four (33%) disagreed with the medical recommendations. Of the 36 women awaiting DNA-test results, 32 made hypothetical treatment choices. The agreement between these hypothetical treatment choices and the decision-analytic recommendations was good (78%). Combining data from all 48 women, being married (OR = 14.00, p = 0.006), having children (OR = 4.71, p = 0.02), low desire to participate (OR = 0.14, p = 0.004), high decisional stress (OR = 5.22, p = 0.01), a lower estimate of the "probability of cure for screen-detected breast cancer" (OR = 0.13, p = 0.004), and higher time-tradeoff values for PM (OR = 182, p < 0.0001) made a choice for PM more likely. Conclusions. The complete agreement between the decision-analytic recommendations and the carriers' choices suggests that women act in accordance with normative decision theory. The disagreement between the carriers' choices and the medical recommendations suggests that women's choices and physicians' recommendations were guided by different arguments. The strong association between time-tradeoff value and treatment choice suggests that the time-tradeoff is a valid method to assess preferences. Key words: breast cancer; prophylactic mastectomy; screening; shared decision making, utilities; time preferences. (Med Decis Making 2000;20:251-262)