Valuing preferences for treating screen detected ductal carcinoma in situ.

Background: Mammographic screening reduces breast cancer mortality but may lead to the overdiagnosis and overtreatment of low-risk breast cancers. Conservative management may reduce the potential harm of overtreatment, yet little is known about the impact upon quality of life.

Objectives: To quantify women's preferences for managing low-risk screen detected ductal carcinoma in situ (DCIS), including the acceptability of active monitoring as an alternative treatment.

Methods: Utilities (cardinal measures of quality of life) were elicited from 172 women using visual analogue scales (VASs), standard gambles, and the Euro-Qol-5D-5L questionnaire for seven health states describing treatments for low-risk DCIS. Sociodemographics and breast cancer history were examined as predictors of utility.

Results: Both patients and non-patients valued active monitoring more favourably on average than conventional treatment. Utilities were lowest for DCIS treated with mastectomy (VAS: 0.454) or breast conserving surgery (BCS) with adjuvant radiotherapy (VAS: 0.575). The utility of active monitoring was comparable to BCS alone but was rated more favourably as progression risk was reduced from 40% to 10%. Disutility for active monitoring was likely driven by anxiety around progression, whereas conventional management impacted other dimensions of quality of life. The heterogeneity between individual preferences could not be explained by sociodemographic variables, suggesting that the factors influencing women's preferences are complex.

Conclusions: Active monitoring of low-risk DCIS is likely to be an acceptable alternative for reducing the impact of overdiagnosis and overtreatment in terms of quality of life. Further research is required to determine subgroups more likely to opt for conservative management.