Finnish translation, validation, and reproducibility of BREAST-Q modules relevant to breast cancer treatment

Background and objective: Breast cancer and its treatments can have a marked impact on the patient health-related quality of life. The aim of this study was to produce and validate Finnish versions of the breast-conserving treatment, mastectomy and breast reconstruction modules of the BREAST-Q, a patient-reported outcome tool designed specifically for women undergoing treatment for breast cancer. Methods: The relevant BREAST-Q modules were translated to Finnish according to established guidelines. Altogether 777 preoperative women were recruited at the Breast Surgery Unit and the Plastic Surgery Unit of Helsinki University Hospital between December 2019 and March 2021. This included 541 patients scheduled for breast-conserving surgery, 86 for mastectomy, and 150 for breast reconstruction. Postoperative patients were recruited through a postal survey, approaching 500 women operated for breast cancer in 2017, including 250 women who had undergone breast-conserving surgery and 250 women who had undergone mastectomy, as well as 339 women who had undergone breast reconstruction between August 2017 and July 2019. The patients were invited to fill the BREAST-Q modules relevant to their treatment and the general health-related quality-of-life instrument SF-36. A repeat administration of the BREAST-Q was done 2 weeks later. Results: A total of 665 (41%) women participated in the study, 339 (44%) preoperatively and 326 (39%) postoperatively. The BREAST-Q subscales showed high internal consistency with most Cronbach's alphas > 0.8. The repeatability of the subscales was excellent with most intra-class correlation coefficients > 0.75. Low or negligible correlation was observed between BREAST-Q subscales and SF-36 domains. Conclusions: The Finnish version of the BREAST-Q modules breast-conserving treatment, mastectomy, and breast reconstruction performs well in assessing the health-related quality of life of women undergoing surgery for breast cancer or breast reconstruction.