Clinical and patient-reported outcomes in women offered oncoplastic breast-conserving surgery as an alternative to mastectomy: ANTHEM multicentre prospective cohort study

Background Oncoplastic breast-conserving surgery may be a better option than mastectomy, but high-quality comparative evidence is lacking. The aim of the ANTHEM study (ISRCTN18238549) was to explore clinical and patient-reported outcomes in a multicentre cohort of women offered oncoplastic breast-conserving surgery as an alternative to mastectomy with or without immediate breast reconstruction.Methods Women with invasive/pre-invasive breast cancer who were offered oncoplastic breast-conserving surgery with volume replacement or displacement techniques to avoid mastectomy were recruited prospectively. Demographic, operative, oncological, and 3- and 12-month complication data were collected. The proportion of women choosing oncoplastic breast-conserving surgery and the proportion in whom breast conservation was successful were calculated. Participants completed the validated BREAST-Q questionnaire at baseline, 3 months after surgery, and 12 months after surgery. Questionnaires were scored according to the developers' instructions and scores for each group were compared over time.Results In total, 362 women from 32 UK breast units participated, of whom 294 (81.2%) chose oncoplastic breast-conserving surgery. Of the oncoplastic breast-conserving surgery patients in whom postoperative margin status was reported, 210 of 255 (82.4%) had clear margins after initial surgery and only 10 (3.9%) required completion mastectomy. Major complications were significantly more likely after immediate breast reconstruction. Women having oncoplastic breast-conserving surgery with volume displacement techniques reported significant improvements in baseline 'satisfaction with breasts' and 'psychosocial well-being' scores at 3 and 12 months, but both oncoplastic breast-conserving surgery groups reported significant decreases in 'physical well-being: chest' at 3 and 12 months.Conclusion Oncoplastic breast-conserving surgery allows greater than 95% of women to avoid mastectomy, with lower major complication rates than immediate breast reconstruction, and may improve satisfaction with outcome. Oncoplastic breast-conserving surgery should be offered as an alternative to mastectomy in all women in whom it is technically feasible. Oncoplastic breast-conserving surgery may allow many women to avoid mastectomy, but there are limited data regarding the acceptability of this approach or the outcomes of surgery in a cohort of women offered both options. In this multicentre prospective cohort study, over 80% of women offered oncoplastic breast-conserving surgery to avoid mastectomy chose this option and over 90% had successful breast conservation. Women having oncoplastic breast-conserving surgery experienced lower major complication rates and reported better satisfaction than those having mastectomy with or without breast reconstruction, suggesting oncoplastic breast-conserving surgery may be a better option for many women.