Abstract PS1-48: Factors influencing choice of contralateral prophylactic mastectomy in patients with unilateral breast cancer
Authors: Benson John , Kyriacou Harry , Giono Ilaria , Dumitru Dorin 
Published: February 2021

Abstract
Background: Rates of contralateral prophylactic mastectomy (CPM) have more than doubled in the past decade irrespective of inherited predisposition related to high penetrance genes. Increasing numbers of women with unilateral breast cancer are opting for removal of both the affected ipsilateral and contralateral ‘normal’ breast when otherwise suitable for breast conserving surgery. Reasons for this surge in women choosing maximal surgery are poorly understood but trends in CPM are most evident for younger patients (&lt;40 years) and those with non-invasive and stage I disease. Patient decision-making and surgeon interaction may be dominated by ‘fear of recurrence’ and ‘avoidance of decisional regret’ with healthcare professionals feeling pressurized to accede to demands in the wider context of patient-centered care. Methods: A retrospective analysis examined breast cancer patients undergoing unilateral mastectomy with or without CPM between January 2014 and December 2018. Patient information was extracted from an electronic database with documentation of demographic/clinico-pathological details for each group. A cross-sectional survey was undertaken that was compiled and based on validated questionnaires and responses to defined statements generated using a 5-point Likert scale. This questionnaire was posted to patients and contained specific sections relating to reasons for requesting CPM or not. The questionnaire contained a section on pre-surgical discussion and whether the surgeon’s opinion influenced decisions not only for CPM but also immediate breast reconstruction. Results: A total of 403 unilateral therapeutic mastectomy procedures were performed during the study period. The annual number of CPM cases increased by 50% from 14 in 2014 to 20 in 2018. The total number of CPM cases over this period of 5 years was 78 - mean rate of 16.2% per annum. Amongst those CPM patients who were sent questionnaires (n=75), response rate was almost two-thirds (47/75=63%); more than half of respondents (n=46) had simultaneous CPM with immediate breast reconstruction (IBR) whilst 13 patients had immediate CPM without reconstruction. A total of 16 patients had delayed CPM with (n=10) or without (n=6) IBR. The most common reason for seeking CPM was prevention of recurrent breast cancer (mean score 4.5) followed by a desire for “peace of mind” (mean score 4.4). The third most cited reason was to enable patients to move on with their lives as soon as possible (mean score 4.2). Interestingly, patients undergoing CPM were more likely to have no regrets about their decision than patients who chose not to undergo CPM either as a delayed or immediate procedure (mean score 3.0). The least popular reasons for requesting CPM were to avoid regular check ups (mean score 2.7) and to be balanced and minimize chances of back pain (mean score 2.6).Conclusion: This study revealed a relatively high rate of CPM attributable primarily to patient-driven factors including perceived risk of contralateral recurrence, desire for ‘peace of mind’ and resumption of a normal lifestyle. Patients did not sense surgeons being against patient-led proposals for CPM. Patient education is crucial in promoting psychological comfort without the necessity for surgical risk reduction and is consonant with a patient-centric approach that addresses issues of surgical safety and quality of life.
Citation Format: John Benson, Harry Kyriacou, Ilaria Giono, Dorin Dumitru. Factors influencing choice of contralateral prophylactic mastectomy in patients with unilateral breast cancer [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PS1-48.