Many women eligible for breast conservation therapy (BCT) elect unilateral mastectomy (UM) with or without contralateral prophylactic mastectomy (CPM) and cite a desire for “peace of mind.” This study aimed to characterize how peace of mind is defined and measured and how it relates to surgical choice.

Nine databases were searched for relevant articles through 8 October 2023, and data were extracted from articles meeting the inclusion criteria.

The inclusion criteria were met by 20 studies. Most were prospective cohort studies (65%, 13/20). In the majority of the studies (72%, 13/18), Non-Hispanic white/Caucasian women comprised 80 % or more of the study’s sample. Almost half of the studies used the phrase “peace of mind” in their publication (45%, 9/20), and few directly defined the construct (15%, 3/20). Instead, words representing an absence of peace of mind were common, specifically, “anxiety” (85%, 17/20), “fear” (75%, 15/20), and “concern” (75%, 15/20). Most of the studies (90%, 18/20) measured peace of mind indirectly using questionnaires validated for anxiety, fear, worry, distress, or concern, which were administered at multiple postoperative time points (55%, 11/20). Most of the studies (95%, 18/19) reported at least one statistically significant result showing no difference in peace of mind between BCT, UM, and/or CPM at their latest time of assessment.

Peace of mind is largely framed around concepts that suggest its absence, namely, anxiety, fear, and concern. Existing literature suggests that peace of mind does not differ among average-risk women undergoing BCT, UM, or CPM. Shared surgical decisions should emphasize at least comparable emotional and/or psychosocial well-being between CPM and breast conservation.