Positive psychological capital as a mediator between body image disturbance and post-traumatic growth in reproductive-age breast cancer patients: a cross-sectional study

Background Reproductive-age breast cancer patients frequently experience significant body image disturbance (BID) following surgery. While such trauma typically triggers distress, it can also catalyze post-traumatic growth (PTG). However, the internal psychological mechanisms facilitating this transformation remain insufficiently understood. Objective This cross-sectional study aimed to investigate the relationship between BID and PTG, specifically examining the mediating role of positive psychological capital (PsyCap). Methods A total of 232 hospitalized patients were recruited from two tertiary hospitals in Hunan Province, China. Data on BID, PsyCap, and PTG were collected using the Body Image Disturbance Questionnaire, the Psychological Capital Questionnaire, and the Post-traumatic Growth Inventory. PROCESS Model 4 was employed to analyze the mediating effect. Results BID significantly and negatively predicted PsyCap (a = − 0.424, P < 0.001), while PsyCap significantly and positively predicted PTG (b = 0.256, P < 0.001). The direct effect of BID on PTG proved non-significant (c’=0.048, P = 0.624). Bootstrap analysis confirmed a significant indirect effect via PsyCap (ab = − 0.108, 95% CI [− 0.227, − 0.033]), indicating a complete mediating role. Conclusions PsyCap serves as a critical bridge linking BID to PTG. Cultivating PsyCap may effectively transform body image distress into psychological growth among young breast cancer survivors.