The Association of Hand Dominance With the Development of Breast Cancer-related Lymphedema After Mastectomy: A Retrospective Analysis.

Background: Risk factors for developing breast cancer-related lymphedema (BCRL) are well studied, but little is known about the effect of hand dominance (HD). This study aimed to investigate the relationship between HD and postmastectomy BCRL for unilateral breast cancer (BC). Because BCRL treatment involves movement of the affected limb, we postulated that the inherently increased use of a dominant upper extremity may be protective against BCRL. Methods: A retrospective cohort study of female patients with unilateral BC who underwent mastectomy at a single institution between 2012 and 2022 was performed. BCRL was confirmed by a certified lymphedema therapist. The laterality of HD and BC was categorized as ipsilateral or contralateral. Results: Of the 266 patients included in the analysis, 70 (26.3%) developed BCRL. A greater proportion of patients with HD contralateral BC developed BCRL (30.3% versus 22.4%; P = 0.129) compared with those with HD ipsilateral BC. No statistically significant difference in BCRL development based on BC and HD laterality was demonstrated regardless of lymph node management type. Multivariable analysis showed significant associations between the development of BCRL, and the number of lymph nodes removed (P < 0.001) and adjuvant radiation therapy (P < 0.001). Conclusions: Although a greater proportion of patients with contralateral HD and BC developed BCRL, our results demonstrated no statistically significant relationship. Known risk factors such as increased number of lymph nodes removed and adjuvant radiation therapy were significantly associated with BCRL. Further studies including larger and multicenter populations are required to comprehensively elucidate the relationship between HD and BCRL.