The Effects of Radiation Treatment in Breast Cancer Patients on the Subsequent Development of Adhesive Capsulitis.

BACKGROUND

Adhesive capsulitis (AC) is a disabling condition associated with shoulder pain and restricted range of motion. Although breast cancer treatment has been linked to increased AC risk, the independent contribution of radiation therapy remains unclear.

PATIENTS AND

METHODS

A retrospective cohort study was performed using the PearlDiver MARINER database (2014-2023). Female patients with a primary diagnosis of breast cancer and ≥ 2 years of follow-up were included. Patients with prior shoulder pathology were excluded. Cohorts were stratified by radiation exposure and surgical treatment. Propensity score matching was conducted based on age and Charlson Comorbidity Index (CCI). Outcomes were compared using chi-square tests and odds ratios (ORs).

RESULTS

A total of 1,672,952 patients met inclusion criteria, of whom 22,964 (1.37%) developed AC. Radiation therapy was associated with an increased risk of AC compared with no radiation (OR 1.292, 95% confidence interval 1.251-1.334; P < .001). This association persisted in surgical patients (OR 1.364, P < .001) and across surgical subgroups, including breast-conserving surgery, mastectomy, and mastectomy with reconstruction. Radiation exposure was also associated with increased AC risk in nonsurgical patients (OR 1.172, P < .001).

CONCLUSION

Radiation therapy is independently associated with an increased risk of adhesive capsulitis following breast cancer diagnosis. These findings underscore the importance of recognizing treatment-related shoulder morbidity and may inform surveillance and early intervention strategies in breast cancer survivorship care.