The Importance of Timing of Physical Therapy in Relation to Radiation Therapy during Multimodality Breast Cancer Treatment to Maximize Shoulder Range of Motion

Abstract

Physical therapy (PT) is an effective tool for improving range of motion (ROM) for breast cancer patients to reduce long-term impairment. There is a paucity of data surrounding when PT should be initiated to optimally reduce upper limb disability. We hypothesized that patients who initiated PT early after surgery and before radiation therapy (RT), would experience greater gains in functionality compared to PT during/after RT. Demographic/clinical variables were assessed via retrospective chart review for patients referred to outpatient PT and receiving multimodality treatment for breast cancer between January 2015 and August 2021. Three distinct cohorts were established: patients who received PT and no RT, PT initiated before radiation therapy (pre-RT), and PT initiated during/after RT (d/a RT). The primary endpoint was percent change of total ROM of the ipsilateral shoulder between the first and last PT visits. Secondary endpoints included absolute change in degrees of total ROM of the ipsilateral shoulder between first and last PT visits. Associations between ROM across PT groups and baseline characteristics were evaluated with analysis of variance (ANOVA) testing. Thirty-seven patients were identified, median age 47 years (range 28-76). Higher tumor stage and axillary lymph node dissection were associated with the receipt of RT (p = 0.023, p = 0.003 respectively). Baseline ROM was associated with both percent and absolute improvement in ROM (p = 0.007). Patients receiving no RT demonstrated the greatest mean percent improvement in ROM with PT (84%), compared to the pre-RT and d/a RT cohorts, which demonstrated a 63% and 40% improvement, respectively. In pairwise comparisons, patients in the no RT group and those in the PT pre-RT group both demonstrated a statistically greater improvement in percent change in ROM compared to patients receiving PT d/a RT (no RT 74% vs d/a RT 20%, p = 0.006; pre-RT 59% vs d/a RT 20%, p = 0.045). There was no difference in percent change in ROM between the no RT and pre-RT groups (p = 0.528). On univariate analysis, baseline worse ROM was associated with statistically worse percent change in ROM after PT (p = 0.008), no other baseline characteristics were associated with ROM after PT. When adjusting for baseline ROM, the no RT cohort continued to be associated with improvement in ROM compared to the PT d/a RT group (p = 0.024), while there was no difference in percent change in ROM between patients who received physical therapy pre-RT compared to no RT (p = 0.829). Physical therapy is helpful in improving shoulder ROM at all stages of multimodality breast cancer treatment, however early initiation of PT prior to the start of RT may help maximize range of motion gains.