Acute response to resistance exercise and later development of arm lymphedema in breast cancer survivors: An exploratory follow-up of a randomized cross-over trial.

Background: In breast cancer survivors at risk for lymphedema, variation in lymphatic function and arm volume has been observed related to a bout of exercise, with potential for prediction of breast cancer-related arm lymphedema (BCRaL). This novel, exploratory study examined the acute lymphatic response to resistance exercise and later development of BCRaL in women at high risk for BCRaL. Methods: One year after participation in a cross-over trial evaluating the acute lymphatic response to upper-extremity resistance exercise (low-and heavy-load), participants were assessed for BCRaL (n ​= ​16). The response to exercise was assessed before and after (post, 24- and 72-hrs) each exercise bout as extracellular fluid (L-Dex; bioimpedance spectroscopy (BIS)), interarm volume % difference (IVD; Dual-energy x-ray absorptiometry (DXA)) and symptoms (Numeric rating scale, 0-10 (NRS)). BCRaL at follow-up was defined as presence of one objective indicator (L-Dex >10, change ≥+6.5, IVD >5%) plus one objective or subjective indicator (interarm symptom ≥1 or visual inspection). Descriptive statistics were used to compare the acute response between participants with and without BCRaL at follow-up. Results: No trends indicating a similar acute response to exercise was observed in participants who later developed BCRaL (n ​= ​5). There were no observable differences in acute lymphatic response between participants that developed BCRaL and those who did not, both at an individual and group level. Conclusions: Findings from this exploratory study showed no evidence to suggest that the acute response to resistance exercise can predict BCRaL development.