prevalence of breast cancer-related lymphedema in participants of an exercise intervention utilizing heavy load resistance training
BACKGROUND: There is limited knowledge regarding progressive resistance training during adjuvant chemotherapy and the risk of developing breast cancer-related lymphedema (BCRL). Furthermore, no studies have investigated the safety of resistance training with heavy loads (> 80% 1 repetition maximum) in this population. 'Body and Cancer' is a six-week, nine-hour weekly, supervised, multimodal exercise intervention utilizing progressive resistance training with heavy loads for cancer patients undergoing chemotherapy. The purpose of the present study was to estimate the prevalence of BCRL in former participants, and identify associations between progressive resistance training with heavy loads, and the development of BCRL. MATERIAL AND METHODS: This was a descriptive study. POPULATION: Women treated for breast cancer (n = 149), who had participated in the 'Body and Cancer' exercise intervention between 1 January 2010 and 31 December 2011 participated in a structured telephone interview. The average follow-up time was 14 months (range 4-26). A clinical diagnosis of BCRL reported by the participant was the primary outcome. RESULTS: A total of 27.5% reported that they had been diagnosed with BCRL by a clinician. This was true for 44.4% with axillary node dissection. No statistically significant association between strength gains during the exercise intervention, and the development of BCRL was observed, nor was self-reported participation in progressive resistance training with heavy loads up to three months post-intervention. CONCLUSION: The prevalence of BCRL among former "Body and Cancer" participants at follow-up was 27.5%. There appears to be no association between performing heavy resistance training during adjuvant treatment (chemotherapy/radiotherapy), and the development of BCRL. However randomized controlled trials should be performed to confirm this observation.