Letter to editor re: Shah et al.: “The impact of monitoring techniques on progression to chronic breast cancer-related lymphedema: a meta-analysis comparing bioimpedance spectroscopy versus circumferential measurements”

Abstract

Shah et al. recently published “The impact of monitoring techniques on progression to chronic breast cancer-related lymphedema: a meta-analysis comparing bioimpedance spectroscopy versus circumferential measurements.” We commend the authors for addressing this important topic and for emphasizing that screening may allow earlier detection and intervention for breast cancer-related lymphedema (BCRL). We are strong proponents of prospective BCRL screening and the MGH Lymphedema Screening Program has screened over 5500 women since 2005. Shah et al.’s primary outcome was progression to chronic BCRL, analyzing data from 50 studies grouped by monitoring techniques: (a) background rate of progression (no monitoring or monitoring without standardized BCRL circumference or BIS assessments) (35 studies); (b) monitoring with BIS and early intervention (7 studies); or (c) monitoring with tape measure ± intervention (11 studies). The authors concluded that monitoring with BIS and treating early based on these measurements significantly reduce the risk of chronic BCRL compared to background and circumference studies. We have significant concerns regarding the authors’ methodology and interpretation of the studies included and we believe their conclusion is not supported. Shah et al. state they are evaluating monitoring techniques’ effect on chronic BCRL progression; however, lower progression with BIS monitoring was related to early intervention. Only seven BIS studies were included, six of which reported chronic BCRL rates after early intervention. In the BIS studies included, although 262 of 1924 patients (13.6%) progressed to BCRL per BIS measurements, the authors reported that 68 of 1924 patients (3.5%) progressed to chronic BCRL, after early intervention. In these cases, either early intervention was effective in preventing BCRL progression, or there were false positives with BIS monitoring, which has been found previously in the literature. In one of the BIS studies included in the meta-analysis, for example, of 40 patients diagnosed with BCRL via BIS, nine did not undergo treatment yet all had resolution of BCRL on follow-up [1]. In a previous prospective study, Barrio et al. found that of 25 patients with an abnormal l-Dex score, only four progressed to lymphedema [2]. In 11 circumference studies included, only two included early intervention, accounting for data from 284 patients of 8403. Chronic BCRL rates in the circumference studies reflect monitoring alone, without early intervention. If the authors wish to compare effectiveness of monitoring techniques, early intervention should be equitable across groups. Axillary lymph node dissection (ALND) is the main risk factor for BCRL development, presenting approximately four times the risk of BCRL of a sentinel lymph node biopsy. The percentage of patients who underwent ALND differed significantly between groups, with 73% of patients in the circumference studies, but only 28% of patients in the BIS studies undergoing ALND. There would be a significantly lower progression to chronic BCRL in the BIS group based on nodal surgery alone. In addition, data on regional nodal irradiation, body mass index, and chemotherapy use are * Alphonse G. Taghian [email protected]