To the Editor In their observational study, H眉lp眉sch and colleagues1 concluded that the skin microbiome may be a useful biomarker for the personalized prevention of breast radiation dermatitis (RD). We applaud their efforts, but encourage further validation of the results in a larger patient sample.
First, several known risk factors of RD were not presented in the study, which could confound the results. One critical factor is whether patients adhered to a skincare protocol, as the application of topical agents and differences in cleansing practices could affect the skin microbiome and severity of RD.2 Other treatment-related risk factors including plan heterogeneity (hot spots) and treatment position (supine vs prone)3 were not reported. In addition, the authors did not report whether the known risk factors of body mass index and breast volume differed at baseline among patients with different microbiome patterns. Presenting this information is important because the skin microbiome is known to correlate with obesity.4