de Ruijter TC, et al. - Given that an ongoing challenge in patients suffering from hormone receptor-positive breast cancer is to distinguish between patients with a low and a high risk of recurrence, and additional prognostic value of DNA methylation markers in many cancer types has been confirmed, so, researchers evaluated the number as well as the level of proof of published DNA methylation markers for hormone receptor-positive breast cancer by performing a systematic review of PubMed and EMBASE. They scored all the included studies by the REMARK (REporting recommendations for tumour MARKer prognostic studies) criteria to provide an overview of the reporting quality of those studies. Overall 74 studies with 87 different DNA methylation markers were analyzed. Among multiple independent populations, 18 single markers and 1 marker panel were analyzed. A statistically significant link with poor disease outcome was displayed by hypermethylation of the markers RASSF1, BRCA, PITX2, CDH1, RARB, PCDH10 and PGR, and the marker panel GSTP1, RASSF1 and RARB, and this was verified in at least one other, independent study. This inquiry affords a summary of published prognostic DNA methylation markers for hormone receptor-positive breast cancer and reveals eight markers that have been independently confirmed. Standardised reporting guidelines might benefit future inquiry on this subject, as indicated by examination of the reporting quality of the included studies.