ERBB2 and neoplasm: Leveraging PAM50 subtypes, we found early menarche was associated with basal-like and HER2-enriched intrinsic molecular subtypes, which are considered more aggressive diseases with worsened prognosis [24], higher tumor proliferative index, and increased risk of recurrence score, which has been found to be highly predictive of risk of distant relapse, performing better than other methods of risk prediction [23], together bolstering our suspicions that these tumors may possess more aggressive molecular and pathological features.