A small retrospective study conducted at the European Institute of Oncology reported that age ≥70 years was an independent prognostic factor of reduced OS for lobular breast cancer patients, however, there was very few (n = 9) young cases (<35 years) in their study cohort, and no in-depth analysis has been performed to assess the effect of age on OS according to the ER/PR status [17]. Here, ESR1 is linked to Hereditary breast cancer.