* [[abortion]]<ref>The increase in risk of breast cancer due to abortion is explained and supported with numerous citations in our [[abortion|abortion entry]].</ref>
* family history if such a history involves having several generations affected by breast cancer or having many relatives diagnosed with breast cancer at less than 50 years old <ref> http://www.breastcancer.org/cmn_who_indrisk.html </ref>
* family history if such a history involves having several generations affected by breast cancer or having many relatives diagnosed with breast cancer at less than 50 years old <ref> http://www.breastcancer.org/cmn_who_indrisk.html </ref>
* prolonged uninterrupted exposure to estrogen (e.g. by having an early [[menarche]] and late [[menopause]] or by having no full-term pregnancies).<ref> http://www.breastcancer.org/cmn_who_indrisk.html </ref>
* prolonged uninterrupted exposure to estrogen (e.g. by having an early [[menarche]] and late [[menopause]] or by having no full-term pregnancies).<ref> http://www.breastcancer.org/cmn_who_indrisk.html </ref>