{"id":1874,"date":"2026-02-07T19:51:39","date_gmt":"2026-02-07T10:51:39","guid":{"rendered":"https:\/\/dev.rftcjapan.org\/?page_id=1874"},"modified":"2026-06-03T13:21:46","modified_gmt":"2026-06-03T04:21:46","slug":"early-life-exposures","status":"publish","type":"page","link":"https:\/\/rftcjapan.org\/en\/about-breast-cancer\/early-life-exposures\/","title":{"rendered":"Early Life Exposures"},"content":{"rendered":"\t\t<div data-elementor-type=\"wp-page\" data-elementor-id=\"1874\" class=\"elementor elementor-1874\" data-elementor-post-type=\"page\">\n\t\t\t\t<div class=\"elementor-element elementor-element-a9e63ae e-flex e-con-boxed e-con e-parent\" data-id=\"a9e63ae\" data-element_type=\"container\" data-e-type=\"container\">\n\t\t\t\t\t<div class=\"e-con-inner\">\n\t\t<div class=\"elementor-element elementor-element-b601319 e-con-full elementor-hidden-mobile e-flex e-con e-child\" data-id=\"b601319\" data-element_type=\"container\" data-e-type=\"container\">\n\t\t<div class=\"elementor-element elementor-element-e1a5fc8 e-con-full e-flex e-con e-child\" data-id=\"e1a5fc8\" data-element_type=\"container\" data-e-type=\"container\" data-settings=\"{&quot;sticky&quot;:&quot;top&quot;,&quot;sticky_on&quot;:[&quot;desktop&quot;,&quot;tablet&quot;],&quot;sticky_offset&quot;:100,&quot;sticky_parent&quot;:&quot;yes&quot;,&quot;sticky_effects_offset&quot;:0,&quot;sticky_anchor_link_offset&quot;:0}\">\n\t\t\t\t<div class=\"elementor-element elementor-element-04c70f7 elementor-toc--minimized-on-tablet elementor-widget elementor-widget-table-of-contents\" data-id=\"04c70f7\" data-element_type=\"widget\" data-e-type=\"widget\" data-settings=\"{&quot;headings_by_tags&quot;:[&quot;h2&quot;],&quot;exclude_headings_by_selector&quot;:[],&quot;marker_view&quot;:&quot;numbers&quot;,&quot;minimize_box&quot;:&quot;yes&quot;,&quot;minimized_on&quot;:&quot;tablet&quot;,&quot;hierarchical_view&quot;:&quot;yes&quot;,&quot;min_height&quot;:{&quot;unit&quot;:&quot;px&quot;,&quot;size&quot;:&quot;&quot;,&quot;sizes&quot;:[]},&quot;min_height_tablet&quot;:{&quot;unit&quot;:&quot;px&quot;,&quot;size&quot;:&quot;&quot;,&quot;sizes&quot;:[]},&quot;min_height_mobile&quot;:{&quot;unit&quot;:&quot;px&quot;,&quot;size&quot;:&quot;&quot;,&quot;sizes&quot;:[]}}\" data-widget_type=\"table-of-contents.default\">\n\t\t\t\t\t\t\t\t\t<div class=\"elementor-toc__header\">\n\t\t\t\t\t\t<h2 class=\"elementor-toc__header-title\">\n\t\t\t\tTable of Contents\t\t\t<\/h2>\n\t\t\t\t\t\t\t\t\t\t<div class=\"elementor-toc__toggle-button elementor-toc__toggle-button--expand\" role=\"button\" tabindex=\"0\" aria-controls=\"elementor-toc__04c70f7\" aria-expanded=\"true\" aria-label=\"Open table of contents\"><svg aria-hidden=\"true\" class=\"e-font-icon-svg e-fas-angle-down\" viewBox=\"0 0 320 512\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\"><path d=\"M143 352.3L7 216.3c-9.4-9.4-9.4-24.6 0-33.9l22.6-22.6c9.4-9.4 24.6-9.4 33.9 0l96.4 96.4 96.4-96.4c9.4-9.4 24.6-9.4 33.9 0l22.6 22.6c9.4 9.4 9.4 24.6 0 33.9l-136 136c-9.2 9.4-24.4 9.4-33.8 0z\"><\/path><\/svg><\/div>\n\t\t\t\t<div class=\"elementor-toc__toggle-button elementor-toc__toggle-button--collapse\" role=\"button\" tabindex=\"0\" aria-controls=\"elementor-toc__04c70f7\" aria-expanded=\"true\" aria-label=\"Close table of contents\"><svg aria-hidden=\"true\" class=\"e-font-icon-svg e-fas-angle-up\" viewBox=\"0 0 320 512\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\"><path d=\"M177 159.7l136 136c9.4 9.4 9.4 24.6 0 33.9l-22.6 22.6c-9.4 9.4-24.6 9.4-33.9 0L160 255.9l-96.4 96.4c-9.4 9.4-24.6 9.4-33.9 0L7 329.7c-9.4-9.4-9.4-24.6 0-33.9l136-136c9.4-9.5 24.6-9.5 34-.1z\"><\/path><\/svg><\/div>\n\t\t\t\t\t<\/div>\n\t\t\t\t<div id=\"elementor-toc__04c70f7\" class=\"elementor-toc__body\">\n\t\t\t<div class=\"elementor-toc__spinner-container\">\n\t\t\t\t<svg class=\"elementor-toc__spinner eicon-animation-spin e-font-icon-svg e-eicon-loading\" aria-hidden=\"true\" viewBox=\"0 0 1000 1000\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\"><path d=\"M500 975V858C696 858 858 696 858 500S696 142 500 142 142 304 142 500H25C25 237 238 25 500 25S975 237 975 500 763 975 500 975Z\"><\/path><\/svg>\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-69f2d47 elementor-widget elementor-widget-heading\" data-id=\"69f2d47\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t\t<h6 class=\"elementor-heading-title elementor-size-default\">About Breast Cancer<\/h6>\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-ffd7575 elementor-widget elementor-widget-template\" data-id=\"ffd7575\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"template.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t<div class=\"elementor-template\">\n\t\t\t\t\t<div data-elementor-type=\"section\" data-elementor-id=\"3044\" class=\"elementor elementor-3044\" data-elementor-post-type=\"elementor_library\">\n\t\t\t<div role=\"region\" aria-labelledby=\"e-n-accordion-item-2330\" class=\"elementor-element elementor-element-fd830c6 e-con-full e-grid e-con e-child\" data-id=\"fd830c6\" data-element_type=\"container\" data-e-type=\"container\">\n\t\t<div role=\"region\" aria-labelledby=\"e-n-accordion-item-2330\" class=\"elementor-element elementor-element-3717cd6 e-con-full e-flex e-con e-child\" data-id=\"3717cd6\" data-element_type=\"container\" data-e-type=\"container\">\n\t\t\t\t<div class=\"elementor-element elementor-element-e6c4d06 elementor-widget elementor-widget-heading\" data-id=\"e6c4d06\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t\t<h4 class=\"elementor-heading-title elementor-size-default\">Breast Cancer Basics<\/h4>\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-c84b33f elementor-nav-menu--dropdown-none elementor-widget elementor-widget-nav-menu\" data-id=\"c84b33f\" data-element_type=\"widget\" data-e-type=\"widget\" data-settings=\"{&quot;layout&quot;:&quot;vertical&quot;,&quot;submenu_icon&quot;:{&quot;value&quot;:&quot;&lt;i aria-hidden=\\&quot;true\\&quot; class=\\&quot;\\&quot;&gt;&lt;\\\/i&gt;&quot;,&quot;library&quot;:&quot;&quot;}}\" data-widget_type=\"nav-menu.default\">\n\t\t\t\t\t\t\t\t<nav aria-label=\"\u30e1\u30cb\u30e5\u30fc\" class=\"elementor-nav-menu--main elementor-nav-menu__container elementor-nav-menu--layout-vertical e--pointer-none\">\n\t\t\t\t<ul id=\"menu-1-c84b33f\" class=\"elementor-nav-menu sm-vertical\"><li class=\"menu-item menu-item-type-post_type menu-item-object-page menu-item-2517\"><a href=\"https:\/\/rftcjapan.org\/en\/about-breast-cancer\/what-is-breast-cancer\/\" class=\"elementor-item\">What is Breast Cancer?<\/a><\/li>\n<li class=\"menu-item menu-item-type-post_type menu-item-object-page menu-item-2515\"><a href=\"https:\/\/rftcjapan.org\/en\/about-breast-cancer\/breast-cancer-statistics-global-japan\/\" class=\"elementor-item\">Breast Cancer Statistics (Global &amp; Japan)<\/a><\/li>\n<li class=\"menu-item menu-item-type-post_type menu-item-object-page menu-item-2516\"><a href=\"https:\/\/rftcjapan.org\/en\/about-breast-cancer\/understanding-the-risk-of-breast-cancer\/\" class=\"elementor-item\">Understanding the Risk of Breast Cancer<\/a><\/li>\n<\/ul>\t\t\t<\/nav>\n\t\t\t\t\t\t<nav class=\"elementor-nav-menu--dropdown elementor-nav-menu__container\" aria-hidden=\"true\">\n\t\t\t\t<ul id=\"menu-2-c84b33f\" class=\"elementor-nav-menu sm-vertical\"><li class=\"menu-item menu-item-type-post_type menu-item-object-page menu-item-2517\"><a href=\"https:\/\/rftcjapan.org\/en\/about-breast-cancer\/what-is-breast-cancer\/\" class=\"elementor-item\" tabindex=\"-1\">What is Breast Cancer?<\/a><\/li>\n<li class=\"menu-item menu-item-type-post_type menu-item-object-page menu-item-2515\"><a href=\"https:\/\/rftcjapan.org\/en\/about-breast-cancer\/breast-cancer-statistics-global-japan\/\" class=\"elementor-item\" tabindex=\"-1\">Breast Cancer Statistics (Global &amp; Japan)<\/a><\/li>\n<li class=\"menu-item menu-item-type-post_type menu-item-object-page menu-item-2516\"><a href=\"https:\/\/rftcjapan.org\/en\/about-breast-cancer\/understanding-the-risk-of-breast-cancer\/\" class=\"elementor-item\" tabindex=\"-1\">Understanding the Risk of Breast Cancer<\/a><\/li>\n<\/ul>\t\t\t<\/nav>\n\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t<div role=\"region\" aria-labelledby=\"e-n-accordion-item-2330\" class=\"elementor-element elementor-element-67a9bd1 e-con-full e-flex e-con e-child\" data-id=\"67a9bd1\" data-element_type=\"container\" data-e-type=\"container\">\n\t\t\t\t<div class=\"elementor-element elementor-element-ed0de9e elementor-widget elementor-widget-heading\" data-id=\"ed0de9e\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t\t<h4 class=\"elementor-heading-title elementor-size-default\">Diagnosis &amp; Staging<\/h4>\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-c981917 elementor-nav-menu--dropdown-none elementor-widget elementor-widget-nav-menu\" data-id=\"c981917\" data-element_type=\"widget\" data-e-type=\"widget\" data-settings=\"{&quot;layout&quot;:&quot;vertical&quot;,&quot;submenu_icon&quot;:{&quot;value&quot;:&quot;&lt;svg aria-hidden=\\&quot;true\\&quot; class=\\&quot;e-font-icon-svg e-fas-caret-down\\&quot; viewBox=\\&quot;0 0 320 512\\&quot; xmlns=\\&quot;http:\\\/\\\/www.w3.org\\\/2000\\\/svg\\&quot;&gt;&lt;path d=\\&quot;M31.3 192h257.3c17.8 0 26.7 21.5 14.1 34.1L174.1 354.8c-7.8 7.8-20.5 7.8-28.3 0L17.2 226.1C4.6 213.5 13.5 192 31.3 192z\\&quot;&gt;&lt;\\\/path&gt;&lt;\\\/svg&gt;&quot;,&quot;library&quot;:&quot;fa-solid&quot;}}\" data-widget_type=\"nav-menu.default\">\n\t\t\t\t\t\t\t\t<nav aria-label=\"\u30e1\u30cb\u30e5\u30fc\" class=\"elementor-nav-menu--main elementor-nav-menu__container elementor-nav-menu--layout-vertical e--pointer-none\">\n\t\t\t\t<ul id=\"menu-1-c981917\" class=\"elementor-nav-menu sm-vertical\"><li class=\"menu-item menu-item-type-post_type menu-item-object-page menu-item-2521\"><a href=\"https:\/\/rftcjapan.org\/en\/about-breast-cancer\/signs-and-symptoms\/\" class=\"elementor-item\">Signs and Symptoms<\/a><\/li>\n<li class=\"menu-item menu-item-type-post_type menu-item-object-page menu-item-2522\"><a href=\"https:\/\/rftcjapan.org\/en\/about-breast-cancer\/the-stages-of-breast-cancer\/\" class=\"elementor-item\">The Stages of Breast Cancer<\/a><\/li>\n<li class=\"menu-item menu-item-type-post_type menu-item-object-page menu-item-2523\"><a href=\"https:\/\/rftcjapan.org\/en\/about-breast-cancer\/tumor-size-and-staging\/\" class=\"elementor-item\">Tumor Size and Staging<\/a><\/li>\n<li class=\"menu-item menu-item-type-post_type menu-item-object-page menu-item-2520\"><a href=\"https:\/\/rftcjapan.org\/en\/about-breast-cancer\/metastases-and-staging\/\" class=\"elementor-item\">Metastases and Staging<\/a><\/li>\n<li class=\"menu-item menu-item-type-post_type menu-item-object-page menu-item-2519\"><a href=\"https:\/\/rftcjapan.org\/en\/about-breast-cancer\/early-stage-breast-cancers-non-invasive\/\" class=\"elementor-item\">Early-Stage Breast Cancers (Non-invasive)<\/a><\/li>\n<\/ul>\t\t\t<\/nav>\n\t\t\t\t\t\t<nav class=\"elementor-nav-menu--dropdown elementor-nav-menu__container\" aria-hidden=\"true\">\n\t\t\t\t<ul id=\"menu-2-c981917\" class=\"elementor-nav-menu sm-vertical\"><li class=\"menu-item menu-item-type-post_type menu-item-object-page menu-item-2521\"><a href=\"https:\/\/rftcjapan.org\/en\/about-breast-cancer\/signs-and-symptoms\/\" class=\"elementor-item\" tabindex=\"-1\">Signs and Symptoms<\/a><\/li>\n<li class=\"menu-item menu-item-type-post_type menu-item-object-page menu-item-2522\"><a href=\"https:\/\/rftcjapan.org\/en\/about-breast-cancer\/the-stages-of-breast-cancer\/\" class=\"elementor-item\" tabindex=\"-1\">The Stages of Breast Cancer<\/a><\/li>\n<li class=\"menu-item menu-item-type-post_type menu-item-object-page menu-item-2523\"><a href=\"https:\/\/rftcjapan.org\/en\/about-breast-cancer\/tumor-size-and-staging\/\" class=\"elementor-item\" tabindex=\"-1\">Tumor Size and Staging<\/a><\/li>\n<li class=\"menu-item menu-item-type-post_type menu-item-object-page menu-item-2520\"><a href=\"https:\/\/rftcjapan.org\/en\/about-breast-cancer\/metastases-and-staging\/\" class=\"elementor-item\" tabindex=\"-1\">Metastases and Staging<\/a><\/li>\n<li class=\"menu-item menu-item-type-post_type menu-item-object-page menu-item-2519\"><a href=\"https:\/\/rftcjapan.org\/en\/about-breast-cancer\/early-stage-breast-cancers-non-invasive\/\" class=\"elementor-item\" tabindex=\"-1\">Early-Stage Breast Cancers (Non-invasive)<\/a><\/li>\n<\/ul>\t\t\t<\/nav>\n\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t<div role=\"region\" aria-labelledby=\"e-n-accordion-item-2330\" class=\"elementor-element elementor-element-dd578e0 e-con-full e-flex e-con e-child\" data-id=\"dd578e0\" data-element_type=\"container\" data-e-type=\"container\">\n\t\t\t\t<div class=\"elementor-element elementor-element-6342a8d elementor-widget elementor-widget-heading\" data-id=\"6342a8d\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t\t<h4 class=\"elementor-heading-title elementor-size-default\">Risk Factors &amp; Genetics<\/h4>\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-857c29f elementor-nav-menu--dropdown-none elementor-widget elementor-widget-nav-menu\" data-id=\"857c29f\" data-element_type=\"widget\" data-e-type=\"widget\" data-settings=\"{&quot;layout&quot;:&quot;vertical&quot;,&quot;submenu_icon&quot;:{&quot;value&quot;:&quot;&lt;svg aria-hidden=\\&quot;true\\&quot; class=\\&quot;e-font-icon-svg e-fas-caret-down\\&quot; viewBox=\\&quot;0 0 320 512\\&quot; xmlns=\\&quot;http:\\\/\\\/www.w3.org\\\/2000\\\/svg\\&quot;&gt;&lt;path d=\\&quot;M31.3 192h257.3c17.8 0 26.7 21.5 14.1 34.1L174.1 354.8c-7.8 7.8-20.5 7.8-28.3 0L17.2 226.1C4.6 213.5 13.5 192 31.3 192z\\&quot;&gt;&lt;\\\/path&gt;&lt;\\\/svg&gt;&quot;,&quot;library&quot;:&quot;fa-solid&quot;}}\" data-widget_type=\"nav-menu.default\">\n\t\t\t\t\t\t\t\t<nav aria-label=\"\u30e1\u30cb\u30e5\u30fc\" class=\"elementor-nav-menu--main elementor-nav-menu__container elementor-nav-menu--layout-vertical e--pointer-none\">\n\t\t\t\t<ul id=\"menu-1-857c29f\" class=\"elementor-nav-menu sm-vertical\"><li class=\"menu-item menu-item-type-post_type menu-item-object-page menu-item-2525\"><a href=\"https:\/\/rftcjapan.org\/en\/about-breast-cancer\/brca1-and-brca2-mutations-in-men\/\" class=\"elementor-item\">BRCA1 and BRCA2 Mutations in Men<\/a><\/li>\n<li class=\"menu-item menu-item-type-post_type menu-item-object-page menu-item-2526\"><a href=\"https:\/\/rftcjapan.org\/en\/about-breast-cancer\/brca1-and-brca2-mutations-in-women\/\" class=\"elementor-item\">BRCA1 and BRCA2 Mutations in Women<\/a><\/li>\n<li class=\"menu-item menu-item-type-post_type menu-item-object-page menu-item-2528\"><a href=\"https:\/\/rftcjapan.org\/en\/about-breast-cancer\/lobular-carcinoma-in-situ-lcis\/\" class=\"elementor-item\">Lobular Carcinoma in Situ (LCIS)<\/a><\/li>\n<li class=\"menu-item menu-item-type-post_type menu-item-object-page menu-item-2527\"><a href=\"https:\/\/rftcjapan.org\/en\/about-breast-cancer\/early-life-exposures\/\" class=\"elementor-item\">Early Life Exposures<\/a><\/li>\n<\/ul>\t\t\t<\/nav>\n\t\t\t\t\t\t<nav class=\"elementor-nav-menu--dropdown elementor-nav-menu__container\" aria-hidden=\"true\">\n\t\t\t\t<ul id=\"menu-2-857c29f\" class=\"elementor-nav-menu sm-vertical\"><li class=\"menu-item menu-item-type-post_type menu-item-object-page menu-item-2525\"><a href=\"https:\/\/rftcjapan.org\/en\/about-breast-cancer\/brca1-and-brca2-mutations-in-men\/\" class=\"elementor-item\" tabindex=\"-1\">BRCA1 and BRCA2 Mutations in Men<\/a><\/li>\n<li class=\"menu-item menu-item-type-post_type menu-item-object-page menu-item-2526\"><a href=\"https:\/\/rftcjapan.org\/en\/about-breast-cancer\/brca1-and-brca2-mutations-in-women\/\" class=\"elementor-item\" tabindex=\"-1\">BRCA1 and BRCA2 Mutations in Women<\/a><\/li>\n<li class=\"menu-item menu-item-type-post_type menu-item-object-page menu-item-2528\"><a href=\"https:\/\/rftcjapan.org\/en\/about-breast-cancer\/lobular-carcinoma-in-situ-lcis\/\" class=\"elementor-item\" tabindex=\"-1\">Lobular Carcinoma in Situ (LCIS)<\/a><\/li>\n<li class=\"menu-item menu-item-type-post_type menu-item-object-page menu-item-2527\"><a href=\"https:\/\/rftcjapan.org\/en\/about-breast-cancer\/early-life-exposures\/\" class=\"elementor-item\" tabindex=\"-1\">Early Life Exposures<\/a><\/li>\n<\/ul>\t\t\t<\/nav>\n\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t<div role=\"region\" aria-labelledby=\"e-n-accordion-item-2330\" class=\"elementor-element elementor-element-8382bf4 e-con-full e-flex e-con e-child\" data-id=\"8382bf4\" data-element_type=\"container\" data-e-type=\"container\">\n\t\t\t\t<div class=\"elementor-element elementor-element-f24ff62 elementor-widget elementor-widget-heading\" data-id=\"f24ff62\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t\t<h4 class=\"elementor-heading-title elementor-size-default\">Benign Breast Conditions<\/h4>\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-e396cf6 elementor-nav-menu--dropdown-none elementor-widget elementor-widget-nav-menu\" data-id=\"e396cf6\" data-element_type=\"widget\" data-e-type=\"widget\" data-settings=\"{&quot;layout&quot;:&quot;vertical&quot;,&quot;submenu_icon&quot;:{&quot;value&quot;:&quot;&lt;svg aria-hidden=\\&quot;true\\&quot; class=\\&quot;e-font-icon-svg e-fas-caret-down\\&quot; viewBox=\\&quot;0 0 320 512\\&quot; xmlns=\\&quot;http:\\\/\\\/www.w3.org\\\/2000\\\/svg\\&quot;&gt;&lt;path d=\\&quot;M31.3 192h257.3c17.8 0 26.7 21.5 14.1 34.1L174.1 354.8c-7.8 7.8-20.5 7.8-28.3 0L17.2 226.1C4.6 213.5 13.5 192 31.3 192z\\&quot;&gt;&lt;\\\/path&gt;&lt;\\\/svg&gt;&quot;,&quot;library&quot;:&quot;fa-solid&quot;}}\" data-widget_type=\"nav-menu.default\">\n\t\t\t\t\t\t\t\t<nav aria-label=\"\u30e1\u30cb\u30e5\u30fc\" class=\"elementor-nav-menu--main elementor-nav-menu__container elementor-nav-menu--layout-vertical e--pointer-none\">\n\t\t\t\t<ul id=\"menu-1-e396cf6\" class=\"elementor-nav-menu sm-vertical\"><li class=\"menu-item menu-item-type-post_type menu-item-object-page menu-item-7721\"><a href=\"https:\/\/rftcjapan.org\/en\/about-breast-cancer\/chemo-side-effects\/\" class=\"elementor-item\">Chemo side effects<\/a><\/li>\n<li class=\"menu-item menu-item-type-post_type menu-item-object-page menu-item-2529\"><a href=\"https:\/\/rftcjapan.org\/en\/about-breast-cancer\/patient-faq\/\" class=\"elementor-item\">Patient FAQ<\/a><\/li>\n<\/ul>\t\t\t<\/nav>\n\t\t\t\t\t\t<nav class=\"elementor-nav-menu--dropdown elementor-nav-menu__container\" aria-hidden=\"true\">\n\t\t\t\t<ul id=\"menu-2-e396cf6\" class=\"elementor-nav-menu sm-vertical\"><li class=\"menu-item menu-item-type-post_type menu-item-object-page menu-item-7721\"><a href=\"https:\/\/rftcjapan.org\/en\/about-breast-cancer\/chemo-side-effects\/\" class=\"elementor-item\" tabindex=\"-1\">Chemo side effects<\/a><\/li>\n<li class=\"menu-item menu-item-type-post_type menu-item-object-page menu-item-2529\"><a href=\"https:\/\/rftcjapan.org\/en\/about-breast-cancer\/patient-faq\/\" class=\"elementor-item\" tabindex=\"-1\">Patient FAQ<\/a><\/li>\n<\/ul>\t\t\t<\/nav>\n\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t<div class=\"elementor-element elementor-element-4af1475 e-con-full e-flex e-con e-child\" data-id=\"4af1475\" data-element_type=\"container\" data-e-type=\"container\">\n\t\t\t\t<div class=\"elementor-element elementor-element-8bbf593 elementor-widget elementor-widget-heading\" data-id=\"8bbf593\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t\t<h1 class=\"elementor-heading-title elementor-size-default\">Early Life Exposures<\/h1>\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-d31a6b1 elementor-widget elementor-widget-text-editor\" data-id=\"d31a6b1\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t\t\t\t\t\t<p>Research shows that experiences and exposures early in life\u2014from before birth through adolescence\u2014can influence breast cancer risk later on. During these stages, breast tissue is still developing and may be more sensitive to <strong>environmental and lifestyle factors<\/strong>.<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-bf0c3d6 elementor-widget elementor-widget-image\" data-id=\"bf0c3d6\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"image.default\">\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<img fetchpriority=\"high\" decoding=\"async\" width=\"800\" height=\"600\" src=\"https:\/\/rftcjapan.org\/wpdata\/wp-content\/uploads\/2026\/02\/graphic-early-life-exposure.svg\" class=\"attachment-large size-large wp-image-6683\" alt=\"\" \/>\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<\/div>\n\t\t<div class=\"elementor-element elementor-element-8cc9c33 e-con-full e-flex e-con e-child\" data-id=\"8cc9c33\" data-element_type=\"container\" data-e-type=\"container\">\n\t\t\t\t<div class=\"elementor-element elementor-element-bce2575 elementor-widget elementor-widget-heading\" data-id=\"bce2575\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t\t<h2 class=\"elementor-heading-title elementor-size-default\">Before Birth and Infancy<\/h2>\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-fa8dc45 color-bullet-list elementor-widget elementor-widget-text-editor\" data-id=\"fa8dc45\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t\t\t\t\t\t<ul><li><strong>Hormone exposure during pregnancy:<\/strong> Levels of estrogen and other hormones in the womb may affect how breast tissue develops.<\/li><li><strong>Maternal health and lifestyle:<\/strong> A mother\u2019s nutrition, weight, and exposure to tobacco smoke or certain chemicals may play a role.<\/li><\/ul>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-a41299b elementor-widget elementor-widget-heading\" data-id=\"a41299b\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t\t<h2 class=\"elementor-heading-title elementor-size-default\">Childhood<\/h2>\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-d049f21 color-bullet-list elementor-widget elementor-widget-text-editor\" data-id=\"d049f21\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t\t\t\t\t\t<ul><li><strong>Exposure to radiation:<\/strong> Medical radiation to the chest during childhood or adolescence (for example, some cancer treatments) is a well-established risk factor.<\/li><li><strong>Environmental chemicals:<\/strong> Ongoing research is examining how early exposure to endocrine-disrupting chemicals may influence long-term risk.<\/li><\/ul>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-13a9939 elementor-widget elementor-widget-heading\" data-id=\"13a9939\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t\t<h2 class=\"elementor-heading-title elementor-size-default\">Adolescence<\/h2>\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-72c3bb1 color-bullet-list elementor-widget elementor-widget-text-editor\" data-id=\"72c3bb1\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t\t\t\t\t\t<ul><li><strong>Early onset of menstruation:<\/strong> Starting periods at a younger age increases lifetime exposure to estrogen, which is linked to higher risk.<\/li><li><strong>Body weight and physical activity:<\/strong> Obesity in adolescence and low levels of physical activity may increase risk later in life.<\/li><li><strong>Diet and alcohol:<\/strong> Poor diet quality and early alcohol consumption have been associated with increased breast cancer risk.<\/li><\/ul>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-4903fb8 elementor-widget elementor-widget-heading\" data-id=\"4903fb8\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t\t<h2 class=\"elementor-heading-title elementor-size-default\">Puberty<\/h2>\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-8a76117 color-bullet-list elementor-widget elementor-widget-text-editor\" data-id=\"8a76117\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t\t\t\t\t\t<ul><li><strong>Periods of rapid growth<\/strong>, especially during <strong>puberty<\/strong>, may be particularly important. Factors that influence growth\u2014such as nutrition, physical activity, and hormone levels\u2014can affect how breast tissue develops and responds to future exposures.<\/li><\/ul>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t<div class=\"elementor-element elementor-element-ad05aee e-con-full e-flex e-con e-child\" data-id=\"ad05aee\" data-element_type=\"container\" data-e-type=\"container\">\n\t\t\t\t<div class=\"elementor-element elementor-element-7c9bb21 elementor-widget elementor-widget-heading\" data-id=\"7c9bb21\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t\t<h2 class=\"elementor-heading-title elementor-size-default\">What this means<\/h2>\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-97b4621 color-bullet-list elementor-widget elementor-widget-text-editor\" data-id=\"97b4621\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t\t\t\t\t\t<p>Having early life risk factors does not mean someone will develop breast cancer. Risk is shaped by a combination of genetics, life experiences, and adult lifestyle factors. Many early exposures cannot be changed, but understanding them helps guide prevention, screening, and awareness.<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t<div class=\"elementor-element elementor-element-aeca3e2 e-con-full e-flex e-con e-child\" data-id=\"aeca3e2\" data-element_type=\"container\" data-e-type=\"container\" data-settings=\"{&quot;background_background&quot;:&quot;classic&quot;}\">\n\t\t<div class=\"elementor-element elementor-element-fecae95 e-con-full e-flex e-con e-child\" data-id=\"fecae95\" data-element_type=\"container\" data-e-type=\"container\" data-settings=\"{&quot;background_background&quot;:&quot;classic&quot;}\">\n\t\t<div class=\"elementor-element elementor-element-d3c2070 e-con-full e-flex e-con e-child\" data-id=\"d3c2070\" data-element_type=\"container\" data-e-type=\"container\">\n\t\t\t\t<div class=\"elementor-element elementor-element-bf8f2b2 elementor-widget elementor-widget-heading\" data-id=\"bf8f2b2\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t\t<h5 class=\"elementor-heading-title elementor-size-default\">Steps you can take\u200b<\/h5>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t<div class=\"elementor-element elementor-element-75b55e3 e-con-full e-flex e-con e-child\" data-id=\"75b55e3\" data-element_type=\"container\" data-e-type=\"container\">\n\t\t\t\t<div class=\"elementor-element elementor-element-1f07a9a color-bullet-list elementor-widget elementor-widget-text-editor\" data-id=\"1f07a9a\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t\t\t\t\t\t<ul><li>Encourage healthy nutrition and physical activity from childhood through adolescence<\/li><li>Limit unnecessary medical radiation, especially in young people<\/li><li>Avoid tobacco smoke and delay or reduce alcohol consumption<\/li><li>Follow recommended breast cancer screening guidelines as an adult<\/li><\/ul><p>Understanding how early life influences breast health empowers individuals and families to make informed choices and support lifelong prevention and early detection<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t","protected":false},"excerpt":{"rendered":"<p>Table of Contents About Breast Cancer Research shows that experiences and exposures early in life\u2014from before birth through adolescence\u2014can influence breast cancer risk later on. During these stages, breast tissue is still developing and may be more sensitive to environmental and lifestyle factors. Before Birth and Infancy Hormone exposure during pregnancy: Levels of estrogen and [&hellip;]<\/p>\n","protected":false},"author":2,"featured_media":0,"parent":27,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"class_list":["post-1874","page","type-page","status-publish","hentry"],"yoast_head":"<!-- This site is optimized with the Yoast SEO plugin v27.7 - https:\/\/yoast.com\/product\/yoast-seo-wordpress\/ -->\n<title>Early Life Exposures - RFTC Japan<\/title>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/rftcjapan.org\/en\/about-breast-cancer\/early-life-exposures\/\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"Early Life Exposures - RFTC Japan\" \/>\n<meta property=\"og:description\" content=\"Table of Contents About Breast Cancer Research shows that experiences and exposures early in life\u2014from before birth through adolescence\u2014can influence breast cancer risk later on. 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