{"id":117521,"date":"2026-10-01T08:03:50","date_gmt":"2026-10-01T12:03:50","guid":{"rendered":"https:\/\/bgodinspired.com\/?p=117521"},"modified":"2026-10-01T08:03:50","modified_gmt":"2026-10-01T12:03:50","slug":"mammogram-overdiagnosis","status":"publish","type":"post","link":"https:\/\/bgodinspired.com\/index.php\/health-and-wellness\/mammogram-overdiagnosis\/","title":{"rendered":"Mammogram Overdiagnosis: New Study Says Below 5%, Not 30%"},"content":{"rendered":"<div class='booster-block booster-read-block'>\n                <div class=\"twp-read-time\">\n                \t<i class=\"booster-icon twp-clock\"><\/i> <span>Read Time:<\/span>8 Minute, 37 Second                <\/div>\n\n            <\/div><p>Breast Cancer Awareness Month starts today. For a lot of women, that means a reminder about a mammogram they have been putting off.<\/p>\n\n<p>Sometimes the putting off has a reason with a name. You may have heard that mammograms find cancers that never would have hurt you, and that some women get surgery, radiation or drugs they never needed. That worry is called <strong>mammogram overdiagnosis<\/strong>. For years, some widely cited estimates said it could be as high as 30 to 50 percent of screen-found cancers.<\/p>\n\n<p>A new study says that number was probably wrong. Not a little wrong. A lot.<\/p>\n\n<h2>What the New Mammogram Overdiagnosis Study Found<\/h2>\n\n<p>On 14 September 2026, a team of researchers from Denmark and the UK published a new analysis in the <em>Journal of the National Cancer Institute<\/em>. The lead author is Sisse Helle Njor of the University of Southern Denmark and Lilleb\u00e6lt Hospital. Her co-authors include Elsebeth Lynge of the University of Copenhagen and Matejka Rebolj of Queen Mary University of London.<\/p>\n\n<p>They did not run a new trial. They went back to the eight big randomised trials that most of what we know about mammograms is built on. Those trials ran in New York, Sweden (Malm\u00f6, Stockholm, Gothenburg and the Two-County trial), Scotland (Edinburgh), Canada, and the UK.<\/p>\n\n<p>Their result: the data are consistent with overdiagnosis <strong>below 5 percent<\/strong>. Not 30. Not 50. Under 5.<\/p>\n\n<p>Njor put it this way: &#8220;Most women will not develop breast cancer, but with this study we can now be reassured that the benefits of detecting breast cancer early and preventing premature death will outweigh the small risk of unnecessary treatment.&#8221;<\/p>\n\n<p>Notice what that does not say. It does not say overdiagnosis is zero. It says small.<\/p>\n\n<div class=\"convertkit-form wp-block-convertkit-form\" style=\"\"><script async data-uid=\"c87e3ed518\" src=\"https:\/\/bgodinspired.kit.com\/c87e3ed518\/index.js\" data-jetpack-boost=\"ignore\" data-no-defer=\"1\" data-no-optimize=\"1\" nowprocket><\/script><\/div>\n\n\n<h2>Why the Old Numbers Ran So High<\/h2>\n\n<p>This is the part worth understanding, because it is simple once you see it.<\/p>\n\n<p>When you start screening a group of women, you find more cancers. Of course you do. You are finding cancers early, before they would have shown up on their own. Elsebeth Lynge described it like this: &#8220;When screening is introduced, the number of breast cancer diagnoses initially rises because cancers are detected earlier than they would have been without screening.&#8221;<\/p>\n\n<p>But that early bump should be paid back later. Some of the cancers found today are cancers that would have been found anyway in two, three or five years. So if you wait long enough, the screened group should see <em>fewer<\/em> new cancers than the unscreened group for a while. The rise and the dip should roughly cancel out.<\/p>\n\n<p>Think of it like picking apples a week early. You get a big basket today. Next week, there are fewer apples left to pick. If you only count today&#8217;s basket, it looks like screening made more apples.<\/p>\n\n<p>The researchers point to three things that hid the dip in older estimates:<\/p>\n\n<ul>\n<li><strong>Follow-up was cut short.<\/strong> Some analyses stopped counting before the dip had time to show.<\/li>\n<li><strong>The comparison group got screened too.<\/strong> In several trials, the women who were not supposed to be screened were offered mammograms after the trial ended. That blurs the difference between the two groups.<\/li>\n<li><strong>The number of screening rounds varied.<\/strong> Trials offered different numbers of mammograms, which changes how big the early bump is.<\/li>\n<\/ul>\n\n<p>Matejka Rebolj summed it up: &#8220;Taken together, we believe some previous high estimates of overdiagnosis, which influenced screening guidelines and communication, were based on evidence before trial data had fully matured.&#8221;<\/p>\n\n<h2>The Part the Headlines Skip<\/h2>\n\n<p>Here is something most coverage does not mention.<\/p>\n\n<p>To judge what the trials &#8220;should&#8221; look like if overdiagnosis were low, the team compared them against data from a Danish regional screening programme in Funen. That Funen benchmark comes from a 2013 study in the <em>BMJ<\/em>, and the first author of that 2013 study was also Sisse Helle Njor.<\/p>\n\n<p>That is not a scandal. Scientists build on their own earlier work all the time, and the Funen data have been studied for years. But critics have fairly pointed out that the new paper does not independently re-check that benchmark. If the trials match Funen, that tells you they look like Funen. It only tells you overdiagnosis is low if Funen itself is right.<\/p>\n\n<p>There is also a longer history here. Earlier reviews, using other methods, have landed on higher numbers. This new paper is a strong entry in a long-running debate. It is not the final word, and the researchers themselves use careful words: their results are &#8220;consistent with&#8221; overdiagnosis below 5 percent.<\/p>\n\n<p>So the honest summary is this: the best current reading of the biggest trials says overdiagnosis is probably much smaller than you were told. &#8220;Probably&#8221; is doing real work in that sentence.<\/p>\n\n<h2>What This Does Not Change<\/h2>\n\n<p>A lower overdiagnosis number does not make mammograms perfect. Other parts of screening are still real:<\/p>\n\n<ul>\n<li><strong>Call-backs happen.<\/strong> Many women get asked to come back for more pictures. Most of those turn out fine, but the wait is hard.<\/li>\n<li><strong>Screening is not a promise.<\/strong> A clear mammogram is good news, not a guarantee.<\/li>\n<li><strong>Your situation matters.<\/strong> The authors note that screening may help less for women in poor health or with a short life expectancy. Your age, family history and where you live all shape what makes sense for you.<\/li>\n<\/ul>\n\n<p>This article is not medical advice. If you are unsure whether or when to be screened, ask a doctor, nurse or clinic near you. Many places run free or low-cost screening, especially in October.<\/p>\n\n<p>We have written before about how cancer research is moving fast, from <a href=\"https:\/\/bgodinspired.com\/index.php\/bgodinspired-news\/bgodinspired-health-news\/cancer-blood-test-before-symptoms\/\">a new blood test that may catch some cancers before you feel sick<\/a> to <a href=\"https:\/\/bgodinspired.com\/index.php\/health-and-wellness\/dormant-breast-cancer-cells-where-they-hide\/\">where dormant breast cancer cells hide inside a tumour<\/a>. The pattern keeps repeating: the first headline is rarely the whole story.<\/p>\n\n<h2>The Fear the Numbers Can&#8217;t Touch<\/h2>\n\n<p>Here is the thing, though. For a lot of women, overdiagnosis was never really why the appointment kept slipping.<\/p>\n\n<p>The real fear is simpler. It is the phone call. The envelope. The &#8220;we&#8217;d like you to come back in.&#8221; It is lying awake the night before results, writing a whole future in your head that has not happened yet.<\/p>\n\n<p>No study can lower that number. Five percent or fifty, the waiting feels the same.<\/p>\n\n<p>There is a very old piece of wisdom that speaks right to this. It describes a person who is not afraid of bad news. Not because bad news never comes to them. It does. But because their heart is already steady, already settled in trusting God, before the phone ever rings. Their peace is not waiting on the result. It got there first.<\/p>\n\n<p>That is a different kind of courage than &#8220;think positive.&#8221; It does not pretend the call can&#8217;t come. It just refuses to let a call that hasn&#8217;t come yet run your life today.<\/p>\n\n<p>If the waiting part is what keeps you up at night, you might find it useful to take our free <a href=\"https:\/\/bgodinspired.com\/index.php\/how-anxious-am-i\/\">How Anxious Am I?<\/a> check. It takes a few minutes and is private.<\/p>\n\n<h2>So, Should You Book It?<\/h2>\n\n<p>That is your call, made with someone who knows your health. But if the old 30-to-50-percent figure was the thing holding you back, it is fair to know that the best new look at the evidence says that worry was likely much too big.<\/p>\n\n<p>The rest, the waiting, the what-ifs, you don&#8217;t have to carry alone. Book it, tell a friend the date, and let someone sit with you while you wait.<\/p>\n\n<h3>What would you do?<\/h3>\n\n<p><strong>Does a lower overdiagnosis number change how you feel about mammograms, or was that never the real reason people put them off? Tell us what you think in the comments.<\/strong><\/p>\n\n<div class=\"convertkit-form wp-block-convertkit-form\" style=\"\"><script async data-uid=\"c87e3ed518\" src=\"https:\/\/bgodinspired.kit.com\/c87e3ed518\/index.js\" data-jetpack-boost=\"ignore\" data-no-defer=\"1\" data-no-optimize=\"1\" nowprocket><\/script><\/div>\n\n\n<h3>Share This<\/h3>\n\n<ul>\n<li>A new look at all 8 big mammogram trials says overdiagnosis is likely under 5%, not the 30-50% we kept hearing. Worth knowing this October. https:\/\/bgodinspired.com\/?p=117521<\/li>\n<li>I always heard mammograms &#8220;find cancers that would never hurt you&#8221; a third of the time or more. New analysis says the old numbers were counted too early, before the dip that comes after screening. Still debated, but the gap is huge. https:\/\/bgodinspired.com\/?p=117521<\/li>\n<li>Good reminder for Breast Cancer Awareness Month: the statistics are only one fear. The waiting is the other one. This piece was honest about both. https:\/\/bgodinspired.com\/?p=117521<\/li>\n<\/ul>\n\n<h3>Questions People Are Asking<\/h3>\n\n<p><strong>What is mammogram overdiagnosis?<\/strong><br>\nMammogram overdiagnosis is when breast screening finds a cancer that would never have caused symptoms or threatened a woman&#8217;s life if it had not been found. Because doctors cannot always tell which cancers will grow, an overdiagnosed cancer is often treated anyway, which means treatment that was not needed.<\/p>\n\n<p><strong>How common is overdiagnosis from mammograms?<\/strong><br>\nA 2026 reanalysis of the eight major randomised mammography trials, published in the Journal of the National Cancer Institute by Sisse Helle Njor and colleagues, found results consistent with overdiagnosis below 5 percent. Some earlier, widely cited estimates had suggested figures as high as 30 to 50 percent. The question is still debated among researchers.<\/p>\n\n<p><strong>Why were earlier estimates of mammogram overdiagnosis so high?<\/strong><br>\nAccording to the 2026 JNCI reanalysis, earlier high estimates of mammogram overdiagnosis were affected by three things: follow-up that ended before the later drop in cancer cases could show up, women in the trials&#8217; comparison groups being screened after the trials ended, and differences in how many screening rounds each trial offered.<\/p>\n\n<p><strong>Is the new mammogram overdiagnosis study controversial?<\/strong><br>\nYes, to some degree. The 2026 JNCI study compared the trials against Danish screening data from Funen that came from a 2013 BMJ study led by the same first author, Sisse Helle Njor, and critics note the new paper does not independently re-check that benchmark. Other reviews using different methods have produced higher estimates.<\/p>\n\n<p><strong>Should I still get a mammogram?<\/strong><br>\nWhether to get a mammogram depends on age, family history, overall health and local screening guidelines, so it is best decided with a doctor, nurse or local clinic. 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A new look at all eight big trials puts it below 5%. What it means and what it leaves out.<\/p>\n","protected":false},"author":1,"featured_media":117519,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_monsterinsights_skip_tracking":false,"_wp_convertkit_post_meta":{"form":"-1","landing_page":"0","tag":"0","restrict_content":"0"},"footnotes":""},"categories":[5224,3711],"tags":[],"class_list":["post-117521","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-bgodinspired-health-news","category-health-and-wellness"],"_links":{"self":[{"href":"https:\/\/bgodinspired.com\/index.php\/wp-json\/wp\/v2\/posts\/117521","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/bgodinspired.com\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/bgodinspired.com\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/bgodinspired.com\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/bgodinspired.com\/index.php\/wp-json\/wp\/v2\/comments?post=117521"}],"version-history":[{"count":2,"href":"https:\/\/bgodinspired.com\/index.php\/wp-json\/wp\/v2\/posts\/117521\/revisions"}],"predecessor-version":[{"id":117523,"href":"https:\/\/bgodinspired.com\/index.php\/wp-json\/wp\/v2\/posts\/117521\/revisions\/117523"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/bgodinspired.com\/index.php\/wp-json\/wp\/v2\/media\/117519"}],"wp:attachment":[{"href":"https:\/\/bgodinspired.com\/index.php\/wp-json\/wp\/v2\/media?parent=117521"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/bgodinspired.com\/index.php\/wp-json\/wp\/v2\/categories?post=117521"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/bgodinspired.com\/index.php\/wp-json\/wp\/v2\/tags?post=117521"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}