DCIS 411
Mammogram Harms
Women deserve more than marketing slogans. We deserve honest, evidence-based information. Informed consent is not just a formality. It’s a right. “Informed consent as a fundamental ethical standard in research and clinical practice.”
The following are the required elements for documentation of the informed consent discussion: (1) the nature of the procedure, (2) the risks and benefits and the procedure, (3) reasonable alternatives, (4) risks and benefits of alternatives, and (5) assessment of the patient’s understanding of elements 1 through 4. Before you screen, make sure you’ve had a real conversation about the harms of mammography.
Mammogram harms include overdiagnosis, missed cancers, unnecessary biopsies, radiation exposure, compression trauma and psychological harm. For additional resources, please see: The GreenMedInfo compilations of articles and studies on X-ray mammography with concerns around radiation exposure, overdiagnosis, false positives, overtreatment, and informed consent.
Did you know that mammography misses 40% or more of invasive cancers in women with dense breasts? Dense tissue and tumors both appear white on a mammogram, making it like “looking for a snowball in a snowstorm.” Increased density = decreased mammogram accuracy. Unfortunately, this also means increased radiation. Digital breast tomosynthesis (DBT), or 3D mammography, takes multiple X-ray images from different angles to create a layered, 3D-like image of the breast. It is aggressively marketed as an “improved” tool for women with dense breasts. But many women aren’t told the full story — particularly about increased radiation exposure and lack of proven benefit.
More than half of women have dense breasts. As of September 2024, women receiving mammograms in the US are officially notified whether or not they have “dense breasts.” While intended to improve transparency, this new requirement carries serious repercussions: psychological distress from a label that sounds alarming, confusion without a clear explanation, and, in many cases, women feel pressured into additional imaging such as 3D mammography, which exposes them to higher levels of radiation.
Dense breasts have more fibroglandular tissue than fat. About 40–50% of women aged 40–74 have dense breasts. Breast density is influenced by genetics, hormones, age, body composition, pregnancy. Density usually decreases with age. Thinner women and those with fewer pregnancies tend to have denser breasts. Breast density changes over time.
“For women with dense breast tissue, who are at much higher risk for developing breast cancer, the performance of mammography is at its worst. Consequently, many early cancers go undetected when they are the most treatable. Improved cancer detection for women with dense breasts would decrease the proportion of breast cancers diagnosed at later stages, which would significantly lower the mortality rate. The emergence of whole breast ultrasound provides good performance for women with dense breast tissue, and may eliminate the current trade-off between the cost effectiveness of mammography and the imaging performance of more expensive systems such as magnetic resonance imaging.” PMCID: PMC10079278
Dense Breasts, Younger Screening: A Double Burden for Women
In April 2024, the U.S. Preventive Services Task Force (USPSTF) updated its breast cancer screening guidelines, lowering the recommended age for routine biennial mammograms from 50 to 40 for women at average risk. In contrast, several European perspectives have taken a more cautious stance. The Nordic Cochrane review, for example, has argued that with advances in treatment and the mounting risks of overdiagnosis and overtreatment, broad-based mammography screening may no longer be justifiable at any age—concluding that inviting women to screening “no longer seems reasonable.”
Same year in September 2024, U.S. mammography facilities started to notify patients whether they have “dense breasts” or “not dense breasts.” While this rule was designed to promote transparency, it carries unintended consequences: psychological distress from an alarming label, confusion in the absence of clear guidance, and pressure to pursue additional imaging such as 3D mammography, which exposes women to higher radiation doses.
These two policy shifts—lowering the screening age to 40 and mandating breast density notification—create a particularly troubling overlap. Women in their 40s are the group most likely to have dense breast tissue, with density at its peak during these years. As a result, millions of women newly pulled into screening will now not only be told they have dense breasts but may also feel compelled to undergo more imaging, despite the lack of proven survival benefit and the added risks of higher radiation, false positives, and overdiagnosis.
Women who carry BRCA1 or BRCA2 gene mutations are considered high-risk individuals, medical guidelines recommend earlier and more frequent screening, including annual mammograms starting as early as age 30 (Cancer.org). However, initiating mammography at a younger age means women are exposed to more cumulative radiation over their lifetimes, a concern that is especially relevant given the heightened sensitivity of breast tissue in premenopausal women (National Cancer Institute). Careful counseling is essential to ensure women understand both the protective role and the potential harms of prolonged imaging surveillance.
Radiation Harm
Mammography is an X-ray test. Like any X-ray, it involves ionizing radiation and mechanical compression. X-rays were originally developed to look through dense bone, not soft tissue. This distinction matters, because imaging soft tissue like the breast requires different techniques: greater compression and often higher and repeated radiation exposures. Fat, glandular tissue, and connective tissue in the breast absorb X-rays poorly compared to bone. To overcome this, mammography uses lower-energy X-rays (around 20–30 keV range) to improve contrast between fat and glandular tissue. But this also means that more radiation is absorbed by breast tissue, which is more sensitive to radiation damage than bone. Radiation is cumulative and can cause cancer.
“Routine Mammograms do not save lives, the research is clear.”
Mammography is a type of X-ray imaging that utilizes ionizing radiation and breast compression. Unlike bone, which X-rays were designed to image, breast tissue is soft and absorbs radiation poorly. To enhance contrast between fat and glandular tissue, mammograms use lower-energy X-rays (20–30 keV). However, this increases radiation absorption in the breast, a tissue especially vulnerable to radiation damage. Since exposure is cumulative, repeated mammograms carry a risk of contributing to cancer development.
The U.S. National Cancer Institute states that while mammograms use small doses, “repeated x-rays have the potential to cause cancer,” so patients should discuss the need for each exam. Cancer.gov
Radiation Induced Cancer & Death
Annual mammography screening carries a measurable risk of radiation-induced breast cancer and related deaths. The earlier women begin regular mammograms, the greater their cumulative risk over time. Women with higher radiation exposure or those requiring additional imaging, such as women with larger or dense breasts, face an increased risk compared to others.
“There is no safe level of exposure and there is no dose of radiation so low that the risk of a malignancy is zero” -Dr. Karl Z. Morgan, dubbed the father of Health Physics
Radiation-Induced Breast Cancer Incidence and Mortality from Digital Mammography Screening: A Modeling Study explains, on average, annual screening of 100,000 women aged 40 to 74 years was projected to induce 125 breast cancers (95% confidence interval [CI]=88–178) leading to 16 deaths (95% CI=11–23), relative to 968 breast cancer deaths averted by early detection from screening. Women exposed at the 95th percentile were projected to develop 246 radiation-induced breast cancers leading to 32 deaths per 100,000 women. Women with large breasts requiring extra views for complete breast examination (8% of population) were projected to have higher radiation-induced breast cancer incidence and mortality (266 cancers, 35 deaths per 100,000 women), compared to women with small or average breasts (113 cancers, 15 deaths per 100,000 women).
Both standard 2D mammograms and 3D tomosynthesis (DBT) expose the breast to ionizing radiation, which can increase the risk of cancer over time. DBT takes multiple images from different angles, and while each individual image uses less radiation than a single 2D mammogram, the total radiation exposure is higher, especially when DBT is combined with traditional 2D images as is the case typically. Using synthetic 2D images can reduce the dose somewhat, but exposure still occurs and varies depending on breast size, density, and imaging technique.
What’s the risk? John W. Gofman’s 1998 analysis, “Mammography: An Individual’s Estimated Risk that the Examination Itself Will Cause Radiation-Induced Breast Cancer,” provides estimates of cancer risk associated with mammography based on radiation exposure. More recent research about “Mammography-induced cancers” by Daniel Corcos is discussed in video here.
Digital breast tomosynthesis (DBT)
Since FDA approval in 2011, 3D mammography, or digital breast tomosynthesis (DBT), has been heavily marketed as a superior alternative to standard 2D mammography by manufacturers, must-have upgrade, branded as “genius 3D” or “smart 3D” technology“. Hospitals and clinics advertise it as “safer,” “clearer,” or “more accurate” without always disclosing that it involves increased radiation dose compared to 2D and the financial incentives which drive agressive marketing.
The combination of Medicare coverage, state mandates, and higher reimbursement rates has created a strong financial incentive to promote 3D mammography (DBT). In 2014, Medicare began reimbursing DBT when performed with standard 2D mammography, and by 2021, 17 states required private insurers to cover DBT without cost-sharing. Radiology providers can earn more for performing DBT than standard 2D mammograms, which has driven aggressive marketing of DBT as a “must-have” upgrade. These financial pressures can influence clinics to prioritize adoption and patient uptake, overshadowing honest, evidence-based discussions about whether DBT is medically necessary for each individual, leading to screening decisions that are motivated by profit.
Early Screening means more Radiation
In 2024, U.S. breast cancer screening policy shifted significantly. The USPSTF lowered the recommended age for biennial mammograms from 50 to 40 for women at average risk. For BRCA1 and BRCA2 mutation carriers, guidelines recommend earlier, more frequent monitoring, with mammograms starting at age 30 (American Cancer Society). Yet this also increases cumulative lifetime radiation and therefore cancer risk. In addition, U.S. facilities also began notifying women of their breast density with encouragement to pursue additional—higher radiation—imaging such as 3D mammography. Learn more about Dense Breasts and Underdiagnosis here.
“The risk of breast cancer almost doubled after 15 years of screening. Additional cancers began to occur less than 6 years after mammography. These results are evidence that X-ray-induced carcinogenesis, rather than overdiagnosis, is the cause of the increase in breast cancer incidence.” – Daniel Corcos
Over-diagnosis leads directly to over treatment
Overdiagnosis happens when a mammogram finds something that looks like cancer but would never have grown, spread, or threatened a woman’s life. The most common example is ductal carcinoma in situ (DCIS)—sometimes called stage 0 breast cancer.
DCIS is detected almost entirely through mammograms, not because it causes symptoms. The problem is that while mammography picks it up frequently, only about 5% of DCIS ever progresses to invasive breast cancer. This means the vast majority of women diagnosed with DCIS through screening undergo treatment for a “cancer” that may never have harmed them. By finding and aggressively treating lesions like DCIS, the medical system turns healthy women into patients and exposes them to risks without delivering clear survival benefit (Gøtzsche & Jørgensen).
Once something is found, most women feel they have no choice but to treat it—regardless of whether it’s dangerous or not. This can lead to unnecessary biopsies, lumpectomies, mastectomies, radiation, and chemotherapy for conditions that may never have progressed or become life-threatening.
Since the release of the COMET trial results, leading medical journals, cancer centers, and professional associations have begun to question the routine use of surgery for ductal carcinoma in situ (DCIS). A growing body of evidence now shows that active monitoring can be just as safe—and in some cases better—than surgery, while also reducing unnecessary treatment and preserving quality of life. The following articles and expert commentaries highlight this shift and provide resources for patients and clinicians considering active surveillance.
JAMA Oncology – Active Monitoring With or Without Endocrine Therapy for Low-Risk DCIS Official COMET trial publication reporting equivalent or better outcomes with active monitoring. Read on JAMA
AAFP (American Academy of Family Physicians) – POEMs: Active Monitoring vs Surgery for DCIS Bottom line: active monitoring is a safe, non-inferior alternative to surgery. Read on AAFP
American College of Surgeons (ACS Brief) – Is It Time to Abandon Surgery for Low-Risk DCIS? Commentary following COMET asking if monitoring should replace surgery for many patients. Read on ACS
ObG Project – Can Women With Low-Risk DCIS Undergo Active Monitoring Instead of Surgery? Clear summary showing monitoring is noninferior to surgery with fewer risks. Read on ObG Project
Cancer Network – Active Monitoring May Be Safe vs Surgery in Certain Low-Risk DCIS Populations Expert commentary at Miami Breast Cancer Conference, supporting surveillance for select patients. Read on Cancer Network
Dana-Farber Cancer Institute – Quality of Life Maintained With Active Monitoring for DCIS No significant differences in quality of life, anxiety, or depression between monitoring and surgery. Read on Dana-Farber
AACR News Release – Quality of Life Similar Among Patients Choosing Monitoring or Surgery COMET confirms monitoring as a reasonable option without negative emotional effects. Read on AACR
Reuters – Surgery May Be Unnecessary for Common Precancerous Breast Condition Coverage of COMET results: progression rates similar or better with monitoring vs surgery. Read on Reuters
AP News – Active Monitoring Safe Alternative for DCIS Mainstream report on SABCS 2024 data showing surveillance is a valid treatment option. Read on AP
Compression Cause Serious Harm
Mammography works by pressing the breast between two plates to flatten tissue so X-rays can capture clearer images. While this step is necessary for image quality, it often causes discomfort — in fact, most women report some degree of pain, and many describe it as moderate to severe. If there is already inflammation, a lump, or a recent biopsy, compression can worsen the situation. Though usually described as a “necessary discomfort,” the reality is that mammographic compression can cause real physical harm in addition to temporary pain.
Additionally, the size and density of the breast affect the amount of radiation and pain from compression.
Mammography Compression Pain
Compression is one of the most controversial aspects of mammography. To obtain images, the breast must be pressed between two plates. While compression helps spread out tissue and reduce motion blur, it also has physical consequences that vary depending on breast size.
Compression Causes Serious Harm
Compression holds the breast still to reduce blurring, it spreads out overlapping tissue for clearer images and reduces thickness of tissue. Little is known about the relationship between the amount of breast compression and breast cancer detectability.
Most mammography systems apply a compression force between 100–200 Newtons (N), roughly equivalent to pressing with 10–20 kg or 22-45 lbs of weight. The less compression (and therefore less pain), the more radiation is required for images.
Compression thickness (how “flat” the breast becomes) is also tracked. A typical compressed breast is 4–6 cm thick, but can be thinner or thicker depending on breast size and density. Some machines are automated and stop at a preset pressure level, while others rely on the technologist’s judgment. Different technicians may use different amounts of force depending on training, patient tolerance, and habit. How does this translate to pain and image clarity? More compression = better image clarity, lower radiation dose, but more pain. Less compression = more comfortable, but higher chance of blurry or overlapping tissue, false positives, and higher radiation.
Compression can lead to temporary bruising, swelling, or tenderness, and in some cases has been linked to hematomas (internal bleeding in breast tissue) and complications for women with implants, including reports of rupture submitted to the FDA. Women with small breasts may experience more pain because the same force is applied over a smaller surface area, while women with very large or dense breasts can suffer uneven compression and repeated repositioning. If there is already inflammation, a lump, or a recent biopsy, compression can worsen sensitivity. Though usually described as a “necessary discomfort,” the reality is that mammographic compression can cause real physical harm in addition to temporary pain. This pain isn’t just uncomfortable—it can signal real harm.
There is sufficient evidence to conclude that painful mammography contributes to non-re-attendance.
Breast cancer screening, while intended to save lives, carries substantial psychological consequences. For example, mammography can lead to false positives, with more than 200 women out of every 2,000 screened over 10 years experiencing significant anxiety, uncertainty, and stress—even when no cancer is present. At the same time, overdiagnosis and overtreatment will cause unnecessary medical procedures and long-term mental distress.
Dense Breast Notifications and Mammograms Affect Mental Health
Screening mammograms often detect “something suspicious” that turns out to be nothing. This leads to anxiety, extra testing, and invasive procedures that carry their own risks. False alarms and unnecessary diagnoses can cause long-lasting emotional distress, depression, and even PTSD-like symptoms.
Once a patient is told they have “cancer,” even if planned management is safe and non‑invasive, anxiety and distress tend to follow, regardless of whether they opt for surgery or monitoring. Similarly, when women are told they have dense breasts, they may experience heightened worry and uncertainty, even if the information does not necessarily indicate an increased immediate risk.
This emotional burden—rooted in the label itself—can strongly influence patients toward more aggressive treatment, even when their clinical risk is low.
Being told one has dense breasts is another source of psychological harm. Awareness of dense breast tissue can trigger anxiety and heightened perception of cancer risk, especially among women with lower health literacy or those from racial and ethnic minority backgrounds. Many women misunderstand what “dense breasts” mean, leading to confusion, worry, and increased pressure to pursue additional screening.
Underlying much of this distress is “cancerphobia”, the culturally ingrained fear of a cancer diagnosis. Even when cancers are low-risk or non-threatening—such as DCIS —the presence of the word “cancer” in a diagnosis can drive patients to choose aggressive and risky treatments unnecessarily, causing harm that far exceeds the small number of lives saved. Together, these factors illustrate that the emotional and psychological costs of breast screening and overdiagnosis are substantial, affecting thousands of women annually. In today’s patient-centered care environment, individuals are increasingly involved in medical decisions. Studies show that patients often favor aggressive treatments—even when the risks outweigh the benefits. A 2005 study in Medical Decision Making, titled “Cure Me Even If It Kills Me,” found that people presented with hypothetical cancer diagnoses chose surgery despite being told it could cause more harm than good. This tendency highlights the psychological influence of fear and risk perception on treatment choices, particularly for conditions like DCIS.
Recent evidence from the COMET trial further highlights the emotional impact of the cancer label itself. The study, published in JAMA Oncology, found that quality of life—across physical, emotional, and psychological well-being—was similar over two years for women with low-risk DCIS, whether they underwent surgery or were monitored (COMET study, JAMA Oncology). A critical insight is that once a patient is told they have “cancer,” anxiety and distress often follow, regardless of treatment choice. This emotional burden can strongly influence patients toward more aggressive treatment, even when their clinical risk is low. The study suggests that the label itself may have as much impact on quality of life as the type of treatment.