Missed or delayed breast cancer diagnosis

The National Cancer Institute says the signs may include a lump or other change in the breast (opens in a new tab), and that early breast cancer often has no symptoms. It calls a biopsy, in which a pathologist studies removed cells or tissue under a microscope, the only sure way to diagnose breast cancer (opens in a new tab).

Screening means testing people without symptoms. The U.S. Preventive Services Task Force recommends a screening mammogram every 2 years for women aged 40 to 74 years (opens in a new tab), a grade B recommendation dated April 30, 2024. Its 2016 statement had left screening in a woman’s forties to an individual decision (opens in a new tab). The recommendation does not apply to women with a genetic marker linked to a high risk of breast cancer, high-dose radiation to the chest at a young age, or a previous breast cancer or high-risk breast lesion (opens in a new tab). A recommendation is not law.

The Task Force lists false-negative results among the potential harms of screening (opens in a new tab). A false negative is a normal reading when cancer is present. The Task Force finds the evidence insufficient to assess the balance of benefits and harms of screening mammography in women 75 or older, or of adding ultrasound or MRI for women with dense breasts and an otherwise negative mammogram (opens in a new tab). That is neither a recommendation for nor a recommendation against.

For mammograms, a federal regulation sets out what must be sent, to whom and by when. The Food and Drug Administration’s present rules took effect on September 10, 2024 (opens in a new tab). This page does not describe the text that governed earlier mammograms.

The facility must give each patient a summary of the report in lay terms within 30 calendar days of the mammographic examination (opens in a new tab). The written report goes to the patient’s referring or named health care provider as soon as possible, but no later than 30 days from the date of the mammography examination (opens in a new tab). When the report’s overall assessment is “Suspicious” or “Highly Suggestive of Malignancy,” both are due within 7 calendar days of the final interpretation of the mammograms (opens in a new tab).

The regulation fixes the words of each assessment and requires the report to include recommendations made to the healthcare provider about what additional actions, if any, should be taken (opens in a new tab). It does not name the test that must follow a final assessment such as “Suspicious.” These are a regulator’s rules. What careful practice required for a particular patient is for a qualified physician to explain.

A cancer found after a normal mammogram is not, for that reason alone, a missed cancer. In a 2017 benchmark study of digital screening mammograms read at 95 U.S. facilities, mean sensitivity was 86.9% (opens in a new tab). Sensitivity is the share of cancers present that the test flagged.

For a 2001 study, four community radiologists re-read screening mammograms from one regional registry. The authors estimated that 29% of the cancers missed at screening were detectable, and concluded that 71% would not have been investigated further by peers in the same community (opens in a new tab).

In a 2002 study of breast cancer patients at one specialist practice, the authors judged that 21 women (5%) had been inappropriately reassured, without a biopsy, that a cancerous lump was benign, and 14 (3%) had a misread mammogram (opens in a new tab). Delay was associated with a benign mammography report (opens in a new tab).

Malpractice claims need a caution. In a 2006 study, reviewers found a harmful diagnostic error in 181 closed outpatient claims, and breast cancer was the diagnosis in 44 of them (24%) (opens in a new tab). That is a share of lawsuits, and says nothing about how often breast cancer is diagnosed late among patients.

The studies do not agree. A 1999 review of 87 studies concluded that delays of 3 to 6 months between first symptoms and treatment are associated with lower survival (opens in a new tab). That delay included delay by patients. The review also found that longer delays were associated with more advanced stage, and that in studies that controlled for stage, longer delay was not associated with shorter survival.

A study from the same year reported that the consequences of physician delay for stage at diagnosis, treatment and outcome were not statistically significant (opens in a new tab), though cancers in the delayed patients were larger on average. With only 51 delayed patients, that does not show delay is harmless.

None of these studies says what a delay meant for one person. In Illinois a patient has to prove that the care was negligent and that the negligence more probably than not caused the harm, which can be a lost chance of a better outcome. That takes expert proof in each case.

A mammography facility must keep the original mammograms and reports for not less than 5 years, or not less than 10 years if the patient has no further mammograms there (opens in a new tab), or longer if State or local law requires. The exception is an original mammogram the facility has transferred at the patient’s request (opens in a new tab). Illinois has its own minimum, 60 months, for images that have not been transferred directly to the patient or the patient’s physician (opens in a new tab).

On your request, the facility must transfer the original mammograms and copies of the reports to you, your physician or another medical institution within 15 calendar days of receiving the request (opens in a new tab).

It helps to write down the dates of your visits, mammograms and biopsies, and what you were told after each.