Breast cancer screening associated with substantial overdiagnosis in Danish study

January 9, 2017, American College of Physicians

Breast cancer screening in Denmark was associated with a substantial increase in the incidence of nonadvanced tumors and DCIS but not with a reduction in the incidence of advanced tumors. The rate of overdiagnosis was also substantial. The findings of a cohort study are published in Annals of Internal Medicine.

Effective should detect early-stage cancer and prevent advanced disease. Overdiagnosis occurs when mammography detects small tumors that may never affect the patient's health during a lifetime. The problem with is that it exposes patients to the potential harms of treatment, such as surgery, chemotherapy, and radiation, without a clinical benefit. Whether reduces the incidence of advanced tumors has important treatment implications.

Using data from two comprehensive Danish cancer registries, researchers sought to examine the association of screening with a reduction in the incidence of advanced cancer and estimate the level of overdiagnosis in the country's breast screening program, which offered biennial mammography for women aged 50 - 69 years beginning in different regions at different times. The authors measured the incidence of advanced and nonadvanced tumors in screened and unscreened women. To examine trends in overdiagnosis, the authors compared the incidence of advanced tumors in women aged 50 to 84 in screening and nonscreening areas and compared the incidence for nonadvanced tumors among women aged 35 to 49, 50 to 69, and 70 to 84 years in both screening and nonscreening areas. They concluded that screening was not associated with lower incidence of advanced tumors and approximately 1 in 3 and cases of DCIS diagnosed in screened women represent overdiagnosis.

In an accompanying editorial, Otis Brawley, MD, MACP, Chief Medical Officer of the American Cancer Society says that it's time to accept that overdiagnosis is real and that the benefits of breast screening have been overstated. He writes that "considering all small breast cancer lesions to be deadly aggressive cancer is the "pathology equivalent of racial profiling." This does not mean that screening should be abandoned, but we should try to recognize its limitations, use it in the most effective way possible, and try to improve it. Dr. Brawley suggests that more emphasis should be focused on preventing breast cancer through diet, weight control, and exercise.

Explore further: Breast density and risk may be useful for guiding mammography screening frequency

More information: Paper: annals.org/aim/article/doi/10.7326/M16-0270
Editorial: annals.org/aim/article/doi/10.7326/M16-2850

Related Stories

Breast density and risk may be useful for guiding mammography screening frequency

August 22, 2016
Women between the ages of 50 and 74 may benefit from more or less frequent mammography screening than is generally recommended, depending on breast density and risk. For average-risk women with lower breast density, which ...

Detecting more small cancers in screening mammography suggests overdiagnosis

July 6, 2015
Screening mammography was associated with increased diagnosis of small cancers in a study across U.S. counties but not with significant changes in breast cancer deaths or a decreased incidence of larger breast cancers, which ...

Breast screening program effective in preventing some invasive cancers

December 4, 2015
Screening for and treatment of an early form of breast cancer has been found to prevent subsequent invasive cancer, according to research led by Queen Mary University of London (QMUL).

Screening to blame for thyroid cancer 'epidemic' in South Korea

November 30, 2016
The current "epidemic" of thyroid cancer in South Korea is due to an increase in the detection of small tumours, most likely as a result of overdetection by screening, finds a study published by The BMJ today.

Public not being informed about dangers of medical overdiagnosis

May 20, 2015
A national survey reveals that only one in ten Australians report being told about the risk of overdiagnosis by their doctors, according to research published today in the scientific journal PLOS ONE.

New study suggests benefit of screening on breast cancer deaths

June 17, 2014
Invitation to modern mammography screening may reduce deaths from breast cancer by about 28 percent, suggests a study from Norway published in BMJ. This means that for every 10,000 women invited to screening, about 27 deaths ...

Recommended for you

Single blood test screens for eight cancer types

January 18, 2018
Johns Hopkins Kimmel Cancer Center researchers developed a single blood test that screens for eight common cancer types and helps identify the location of the cancer.

How cancer metastasis happens: Researchers reveal a key mechanism

January 18, 2018
Cancer metastasis, the migration of cells from a primary tumor to form distant tumors in the body, can be triggered by a chronic leakage of DNA within tumor cells, according to a team led by Weill Cornell Medicine and Memorial ...

These foods may up your odds for colon cancer

January 18, 2018
(HealthDay)—Chowing down on red meat, white bread and sugar-laden drinks might increase your long-term risk of colon cancer, a new study suggests.

The pill lowers ovarian cancer risk, even for smokers

January 18, 2018
(HealthDay)—It's known that use of the birth control pill is tied to lower odds for ovarian cancer, but new research shows the benefit extends to smokers or women who are obese.

Researchers find a way to 'starve' cancer

January 18, 2018
Researchers at Vanderbilt University Medical Center (VUMC) have demonstrated for the first time that it is possible to starve a tumor and stop its growth with a newly discovered small compound that blocks uptake of the vital ...

Modular gene enhancer promotes leukemia and regulates effectiveness of chemotherapy

January 18, 2018
Every day, billions of new blood cells are generated in the bone marrow. The gene Myc is known to play an important role in this process, and is also known to play a role in cancer. Scientists from the German Cancer Research ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.