Breast cancer

29 June 2011

More benefits of mammograms

The longest-running breast cancer screening study conducted has shown that regular mammograms prevent deaths from breast cancer, and the number of lives saved increases over time.


The longest-running breast cancer screening study ever conducted has shown that regular mammograms prevent deaths from breast cancer, and the number of lives saved increases over time, an international research team said.

The study of 130,000 women in two communities in Sweden showed 30% fewer women in the screening group died of breast cancer and that this effect persisted year after year.

Now, 29 years after the study began, the researchers found that the number of women saved from breast cancer goes up with each year of screening.

"We've found that the longer we look, the more lives are saved," Professor Stephen Duffy of Queen Mary, University of London, whose study is to appear online in Radiology, said.

Dr Stamatia Destounis, a radiologist at Elizabeth Wende Breast Care in Rochester, New York, who wasn't involved in the study, said radiologists have been quoting results of the Swedish study for years and the new findings show breast cancer screening is "even more of a benefit than we understood".

Screenings cause confusion

She said sweeping changes in the US screening guidelines two years ago that scaled back recommendations on breast cancer screening caused a lot of confusion among doctors and patients about the benefits of mammograms.

"We've had to do a lot of education of the patients and their doctors. This will help for that," Dr Destounis said.

In the study, women were divided into two groups, one that received an invitation to have breast cancer screening and another that received usual care.

The screening phase of the trial lasted about seven years. Women between 40 and 49 were screened every two years, and women 50 to 74 were screened roughly every three years.

"Our results indicate that in 1,000 women screened for 10 years, three breast cancer deaths would be prevented," Dr Duffy said, adding that most of the deaths prevented would have occurred more than a decade after the screening had started.

"This indicates that the long-term benefits of screening in terms of deaths prevented are more than double those often quoted for short-term follow-up."

The new data adds to evidence on the long-term benefits of regular mammography screening.

Screening controversy

New breast screening recommendations issued in 2009 by the influential US Preventive Services Task Force, recommended against routine mammograms for women in their 40s and said women in their 50s should get mammograms every other year instead of every year.

The guidelines contradicted years of messages about the need for routine breast cancer screening starting at age 40, eliciting protests from breast cancer experts and advocacy groups who argued the recommendation for fewer screenings would confuse women and result in more deaths from breast cancer.

The changes were meant to spare women some of the worry and expense of extra tests needed to distinguish between cancer and harmless lumps. But the latest results from the Swedish study show the rate of false positive results was low.

"We saw the actual number of overdiagnosed cases was really very small - less than 5 percent of the total," Dr Robert Smith, director of cancer screening at the American Cancer Society and one of the study's authors said.

Many groups still loyal

Many groups, including the American Cancer Society, have stuck by their long-standing recommendations of a yearly breast exam for women starting at age 40, stressing that the breast X-rays have been proven to save lives by spotting tumours early, when they are most easily treated.

"I think for anybody who was beginning to have their faith shaken in the value of mammography, these data show mammography is quite valuable as a public health approach to reducing deaths from breast cancer," Dr Smith said.

Dr Duffy said he thinks screening women 40 to 54 every 18 months and screening women 55 and older every two years would be a reasonable schedule.

He said the new findings do not speak to the frequency of screening issue, but they do make clear that screening works.

"Everyone must make up their own mind, but certainly from combined results from all the screening trials, mammography in women aged 40-49 does reduce deaths from breast cancer," he said.

Breast cancer is the second-leading cause of cancer death among US women, after lung cancer. It kills 500,000 people globally every year and is diagnosed in close to 1.3 million people around the world.

(Reuters Health, Julie Steenhuysen, June 2011)

Read more:

Breast lumps and breast pain

Breast abcsess


Read Health24’s Comments Policy

Comment on this story
Comments have been closed for this article.

Ask the Expert

Breast cancer expert

Dr Gudgeon qualified in Birmingham, England, in 1968. She has more than 40 years experience in oncology, and in 1994 she founded her practice, Cape Breast Care, where she treats benign and malignant breast cancers. Dr Boeddinghaus obtained her qualification at UCT Medical School in 1994 and her MRCP in London in 1998. She has worked extensively in the field of oncology and has a special interest in the hormonal management of breast cancer. She now works with Dr Gudgeon at Cape Breast Care. Read more.

Still have a question?

Get free advice from our panel of experts

The information provided does not constitute a diagnosis of your condition. You should consult a medical practitioner or other appropriate health care professional for a physical exmanication, diagnosis and formal advice. Health24 and the expert accept no responsibility or liability for any damage or personal harm you may suffer resulting from making use of this content.

* You must accept our condition

Forum Rules