Medical Device Daily

Toward the end of 2006, women have been presented with one more piece of confusing health news and advice — as it relates to breast cancer screening/mammography — in the form of a study recently completed by The Institute of Cancer Research (London).

A 10-year study in which women between the ages of 40 and 50 were invited for annual breast screening did not show a significant reduction in breast cancer mortality — confusing, in that the American Cancer Society (ACS; Atlanta) and most physicians suggest to their patients — at least in the U.S. — that they begin annual screening mammograms at age 40. And the new report adds to a variety of studies which periodically question the overall usefulness of mid-life disease screening.

The report by researchers at The Institute of Cancer Research was published in the December issue of the Lancet. The trial was funded by Cancer Research UK (London), the Medical Research Council and the Department of Health. It involved around 160,000 women, of whom one-third received annual screening invitations and two-thirds who used what was termed “usual medical care.”

The researchers said that the trial was the first of its kind to invite only women 40 or 41 years of age at the start of the trial to ensure all results were based solely on screening before age 50. Currently, when women reach the age of 50 they are invited for screening every three years by the National Health Service Breast Screening Programme.

The researchers estimated that screening from age 40 could save four lives for every 10,000 women screened.

But it was reported that the benefit of screening women in their 40s needs to be balanced against possible negative considerations such as increased radiation exposure — which can contribute to breast cancer risk — and recalling women who do not have cancer for further tests, leading to anxiety and often resulting in higher financial costs for the screening program.

In an e-mail reply to questions from Medical Device Daily, Sue Moss, MD, lead author of the study, said, “More evidence on the efficacy of screening younger women will come from further follow-up of the trial, but women in this age group should be informed of both the potential advantages and disadvantages of screening. Women in all age groups should continue to be ‘breast aware.’”

Of those women invited for the first screening 68% attended, the institute said. But the figure fell in later rounds, partly due to women moving away from the study areas, the researchers said. That led scientists to conclude that the potential benefits of screening for those under age 50 could be greater than that observed, according to the institute.

This most recent study used two X-ray views of the breasts at the first screen and a single view subsequently. Currently, the standard procedure in the National Health Service screening program is to take two views at all screens because it improves screening quality and increases the number of lives saved, But it also involves higher costs and a greater radiation dose to the woman screened.

Moss said: “The results of this study are consistent with similar studies which have included women under age 50 years at entry but in which some of the screening will have taken place at older ages. Longer follow-up of this trial will provide further information. It is important that all the potential advantages and disadvantages of screening are taken into account when considering any changes in policy.”

Professor John Toy, medical director of Cancer Research UK, said: “This paper shows no definitive evidence presently for women in their 40s to be included in the NHS Screening Programme. More years of follow-up, however, might reveal a benefit. We encourage women of all ages, and particularly older women in whom breast cancer is more common, to be breast aware and to see their doctor straight away if they notice any change in their breasts.”

The National Breast Cancer Screening Programme in the UK invites women between the ages of 50 and 70 for breast screening every three years. Nearly 1.5 million women are screened each year and latest figures from the Breast Cancer Advisory Committee report that screening saves 1,400 lives a year in the UK.

Age is the most important risk factor for breast cancer. More than 80% of all breast cancer cases are diagnosed in women over 50. There are around 41,700 cases of breast cancer diagnosed in the UK each year and 12,350 deaths.

Among women between the ages of 40 and 49, there are 5,780 cases of breast cancer diagnosed each year and just over 1,000 deaths in the UK.

According to the ACS, in 2005 there were expected to be 211,240 new cases of invasive breast cancer in the U.S. and 40,410 deaths attributed to the disease.

ACS guidelines call for annual mammograms in women beginning at age 40, an annual clinical breast examination and monthly self-exams.

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