Cochrane Collaboration College for Policy
College of Humanities and Social Sciences

Mammogram Uncertainties: A New Study Adds to the long-running Debate

The benefits of mammography have been long debated, although in the United States about 37 million mammograms are performed annually at a cost of $100 per mammogram. Mammogram screening has been scrutinized by those who believe that the screens result in over-diagnosing breast cancer, by detecting and treating cancer that may not be clinically apparent during women’s lifetimes. A recent study, published in The British Medical Journal, supports this claim of over-diagnosis, and has raised more doubts on whether mammograms actually reduce mortality rates for individuals with breast cancer. This longitudinal, randomized screening trial study was conducted in 15 screening centers in 6 Canadian Providences, over a time frame of 22 years, examining the benefits of mammography screening compared to usual preventative care (manual breast examination). Results from the Canadian study showed that death rates due to breast cancer were the same for those who did, compared to those who did not, receive mammogram screening. An in-tune, observation from Dr. Peter Juni, a member of the Swiss Medical Board, highlights that mammography was not reducing the death rates but rather was increasing over-diagnosing and leading to false positives and needless biopsies.

 

The above argument is based on the fact that cancer cells come in many different forms and some may even shrink and disappear on their own over time; nevertheless, once cancer is detected, it is hard to know if it is dangerous and so it gets treated. However, the chief of cancer control for the American Cancer Society (ACS) says that decisions to change guidelines on screening will be based on assessing data from all studies on mammography.

 

Unfortunately, evidence from prior studies on screening is divided; so are current recommendations on guidelines for screening.  The most recent breast screening recommendation update from the US Preventive Services and Task Force (USPSTF), announced in November 2009, advised against routine mammogram screening for women in their forties. Instead the USPSTF, based on a systematic review published in the Annals of Internal Medicine, recommends biennial mammograms for women 50 years or older. This policy change has been receiving much flak from the medical community with the ACS and National Cancer Institute (NCI) continuing to recommend routine mammogram screening for women 40 years or older. The findings of the Canadian study have not been immune to criticism either.

 

While the ambiguity around the benefits of and recommendations for mammogram screening persists, the state of Virginia is mobilizing response towards promoting a coordinated breast cancer awareness and prevention drive particularly among the underserved women. A Bill (HJ762ER) passed by both Houses in the 2013 legislative session provides a platform to improve outcomes for one of the most intractable diseases in the state for women. Indeed, Virginia is among the few states ranked higher for death risk than for incidence risk of breast cancer. Breast cancer is the most frequently diagnosed cancer among women in Virginia.  It is the second leading cause of death by cancer for women in the state, according to the United States Cancer Statistics. Given that, Virginia’s local health delivery system is a complex web of local, state and private agencies, compiling awareness and prevention campaign protocols that incorporate the best evidence available, coupled with data-driven assessments of localities’ needs for their population will be an exceedingly complicated task. In recognition of this challenge, Cochrane at Mason is undertaking an accelerated evidence synthesis to analyze research on best practices in promoting awareness on breast cancer and early detection through routine screening.

 

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