The U.S. Preventive Services Task Force (USPSTF) guidelines on mammography screening “ignore the facts and the scientific evidence” about the benefits of screening, according to a perspective published in this month's Journal of the American College of Radiology.
According to Daniel Kopans, MD, of the Massachusetts General Hospital department of radiology in Boston, implementation of these guidelines “will severely reduce the benefit that has been achieved and, by the agency's own admission, result in unnecessary deaths from breast cancer that could be avoided by annual screening beginning at age 40.”
Kopans wrote that the USPSTF “did not think through the consequences of its guidelines.” For example, it’s recommendations regarding screening and breast self-examinations for women in their 40s means, he said, that the USPSTF is telling women that they should wait until their cancers are so large that they can longer ignore them before seeing their doctors. “Is this what we should advise our patients?” he asked.
In coming up with its recommendations, Kopans said, the USPSTF misled women and their physicians when it said its guidelines were evidence-based because it had reviewed all of the pertinent data and literature on breast cancer.
Instead, charged Kopans, the USPSTF “selected the information that suits its agenda. The death rate from breast cancer has decreased by 30 percent since 1990. This is directly linked to the onset of annual mammographic screening for women aged of at least 40 years in the mid-1980s. Before mammographic screening, nothing had influenced the death rate since 1940."
Kopans presented a number of “facts” that he said discredits the USPSTF guidelines, including:
- The USPSTF continued to use the results of the Canadian National Breast Screening Study-1 that Kopans said “was clearly compromised by its failure to adhere to the requirement of blinded randomization.”
- The task force used the age of 50 years as an arbitrary threshold. “There are no ungrouped data, none at all, supporting the idea that any of the parameters of screening change abruptly at age 50 or any other age, so there is no scientific support for using the age of 50 years as any but an arbitrary threshold."
- The USPSTF “used the smallest benefit (15 percent) it could find” from the results of randomized control trials (RCTs) of mammographic screening and “ignored statistically significant benefits that were at least double those.”
- The task force “clearly does not realize “ that 40 percent or more of the years of life lost to breast cancer are due to cancers diagnosed in women in their 40s.
- There are no indications that overdiagnosis is a major problem despite the concerns raised by the USPSTF. “The bottom line is that overdiagnosis, if it exists, is the fault not of mammography but rather of the inability of pathologists to, as yet, determine the precise lethality of any given lesion.”
- There is no scientific justification for screening at-risk women in their 40s. “The USPSTF agrees that the RCTs are the only way to prove a benefit from screening, yet it ignored the fact that none of the RCTs stratified by risk, so there is no scientific evidence that screening only high-risk women will save any lives,” he wrote.
In conclusion, Kopans wrote that the “USPSTF guidelines will set back women's health by more than 20 years and should be rescinded.”