The incidence of later-stage breast cancer has not kept pace with a substantial increase in diagnosed breast cancers, an increase achieved largely by the use of better imaging equipment and a nearly 70% screening rate among women 40 years and older. This fact, underscored in a special communication in the Journal of the American Medical Association, pokes holes in the widely held public belief that early diagnosis will prevent the majority of breast cancer deaths.
The reason is that all breast cancers do not pose the same threat. Not only does this realization temper the hope that breast cancer can be defeated through the use of current screening programs, but it also raises the very real chance that these efforts are actually harming patients, wrote Laura Esserman, MD, MBA, and colleagues. Dr. Esserman is the director of the Carol Franc Buck Breast Care Center at the University of California, San Francisco, and co-leader of the breast oncology program at the UCSF Helen Diller Family Comprehensive Cancer Center.
“Without the ability to distinguish cancers that pose minimal risk from those posing substantial risk and with highly sensitive screening tests, there is an increased risk that the population will be over-treated,” Dr. Esserman and coauthors wrote (JAMA 302:1685-1692, 2009).
An imperfect but beneficial test
When the JAMA commentary appeared, a subsequent article in the New York Times reported that on the basis of comments made by Otis Brawley, MD, American Cancer Society chief medical officer, the ACS was questioning its current recommendations for breast cancer screening because of concerns about overtreatment. The ACS fired back that Dr. Brawley’s comments to the newspaper reporter were misinterpreted and stressed that its policy was unchanged (New York Times, “Cancer Group Has Concerns on Screenings,” October 21, 2009).
In a prepared statement, Dr. Brawley said the ACS stands by its recommendation that women 40 years and older should receive annual mammography screening, and women at high risk should talk with their doctors about when screening should begin based on their family history.
“This test is beneficial in that it saves lives,” he said in the statement. “But it is not perfect. It can miss cancers that need treatment and, in some cases, find disease that does not need treatment” (American Cancer Society, October 21, 2009, www.cancer.org).
Dr. Brawley had been saying this for years about mammography and also about prostate-specific antigen (PSA) testing for prostate cancer (see “Introduction of PSA testing leads to dramatic rise in cancer incidence,” page 35, September 2009). Dr. Esserman and colleagues argued that the benefit from breast and prostate cancer screening falls far short of public expectations, because these technologies are adept at finding cancers that may not be life-threatening and not so adept at uncovering the more dangerous ones.
This realization, after decades of hearing that early detection will dramatically reduce cancer mortality, is humbling, said Andrew Seidman, MD. But Dr. Seidman, an attending physician at Memorial Sloan-Kettering Cancer Center in New York, said it should not be seen as a reason to abandon screening.
“Therein lies the inherent danger of misinterpreting the shortcomings of current screening programs for breast and prostate cancer,” Dr. Seidman told Oncology News International.
Dr. Esserman agreed. “The message is to use screening more wisely and to do a better job with the information that we generate from screening,” she told Oncology News International.
Judd W. Moul, MD, professor of surgery and chief of the division of urologic surgery at Duke University Medical Center in Durham, N.C., echoed those sentiments for PSA screening. “As a clinician, one of the things that I don’t want to see happen is for us to go back to what I call the pre-PSA era. I don’t want us to stick our head in the sand,” Dr. Moul said.
In the 1980s, before PSA testing, between 20% and 25% of men who received a diagnosis of prostate cancer had bone metastases, according to Dr. Moul. This was “pretty much a death sentence,” he said. Back then, more than 40,000 men died of the disease annually. This number has since been cut in half.