CHAMPAIGN — Two local doctors are urging women to continue getting annual mammograms, after a large and long-running Canadian study has launched a new controversy about the value of the annual breast cancer screening.
Published earlier this month in the medical journal BMJ, the 25-year study involving nearly 90,000 middle-aged women found 22 percent of invasive cancers discovered through mammograms were over-diagnosed — one for every 424 women who received mammography screening in the trial.
Over-diagnosis means it was possible the cancers might not have otherwise become apparent in the women's lifetime.
The authors concluded mammography, which is X-ray screening of the breasts, doesn't reduce breast cancer deaths for women ages 40-59 beyond what a physical exam and usual care in the community offers, and suggested the value of mammogram screening should be reassessed.
Dr. Mitchell Sussman, director of breast imaging at Carle, and Dr. Delores Fernandez of Christie Clinic — both radiologists — are sharply critical of the study.
The point of mammography is to find cancers before they become palpable, or can be felt in a physical exam, "because if we can't do that there is really no point to it," Sussman says.
"The smaller your cancer is when found, the better chance of a cure," he says.
Carle officials say they will continue to follow the American Cancer Society recommendations calling for women to undergo an annual mammogram starting at age 40 to screen for breast cancer.
Fernandez says Christie Clinic providers will do likewise.
"What I would recommend to every woman is get screened according to the American Cancer Society guidelines," she advises.
Both doctors, along with the American College of Radiology and Society of Breast Imaging, contend the results of the Canadian study were muddied, in part, by flaws with the mammography quality and the way women were sorted into the study groups.
Since the women were examined by a nurse first, the sorting wasn't genuinely randomized, they say.
"So most people would not consider it a serious study," Fernandez says.
Sussman says there's no comparison with the mammography equipment used decades ago and the equipment used today.
Mammography equipment available today is far superior, he and Fernandez say.
The study authors wrote they believe the lack of impact that mammography screening had on breast cancer deaths can't be explained by such factors as study design issues and poor quality mammography.
Two things about mammograms Sussman points out:
— If women are concerned about cancers being over-diagnosed and overtreated and want to roll the dice on getting mammograms, the option is there, Sussman says.
However, he also says, "the vast majority of cancers will grow, and if left untreated will kill you, and your survival is best when they're found tiny."
— Mammograms can pick up tumors as small as 3 millimeters, and at that point, "your cure rate is 95 percent," he says.
Fernandez also stresses the best option is finding cancer early and removing it.
"I would not want to leave anything cancerous, or precancerous, in my breast, no matter how small," she says.
That's not just because the risk of death is there, she says, but because once a small tumor in the breast grows into a larger one, women lose the option for less invasive treatments.
"The smaller it is, the less invasive the surgery is, and a lot of the times, if you get a very small cancer, you don't have to do anything but the surgery. You don't have any need for radiation or chemotherapy," she says.
In addition to following the American Cancer Society's recommendations on screening, Fernandez advises getting mammograms done at practices that are accredited and where providers reading the results are well-experienced.
And make it digital mammography for a state-of-the-art screening, she advises.
Know your mammogram
— A screening mammogram is an X-ray screening of the breasts when there are no symptoms present.
— A diagnostic mammogram is done when there are symptoms present, and it takes longer because more x-rays are needed.
— The American Cancer Society recommends annual mammograms starting at age 40 and continuing for as long as a woman is in good health.
— The U.S. Preventive Services Task Force recommends biennial mammograms for women aged 50-74.
— Mammograms come with low-dose radiation exposure, but many medical experts believe the benefit outweighs the risk.
— The American Cancer Society offers this comparison to illustrate how much radiation exposure comes with an annual mammogram: A woman receiving radiation treatment for breast cancer will receive about 5,000 rads. A woman undergoing annual mammograms from age 40-90 will have received 20 to 40 rads.