Study: Mammograms after 40 increase women's survival rates

Study:  Mammograms after 40 increase women's survival rates

SEATTLE -- A study by Swedish Cancer Institute researchers found that women in their 40’s who discovered they had breast cancer from a mammogram had greater chances of surviving and required less aggressive treatment than those who did not have the screening done. This conflicts with the U.S. Preventive Services Task Force’s recommendation in 2009 that women wait until they are 50 to have a mammogram.

The Swedish study involved nearly 2000 women treated at the cancer institute from 1990 to 2008. Judith Malmgren, Ph.D., Henry Kaplan, M.D. and their colleagues considered how the patients were diagnosed, their cancer stage at diagnosis, their treatment, and annual follow-up information, including recurrence of disease.
Over the years, more breast cancer cases were detected by mammography, increasing from 28 percent in 1990 to 58 percent in 2008. Over the same period, patient- and physician-detected breast cancer declined from 73 percent in 1990 to 42 percent in 2008.
The study found that women ages 40 to 49 whose breast cancer was detected by mammography were easier to treat, had less recurring disease and fewer died from the disease (4 percent versus 11 percent) because their cancer was found at an earlier stage.
Most forms of breast cancer are slow growing, so it can take months or years before a woman notices any symptoms. Before the disease becomes apparent, Kaplan says a mammogram can detect cancerous tissue.
Catching breast cancer earlier can also mean patients may not need a mastectomy or chemotherapy. Compared to women whose cancers were detected by themselves or a physician, women who had mammograms were more likely to have only cancerous tissue removed in a lumpectomy  (67 percent versus 48 percent) and less likely to have their entire breast removed in a modified radical mastectomy (25 percent versus 47 percent).
“The shift toward more mammography-detected breast cancer cases was accompanied by a shift toward diagnosis at an earlier stage of disease that required less treatment,” Malmgren said.
Kaplan has seen women who undergo a mastectomy face intimacy issues and even require psychiatric care.
“For some women [a mastectomy] is really devastating,” Kaplan said. “If there is a way to keep their breast, that’s really important.”
Chemotherapy can also have lifelong side effects including premature menopause and an increased risk of secondary cancer.
“If you can give these women less treatment, that’s an important thing to consider,” Kaplan said.
“The shift toward more mammography-detected breast cancer cases was accompanied by a shift toward diagnosis at an earlier stage of disease that required less treatment,” Malmgren said.
U.S. Preventive Services Task Force’s 2009 recommendation did not consider how mammograms affect treatment options, but instead argued thatgetting screened for breast cancer before 50 is harmful, causing too many false alarms and unneeded biopsies without substantially improving women's odds of surviving the disease.
Meanwhile, the American Cancer Society and Swedish Cancer Institute have continued to recommend women receive annual mammograms starting at age 40.
We are waiting to hear comment from the task force on this study.
As mammograms increased over the study years, the detection of precancerous lesions also increased by 66 percent. The majority of these cases were ductal carcinoma in situ (DCIS), a non-invasive cancer that is confined to a milk duct. Treating DCIS is controversial because some physicians believe it does not always lead to life-threatening cancer. Kaplan says at this time, oncologists can’t tell which cases will lead to cancer.
“Until we know that, we feel obligated to treat women [with DCIS,]” Kaplan said. “We think we should find [these lesions] and treat them with the best research we have.”
Swedish researchers will be releasing a study next month that considers whether it is beneficial for women ages 20-39 to have mammograms.
To summarize their findings, Kaplan says it is not worthwhile for women under 30 to have the tests routinely, and it is not clear whether women ages 30 to 40 would benefit from routine tests. One reason for the recommendation is that few women under 40 have breast cancer. For those who do, tumors are less likely to show up on a mammogram because breast tissue is denser.
Still, women under 40 do get this disease. So Kaplan recommends that women with additional risk factors, such as relatives with breast cancer or a genetic mutation, seek medical attention and perhaps have a regular MRI scan to ensure they have no disease.
There is also no risk to having regular physical exams, Kaplan said.