Birth Control Pill Can Increase Breast Cancer Risk
Longer use heightens the odds, European conference hears
SATURDAY, March 23, 2002 (HealthDayNews) -- For women who use oral contraceptives comes a new word of caution today: using the Pill marginally increases your risk of breast cancer, and the longer you use it, the higher your risk of disease.
The finding, which echoes the much-debated historical link between the Pill and breast cancer, was reported on the final day of the week-long Third Annual European Breast Cancer Conference in Barcelona.
The conference also heard compelling new research on why some women with breast cancer can safely avoid chemotherapy, on how high-tech gene scanners can determine who is really at risk for this disease, and on a standard surgical tool that is being redeployed to possibly diagnose breast cancer 10 years before symptoms normally appear.
The study on Pill use was a collaboration among Norwegian, Swedish and French doctors. They analyzed data from the large Norwegian-Swedish "Women's Lifestyle and Health Study," which began in 1991 and tracked lifestyles, including Pill use, of women between the ages of 30 and 49.
The researchers followed the women for almost 10 years, during which time 1,008 cases of breast cancer were diagnosed.
For those women who reported any Pill use, the risk of breast cancer was about 26 percent higher than for those who didn't use oral contraceptives.
But for women who used the pill throughout the 10-year study, the risk shot up to 58 percent higher than non-Pill users, the doctors report.
The group at highest risk appeared to be those still using the Pill after age 45. Their risk was almost one and half times -- or 144 percent - that of non-Pill users.
On the other hand, the study also showed that women who used the Pill before age 20 and then stopped, or who used it only before their first full-term pregnancy and then stopped, had no increased risk.
The study's author, Dr Merethe Kumle, an epidemiologist from the Institute of Community Medicine in Tromso, Norway, cautioned conference participants that the research should not dissuade most women from using the Pill.
"The total number of deaths from any cause amongst women who use oral contraceptives is likely to be lower than women who have never used the Pill, just as we have seen with hormone replacement therapy," Kumle reported to the conference.
Dr. Loren Wissner Greene, an endocrinologist at New York University School of Medicine, is quick to agree.
"Even if women who use the Pill do get breast cancer, they are far more likely to survive than those who don't use the Pill and get breast cancer," Wissner Greene says, pointing to studies that have shown women who take birth control pills generally get a less-virulent form of breast cancer.
In other conference news, doctors from Guys Hospital in London announced a new breast-cancer detection technique that will soon undergo its first clinical trial.
The procedure could help detect changes in breast cells up to 10 years before any cancer would appear through a mammogram or other diagnostic tool.
The process involves the use of a tiny endoscope, a probe no thicker than a few strands of hair, which is passed through the nipple into the center of the breast to search the entire area for signs of tissue abnormalities. If abnormalities are found, the suspect cells can be removed, and that could help keep the cancer from ever developing.
Belgium researchers have developed high-tech methods of scanning thousands of genes at once, which they say enabled them to identify groups of markers associated with specific types of breast cancer, as well as the stages of those cancers. Identification of certain genes, they say, can even help predict breast cancer survival.
In a collaborative effort with doctors from England and the U.S. National Cancer Institute, the researchers from the Free University of Brussels used a microchip coded with data on 7,600 genes to analyze the genetic material from 99 breast cancer patients.
By running comparisons, the researchers say they could identify patterns of activity that might one day help doctors more accurately identify and stage tumors, as well as predict cancer outcomes.
Finally, a group of American researchers from the University of Chicago revealed how biochemical markers found in breast cancer patients can help predict which women may need chemotherapy after surgery and which may not.
Professor Ruth Heimann told conference participants her team discovered four such markers in breast cancer tissue samples -- factors that can adequately predict whether a woman's cancer may spread.
"If we have more accurate knowledge of the risk of metastasis in an individual patient, based on these biomarkers, we could tailor treatments and give chemotherapy only to the women who really need it," Heimann reported at the proceedings.
Although the American researchers say they can now accurately predict women at lowest and highest risk for cancer spreading, they remain unsure about those in the middle. More study is needed, they say, before the finding can benefit all breast cancer patients.
What To Do
To learn more about breast cancer, visit The National Breast Cancer Foundation.
Or to find more on the latest in breast cancer advances, including the newest clinical trials being conducted in the United States, visit The National Institutes of Health.