Breast cancer risk assessment and prevention should start much earlier in life than it currently does, say Canadian researchers who examined breast cancer risk factors in young women.
The study was published in the medical journal The Lancet Oncology.
The study of 400 women, ages 15 to 39, and their mothers found that breast tissue composition in young women may be associated with their risk for breast cancer in middle age and older.
"It is known that the breast is most susceptible to the effects of carcinogens at early ages. Our findings suggest that differences in breast tissue composition in early life may be a potential mechanism for this increased susceptibility," says lead researcher Dr. Norman Boyd, of the Campbell Family Institute for Breast Cancer Research, Toronto.
"By identifying the environmental and genetic factors that influence breast tissue composition early in life, we may be able to develop safe and effective methods of prevention," he says.
In this study, the researchers looked at the amount of dense breast tissue (mammographic density, or MD), which varies considerably among women and is a significant risk factor for breast cancer in middle-aged and older women.
Experts know that the risk of breast cancer increases as MD increases.
However, little has been known about the development of MD early in life or how the MD of young women is related to their height, weight, age, and their mother's MD.
The study authors conclude that a high degree of mammographic density in middle age, when it is a strong risk factor for breast cancer, may arise from the subset of the population with the greatest amount of fibro-glandular tissue in early life.
This is when susceptibility to potential carcinogens is greatest.
"Interventions directed at the prevention of breast cancer may therefore be more effective if they are started in early life rather than adult life," Dr, Boyd says.
For years, researchers have known that breast density is almost as important as age in predicting who will develop breast cancer.
But now they are discovering how the density of a woman's breast tissue can also predict how she will respond to cancer treatment and whether her cancer will recur.
The denser a woman's breasts, the less fat they have, explains Diana Buist, Ph.D., of Group Health Center for Health Studies in Seattle. "If you have a dense breast, it's harder to see breast tumors on a mammogram."
Women with dense breasts are more likely to have abnormal mammograms, says Buist.
"Density on a mammogram is white, cancer on a mammogram is white," she says, which makes it more difficult to detect signs of cancer and can prompt reports of possible abnormalities.
According to Dr. Karla Kerlikowske, at the University of California, San Francisco, about 10 percent to 15 percent of women have low-density breasts, another 10 percent to 15 percent have very dense breasts, and the rest have breasts with a density somewhere in the middle.
But the average woman may not have a clue whether her breasts are dense, she says. For one thing, Dr. Kerlikowske adds, it is not as easy to measure density as it is to measure cholesterol.
"In the last 10 years, a lot of researchers have focused on how to measure it better, and what does it mean to have that density," she notes.
Dr. Kerlikowske was part of a research team that discovered that high breast density predicts local, but not distant, recurrence of cancer after a lumpectomy and radiation for invasive breast cancer.
Another group of researchers found that changes in breast density during treatment with tamoxifen, a drug used to lower breast cancer risk, help predict how well the drug is working.
Dr. Kerlikowske says that women with very high-density breasts have about a four-fold increase in risk compared with women who have very low-density breasts. And though density often decreases with age, especially after menopause, it remains a risk factor - and one which women cannot do much about, says Dr. Kerlikowske.
Always consult your physician for more information.
A mammogram is an x-ray examination of the breast. It is used to detect and diagnose breast disease in women who either have breast problems such as a lump, pain, or nipple discharge, as well as for women who have no breast complaints. The procedure allows detection of breast cancers, benign tumors, and cysts before they can be detected by palpation (touch).
Mammography cannot prove that an abnormal area is cancer, but if it raises a significant suspicion of cancer, tissue will be removed for a biopsy. Tissue may be removed by needle or open surgical biopsy and examined under a microscope to determine if it is cancer.
Mammography has been used for about 30 years, and in the past 15 years technical advancements have greatly improved both the technique and results.
Today, dedicated equipment, used only for breast x-rays, produces studies that are high in quality but low in radiation dose. Radiation risks are considered to be negligible.
The recent development of digital mammography technology shows promise for improved breast imaging, in particular, for women less than 50 years of age, women with dense breast tissue, and women who are premenopausal or perimenopausal.
Digital mammography provides electronic images of the breasts that can be enhanced by computer technology, stored on computers, and even transmitted electronically in situations where remote access to the mammogram is required. The procedure for a digital mammography is basically performed the same way as a standard mammogram.
According to the National Cancer Institute screening mammogram is an x-ray of the breast used to detect breast changes in women who have no signs of breast cancer. It usually involves two x-rays of each breast. Using a mammogram, it is possible to detect a tumor that cannot be felt.
A diagnostic mammogram is an x-ray of the breast used to diagnose unusual breast changes, such as a lump, pain, nipple thickening or discharge, or a change in breast size or shape.
A diagnostic mammogram is also used to evaluate abnormalities detected on a screening mammogram. It is a basic medical tool and is appropriate in the workup of breast changes, regardless of a woman's age.
Always consult your physician for more information.