It is estimated that there will be 230,000 cases of breast cancer, in 2011, in women. There will be another 2000 cases in men. If one looks back, since 1975, there has been a gradual increase in the incidents of breast cancer with the exception being a slight drop in 2001, which has been attributed to the information coming from the Women’s Health Initiative suggesting the possibility that hormones might be playing a risk in the incidents of breast cancer. The cause of the drop in 2001 is still, however, somewhat debatable. Gradually, if one looks at the overall curves, the incidents of breast cancer has gradually been increasing. Some of this has been attributable to something called lead time bias: Which is, simply, more women are having mammograms and we are diagnosing breast cancer in women that might never clinically evolve.
The various theories regarding the incidents of breast cancer rising, or risk factors shall we say, are well known. Early menarche (that is the earliest a woman has her first menstrual period) and late menopause are two known contributors to possible risks for breast cancer. Being nulliparous (no children), or not having the first child until after age 30, is a known risk factor. Family history is obviously a risk factor, but it is interesting to observe that most women who develop breast cancer have no family history. Exposure to radiation has been known, for years, to contribute an increased risk for breast cancer: Women’s breasts that are exposed to radiation, such as women who are treated with radiation for Hodgkin’s disease, have higher incidents. Women who were in TB sanitariums, who had frequent fluoroscopic examinations of their chest, were shown to be at increased risk. Furthermore, a treatment for mastitis in the postpartum period, back in the 30s, used to be to radiate the breasts and this now is known to increase the risks for breast cancer. Birth control pills and hormone replacement therapy, statistically, have been implicated for increased risks, but the exact contribution is really unknown. Identification of certain deleterious genes, as in the BRCA1 and BRCA2 systems, are known to convey a higher risk for both breast and ovarian cancer. It is a small minority of the population, however, who had these deleterious genes.
The good news is that the death rate from breast cancer is decreasing. This undoubtedly is mainly attributable to early detection, i.e. women affording themselves of mammography that detects breast cancer at an earlier stage.
Unfortunately, we may be seeing an increased number of young women who have breast cancer and those women, of course, are not being screened because the attack rate in young women is very low. The density of the breasts in young women is also very high and, in general, it may be difficult to identify a breast cancer in the younger women. In fact, breast density has been suggested to be a slight risk factor for breast cancer. Dietary habits have been implicated in certain populations groups. Allegedly, populations that have a high animal fat diet may have an increased risk for breast cancer. Certainly obesity and perhaps alcohol intake have been implicated as risk factors for breast cancer.
What, therefore, can women do to decrease their risks for breast cancer and perhaps to increase the curability if they happen to get that disease. Most physicians believe that it is important to have a healthy lifestyle and that would include exercise, dietary intake of less fat, and perhaps less alcohol.
It remains somewhat controversial as to what age mammographic screening should occur. I believe in screening women by doing a baseline mammogram at age 35, and then doing mammograms annually after age 40. In higher risk groups, mammography may be used earlier. The recent use of MRI in high risk populations has been shown to be able to detect breast cancer earlier in women, particularly with dense breasts, and who are at high risk. We will be able to decrease the mortality rate in these women, more so if they would have their annual mammogram and perhaps ultrasound. The ultrasound is an excellent modality to use in symptomatic women, but its exact rule in the screening of women is unknown.
In future columns, I will discuss the history and the evolution of surgery for breast cancer, early adjuvant trials with chemotherapy and radiation, current therapies including targeted therapies for breast cancer, and possibilities for the future.
Robert P. DerHagopian, M.D., F.A.C.S.
Chief, Baptist Health Breast Center