Experts’ don’t agree on what age women should start, stop having mammograms
The numbers are staggering. This year alone, 316,120 women will be diagnosed with breast cancer, and 40,610 will die from the disease. By comparison, the number of annual traffic-related fatalities in the U.S. stands at 37,461.
The chance of developing breast cancer during your life is an unfortunate reality for all women. One in 8 women will develop breast cancer in their lifetime. Women have no control over these numbers; however, they do have significant control over whether they are going to die from this horrible disease.
At some point in the disease’s progression, every breast cancer is curable. Although every breast cancer is treatable at the time of diagnosis, not all breast cancers are curable at the time of discovery because many breast cancers are discovered too late to be completely cured.
Nobody wants to learn the dreaded news that they have breast cancer. The time of discovery is critical in determining the odds of survival. Every breast cancer has a threshold at which point it changes from being curable into being untreatable. In other words, every breast cancer can be cured if found early enough. Early detection, therefore, is the key to survival.
Cure rates and odds are determined by two main factors: grade and stage of the breast cancer at the time of diagnosis. Grade is how aggressive the breast cancer cells look under the microscope and how fast the cells are dividing (growing). The lower the grade, the slower the growth and the longer it takes for the cancer to cross over the threshold from curable to deadly. Stage is how large the cancer has become and how far it has traveled in the body at the time of diagnosis. The smaller and the more localized the cancer is, the easier it is to cure. Low grade and stage mean a better chance for cure; high grade and stage mean decreased odds of survival.
The grade (aggressiveness) of a breast cancer cannot be controlled by screening. Cancers that form in younger women (40 to 50) tend to be higher in grade, which makes them deadlier. Screening mammography allows to identify breast cancer before the disease progresses to a more serious stage (size and extent). This is great news.
Cancers as small as a pin head can be detected by mammography. These early cancers typically are the kind that are confined in the ducts and glands where all breast cancers first form. These early cancers are called ductal carcinoma in situ, or DCIS. If detected at this stage, the cancer is almost 100 percent curable by lumpectomy and radiation of the breast.
If not detected at this early stage, the DCIS cells can invade the surrounding breast tissue -- called stroma -- and the cancer then becomes invasive ductal carcinoma, or IDC. At this stage, the body tries to corral the invading cancer cells with reactive scar tissue that the woman eventually feels as a new breast lump. As it continues to grow and invade the stroma, it can be picked up by lymphatic ducts and transported to the regional lymph nodes in the arm pit.
Fifty percent of women who feel a lump in the breast will have at least microscopic spread to regional lymph nodes. At this point, the cancer stage increases and the chances of a cure decrease. Although still potentially curable at this stage, chemotherapy must be used to kill the invading cancer cells. Once the cancer cells spread through the lymph nodes and travel to other parts of the body -- such as bone, liver and lung -- the cancer is in metastatic stage 4 (the highest) and crosses the threshold from curable to only treatable. It is these women who ultimately will succumb to the disease.
In my opinion that is tragic result, because it doesn’t have to be this way.
Mammography saves lives because it discovers breast cancers at an early stage and allows for early treatment leading to a cure. Improved cancer therapy has led to more cures at later stages but has not eliminated the need for early detection.
We have a screening test that saves countless lives, and we have a test that can lead to breast cancer cure in most women if used properly and regularly. But there is controversy concerning the age a woman should start taking advantage of this life-saving screening process.
Unfortunately, there is no consensus on when a woman should start screening mammography, how often she should get mammograms and when she should stop getting annual mammograms because of advanced age.
The U.S. Preventive Service Task Force that sets recommendations for Medicare recipients calls for screening mammography to begin at age 50 and proceed every other year until age 75. The American Cancer Society recommends that women 40 to 44 can start mammograms if they wish to do so, women 45 to 54 should get mammograms every year, and women 55 and older can get mammograms every two years. The American College of Radiology/Society of Breast Imaging recommends annual mammograms from 40 until 74 or older for those women with other health problems.
So, should you start at age 40, 45 or 50? Should you get a mammogram once a year or once every other year? I have been a radiologist and mammographer for more than 30 years, and I would like to give my perspective.
Most people would say a family history of breast cancer is the biggest risk factor for a woman to develop the disease. Although family history is an important factor, only 25 percent of all breast cancers arise in women with a strong family history. This means that 75 percent of all breast cancers occur in women without a family history of the disease. This statistic shocked me when I first read it.
The No. 1 risk factor for developing breast cancer is age. Peak incidence is between the age of 65 and 70. Most women begin dying of other causes, such as heart disease and smoking-related illnesses, after age 70, which brings down the number of breast cancer-related deaths.
So, if getting older is the biggest risk factor in developing breast cancer, why does controversy surround the recommendation of starting mammograms at age 40? This is because while the incidence of breast cancer in average-risk women – those between 40 and 50 -- is relatively low, it is not zero.
Breast cancer incidence increases substantially around age 40. The incidence of breast cancer in women between 40 and 44 is double that of women 35 to 39; the incidence doubles again between 45 and 49. The cancers that develop between 40 and 49 account for almost 20 percent of all breast cancers and for about 40 percent of all years of life saved by mammography because women in their 40s live longer after they are cured. Annual mammograms reduce by 40 percent the average mortality in women between 40 and 49.
The other factor that influences the effectiveness of mammography in detecting breast cancer in women between the ages of 40 and 49 is breast density. The younger a woman is, the more likely she will have dense breasts that reflects remaining glands, ducts and fibrosis in the breasts. Dense breasts have a negative effect on the ability of mammography to detect cancer. Dense breast tissue allows cancer to hide, which is why we have started to recommend breast screening ultrasound in women with dense breasts. Screening ultrasound enables us to detect many cancers that mammography misses. This has greatly improved our ability to detect invasive breast cancers in younger women with dense breasts. 3D mammograms have also enhanced our ability to detect breast cancer in women with dense breasts. 3D mammograms also enhance our ability to detect breast cancer in average density and fatty breasts and is fast becoming the standard of care for screening mammography.
A recent study published in the medical journal Cancer showed that more than 70 percent of women who died from breast cancer in their 40s at major Harvard teaching hospitals were among the 20 percent of women who were not being screened. Because medical science cannot determine which cancers will advance to kill a woman and which will not, all women 40 and older should be screened annually.
With the recommendation of annual screening between 40 and 84, average mortality reduction is 39.6 percent; with the recommendation of screening annually between 45 and 54 and then every other year until 79, average mortality reduction is 30.8 percent; and with the recommendation of screening every other year between 50 and 74, average mortality reduction is 23.2 percent.
These are the facts. Now it’s your turn to act on them. My advice: Go get your mammogram.