Early Detection of Breast Cancer
Francis C. Evans, M.D., FACS
Despite the great advances in medicine, breast cancer remains, for the most part, an unpreventable disease, and is the most common cancer in women. The majority of women with breast cancer indeed are cured of their disease; nonetheless, breast cancer is only secondary to lung cancer among the causes of deaths from malignancy in American women. Recent advances, particularly early detection, have improved survival in women with breast cancer.
Breast cancers typically are detected in one or more of three ways: examination by a physician or other person, by breast self-examination, and since the late 1960’s, by mammography; X-ray examination of the breasts. Of these, only mammography has definitively been demonstrated to make an improvement in the cure rate of the disease, presumably because of earlier discovery.
Current recommendations for “screening mammography” [performing the examination when there is nothing known to be abnormal in the breast] in women without high risk of breast cancer include a ‘baseline’ mammogram between ages 35 and 40, and annual mammography screening starting at age 40. How long this should continue late into life is somewhat controversial; it is this surgeon’s opinion, and that of many other physicians, that annual screening should continue as long as a woman remains in generally good health. In special high-risk instances, such as when close family members have had breast cancer, the initiation of screening might well start at an earlier age.
It is most important that mammography be performed at a facility that is accredited by the American College of Radiology. Interpreting mammograms requires considerable skill, and should be done by a physician who is board certified or board eligible in radiology (the field of interpreting X-rays and other imaging studies).
Mammograms are relatively inexpensive; modest discomfort at most can be expected during the procedure. Most studies obviously are normal, but a suspicious finding on mammography does not mean breast cancer; it merely is the proper result of the screening examination, indeed the very purpose of doing the study. Of necessity, radiologists must call attention to all potentially significant abnormalities on mammography X-rays; far less than half eventually turn out to be cancer.
Mammography is not perfect. Some 8 to 12 percent of cancers simply are not detectable by X-ray. If an abnormality is found on a mammogram, the radiologist may recommend biopsy, request additional X-ray views, or recommend close follow-up, with a repeat study in perhaps three to six months. An ultrasound study may be requested to see if the lesion is a cyst (fluid filled); if so, it likely is not of concern. When biopsy is recommended, several options are available: the most common method when a breast lesion cannot be felt is to do a needle-directed biopsy, whereby the radiologist marks the lesion with a fine wire, and then subsequently a surgeon takes out the area in question. Other methods of breast biopsy include needle aspiration, and the use of X-ray guided stereotactic methods. These are discussed in the separate article on surgery for breast lumps.
Evaluation of Breast Lumps:
If a woman, or her doctor, husband, or other person finds a lump in her breast, it must be explained ‘ either by its complete disappearance when a needle is placed within it and fluid removed or by its complete surgical removal and subsequent pathological examination (excisional biopsy). When a woman presents with a breast lump the next step often is mammography. The primary purpose of the X-ray in this instance is not the evaluation of the lesion in question, but rather to search for additional undetected lesions.
IT IS A GRAVE MISTAKE TO ASSUME THAT A BREAST LUMP IS NOT CANCER BECAUSE THE MAMMOGRAM IS NORMAL.
Many surgeons and other physicians perform an aspiration as the first step in the evaluation of a breast lump, often at the initial office consultation. Using local anesthesia, a needle is placed into the lump. If it is a cyst, it likely will disappear as the fluid is aspirated into the syringe. Unless the fluid is bloody, a woman can be reassured that all is fine. Simple follow-up to be sure that the lump stays resolved is all that is needed.
If the lump proves to be solid on the initial needle aspiration, a sample of the microscopic cells suctioned into the syringe may be sent for microscopic evaluation. This fine needle aspiration cytology can be very helpful; the important thing to remember is that it is definitive only when positive for cancer. If it is negative or indeterminate, it does not mean there is no cancer, although such a negative study can be somewhat reassuring.
The only compete and definitive method of evaluating a breast lump to be sure it is not cancer, other than its disappearance when aspirated, is its complete removal and examination by a pathologist. Anything less is unacceptable, and could result in the potential opportunity to cure cancer being lost.
What if a lump is found to be a cyst on mammography and/or ultrasound? Cysts are benign ‘ is any further treatment needed? Most authorities agree that if a lump is shown to be a fluid filled cyst by ultrasound study, and it cannot be felt on examination, leaving it alone is safe. If it can be felt, it has to be treated by needle aspiration, or if that fails, by removal.
If a mammogram is consistently normal year after year, do I still need the study every year — after all, Medicare pays for screening only every two years? The reason Medicare reimburses for screening mammography only once every two years is based on financial concerns of the Medicare program, not any scientific study. No one knows the ‘lead time’ necessary to detect cancers before they spread and are less likely to be curable. The one-year standard we have adopted for mammography is somewhat arbitrary. The average breast cancer takes at least three years to grow from a tiny cell division gone awry to the development of invasive cancer. Numerous studies have proven the one-year interval to be safe and cost effective. One has to balance the rate of growth of the cancer versus our ability to detect it, and leave some room to correct the unavoidable errors that occur in any human endeavor.
Treatment of breast cancer is beyond the scope of this short article. With early detection, before a cancer can even be felt, cure is far more likely than when the cancer is not found until it grows large enough to be felt. Further, breast conservation treatment, avoiding the disfigurement of breast removal, is much more likely to be both feasible and successful earlier rather than later, when the lump is larger and treatment options more limited.