1. Self breast examination beginning at age 20;
2. Baseline mammograms between the ages of 35 and 40;
3. Mammograms every other year between the ages of 40-49;
4. Yearly mammograms after the age of 50;
5. Women with personal or family history of breast cancer should consult their physicians about the need for earlier and more frequent examinations.
Coupled with the current recommendations for screening asymptomatic women with mammography comes the question of the risk of low dose radiation to the female breast. To date, there is no proof that radiation at diagnostic levels causes breast cancer. Although radiation has been shown to cause breast cancer in a number of studies (Hiroshima and Nagasaki, chest fluoroscopy for tuberculosis, radiation therapy for postpartum mastitis and other benign breast conditions, and female radium dial workers), these studies are not necessarily applicable to women over 35 receiving small, fractionated doses.
The most important risk factor is age; two out of three cancers occurs over age 50. The risk factor increases with family history; doubled if mother or sister had breast cancer and tripled if mother had breast cancer. If the patient has history of previous cancer in one breast she is four to five times more likely to have it occur in the opposite breast. The following are some general guidelines that have been developed by the University of California at San Diego Medical Center and are currently in use:
- Women under 30 with only mastodynia and a normal breast examination are not imaged initially but are followed clinically until the pain resolves. Persistence or an increase in pain and of an abnormal breast examination warrant imaging.
- Women under 30 with a clinically palpable mass are examined ultrasonically first. If the clinical and ultrasonographic diagnosis is fibroadenoma, no screening mammogram is performed. Depending upon the surgeon, the presumed fibroadenoma is generally removed but may be followed clinically if the patient has already noted a reduction in size.
- If a woman under 30 has a clinically palpable mass which has all ultrasonic characteristics of a simple cyst, no mammogram is performed. Depending upon the surgeon, cyst aspiration may be performed. The main reason given by the surgeons for aspiration of such a cyst is not for diagnosis but to aid in rapid and hopefully permanent resolution of the cyst.
- If a woman under 30 has a clinically palpable mass which has the clinical or ultrasonographic appearance of a carcinoma, a preoperative mammogram is performed prior to removal.
- All women over 35, no matter what symptoms, receive a screening mammogram following the guidelines of the American Cancer Society.
- If a woman over 35, who already had a screening mammogram, develops a mass in the interim, ultrasonography is the first imaging modality. Unless the mass can be shown to be a simple cyst, mammography is performed.
- If a woman over 35 has a non-palpable dominant mass identified on a mammography, ultrasonography is performed to exclude the possibility of a cyst. Unless the lesion is a cyst, preoperative localization is performed.
- If a woman over 35 has a clinically palpable mass with abnormal mammogram, ultrasonography is performed. Unless the lesion is a cyst, biopsy is performed.
- If the patient demonstrates a mammographically obvious carcinoma, no ultrasonography is necessary.
Some pitfalls should be noted: Approximately 10% of breast cancers are not demonstrable by mammography. Thus a normal mammogram should not dissuade the clinician from pursuing a clinically suspicious mass. Some cancers have a normal ultrasound, and thermography and ultrasonography have been shown to be unacceptable as screening modalities.
Deborah Pate, D.C., D.A.C.B.R.
San Diego, California
Dr. Pate's book, Case Studies in Chiropractic Radiology is now available through MPI's Preferred Reading and Viewing list. Please see pages XX, Part# T-123 for further information on how to order your copy.
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