ASK THE DOCTOR: Breast Cancer Screening
By DR. JIM MITTERANDO
The Patriot Ledger

Q.I am 43 years old and was recently told that I have an abnormal mammogram. I was told it is probably nothing but they wanted me to come back for additional X-rays and an ultrasound. I am very worried.

Q I am 74 years old. Should I continue having mammograms?

A. Breast cancer screening is intended to find cancer early so it can be treated before it spreads or kills. Early breast cancer can be cured in nine out of 10 women. It is important to understand the benefits, limitations and risks of breast cancer screening. Screening not only can help women but it also can also create fears, false positive tests and even miss cancer.

Screening involves regular breast exams and mammograms (X-rays of the breast). Monthly self-exams are still important since women may detect breast cancers missed by mammography. Breasts can be lumpy. Doing regular exams helps a woman to know these lumps and improves her ability to notice any changes. You should contact your doctor if you notice a change that persists for more than a month. Breasts change throughout the menstrual cycle and, ideally, should be checked around a week after your period starts.

Screening, clinical breast exams by a health care provider are probably not as useful as self-exams at finding early cancers since the examiner does not know your breasts. Current recommendations for clinical breast exam for a woman in her 20s or 30s is every three years. After age 40, you should have a breast exam every one to two years. Women at higher risk for breast cancer will need more frequent exams and mammograms.

Mammograms start at age 40. Mammograms should be done every one to two years. Ultrasounds are sometimes done to differentiate a fluid cyst from a solid tumor.
The benefits of screening lie more in finding and treating an early cancer rather than preventing deaths. To prevent one breast cancer death, 800 women need to be screened regularly over a 14-year period.

The mammogram is not a perfect screening tool. It can miss cancers as well as lead to false-positive tests that result in unwanted anxiety and additional testing.

Before menopause, the breasts are dense and X-rays do not penetrate as well as they do in post-menopause breasts. A woman in her 40s has a 50 percent (one in two) chance of having an abnormal mammogram over the next 10 years that will prompt further X-rays, ultrasounds or biopsies. Most of these mammograms are false-positive and most of the breast biopsies are benign.

In your 40s, a positive mammogram means that you have a 4 percent (one in 25) chance of cancer; in other words, you have a 96 percent chance of not having cancer. Knowing this statistic may provide some peace of mind and may help counteract the natural tendency to assume that you have breast cancer when confronted with an abnormal mammogram.

The mammogram improves as a screening test as a woman ages. After menopause, the risk of breast cancer increases and X-rays better penetrate the breast. In your 50s, a positive mammogram means that you have a 9 percent ( one in 11) chance of breast cancer.

Conversely, you have a 91 percent chance that you do not have breast cancer. After age 60 a positive mammogram reveals breast cancer 17 percent ( one in six) of the time.

Unfortunately, concerns about increased lawsuits for missing a breast cancer have caused radiologists to read mammograms more cautiously leading to more false-positive mammograms.

Mammograms can be stopped when a woman has a life expectancy of less than 10 years or reaches the age of 80. For example, if a woman has congestive heart failure or emphysema, these diseases are more likely to cause death than a newly diagnosed breast cancer that, generally, takes years to progress. If you are a healthy 74-year old woman, you may want to continue mammograms and consider stopping at age 80. If you have health problems, you may want to consider stopping mammograms.

Dr. Jim Mitterando is a family doctor at Cohasset Family Practice and a staff member at South Shore Hospital in Weymouth.

Readers should send questions to: Ask the Doctor, The Patriot Ledger, P.O. Box 699159, Quincy, MA 02269-9159, or by E-mail to his attention at features@ledger.com.

Questions of general interest will be answered in this column. The information in this column is not intended to diagnose individual conditions, and individual replies are not possible. Readers should see their own doctors about specific problems.

Copyright 2003 The Patriot Ledger
Transmitted Tuesday, November 11, 2003