Do mammograms increase your risk of breast cancer?

Mammograms, like all x-rays, do transmit radiation and theoretically, this radiation in large enough doses could cause cancer. However, there has never been any proof that patients receiving x-rays or mammograms have developed cancers from the radiation. The radiation dose from a mammogram is minuscule (less than the radiation you are exposed to living in Johannesburg for one year).

The theoretical likelihood of getting breast cancer from mammograms is 1 in 70,000. Your chance of getting breast cancer during your lifetime (with or without mammograms) is 1 in 8. Clearly, the benefits of early detection of such a common and treatable cancer outweigh the remote theoretical risks!

There is also a bizarre theory that the compression of the breasts during a mammogram will create cancer or cause cancer to disseminate. This concept is without any scientific reasoning

Do mammograms cause thyroid cancer and should I wear a thyroid shield when having a mammogram?

No. Mammograms do NOT cause thyroid cancer. The radiation from a mammogram is extremely low and insignificant dosages reach the thyroid gland. We certainly do not see increased rates of thyroid cancer in women who have had many mammograms. Although there is an increase in thyroid cancer numbers this is for men too (who are not receiving mammograms!)

A thyroid shield is unnecessary and may affect the quality of the mammogram

What about overdiagnosis?

One of the biggest criticisms of screening mammograms, both from the lay and medical press, is that of overdiagnosis. In other words, the allegation is that mammograms pick up too many cancers and since many of those cancers will either regress or remain static, many patients undergo unnecessary treatment some of which is harmful.

None knows the exact figure for overdiagnosis. It is generally based on assumption, not fact. Despite some claims of 30 – 40% of breast cancers being called “harmless” and therefore diagnosed unnecessarily, the real figure is probably closer to 2 – 3%. There has never been a documented case of spontaneous breast cancer regression. And although some cancers are very slow growing, we cannot know which without at least doing a biopsy and pathology tests.

Treatment these days is dependent on the type of cancer diagnosed with biopsy. Cancers that are high-grade, hormone receptor-negative, and rapidly growing are treated more aggressively, while low-grade hormone-responsive, slow-growing cancers are treated less aggressively.

Mammograms are not compulsory. They are electives. If as an informed adult, you choose to have mammogram screening, you are electing to find out if you have cancer, slow growing or fast. The diagnosis isn’t the point. It’s a question of overtreatment or not. The treatment decided on must be appropriate for your type of cancer. And that is largely dependent on detailed pathology and astute breast surgeons and oncologists.

Lastly, we know that mammogram screening has reduced death from breast cancer by ±30%. That’s a well-proven fact. The supposed harm from overdiagnosis is largely hypothetical. Not to say treatments such as mastectomy, chemotherapy, and radiation aren’t without risks or complications. However, death and severe disability for modern breast cancer treatments are negligible. The benefit: risk ratio is pretty clear.

To learn more about mammograms please visit http://parklaneradiology.co.za/