Mammography: what you need to know

Mammography is a radiological examination of the breast, which can identify small tumors before they are clinically palpable. The mammography does not prevent the occurrence of breast cancer, but can detect it in very early stages and with this, greatly increases the chances of cure, with the least possible harm to women. Women who perform regular mammograms have smaller tumors, with a greater chance of healing than those who do not.

The age at which asymptomatic women began to be screened through mammography has been questioned in several countries and different recommendations can be seen, based on different points of view.

Who should do the mammogram?

The Brazilian Society of Mastology (SBM) along with the American Medical Association, the American College of Obstetricians and Gynecologists, the American College of Radiology, the American Cancer Society, the National Cancer Institute, and the National Comprehensive Cancer Network recommend mammography every year in women over the age of 40 years.

The Ministry of Health recommends bi-annual mammography in women over 50 (MS – INCA).

The different recommendations are based on interpretations of evidence that analyze not only the benefit but risks and costs of routine population screening.

Is only mammography enough?

Like any "diagnostic test" the mammogram is not a perfect exam. Especially in young women, due to increased breast density, mammography may not show small tumors. (Called False Negative Exam). Otherwise, it is considered false positive, the presence of images classified as suspected mammography, caused by benign pathologies, that confuse with the signs also present in the cancer and require the performance of other examinations and even biopsies.

The need for other complementary tests, such as breast ultrasonography and magnetic resonance imaging, and especially when biopsies are indicated, greatly increases the costs related to mammography and is also responsible in several stress studies in women who perform and obtain an examination with a false positive result.

Tracking

Recently, some authors have shown that the main benefit of reducing breast cancer mortality is mainly due to advances in medical-pharmacological treatment, rather than to the screening of the asymptomatic population.

In developed countries, where the government offers mammographic screening coverage for at least 70% of the population, it is discussed whether "overdiagnosis" can occur. Overdiagnosis would be to discover very early tumors, which probably would not pose a threat to women, especially the elderly.

Unfortunately in Brazil there is no population screening program, and several studies show that in the public network, mammography screening covers only about 20-35% of the population that should be screened, depending on the region in which the woman is. The WHO recommends that the mammographic coverage should be 70% to have the expected effectiveness.

In 2017, the Brazilian Society of Mastology, the Brazilian College of Radiology and the Brazilian Federation of Gynecology and Obstetrics presented recommendations for performing the mammogram annually starting at age 40.

Even though advances in treatment may mean better chances, several studies have already confirmed that patients who regularly undergo mammography are more likely to receive less mutilating surgical treatment and are often less likely to receive chemotherapy.

Important information about mammography:

·         Finding early-stage breast cancer can reduce the risk of dying from breast cancer by 25-30%.

·         Mammography is a fast and safe procedure. (about 15-20 minutes). The amount of radiation received at the mammogram is much less than the amount received on a routine x-ray.

·         Quality of mammography: There are several types of mammography. The best quality and lowest radiation dose is obtained in digital apparatus (DR). Currently the tomosynthesis is a mammography technique that presents better quality and lower dose of radiation. Unfortunately, in Brazil, only 13% of the available devices are digital.

Sources: SBM, Breastcancer.org