The words "breast cancer" bring to mind fear, uncertainty, anxiety or worry. It is not unfounded, far from it: we are talking about nothing less than the leading cause of death of women in the world.

Due to its importance, since 1990 the Public Health System of the different Spanish Autonomous Communities has been incorporating the population screening program. The goal: women between 50 and 69 years of age can have a mammogram every two years in health centers.

But to what extent does this test save lives? Do we really know its benefits and risks?

There are false positives and overtreatment, but it is still the best method of early diagnosis.

To answer, let's imagine that there is a group of 200 women, aged 50-69, who have screening mammography every two years. All of them are followed up for breast cancer diagnosis until they are 80 years old. The following can be expected to occur:

• 1 of them will survive breast cancer thanks to screening (otherwise she would have died of the disease).

• 4 of them will die of breast cancer despite having been screened, but having received adequate treatment and care to alleviate the pain.

• 8 will be diagnosed and will survive, although they would have survived without screening.

• 2 will be diagnosed and treated for breast cancer that would not have been life-threatening because of its type or slow growth (called overtreatment).

• 40 of these women will need additional diagnostic tests to later rule out that the alteration observed in the mammogram was a breast cancer (false positive).

With this information, mammography remains today the best method of early diagnosis. And for this reason it is advisable to continue participating in this routine screening subject . While the uncertainty of diagnosis can generate anxiety, its benefits outweigh the risks for women who participate in the breast cancer screening program.

However, because it is difficult to determine which women would benefit from screening and which might suffer unwanted effects, it would be advisable for them to discuss their personal beliefs and fears about screening with a healthcare professional, be informed about the benefits and disadvantages they may experience, and thus be able to make a more informed decision. status which is contradicted by the recent data that only one in one hundred women have an adequate knowledge of mammography and its effects.

Increasing the effectiveness of screening programs

One possibility to improve the effectiveness of screening programs is to change the current standard screening according to age criteria to one that is personalized according to each woman's risk of being diagnosed with breast cancer. This risk is determined according to personal characteristics, family history, genetic characteristics, previous history of breast disease, among others.

In this way, the screening program can be adjusted more precisely, for each woman and in relation to her risk, in the age of entrance and exit from the program, the frequency and the subject of test. Thus, for example, higher-risk women can enter the screening program earlier and be screened more frequently, while lower-risk women can be screened at a greater distance. In other words, focusing resources on those who require more attention, and achieving a more efficient use of resources.

Although we have come a long way since the implementation of the screening program, there are still challenges ahead of us, for which we are all relevant: clinicians, public authorities, health managers, academics, women, their families, etc.

International Breast Cancer Day is an opportunity to raise awareness of the importance of screening, adopt preventive activities and promote the need to be informed in order to make a decision.

This article was originally published in The Conversation. Read the original.