There is much controversy regarding the application of mammography as a screening method for breast cancer. Not because of its suitability, since up to now it is the best opportunity that can be offered to women to reduce the possibility of dying from breast cancer, which is around 25% (Pesce K. et al., Screening in breast cancer. Controversies); but because of the age range of the population to whom it is offered and its periodicity.
There is no argument that the cancer detection rate changes abruptly at age 50, but the incidence of the disease increases steadily with increasing age.
The controversy with age began in an effort to determine whether menopause had any influence on screening results. Since menopausal registration had not been collected in the initial randomized clinical trials, age 50 years was chosen as a surrogate for subgroup analysis. In addition, none of the randomized clinical trials have included enough women between the ages of 40 and 49 years to statistically powerfully evaluate this group. Only two specifically studied mammographic screening of women aged 40-49 years; the Canadian National 1 (CNBBS1) and the UK AGE study, both of which had methodological problems.
There are studies that show a 39.6% decrease in breast cancer mortality with annual screening in patients aged 40-84 years compared to a 23.2% reduction in mortality in patients screened biannually aged 50-74 years, so that annual screening from age 40 would save 71% more lives than biennial screening from age 50 years (R. Edward Hendrick, Mark A. Helvie. United States Preventive Services Task Force (USPSTF) Screening Mammography Recommendations: Science Ignored. )
Based on the available scientific evidence, the American College of Radiology, the American College of Obstetrics and Gynecology, the American Cancer Society, the NCCN and many other medical societies recommend starting annual mammography screening at age 40. At the EGR Institute of Medicine, we join this criterion, recommending and reminding our patients of the importance of annual breast screening from that age, which allows us to make an early diagnosis, a better prognosis and recommend the ideal treatment in each case.
Risks of mammographic screening:
- Overdiagnosis: diagnosing a “disease” that will never cause symptoms or death of the patient; however, there are no studies on the true frequency of this disease.
- Overtreatment: today, thanks to genomic platforms (mamaprint, oncotype…) we have more information on the need for chemotherapy treatment.
- Risk of false positives: most of them are resolved with simple complementary techniques (localized projections, magnifications, ultrasound scans, etc.).
- Risk of radiation in mammography: even at high doses, the risk to the breast is likely to be limited to adolescent women.
Therefore, taking into account that the risks of screening are very low, that mammography is a screening method that reduces the risk of death from breast cancer, and that there are studies that show a clear decrease in breast cancer mortality in those populations with annual screening from the age of 40, the answer is clear: there is no doubt that it is necessary to start screening at the age of 40.
Authors:
Dr. José María Fernández Moya Dr. Esther Recarte Ortega Dr. Esmeralda de Lorenzo Institute of EGR Medicine.