The benefits and harms of mammography
Screening examination of the breast allows you to detect cancer of this organ at an early stage and start therapy in a timely manner. This improves treatment outcomes and prognosis for patients.
However, both specialists and patients express concern about a sufficiently large number of cases of overdiagnosis. The most common example of overdiagnosis is false positive results accompanied by unnecessary biopsies or other interventions. There are also cases when the tumor detected during screening is surgically removed, after which the woman undergoes a course of radio and / or chemotherapy, which has a number of very adverse side effects. At the same time, if the tumor had gone unnoticed, the woman could have lived a long life without symptoms of the disease. The problem is that mammography does not allow us to distinguish progressive malignant tumors from non-progressive ones.
To assess the relationship between the effectiveness of breast cancer screening and the risk of overdiagnosis, an independent commission of experts was established under the leadership of the UK National cancer specialist Professor Sir Mike Richards and the Chief Executive Officer of the English Cancer Research charity Dr. Harpal Kumar. Experts analyzed data collected during 11 randomized controlled clinical trials, the purpose of which was to compare mortality from breast cancer in populations undergoing and not undergoing regular mammography.
In general, the results of the analysis showed that regular mammograms reduce the relative risk of death from breast cancer by 20%.
At the same time, experts noted that the studies have a number of limitations, including the fact that they were all conducted more than 20 years ago.
Only three studies were devoted to the study of overdiagnosis during routine screening for breast cancer. After evaluating their results, the commission concluded that for approximately 37,000 women, aged 50-52 years, invited to the annual screening, the frequency of overdiagnosis during the subsequent 20-year period was slightly more than 1%.
According to the results of the analysis, approximately 681 cases of breast cancer will be detected in every 10,000 English women who begin screening annually at the age of 50 over the next 20 years, 129 of which will be cases of overdiagnosis. The final result of the screening will be the prevention of 43 deaths from breast cancer.
Thus, every woman should make a choice for herself. On the one hand, screening provides a reduction in breast cancer mortality due to early detection of the disease. On the other hand, it is necessary to realize that participation in screening implies a 1% probability of overdiagnosis and subsequent treatment of a harmless tumor.
Experts emphasize that further studies should be conducted to assess the relationship between the benefits and potential harm of regular mammograms. At the same time, doctors and the media should convey relevant information to women in the most understandable form, who, in turn, should have access to up-to-date information on this issue. This will allow them to make informed decisions about undergoing breast cancer screening.
The expert commission's article The benefits and harms of breast cancer screening: an independent review is published in The Lancet.
Evgeniya Ryabtseva
Portal "Eternal youth" http://vechnayamolodost.ru according to Medical News Today:
Breast Screening – Do Benefits Outweigh The Harms?
01.11.2012