In a new study, scientists have shown that breast cancer screening for women aged 40 may prove beneficial and save lives. These findings were published in The Lancet Oncology journal, on Wednesday.
The randomized controlled study has revived the long debate over breast cancer screening age for women. The new study suggests that the initial screening age for breast cancer may be better at 40 than at 50.
— The Lancet Oncology (@TheLancetOncol) August 13, 2020
The researchers at Queen Mary University of London collected data from 160,000 women between the ages of 39 and 41. All the subjects in the study were randomly assigned to get an annual breast screening or to wait to become eligible for NHS screening. NHS offers screening for women every three years, after they turn 50.
The women in the study were added to the study between 1990 and 1997. At the time, the technologies and treatments were not as effective as they are now. This new study comes after 23 years since the project began. Previous studies from the trial have also found similar results.
The scientists found that the benefits of screening kicked in during the first 10 years. They saw that there were 83 deaths among the women who started screening around the age of 40 compared with 219 in the group who started later. The team observed that though there was a little difference in mortality between the two groups, lives could still be saved by lowering the screening age.
The research team showed that in the long term, one life in 1000 women screened was saved. The number may still little, but it still shows benefit in lowering the age limit for breast cancer screening.
However, some experts do not agree. Kevin McConway, emeritus professor of applied statistics at the Open University, has said that there is statistical uncertainty around the numbers of lives saved. He says that though numbers show that lives were saved, they also indicate “that death from breast cancer was pretty rare in women of that age (below 50). Because breast cancer deaths in younger women are not common, the estimates of breast cancer death rates are not very precise, despite the fact that the trial involved 160,000 women.”
Many others have said that this trial in no way ends the debate regarding the age of breast cancer screening.
Pros and Cons of Breast Cancer Screening
The most important benefit of breast cancer screening at an early age is that the breast cancer if present can be found earlier. This improves chances of survival, remission, and overall health outcomes.
The current evidence suggests that breast screening reduces the number of deaths from breast cancer by about 1,300 a year in the UK. The data also shows that all women diagnosed with breast cancer at the earliest possible stage survive for at least 5 years after diagnosis and are likely to be cured.
However, there are also some serious risks involved with breast cancer screening at as well. Many a times, results can show false positives and false negatives. These results can cause unnecessary worry and anxiety in women. Too much screening can also pick up breast cancers that do not need treatment and would not cause any problems.
A breast screening review in 2012 found that screening leads to around 4,000 women overdiagnosed in the UK each year.
Screening can also cause exposure to radiation frequently, which is not good for health. Each mammogram exposes a woman to small amounts of radiation from the x-rays. If 10,000 women have regular 3 yearly breast screening between the ages of 47 and 73, there will be between 3 and 6 extra breast cancers caused by radiation.
In United Kingdom, if a woman has a history of breast cancer in the family, guidelines recommend her to start annual screenings after turning 40. But without a history it is recommended that women should begin screening at age 50. Women with gene mutations that increases the risk of breast cancer, are recommended to start screening at age 20 for women with a TP53 mutation, and at age 30 for women with a BRCA1 or BRCA2 mutation.
In United States, different health agencies recommend different guidelines for screening. U.S. Preventive Services Task Force leaves it up to the women under the age of 50 to get a screening or not, whereas American Cancer Society recommends that women aged 40 to 44 years should have the choice to start annual breast cancer screening with mammograms if they wish to do so and women aged 45 to 49 years should get mammograms every year.
— JAMA (@JAMA_current) October 20, 2015