Should you get screened for breast cancer annually? New study by US scientists suggests better approach

US researchers conducted a trial of over 28,000 women aged 40-74 to find an effective way of distributing breast cancer screening resources. Results published in JAMA on 12 Dec.

Representational | Pexels

New Delhi: Breast cancer screenings should be geared towards women with high risk, instead of yearly screenings recommended for those aged above 40, a new study has found.

The study, conducted by several US scientists and published in the peer-reviewed journal JAMA on 12 December, involved a randomised trial with over 28,000 women aged 40 to 74 across the US. It was the first-time a randomised trial was used to assess the best method of breast cancer screening. The main goal of the study, as stated by the authors, was to come up with an effective way of distributing breast cancer screening resources.

Given the heavy burden of breast cancer—more than 650,000 women died of it in 2022, according to the World Health Organization (WHO)—and the costs of screening in the US, the researchers wanted to ensure that women at risk get enough resources, and those at low risk aren’t overburdened with yearly tests.

“Is risk-based breast cancer screening as safe, less morbid, and as acceptable to women as annual screening?” asked the researchers in the paper.

The study divided the women into two groups—one which would undergo risk-based breast cancer screening and the other where everyone would be screened, regardless of risk. The risk-based screening group did several tests to determine which women were prone to breast cancer based on genetics and other cancer-susceptibility tests, and each woman was assigned a risk factor from low to high risk.

Based on their analysis, the researchers found that risk-based screenings detected the same amount of advanced/major cancer as normal screenings. This meant that risk-based screenings did not lead to them missing any serious cancers.

Also, while risk-based screenings meant there were fewer mammograms in general, it did not reduce the overall number of biopsies in women. This meant that even though not all women were being screened, the number of follow-up procedures remained the same.

Finally, the study also found that when given the choice, 90 percent of the women preferred the risk-based screening option as compared to annual screenings.

This upheld the study’s conclusions that risk-based screening was just as effective and safe as regular annual screenings, and in fact reduced the number of unnecessary mammograms for women with a lower risk of breast cancer.

Challenges of this approach

The study is not without limitations, however. Firstly, there was little diversity in the cohort since most of the women studied were college-educated, non-Hispanic white women.

Since genetic factors influence breast cancer heavily, this limitation is severe in terms of the range of populations the study can apply to. Also, the authors said that the COVID-19 pandemic happened during the study period, and they’re still examining its impact on the study.

Another main limitation is the concept of risk profiling itself. While age, obesity, alcohol use and family history of breast cancer are main risk factors, they vary widely from individual to individual too. There’s no certainty in common risk factors for breast cancer, so developing a risk profile might also make it difficult to set a schedule for screenings.

“Approximately half of breast cancers develop in women who have no identifiable breast cancer risk factor other than gender (female) and age (over 40 years),” states a WHO article on the disease.

An editorial in JAMA Network, written by two Australian oncologists, hailed the study for showing that a new approach towards breast cancer screening based on risks was possible. However, they pointed out certain other limitations of the study, such as women not adhering to screening recommendations in both groups.

The study was designed such that women had to self-report their screenings, biopsies and diagnoses. So, if low-risk women were asked not to get screened by the study authors, it wasn’t always certain that they followed the guidelines, which could lead in disruptions in the design of the study, and also the results.

(Edited by Nida Fatima Siddiqui)