If you could only pick one screening exam to recommend for women in a year -- just one -- which one would it be? Researchers from the Cleveland Clinic pondered this question and posted their findings in a modeling study published April 29 in JAMA Oncology.
A group of researchers led by Glen Taksler, PhD, wanted to find out if it could improve screening compliance by recommending a smaller number of screening exams in a year, focusing on the ones most likely to confer a mortality benefit.
The team's conclusion? It's actually more important for women who are eligible for lung cancer screening to undergo that test annually, compared with breast screening. The study results offer a "next best alternative" for women who have spotty cancer screening compliance, Taksler et al wrote.
"[Our] study of 20 million simulated U.S. women found that it was possible to reduce screening intensity to one carefully chosen test per year in women who were ineligible for lung cancer screening and two tests per year in eligible women while maintaining 94% or more of the maximum benefits," the researchers wrote.
An important way of reducing cancer-related mortality in women is through screening, and guidelines exist for breast, cervical, colorectal, and lung cancer. But women's adherence to these guidelines varies widely, according to the investigators.
Taksler's group sought to evaluate the benefits and harms of women undergoing some, but not all, guideline-recommended cancer screenings by conducting a modeling study that used four mathematical models from the U.S. National Cancer Institute's Cancer in Intervention and Surveillance Modeling Network based on data from 20 million simulated U.S. women born in 1965. For this study, the authors focused on cancer screening recommendations from the U.S. Preventive Services Task Force's (USPSTF).
They modeled strategies for breast, cervical, colorectal, and/or lung cancer screenings across a variety of frequencies (one, two, three, or four types of screenings per year, or all eligible screenings every five years). Screening approaches included the following:
- No screening
- Screenings according to USPSTF recommendation:
- Colonoscopy every 10 years
- Fecal immunochemical test every year
- Breast every two years
- Cervical every five years
- If eligible, lung cancer screening every year
- Screenings less often than USPSTF recommendations
- All less often
- Some when recommended by USPSTF but others less often or skipped
The researchers then assessed how many modeled life-years would be gained from these different strategies, stratifying the results by lung cancer screening eligibility and comparing the model analysis with 2018 screening exam adherence rates.
Taksler et al found that if women were eligible for lung cancer screening -- such as due to a history of smoking -- it was most important that they receive these exams annually. On the other hand, they found minimal negative effects from women skipping the occasional breast screening or delaying it by a year.
"Among lung cancer-eligible women, lung cancer screening was essential: Strategies omitting it provided 25% or less of the maximum benefits," the group wrote. "The top-ranked strategy restricted to two screenings per year was annual lung cancer screening and alternating fecal immunochemical test with mammography (skipping mammograms when due for cervical cancer screening, 97% of maximum benefits)."
The findings could have to do with women's preferences and logistical factors like the ability to take time off for testing, according to Taksler and colleagues.
"In an era of patient-centered care, it is important to respect patient wishes," they wrote. "Patients may be eligible for up to 41 preventive services, of which four are cancer screenings, and may be time-limited, particularly after managing chronic conditions ... If skipping an occasional mammogram makes it easier for [a woman] to obtain colorectal or lung cancer screenings (e.g., less time off work), then she likely would benefit from doing so."
The study underestimates screening's benefits, particularly for breast cancer, Dr. Sarah Friedewald of Northwestern University in Chicago told AuntMinnie.com via email. Friedewald is also a member of the American College of Radiology's (ACR) Commission on Breast Imaging.
"The model for breast cancer screening in this study uses biennial screening, which underestimates the benefits of screening mammography," she said. "All organizations -- the USPSTF included -- agree that the most lives are saved if patients are screened every year beginning at age 40. Therefore, this model significantly underestimates the benefits of screening mammography."
In any case, it doesn't make sense to discourage evidence-based screening, Friedewald noted.
"Patients should choose for themselves if they want to be compliant rather than organizations advocating against evidence, resulting in patient confusion," she said.