NCI Study Analyzes the Harms From Cancer Screening

A recent study funded by the National Cancer Institute (NCI) evaluated how U.S. cancer screening guidelines characterized harms from screening and raised the issue of whether there should be less screening occurring.

The researchers used a systematic approach to consider the full range of harms across the cancer screening process, including follow-up and treatment of those with abnormal findings at screening, across five different types of cancer: breast, cervical, colorectal, lung and prostate.

The findings, which were published in the Annals of Internal Medicine, showed that harms reporting was inconsistent across the different types of cancer and at each step of the cancer screening process and guidelines. “This comprehensive approach allowed us to identify gaps where guidelines did not provide information about some screening harms or provided information in a suboptimal way,” says Paul Doria-Rose, D.V.M., Ph.D., chief of the healthcare assessment research branch for the NCI and lead author on the study.

The study is the most comprehensive review of how harms are reported in cancer screening guidelines, he says, noting it was conducted by collaborators within the NCI-funded Population-based Research to Optimize the Screening Process (PROSPR) consortium. “Although guidelines-making organizations all have the same goal of synthesizing the best available scientific evidence and providing recommendations for clinical care, we found that whether and how they report evidence on screening harms was highly variable,” Doria-Rose says. “More consistent reporting of (the) harms of screening alongside the benefits may lead to more consistency between guidelines and, ultimately, better patient care.”

Aruna Kamineni, Ph.D., M.P.H., an assistant researcher at the Kaiser Permanente Washington Health Research Institute and lead of the author of the study, says it is not a question of whether there should be more or less screening. The goal, she says, should be to ensure the right people — those for whom the balance of benefits and harms is favorable — receive screening. “Improved reporting of screening harms can help clinicians and the people they care for more clearly understand that balance and make appropriate screening decisions,” she says.

The suggestions Kamineni and her colleagues made include reporting quantitative estimates of harms when available; reporting absolute measures of the risk of harms rather than relative measures; measuring and reporting harms by various subgroups (e.g., age, socioeconomic status, the number and type of chronic conditions that people have); reporting the cumulative risk of harms over multiple screening rounds in addition to risk from a single round; acknowledging uncertainty in the evidence where it exists; and indicating the proportion of screened individuals who may be recommended for follow-up testing and treatment procedures so there is a better understanding of burden measures.

Many clinicians treating patients with cancer believe the benefits of screening far outweigh the harms. “As a breast radiologist who diagnoses breast cancer every single day, I have seen screening mammography at work,” says Katharine Lampen-Sachar, M.D., breast radiologist at the Miami Cancer Institute.

PROSPR is planning additional research to estimate the magnitude of screening harms for cervical, colorectal and lung cancer. Doria-Rose says he hopes the review of how harms are reported will motivate other researchers to measure screening harms in other healthcare delivery settings and encourage guidelines-making bodies to adopt a comprehensive approach to considering screening harms during guidelines development.

Keith Loria is a freelance writer in the Washington, D.C., area.