Cancer screening: Risk-based mammograms and CRC at 45

Health agencies and researchers are sharpening the focus on who should be screened for cancer, when, and how to raise participation, as new evidence and updated guidance continue to move screening away from one-size-fits-all approaches.

A National Institutes of Health (NIH) summary of a recent study says risk-based breast cancer screening appeared to be a “safe alternative” to routine annual screening, while also noting that real-world adherence to assigned screening schedules varied and recommendations continue to evolve, complicating interpretation of results (NIH risk-based breast cancer screening). Separately, a peer-reviewed update on colorectal cancer (CRC) screening reiterates that the American Cancer Society lowered the starting age for average-risk adults to 45 in 2018, citing rising rates among adults younger than 65, and frames the change as part of a broader effort to curb incidence and mortality (CRC screening update).

Together, these developments underscore a central challenge: screening only prevents cancer deaths when people actually get screened—and participation remains uneven, with disparities documented in lung cancer screening and other programs, according to research published in JAMA Network Open (lung screening disparities).

What’s changing in screening—and why it matters

Breast screening: Evidence builds for risk-based strategies

In an NIH “Research Matters” summary, the agency pointed to findings suggesting that tailoring breast screening based on an individual’s risk can be a safe alternative to routine annual screening, while emphasizing key caveats: screening in both randomized groups in the underlying study varied from recommendations, which could have affected outcomes, and risk-based recommendations themselves are evolving (NIH risk-based breast cancer screening).

The NIH framing reflects a broader shift in preventive medicine: moving from age-based triggers alone toward combinations of age, family history, breast density, genetic risk, and other clinical factors. However, the NIH also highlighted that deviations from assigned screening patterns can blur comparisons—an issue that can arise when participants, clinicians, or health systems follow local norms or respond to access barriers.

The practical implication for public health is that even when trials or large comparative studies suggest safety, implementation depends on clear communication, clinician support tools, and equitable access to risk assessment—otherwise, risk-based strategies can inadvertently widen gaps if higher-resource patients are more likely to receive personalized risk evaluation.

Colorectal cancer: Screening starts earlier for average risk

A peer-reviewed update indexed on PubMed notes that CRC remains a leading cause of cancer incidence and mortality in the U.S., and highlights a key shift: in 2018, the American Cancer Society (ACS) lowered the recommended age to begin screening for average-risk adults to 45, amid increasing rates in adults younger than 65 (CRC screening update).

The update situates earlier screening within a landscape of multiple screening modalities and evolving guidance, while emphasizing the population-level rationale for earlier detection and prevention. The ACS move to age 45 has also influenced other guideline discussions and health system screening prompts, contributing to a gradual reset of “normal” screening initiation ages in clinical practice.

In public health terms, earlier starting ages can increase the number of people eligible for screening, which may avert cancers or detect them earlier—but it can also put pressure on screening capacity and requires careful attention to follow-up systems, particularly for abnormal results.

Participation gaps: Disparities remain a central barrier

Even as guidelines evolve, disparities in who participates in screening continue to be a major obstacle. A JAMA Network Open article focused on research attrition and participant-informed retention strategies among cancer survivors points to socioeconomic disparities in lung cancer screening participation, highlighting how structural factors influence whether eligible people engage with screening programs (lung screening disparities).

While the article’s topic centers on study retention and participation, the findings contribute to the larger evidence base showing that screening uptake is not evenly distributed. Barriers can include transportation, time off work, insurance complexity, communication challenges, mistrust, and differences in how—and whether—screening is offered. These factors can reduce the impact of screening advances on cancer outcomes at the population level.

Health systems research: Nudges and navigation for CRC screening

A cluster randomized clinical trial published in JAMA Internal Medicine evaluated an intervention among older adults due for average-risk colorectal cancer screening, testing whether providing more detailed information could affect screening behavior (JAMA Internal Medicine CRC trial). While the specific outcomes and effect sizes are contained in the study, its placement in a major journal reflects ongoing efforts to identify scalable approaches—such as decision aids, reminders, and patient navigation—that can translate eligibility into completed screening.

For health systems, this category of research matters because screening performance is often tracked as a quality metric, and because improved completion rates can reduce late-stage cancer diagnoses. At the same time, interventions that work in one setting may not generalize without adaptation to language, culture, digital access, and local clinical workflows.

Beyond guidelines: New tools for early detection are emerging

Research continues on novel biomarkers and analytic approaches intended to detect gastrointestinal cancers earlier. A 2026 paper in Scientific Reports describes a non-invasive diagnostic model using serum glycopeptide profiling and machine learning for early detection of gastric and colorectal cancers, with inclusion criteria specifying adults aged 18–85 years with histopathologically confirmed primary gastric or colorectal cancer under World Health Organization classification (Scientific Reports glycopeptide model).

Such studies are typically part of an early evidence pipeline: promising models may require validation in broader, prospective populations before they can be considered for routine screening or diagnostic use. Still, the work illustrates how cancer detection research is expanding beyond traditional imaging and stool-based tests toward blood-based and “multi-omic” approaches, which—if validated—could complement existing pathways.

Where readers may see updates first

Clinicians and the public often encounter cancer screening updates through curated journal collections and guideline summaries rather than individual papers. JAMA Network’s collection on cancer screening, prevention, and control is one such hub, aggregating new research and commentary across screening and public health interventions (JAMA screening collection). In parallel, a comprehensive review hosted on PubMed Central outlines key elements for providers, including identifying high-risk individuals, following established guidelines, and referring high-risk patients to specialists when needed—reinforcing that risk stratification is increasingly central to screening practice (PMC screening practices review).

What to watch next

The near-term trajectory of cancer screening policy and practice is likely to be shaped by three factors highlighted across the recent sources: (1) whether risk-based screening strategies can be implemented consistently in real-world care without increasing inequities, as NIH cautioned; (2) whether health systems can raise CRC screening rates as eligibility expands to younger ages; and (3) how quickly emerging diagnostic models can move from proof-of-concept to validated tools that improve outcomes without adding unnecessary testing.

As evidence accumulates, guideline bodies and health systems will face the balancing act at the heart of screening: maximizing early detection and prevention while minimizing harms, confusion, and unequal access.

References & Links

• NIH summary on risk-based breast cancer screening: https://www.nih.gov/news-events/nih-research-matters/testing-risk-based-breast-cancer-screening
• PubMed review on colorectal cancer screening at age 45 and rising early-onset rates: https://pubmed.ncbi.nlm.nih.gov/42200680
• JAMA Network Open on socioeconomic disparities in lung cancer screening participation: https://jamanetwork.com/journals/jamanetworkopen/fullarticle/2854032
• JAMA Internal Medicine cluster trial on interventions for average-risk colorectal cancer screening: https://jamanetwork.com/journals/jamainternmed/articlepdf/10.1001/jamainternmed.2023.5656
• Scientific Reports on serum glycopeptide profiling and machine learning for early GI cancer detection: https://www.nature.com/articles/s41598-026-64643-0
• JAMA Network collection on cancer screening, prevention, and control: https://jamanetwork.com/collections/5543/cancer-screening-prevention-control
• PubMed Central review on current cancer screening practices and guidelines: https://pmc.ncbi.nlm.nih.gov/articles/PMC13284104/

This article summarizes publicly available health news and research. It is not medical advice.