Click to Enlarge Source: Department of Veterans Affairs
ATLANTA — Colorectal cancer (CRC) is, at first glance, a public health success story. Incidence among adults over 50 has fallen nearly 50% since the mid-1980s, driven by the steady expansion of colonoscopy screening and the removal polyps before they can progress. Mortality rates in the over-50 population similarly have declined.
Unfortunately, that’s not the full picture. Colorectal cancer recently became the leading cause of cancer death in adults under 50 in the United States, moving up from fifth place over the last 35 years. Incidence in younger adults nearly doubled between 1985 and 2019, with no single explanation, according to a research letter led by the American Cancer Society.1 Today, 46% of CRC diagnoses occur in individuals under age 65 and 16% in those under age 50.2 The arc of the data bends simultaneously in two directions: in a clearly improving downward trend among older adults traditionally most at risk for CRC and in a quickly rising trend for a younger population not historically screened.
The shift in risk has significant implications for the VA. The veteran population faces multiple elevated CRC risk factors, including toxic exposures, physiologic stress and behavioral barriers to early care, while being served by a healthcare system with the infrastructure and, increasingly, the scientific tools to do something about it.
Changing CRC Demographics Reflected in Veterans
The VA diagnoses approximately 4,000 new cases of colorectal cancer annually, making it one of the three most common malignancies in the veteran population.3 The VA’s colorectal cancer screening rate exceeds the national target rate of 80% and the overall U.S. average screening rate of 68%. Notably, however, the screening rate for veterans aged 45 to 64, lags that of those over age 65 by 5 to 7 percentage points.4
Among veterans, CRC forms a distinct epidemiologic picture shaped by service-specific exposures such as burn pits, care-seeking patterns and demographic characteristics that differ significantly from civilian datasets. Those factors might drive increased rates of the malignancy in younger veterans while contributing to delayed diagnoses.
Even without veteran-specific factors, for younger patients generally, late diagnoses are the norm. Among individuals under age 50, researchers for the American Cancer Society’s Colorectal Cancer Statistics, 2026, found 3 out of 4 present with advanced disease, a proportion that has worsened over the past two decades. Further, among those aged 50 to 64, the increased incidence of CRC of 1.1% to 1.3% annually from 2013 to 2022 was entirely attributable to increased diagnosis of cases at stage III or stage IV and correlated with declining survival rates.
Treatment Evolution From Systemic Chemotherapy to Precision Medicine
Surgery and systemic chemotherapy remain the backbone of CRC treatment. Over the past decade, however, rapid advances in the molecular understanding of the disease revealed that the diagnosis of colorectal adenocarcinoma encompasses multiple molecularly distinct diseases, each potentially with unique treatment pathways and prognoses.
Tumors classification now include not only location and spread but also their molecular drivers. MSI and mismatch repair status, RAS and BRAF mutation profile, HER2 amplification status and PI3K pathway alterations each direct distinct treatment decisions, determining not only which drug to add to a chemotherapy backbone but in some cases whether chemotherapy is the right first-line approach at all.
As an example, in metastatic CRC with RAS and BRAF wild-type tumors arising on the left side of the colon, roughly 40% of metastatic cases, anti-EGFR antibodies such as panitumumab combined with a chemotherapy doublet have become a cornerstone of first-line treatment, with median overall survival now approaching 4 years in optimal responders.5 That number was not achievable a decade ago.
At the same time, the biomarker-guided decision-making in CRC has also moved upstream. New trial data presented at the American Society of Clinical Oncology Gastrointestinal Cancers Symposium in 2025 and published in the New England Journal of Medicine established that patients with stage II and III CRC who carry specific alterations in the PI3K signaling pathway can cut their risk of recurrence in half by taking adjuvant low-dose aspirin.6
What this means in practice is that the molecular report on a veteran’s tumor is now a prerequisite for optimal treatment, serving as the foundation for every major decision point in the CRC treatment algorithm. Obtaining those results requires testing. Consistent access to timely testing requires infrastructure.
The VA has aggressively built out the necessary infrastructure for biomarker-guided oncology, taking a lead nationally since its 2016 launch of the National Precision Oncology Program. In 2022, it expanded to include molecular testing for all patients diagnosed with CRC across 131 VA cancer treatment facilities. In 2023, it added two testing sites to support VA facilities with limited capacity, creating a genomic testing infrastructure that most private health systems would envy.
The challenge remains consistent implementation, translating institutional commitment into uniform practice across a system that includes academic centers, hundreds of community-based clinics and a patient population whose lives and tumors reflect the full complexity of military service.
What Follows
The following three articles examine the veteran-specific dimensions of CRC care today. The second explores the connection between military service and cancer risk and how veterans can access the treatments that molecular science now makes possible. The third tracks the treatment algorithm itself, showing how each molecular result directs a specific clinical decision. The fourth examines the critical biomarkers and their clinical support in greater detail.
What connects them is molecular analysis and the biomarkers that guide precision medicine for a veteran with CRC, potentially the most consequential test their oncologist orders. The series that follows makes the case for taking that seriously for every veteran with CRC, regardless of age, stage or perceived risk.
- Siegel RL, Wagle NS, Jemal A. Leading Cancer Deaths in People Younger Than 50 Years. JAMA. Published online January 22, 2026. doi:10.1001/jama.2025.25467
- Siegel RL, Wagle NS, Star J, Kratzer TB, Smith RA, Jemal A. Colorectal cancer statistics, 2026. CA Cancer J Clin. 2026 Mar-Apr;76(2):e70067. doi: 10.3322/caac.70067. PMID: 41769777; PMCID: PMC12951547.
- U.S. Department of Veterans Affairs. VHA 2024 Annual Report: VA Health Care: A Strong Foundation. A Healthy Future.
- Korshak L. National Veteran Health Equity Report: Colorectal Cancer Screening Information Brief. Office of Health Equity, VHA. March 2022.
- Watanabe J, Muro K, Shitara K, et al. Panitumumab vs Bevacizumab Added to Standard First-line Chemotherapy and Overall Survival Among Patients With RAS Wild-type, Left-Sided Metastatic Colorectal Cancer: A Randomized Clinical Trial. JAMA. 2023 Apr 18;329(15):1271-1282. doi: 10.1001/jama.2023.4428. Erratum in: JAMA. 2023 Jun 27;329(24):2196. doi: 10.1001/jama.2023.10533. PMID: 37071094; PMCID: PMC10114040.
- Martling A, Hed Myrberg I, Nilbert M, et al; ALASCCA Study Group. Low-Dose Aspirin for PI3K-Altered Localized Colorectal Cancer. N Engl J Med. 2025 Sep 18;393(11):1051-1064. doi: 10.1056/NEJMoa2504650. PMID: 40961426.