Colorectal cancer has been rising in young adults for more than two decades and is now the leading cause of cancer death among people under 50. The trend is particularly concerning because overall cancer deaths continue to decline, highlighting the need for better prevention, earlier detection and more effective treatments. Researchers at the UCLA Health Jonsson Comprehensive Cancer Center are addressing this challenge on multiple fronts, from boosting screening and expanding access to care to developing new therapies for advanced disease.
“Colorectal cancer is one of the most preventable cancers,” said Folasade P. May, MD, PhD, associate professor of medicine at UCLA. “Through screening, we can identify and remove precancerous polyps before they even become cancer, which makes expanding access to screening one of our most powerful tools.”
Here’s a look at the latest studies and strategies helping to improve colorectal cancer prevention and treatment:
Screening remains low among adults 45 to 49
Since the recommended screening age was lowered from 50 to 45 in 2021, fewer than 1 in 4 adults in this age group have completed screening, according to a study led by Katherine Chen, MD, PhD, assistant professor of medicine at UCLA; Carol Mangione, MD, chief of the UCLA Division of General Internal Medicine and Health Services Research; and Tina Shih, PhD, director of the Cancer Health Economics Research Program at the UCLA Health Jonsson Comprehensive Cancer Center.
The team analyzed data from more than 13,000 respondents and found that about 22.5% were screened, most commonly through colonoscopy (61%) or stool-based tests (32%). The study also looked at whether unmet social needs, such as housing, transportation, or food insecurity, affected screening. While these factors were linked to lower screening in unadjusted analyses, the differences disappeared after adjusting for income, insurance, education and location. Transportation insecurity was associated with higher use of stool-based tests, but other social barriers were not significant. Improving screening rates in this newly eligible age group will require strategies that make testing more accessible and increase awareness of its importance for early detection.
Combination therapy improves survival for advanced colorectal cancer
A team led by J. Randolph Hecht, MD, professor of clinical medicine at the David Geffen School of Medicine at UCLA, found that combining zanzalintinib, a multi-targeted therapy, with atezolizumab, an immune checkpoint inhibitor, significantly improves survival in patients with previously treated metastatic colorectal cancer. In the trial, patients receiving the combination lived longer and experienced delayed disease progression compared with those treated with the standard therapy, regorafenib. The combination reduced the risk of death by about 20% and doubled the percentage of patients alive at two years. Researchers believe zanzalintinib helps overcome the tumor’s immunosuppressive environment, making it more responsive to immunotherapy — even in patients whose cancers are microsatellite stable, a group that historically has not benefited from immune checkpoint inhibitors.
The findings suggest this combination could offer a promising new treatment option for patients with advanced colorectal cancer whose disease no longer responds to standard therapies.
Off-the-shelf vaccine generates strong immune responses
In a study evaluating a novel immune-based strategy to prevent cancer recurrence, researchers led in part by Zev Wainberg, MD, professor of medicine and co-director of the UCLA GI Oncology Program, found that the investigational vaccine ELI-002 2P generated powerful and lasting immune responses in patients with KRAS-driven pancreatic and colorectal cancers. Final results from the phase 1 trial showed that 84% of patients developed KRAS-specific T cells, including both helper and killer T cells, with many responses sustained over time. Patients who mounted the strongest immune responses experienced markedly longer relapse-free and overall survival, with median survival not reached in the high-response group compared with significantly shorter survival among those with weaker responses. The off-the-shelf vaccine, designed to target common KRAS mutations without requiring a personalized manufacturing process, also cleared tumor biomarkers in a subset of patients and stimulated broader immune activity against additional cancer-associated mutations.
The results highlight the potential of a standardized KRAS-targeted vaccine to meaningfully extend remission and improve outcomes for patients at high risk of their cancer returning.
Mailing at-home test kits boosts screening
In a large study focused on improving early detection, researchers led by Dr. May found that automatically mailing at-home stool-based test kits significantly increased colorectal cancer screening rates among adults ages 45 to 49.
The study evaluated four different outreach strategies in more than 20,000 average-risk patients who had recently become eligible for screening under updated national guidelines. Participants who were asked to actively opt into screening, whether for a fecal immunochemical test (FIT), colonoscopy or a choice between the two, had screening rates ranging from about 14% to 17%. In contrast, when an unsolicited FIT kit was mailed directly to patients without requiring them to opt in, the screening rate was 26.2%, the highest among all groups. The findings highlight a simple, scalable approach to improving early detection in this newly eligible age group.
Blood-based screening test shows promise, but follow-up is key
As blood-based tests emerge as a more convenient option for colorectal cancer screening, new research suggests their effectiveness still hinges on patients completing follow-up care. In a study led by Dr. May, investigators found that only 49% of patients with an abnormal result from the Shield blood test underwent a colonoscopy within six months, and just 56% completed one within two years.
Analyzing medical claims data from more than 6,000 screened individuals, the team found follow-up rates comparable to stool-based tests but still far below recommended targets for timely cancer detection. Patients with Medicare Advantage were significantly less likely to complete follow-up colonoscopy than those with private insurance, while individuals with fewer underlying health conditions were more likely to follow-up. The findings underscore that while blood-based screening may lower barriers to initial testing, its life-saving potential ultimately depends on ensuring patients complete the critical diagnostic colonoscopy needed to confirm and treat colorectal cancer.
Addressing disparities to improve outcomes
A review co-led by Dr. May highlights why Black Americans continue to face higher rates of colorectal cancer and outlines strategies to close these disparities. The paper points to social determinants of health, including limited access to care, financial barriers, structural racism, and neighborhood-level inequities, as key drivers of higher incidence and mortality among Black individuals.
The review emphasizes proven interventions that can reduce these gaps, such as culturally tailored education, patient navigation programs, policy measures like the Affordable Care Act, automated screening reminders and team-based care approaches. Systems that provide equal access, such as the Veterans Health Administration, show that screening disparities disappear when access is equitable.
May and her colleagues propose a two-pronged approach: first, ensure all individuals have insurance and access to guideline-based screening and treatment; second, address long-term social determinants of health such as poverty, discrimination and unequal health care infrastructure.
