Differences in Bowel Cancer Diagnosed Before Age 50

New research reveals that bowel cancer diagnosed before age 50 differs in several ways from cases diagnosed later in life. Key differences appear in tumor characteristics, genetics, and survival rates among younger patients.

Research Findings

Researchers in Australia analyzed data from 1,691 patients whose bowel cancer had spread only to the liver. They compared those diagnosed at 50 years or younger with those diagnosed after 50. The findings suggest early-onset bowel cancer might have distinct features that can influence treatment approaches.

Published in The Medical Journal of Australia, the study comes amidst increasing bowel cancer diagnoses among younger adults in Australia. Professor Savio George Barreto of Flinders University highlights the issue as Australia has one of the world’s highest rates of early-onset bowel cancer.

“We hypothesize that exposures during key life stages may increase cancer risk,” Barreto stated, referencing the PELICan hypothesis. Environmental factors, including lifestyle choices like smoking, alcohol, and illicit drugs, may play roles in these cases, though additional research is required.

Biological Differences

The study noted significant differences between younger and older patients. Younger patients were more often women, with tumors primarily on the left side of the bowel, and were more likely to carry specific genetic mutations.

Younger patients generally survived longer after cancer reached the liver, suggesting early-onset bowel cancer may have a different biological profile than later-onset cases. “The findings confirmed our belief that early-onset cancers display different biology and behavior,” Barreto mentioned.

Genetics and Treatment

Genetics played a crucial role in patient outcomes. Tumors carrying BRAF or KRAS mutations linked to poorer outcomes across age groups emphasize the need for genetic testing. The study also uncovered the importance of NRAS mutations in shaping treatment strategies.

The researchers advocate paying attention to tumor biology and genetics over age in treatment decisions. Genetics is increasingly vital in clinical decision-making, noted Barreto, stressing the relevance of BRAF mutations in treatment planning.

Treatment Approaches for Younger Patients

The study scrutinized treatment strategies, identifying surgery followed by drug treatment as yielding better outcomes for patients. Barreto discussed alternative strategies based on tumor characteristics, noting surgery’s survival benefit for younger patients.

Older patients, especially those with right-sided cancers and later-developed liver metastases, seemed to benefit more from initial chemotherapy. Despite being based on real-world data rather than clinical trials, the study provides valuable insights for future research.

Supporting Younger Patients

Understanding how to support younger survivors is crucial. Barreto underscored the search for biomarkers to identify high-risk individuals early on. Epigenetic blood biomarkers, if proven feasible, could offer targeted screening opportunities.

Overall, the study suggests that early-onset bowel cancer should not be viewed as the same disease as cases diagnosed later. Younger patients may exhibit distinct tumor traits and genetic variations, leading to improved survival when the cancer is liver-confined.

“The main takeaway is that bowel cancer diagnosed before age 50 is not merely the same disease appearing early,” researchers concluded.

Reference:
Savio G. Barreto et al. Early-Onset Colorectal Cancer With Liver-Only Metastases: A Retrospective Cohort Study Integrating Prospectively Collected Real-World Clinical and Molecular Data From an Australian National Database (2009–2024) to Guide Treatment Planning. The Medical Journal of Australia. DOI: 10.5694/mja2.70266

Contact Newsweek editors on this story: Kara Dolman and Emma Lee-Sang.