One of Australia's largest real world studies of younger adults with advanced bowel cancer has identified important differences between cancers diagnosed before and after the age of 50, which could help doctors tailor treatments for younger adults more effectively.
The new study , led by Flinders University and Flinders Medical Centre, and published in the prestigious Medical Journal of Australia, analysed data from 1,691 Australians whose bowel cancer had spread only to the liver – and found that younger patients differed from older patients in tumour biology, disease characteristics and survival outcomes.
The liver is the most common place for bowel cancer to spread and often presents some of the most challenging treatment decisions for patients and their doctors. Researchers compared people diagnosed at age 50 or younger with those diagnosed after 50 to better understand how the disease behaves and which factors may influence outcomes.
Australia has one of the highest rates of early-onset bowel cancer in the world, with increasing numbers of younger adults being diagnosed during some of the busiest years of their lives, often while building careers, raising children and planning for the future.
"Understanding why more young adults are developing bowel cancer is one of the biggest challenges facing researchers and clinicians," says Professor Savio (George) Barreto , a Consultant with the HPB and Liver Transplant Unit at Flinders Medical Centre, SALHN and researcher at Flinders University.
"We still have much to learn about why these cancers develop and how they differ from those diagnosed in older people. Our study helps build a clearer picture of the disease and suggests that younger patients may have distinct tumour characteristics that should be considered when treatment decisions are being made."
The study found younger patients are more likely to be women, more likely to have tumours on the left side of the bowel and their tumours are more likely to carry certain genetic mutations. These patients also lived longer overall than older patients after their cancer had spread to the liver.
Researchers also found that specific genetic mutations known as BRAF and KRAS were associated with poorer outcomes across both age groups, highlighting the growing importance of genetic testing in understanding how an individual's cancer may behave.
"Our findings reinforce the need to look beyond a patient's age when planning treatment because every cancer is unique," says Professor Barreto.
"The more we understand about the biology of a tumour, the better equipped we are to tailor treatment and identify the options most likely to benefit each patient."
The research also found that patients who underwent surgery to remove liver tumours followed by drug therapies generally experienced better outcomes than those receiving other treatment approaches. However, the researchers caution that the study cannot prove one treatment directly caused better survival because it was based on data collected from routine clinical practice rather than a clinical trial.
"Treatment decisions should take into account a person's overall health, the extent of their cancer and the unique characteristics of their tumour," says Professor Barreto.
"Better understanding of these differences is an important step towards delivering more personalised care and improving outcomes for patients and their families."
The researchers say the findings add to growing efforts to understand the rise of bowel cancer in younger adults and could help guide future research and treatment strategies.
Professor Barreto, who is a Consultant Surgeon on the HPB and Liver Transplant Unit at Flinders Medical Centre, has recently published research relating to developments in young onset pancreatic cancers , early onset cancer survivor s and pancreatic cancer .
The paper, ' 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' , by Savio G. Barreto, Christos S. Karapetis, Shahid Ullah, Matthew Burge, Susan Caird, Angus Campbell, Azim Jalali, Ross Jennens, Muhammad A. Khattak, Belinda Lee, Stephanie H. Lim, Shehara Mendis, Louise Nott, Timothy J. Price, Jeremy D. Shapiro, Jeanne Tie, Javier Torres, Colin Williams, Rachel Wong, Vanessa Wong and Peter Gibbs, was published in The Medical Journal of Australia.
Acknowledgements: Savio G. Barreto was funded by a Flinders Foundation Grant (49358025), a National Health and Medical Research Council Ideas Grant (2021009), Pankind 21.R7.INV.CB.UOSA.6.2, the CUREator scheme via Brandon BioCatalyst, the Hospital Research Fund and a Southern Adelaide Local Health Network Enquiry Grant Round, and royalties received from Springer Nature and CRC press for editing books in surgery not related to this study.
