Oral Presentation Clinical Oncology Society of Australia Annual Scientific Meeting 2026

Diagnostic routes, intervals to treatment and perceived delays in diagnosis for early-onset vs older-onset colorectal cancer. (146426)

Rebecca J Bergin 1 2 3 , Jon D Emery 2 4 , Sophie Boffa 5 , Jody Horne 5 , Nik Ding 6 7 , Finlay Macrae 7 8 9 , Dierdre O'Sullivan 1 , Isabella Fortunato 1 , Amanda Piper 10 , Robert Thomas 1 11 , Alexander Heriot 12 , Basil D'Souza 13 , Baxter Smith 14 , Bushra Othman 15 , Chen Lew 16 , Chloe Georgiou 17 , Corina Behrenbruch 18 , Douglas Stupart 19 , Joseph Kong 16 , Justin Yeung 20 , Kristina Vanguardia 16 , Nicole Tham 21 , Paul McMurrick 22 , Ranah Lim 18 , Robert Blum 17 , Sarit Badiani 13 , Shiki Fujino 23 , Suellyn Centauri 23 , Simon Wilkins 22 , Vladimir Bolshinsky 14 , Yasser Arafat 20 , Yui Kaneko 18 , Dallas English 1 24 , Roger Milne 1 24 25 , Victoria White 26 27
  1. Cancer Epidemiology Division, Cancer Council Victoria, Melbourne, VIC, Australia
  2. Department of General Practice and Primary Care, University of Melbourne, Melbourne, Vic, Australia
  3. Centre for Quality and Patient Safety Research, Institute of Health Transformation, Deakin University, Geelong, Vic, Australia
  4. Nanyang Technological University - NTU, Singapore
  5. Consumer representative, Victoria
  6. Gastroenterology Department, St Vincent's Hospital, Melbourne, VIC, Australia
  7. Department of Medicine, University of Melbourne, Melbourne, VIC, Australia
  8. Colorectal Medicine and Genetics, Royal Melbourne Hospital, Melbourne, VIC, Australia
  9. Genomic Medicine and Family Cancer Clinic, Royal Melbourne Hospital, Melbourne, VIC, Australia
  10. Strategy and Support Division , Cancer Council Victoria, Melbourne, VIC, Australia
  11. Faculty of Medicine, Dentistry and Health Sciences, The University of Melbourne, Melbourne, Vic, Australia
  12. Peter MacCallum Cancer Centre, East Melbourne, Vic, Australia
  13. The Northern Hospital, Epping, VIC, Australia
  14. Peninsula Health, Frankston, VIC, Australia
  15. Box Hill Hospital, Box Hill, VIC, Australia
  16. The Alfred Hospital, Melbourne, VIC, Australia
  17. Bendigo Hospital, Bendigo, VIC, Australia
  18. St Vincents Hospital Melbourne, Fitzroy, VIC, Australia
  19. University Hospital Geelong, Geelong, VIC, Australia
  20. Western Health, Footscray, VIC, Australia
  21. Royal Melbourne Hospital, Parkville, VIC, Australia
  22. Cabrini Monash University Dept of Surgery, Malvern, VIC, Australia
  23. Monash Health, Clayton, VIC, Australia
  24. Centre for Epidemiology and Biostatistics, University of Melbourne, Melbourne, VIC, Australia
  25. Precision Medicine, School of Clinical Sciences at Monash Health, Monash University, Melbourne, VIC, Australia
  26. Behavioural Science Division, Cancer Council Victoria, Melbourne, VIC, Australia
  27. School of Psychology, Deakin University, Melbourne, VIC, Australia

Background: Early-onset colorectal cancer (diagnosed before age 50 years) is often late-stage, leading to poor survival and quality of life. Understanding pathways to diagnosis is critical to improving outcomes. This study compared diagnostic routes and intervals from first symptom to treatment for early-onset vs older-onset colorectal cancer cases.

Methods: Cross-sectional questionnaire study of patients aged ≥18 years within 2–9 months of colorectal cancer diagnosis recruited through 12 Victorian hospitals in 2022-2025, with oversampling for younger adults. Participants’ general practitioner (GP) also completed a questionnaire. Comparisons by age used chi-square and Mann-Whitney U tests.

Results: Of those invited, 241 (38%) patients (103 early-onset) and 101 (49%) GPs returned a questionnaire. Early-onset cases were more likely to be female (56% vs 40%, p=0.01) and have stage III or IV disease (48% vs 31%, p<0.0001).

Diagnostic routes differed (p<0.0001): early-onset cases were more likely to be diagnosed after symptom presentation to a doctor (80% vs 62% of older-onset cases) and less likely to be screen-detected (4% vs 24%). A similar proportion of both case groups attended an emergency department (overall 14%).

For symptomatic patients, intervals were longer for early-onset than older-onset adults: from first symptom to presentation, median 39 days (Interquartile range [IQR] 12–134) vs 14 days (IQR 0–70), p<0.006; presentation to referral, median 29 days (IQR 1–62) vs 15 days (IQR 9–33), p=0.04; and presentation to diagnosis, median 72 days (IQR 29–179 days) vs 54 days (IQR 12–126 days), p=0.06.

In all patients, intervals from referral to diagnosis (median 22 days) and diagnosis to treatment (median 24 days) were similar.

More early-onset cases reported that their cancer could have been diagnosed sooner (73% vs 60%).

Conclusions: People with early-onset colorectal cancer experience longer intervals pre-referral. Supporting faster symptom presentation and GP assessment could improve outcomes.