Poster Presentation Clinical Oncology Society of Australia Annual Scientific Meeting 2026

Exploring Background Factors and Diagnostic Pathways in Colorectal Cancer   (141481)

Meghana Maddula 1 , Subotheni Thavaneswaran 1 2 3 4 , Megan Barnet 1 2 3
  1. Faculty of Medicine and Health, University of New South Wales, Kensington, NSW, Australia
  2. Medical Oncology, The Kinghorn Cancer Centre, Sydney, NSW, Australia
  3. Garvan Institute of Medical Research, Sydney, NSW, Australia
  4. NHMRC Clinical Trials Centre, University of Sydney, Sydney, NSW, Australia

Aims

Early-onset colorectal cancer (EOCRC) remains poorly understood and existing research inadequately captures patient-reported outcomes and environmental exposures. This study examined clinical presentations and exposures among patients with EOCRC compared with later-onset colorectal cancer (LOCRC) and age-matched controls, while exploring patient perspectives.

Methods

A cross-sectional survey was conducted including CRC cases and age-matched (healthy) controls. Cases were stratified into EOCRC (<50 years) and LOCRC (≥50 years). Quantitative analyses assessed symptoms, healthcare interactions, environmental exposures, and demographics. Qualitative analysis explored patient-reported outcomes and beliefs.

Results

EOCRC patients (n=14) more frequently reported abdominal pain (64% vs 29%, p=0.13) and rectal bleeding (57% vs 14%, p=0.046) compared with LOCRC (n=14). Compared with both LOCRC patients and age-matched controls (n=13), EOCRC patients reported more frequent intake of sugar-sweetened beverages (36% vs 0% and 15%; p=0.041 and 0.4 respectively), red meat (93% vs 69% and 77%; p=0.2 and 0.3 respectively), and refined grains (79% vs 54% and 69%; p=0.2 and 0.7 respectively). In contrast, age-matched controls reported more frequent whole grain intake compared with EOCRC (85% vs 57%, p=0.2). Compared with age-matched controls, EOCRC participants also reported more frequent alcohol consumption (57% vs 15%, p=0.014) and greater alcohol intake per session (p=0.036). EOCRC patients more frequently reported atopic conditions including asthma and hay fever compared with LOCRC participants (57% vs 7.1%, p=0.02) and age-matched controls (57% vs 0%, p<0.001). Qualitative analysis among EOCRC participants identified recurrent themes of diagnostic delay, healthcare dismissal, and perceived environmental contributors to disease including processed foods, stress, microplastics, and modern lifestyle exposures.

Conclusions

EOCRC patients reported distinct symptom profiles, dietary patterns, prolonged diagnostic pathways characterised by repeated healthcare interactions, and differing patient perceptions regarding contributors to cancer development. By incorporating patient-reported experiences and beliefs not routinely captured in retrospective clinical datasets, this study provides new insights into EOCRC.