Diagnostic Routes and Health Disparities in Advanced Colorectal Cancer: Evidence from a Nationwide Study in China

Background The diagnostic route is an important determinant in advanced colorectal cancer, yet its impact remains understudied in China. Methods In this nationwide cross-sectional study (2020–2021), we enrolled 4,589 patients with advanced colorectal cancer in China. Diagnostic routes included symptomatic presentation, proactive health-seeking, and comorbidity presentation. Multivariable regression models were used to evaluate their determinants and associations with two outcomes: receipt of biomarker testing and post-treatment HRQOL, adjusted for baseline scores and covariates. Results The majority of patients (87.0%) were diagnosed via the symptomatic pathway, with the remainder following Proactive Health-Seeking (6.0%) or comorbidity (6.0%) pathways. Higher educational attainment was a significant predictor of presentation through a non-symptomatic pathway relative to the symptomatic pathway. Analysis of post-diagnosis outcomes revealed divergent associations for these non-symptomatic routes. The Comorbid pathway was independently associated with a higher likelihood of receiving biomarker testing (Odds Ratio [OR], 1.40; 95% CI, 1.05–1.88). A similar positive, though not statistically significant, trend was observed for the Proactive Health-Seeking pathway (OR, 1.33; 95% CI, 0.99–1.80). Conversely, both the Proactive Health-Seeking (β = -2.28; 95% CI, -3.94 to -0.63) and the Comorbid (β = -2.86; 95% CI, -4.49 to -1.23) pathways were significantly associated with a greater decline in the post-treatment physical functioning domain of HRQOL. Conclusions The predominance of symptomatic diagnoses highlights the urgent need for earlier detection. Although non-symptomatic routes improved access to biomarker testing, they were also associated with greater short-term physical decline, underscoring the need to integrate psychosocial support into early diagnostic pathways.