Global Distribution of Colorectal Cancer Staging at Diagnosis: An Evidence Synthesis.

Abstract

Background and aims: Stage at diagnosis is a key prognostic factor for colorectal cancer (CRC) survival. We aimed to assess the global distribution of CRC staging at diagnosis using population-based or hospital-based registry data.

Methods: We systematically searched in MEDLINE and Embase from their inception until 6 December 2023. Grey literature was searched through published cancer reports. Studies from population-based or hospital-based cancer registries reporting the stage distribution of diagnosed CRC were included. We extracted stage-specific proportions among patients with CRC based on TNM, SEER, or Dukes staging systems. Subgroup analyses by sex, age, tumor site, calendar period, and status of population-based screening were performed. Correlations between the Human Development Index (HDI), Socio-Demographic Index (SDI), and the distant metastatic CRC proportion were also evaluated.

Results: 84 eligible studies/reports from 46 countries were analyzed, covering 3.8 million patients. Among 36 countries included in the main analysis, the most recent distant metastatic CRC proportions varied from 16.2% in Puerto Rico to 28.2% in Oman and Latvia, with a median (interquartile range) of 23.7% (21.8%-26.3%). Higher metastatic proportions were observed in younger patients, those with colon cancer, and those without screening implementation, with no apparent difference between males and females. Over time, some countries/regions, such as Southern Portugal (36.5% in 2000 to 22.2% in 2016), showed declining proportions of metastatic CRC, while others remained stable (e.g., Austria, Belgium) or increased (e.g., United States, Slovenia, Spain). Higher HDI and SDI were correlated with lower proportions of distant metastatic CRC (HDI: ρ=-0.48; SDI: ρ=-0.26).

Conclusion: Global disparities in CRC staging exist, indicating a need for targeted interventions to enhance early detection and management, especially in high-metastasis areas.