Nationwide Prevalence of Hepatocellular Carcinoma in Saudi Arabia: A Population-Based Analysis for 2021.

Purpose: Liver cancer, predominantly hepatocellular carcinoma (HCC), represents a significant health burden in Saudi Arabia, ranking as the 8th most common cancer in males and 14th in females. Accurate prevalence estimation is essential for healthcare planning, resource allocation, and understanding disease burden. Challenges in prevalence assessment include incomplete capture of historical cases by the Saudi Cancer Registry (SCR) before its full operational capacity, as well as the absence of dedicated prevalence surveys. This study estimates the point prevalence of HCC in Saudi Arabia for the year 2021 using population-based incidence data, survival estimates, and census information. Patients and Methods: A population-based prevalence estimation study was conducted using incident HCC cases reported to the SCR (2005-2017), population census data (2005-2020), and published national survival data. The study population comprised all newly diagnosed HCC cases reported during the study period. Prevalence was calculated by multiplying incident cases from each diagnosis cohort by their corresponding age- and gender-specific survival probabilities to estimate the number of HCC survivors alive in 2021, divided by the population at risk. Monte Carlo simulation with binomial distribution (n = incident cases; p = survival probability) was performed 1000 times to generate a distribution of prevalent cases, with 2.5th and 97.5th percentiles defining 95% confidence intervals. Age- and gender-specific prevalence rates were standardized to the WHO 2000-2025 World Standard Population using direct standardization for international comparability. Results: Between 2005 and 2020, 6743 HCC cases were newly diagnosed and reported to the SCR, comprising 4685 males (69.5%) and 2058 females (30.5%). By the end of 2020, the estimated number of male HCC survivors was 637.3 (95% CI: 612.8-663.2), while females numbered 496.9 (95% CI: 474.1-521.8). In 2021, the age-standardized prevalence rate of HCC was 8.62 per 100,000 population for males (95% CI: 8.28-8.98) and 6.36 per 100,000 for females (95% CI: 6.08-6.67), with an overall combined age-standardized rate of 7.49 per 100,000 (95% CI: 7.25-7.76). HCC prevalence increased progressively with age, with the highest proportion of diagnosed cases occurring in individuals aged 75 years and above (males: n=1315; females: n=420). Younger cohorts diagnosed after 2015 showed markedly improved survival rates compared to those diagnosed in 2005, reflecting advances in treatment modalities. Conclusion: This study provides a comprehensive population-based estimate of HCC prevalence in Saudi Arabia, demonstrating substantial gender and age disparities in disease burden. The predominance of HCC in males and elderly populations underscores the need for targeted epidemiological research to identify modifiable risk factors, particularly given the markedly lower prevalence of alcohol-related liver disease compared to global HCC endemic regions. The methodological framework utilizing integration of incidence, population-based survival data, and WHO standardization provides a replicable model for disease burden estimation in countries with limited prevalence survey infrastructure. Future research should focus on disease etiology, including the role of chronic hepatitis B, chronic hepatitis C, metabolic-associated steatotic liver disease, and the evolving patterns of liver disease in Saudi Arabia.