Age-Standardized Cancer Incidence Rate and Ethnicity in Iran

Background: Cancer presents a significant global health challenge, with incidence rates influenced by multifaceted factors including ethnicity. Understanding ethnic disparities in cancer occurrence is crucial for identifying vulnerable populations and designing targeted interventions. In Iran, a diverse ethnic landscape offers a unique opportunity to explore these dynamics. Objectives: This study investigates the association between cancer incidence rates and ethnicity, alongside the impact of the Human Development Index (HDI) on cancer incidence. Methods: Utilizing data from Iran's national cancer registration program, we analyzed the age-standardized incidence rates of 12 common cancers across provinces. Poisson regression and spatial analysis techniques were employed to assess the influence of ethnicities and HDI on cancer incidence. Results: The average standardized incidence rate for all cancers was 154.98 per 100,000 people, with notable variations across provinces and ethnic groups. The Fars ethnicity exhibited the highest incidence rate, while the Baloch ethnicity showed the lowest. Significant spatial autocorrelation was observed for colorectal and stomach cancers, with hotspot analysis revealing regional disparities. Interestingly, only HDI emerged as a significant predictor of cancer incidence in regression models. Conclusions: Contrary to individual-level studies, our province-level analysis found no significant association between cancer incidence and ethnicity in Iran. The prominence of HDI underscores the role of socioeconomic factors in cancer occurrence. While some limitations in this study pose challenges, it highlights the need for targeted research at the individual level to better elucidate cancer-ethnicity associations. Such insights are critical for informing tailored interventions and reducing cancer disparities across diverse ethnic populations in Iran.