# Populational analysis of the mortality-to-incidence ratio across 20 cancer groupings in the Russian Federation

## TL;DR

This study analyzed cancer mortality-to-incidence ratios in Russian regions from 2008 to 2018, finding disparities linked to geography, culture, and socioeconomic factors.

## Contribution

The study introduces a populational analysis of MIR trends across 20 cancer types in Russian jurisdictions, highlighting regional and cultural disparities.

## Key findings

- Surrounding jurisdictions had higher MIRs compared to central cities.
- The Republic of Adygea showed outlier MIRs for several cancers compared to neighboring regions.
- Socioeconomic factors like GDP and physician availability were negatively linked to MIR.

## Abstract

Cancer represents a leading cause of death globally. The mortality to incidence ratio (MIR) may vary across populations, reflecting regional disparities in care. We aimed to determine MIR trends by cancer subtype across the 80 recognised jurisdictions of the Russian Federation between 2008 and 2018.

We used publicly accessible data from the Pyotr Alexandrovich Herzen Moscow Oncology Research Institute from 2008–2018. We used descriptive and linear regression analyses to estimate MIR from crude mortality and incidence rates across geographical regions.

Between 2008 and 2018, surrounding adjacent jurisdictions were significantly associated with increased MIRs compared to centring cities. The culturally distinct region of the Republic of Adygea reported outliers in MIR for sigmoid, rectal, and anal cancers (MIR = 0.754; 95% confidence interval (CI) = 0.579, 0.983), lung cancer (MIR = 1.07 (95% CI undefined), breast cancer (MIR = 0.458; 95% CI = 0.341, 0.615), and melanoma (MIR = 0.462; 95% CI = 0.201, 1.059), which was not observed in adjacent predominantly Caucasian-populated/western Krasnodar krai that fully envelops the Republic geographically. Gross domestic product (11-year average), the number of physicians, and the number of oncologists per 10 000 people were significantly negatively associated with increased MIR (P < 0.05).

Differences in MIR for cancer have been observed between capital cities and their surrounding jurisdictions, with increased ratios noted in demographically distinct regions such as the Republic of Adygea. This suggests that population-level differences in MIR and subsequent cancer outcomes are influenced by region, culture, and socioeconomic variations. These findings may inform public health policy on intersectional disparities in MIR across different populations in the Russian Federation, with applicability to other countries.