Geo-epidemiological reporting and spatial clustering of the 10 most prevalent cancers in Iran

Spatial patterns of colorectal cancer survival rates in Malaysia, 2013-2018

BACKGROUND

Large geographical variations in colorectal cancer (CRC) survival rates have been reported across regions. Poorer survival rates were mainly found in socioeconomically deprived areas, highly dense areas, and areas lacking healthcare accessibility. The objective of this study was to identify, compare, and contrast the spatial patterns of 5-year CRC-specific survival rates and identify high-priority areas by districts in Malaysia.

METHODS

This retrospective cohort study utilized secondary data from the National Cancer Registry. CRC patients (ICD10 C18-21) diagnosed between 2013 and 2018 were selected. Patient addresses were geocoded into districts and states via geospatial data from the National Geospatial Centre, whereas district population density data were gathered from the Population Census of Malaysia. Kaplan‒Meier survival analysis and log-rank test were conducted to determine and compare the 5-year CRC-specific survival rates, and the spatial distribution of CRC survival by district was determined via ArcGIS software.

RESULTS

A total of 18,513 CRC patients were registered from 143 districts, with 10,819 deaths occurring during follow-up. The national 5-year CRC-specific survival rate was 42%, with median survival time of 36 months (95% CI: 34.46, 37.54). The eastern region (Kelantan, Terengganu, and Pahang) had the lowest survival (38.0%). Among the 143 districts, eighty-one (56.6%) reported survival rates below the national average while thirty-six (25.2%) were identified as high-priority districts.

CONCLUSION

The differences in CRC survival rates were evident according to geographical location. Area-based targeted interventions to improve CRC detection, management, and access to healthcare are imperative to address cancer survival disparities and help effectively allocate resources.

Cancer patterns in Iran: a gender-specific spatial modelling of cancer incidence during 2014-2017

BACKGROUND

Cancer is a significant public health concern and the second leading cause of death. This study aims to visualize spatial patterns of top common cancer types and identify high-risk and low-risk counties for these cancers in Iran from 2014 to 2017.

METHODS

In this study, we analyzed 482,229 newly diagnosed cancer cases recorded by the Iranian National Population-Based Cancer Registry from 2014 to 2017. We employed a purely spatial scanning model and local Moran I analysis to explore spatial patterns across Iran.

RESULTS

Approximately 53% of all cases were male. The average age of cancer diagnosis was 62.58 ± 17.42 years for males and 56.11 ± 17.33years for females. Stomach cancer was the most common cancer in men. The northern and northwestern regions of Iran were identified as high-risk areas for stomach cancer in both genders, with a relative risk (RR) ranging from 1.26 to 2.64 in males and 1.19 to 3.32 in females. These areas recognized as high-risk areas for trachea, bronchus, and lung (TBL) cancer specifically in males (RR:1.15-2.02). Central regions of Iran were identified as high-risk areas for non-melanoma skin cancers in both genders, ranking as the second most common cancer (RR:1.18-5.93 in males and 1.24-5.38 in females). Furthermore, bladder cancer in males (RR:1.32-2.77) and thyroid cancer in females (RR:1.88-3.10) showed concentration in the central part of Iran. Breast cancer, being the most common cancer among women (RR:1.23-5.54), exhibited concentration in the northern regions of the country. Also, northern regions of Iran were identified as high-risk clusters for colon cancer (RR:1.31-3.31 in males and 1.33-4.13 in females), and prostate cancer in males (RR:1.22-2.31). Brain, nervous system cancer, ranked sixth among women (RR:1.26-5.25) in central areas.

CONCLUSIONS

The study's revelations on the spatial patterns of common cancer incidence in Iran provide crucial insights into the distribution and trends of these diseases. The identification of high-risk areas equips policymakers with valuable information to tailor targeted screening programs, facilitating early diagnosis and effective disease control strategies.

Scientometric Analysis of Articles on Spatial Epidemiology of Cancer in Iran: A Systematic Review

Background

Geographic information system (GIS) plays an important role in identifying areas with a high incidence of cancer. In the present study, based on a systematic review of studies by Iranian researchers, we performed a scientometric analysis of the published articles on the spatial epidemiology of cancer. In addition, the geographical distribution of certain types of cancer in Iran is presented.

Methods

A literature search was conducted using electronic databases such as PubMed and NLM Gateway, Institute for Scientific Information, Scopus, Google Scholar, and Cochrane Library for relevant articles published from 2000 to 2021. The search was performed using a combination of medical subject heading terms and keywords. A narrative synthesis was performed, and descriptive data were expressed as frequency and percentage.

Results

Of the 200 identified articles, 31 studies published in 15 different journals were included in this systematic review. Results showed a wide variation in high-risk breast cancer clusters. However, a similar incidence of gastrointestinal cancers has been reported, and high-risk clusters were identified in the north and the northwest of Iran. Skin cancer and acute lymphoblastic leukemia were more prevalent in the central provinces.

Conclusion

The current volume of studies on the spatial epidemiology of cancer in Iran, with a CiteScore quartile of Q1, is inadequate to guide health policymakers. The geographical distribution of many prevalent types of cancer has not been assessed by Iranian researchers. Furthermore, the classification of high- and low-risk geographical clusters of cancers was not completely homogeneous.