Cancer incidence in Iran in 2016: A study based on the Iranian National Cancer Registry

Abstract Background Cancer poses an escalating public health challenge, necessitating a comprehensive understanding of cancer incidence to formulate effective control strategies. Aims This study aims to present a comprehensive overview of cancer incidence in Iran, utilizing data from the Iranian National Population‐based Cancer Registry (INPCR) for the year 2016. Methods The study employed INPCR data to compute crude and age‐standardized incidence rates (ASR) per 100 000 for the most common cancers among men and women across Iran's 31 provinces. Data analysis utilized Excel (2019) and STATA 14. Results In 2016, 124 833 new cancer cases were registered, with 65 495 (52.90%) occurring in men and 58 312 (47.10%) in women. ASRs for all cancers in the total population were 177.48, with specific rates for men and women at 192.96 and 162.33, respectively. The five most common cancers in men were prostate (23.25), stomach (21.56), colon (19.30), bladder (16.20), and lung (13.15). Among women, the leading cancers were breast (40.60), colon (14.64), thyroid (10.84), stomach (10.25), and lung (5.63). West Azarbaijan had the highest incidence among men, while Yazd topped the list for women. Age‐specific incidence rates revealed peaks in the 67–74 age group for men and the 40–50 age group for women. Conclusion This study affirms that while Iran exhibits a lower cancer incidence compared to global averages, there has been a temporal increase. Disparities in ASR exist across sexes and provinces, with shifts in the ranking of common cancers by sex compared to previous reports.

T A B L E 3 Age-standardized incidence rates (per 100 000) of the 10 most common cancers and all cancers in different regions and provinces of Iran, 2016 (men).colorectal, and stomach cancers among women.However, registry coverage varied widely across states and provinces. 9Cancer incidence in Iran exhibited a rise from 2008 to 2014, 8,9 characterized by significant heterogeneity in cancer type, province, and sex.
5][16] With an aging population, increased life expectancy, and notable risk factors, cancer incidence is rising globally, especially in West Asian populations.
This situation is critical for developing countries like Iran, where cancer management is a significant concern.Consequently, a quantitative evaluation of cancer-related epidemiological metrics is crucial for devising effective prevention and management strategies. 9,17ncer registries play a pivotal role as information sources for cancer-related epidemiology. 18They collect, store, and manage data critical for cancer surveillance, research, and the planning and evaluation of prevention and control interventions. 14This study aims to unveil the latest cancer incidence data, providing ASR for all cancer categories across Iran's 31 provinces in 2016.The inclusive approach covers both genders and all age groups, aiming to inform effective strategies for cancer prevention and management in Iran.

| Study population and data source
The study utilized data from the Iran Statistics Center website 19  After data collection, each university's cancer registry staff performed quality control and data processing, including internal consistency checks and duplicate record verification.Discrepancies between global reports 21,22 and Iranian national reports highlight the importance of referencing national reports for precise information due to variations in data availability from different provinces.Despite differing rankings between genders, lung, brain, and esophagus cancers consistently occupy the 5th, 6th, and 8th positions, respectively, among the 10 most common cancers.This study delves into the three most common cancers in men and women separately for a more nuanced analysis.

| Statistical analysis
Recent statistics indicate that cancer incidence rates (excluding non-melanoma skin cancers) in Iranian men (170.50) and women (148.43) are notably lower than global rates for men (206.9) and women (178.1). 23However, an anticipated increase in life expectancy and the adoption of a westernized lifestyle suggest a future dramatic rise in cancer incidence rates in Iran.
Stomach cancer, though declining globally, remains a prevalent malignancy, ranking fourth in men and seventh in women worldwide. 24In Iran, stomach cancer, especially in men, is still significant.
The shift in rankings from the most common cancer in Iranian men in 2014 to the second most common in 2016 may be attributed to men exhibiting earlier onset, supported by our findings. 9,25Behavioral factors like smoking and alcohol consumption in men might contribute to the higher lifetime risk of developing stomach cancer. 25ostate cancer, despite being the most common cancer in developed regions, 26 was the second most common in Iranian men in 2014. 9However, our 2016 data reveal a surge in prostate cancer incidence, making it the most common cancer among men.However, a to represent the entire Iranian population.According to the 2016 National Population and Housing Census, Iran's total population across 31 provinces was 79 926 270, with 40 498 442 men and 39 427 828 women.To analyze cancer incidence in Iran, the study relied on data from the Iranian National Population-based Cancer Registry (INPCR).Managed by all 60 medical universities under the Iranian Ministry of Health and Medical Education (MOHME), the INPCR covers 31 provinces.The 2016 data collection adhered to International Agency for Research on Cancer (IARC) and International Association of Cancer Registries (IACR) standard protocols.Trained staff in 60 universities facilitated the cancer registry, utilizing pathology reports and clinical/ paraclinical data from hospitals.Patient residence was the basis for registration to prevent duplicate cases in different provinces.However, around 30 679 patients lacking a national ID prompted the use of first name, surname, father name, date of birth, and gender for data pooling.Information gathered included personal details and tumor encoding using the International Classification of Diseases for Oncology, Third Edition (ICD-O-3).20 Data analysis employed Excel (2019) and STATA 14, calculating frequency, percentage, crude and age-standardized incidence rates (ASR) for all cancer types and the 10 major cancer types in both sexes across 31 provinces and nationally.Median and interquartile range (IQR) of age were also computed.The ASR, expressed per 100 000 population and standardized to the Segi-Doll world population, utilized the direct method.This involved adding products of age-specific rates and the number of

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DISCUSSIONCancer, irrespective of human development levels, remains a significant contributor to morbidity and mortality.This study represents the first comprehensive overview of cancer incidence in Iran for 2016.Population-based cancer registries play a crucial role in informing cancer control policymakers, and our study utilized data from a national population-based cancer registry in Iran.
Estimated new cases and age standard rate by sex and cancer type.
6 A B L E 1 Estimated cancer death rates were 65 and 41.1 per 100 000 for men and women, respectively.5Projectionsindicateapotential increase in global cancer cases to 28 million by 2040,6with a 43% rise in new cases in Iran a Non-melanoma skin cancer.
Age-standardized incidence rates (per 100 000) of the 10 most common cancers and all cancers in different regions and provinces of Iran, 2016 (women).
a Non-melanoma skin cancer.T A B L E 4 a Non-melanoma skin cancer.
Five most common age-specific cancer incidence rates (per 100 000) in Iran, 2016 (women).persons in the same age subgroup of the standard population, divided by the sum of weights of the standard population.
Age-specific incidence rates exhibited peaks at 64-74 years for men and 40-50 years for women.The patterns were consistent across sexes, with lower rates in younger age groups and a sharp rise in middle age.Figures1 and 2visually represent age-specific incidence rates for the five most common cancers in both sexes, illustrating this observed pattern.