Malignant neoplasms of the respiratory tract and thoracic organs in the remote period in males of Altai krai affected by first nuclear test at Semipalatinsk test site

Abstract

BACKGROUND: The study of remote effects of radiation exposure on tumor-related morbidity in population remains a matter of great social significance in Altai Krai.
 AIM: To investigate the incidence rate for malignant neoplasms of respiratory tract and thoracic organs in the remote period in the male population born in 1932–1949 and located in the zone of influence of the first nuclear test.
 METHODS: This retrospective cohort study was based on the analysis of anonymized data and surgical records on morphologically verified cases of primary malignant neoplasms in a male cohort for the period from 2007 to 2016. In this paper, we studied a cohort fixed by the date of the first nuclear test, with a total of 6383 male individuals. The main (exposed) cohort included 2291 men, while the control (non-exposed) cohort included 4092 men who lived in rural communities of the region that were not affected during the first nuclear test. The cohort included 156 cases of morphologically verified diagnosis of primary malignant neoplasms of the respiratory tract and thoracic organs (codes C30–C39 according to the International Classification of Diseases). Person-time incidence rate (PtR), standard error (mPtR) and confidence intervals (95% CI) were calculated. The incidence of respiratory and thoracic malignant neoplasms, structure and relative risk (RR) were assessed. Statistical processing of the data was performed using licensed Microsoft Office 2016 software.
 RESULTS: The number of person-years spent at risk for respiratory and thoracic malignancies in the male population in the main cohort was 16 731 person-years, and in the control cohort — 30 747 person-years. In the main cohort, PtR was 436.32×105 person-years, with an mPtR of 51.07 and 95% CI of 334.18–538.45; in the control cohort the PtR was 269.95×105 person-years with an mPtR of 29.63 and 95% CI of 210.68–329.21. The leading localizations of malignant neoplasms of the respiratory and thoracic organs in men in the main and control cohorts were bronchial and lung malignancies and laryngeal malignancies.
 CONCLUSIONS: An increased relative risk of respiratory and thoracic malignant neoplasms manifesting in the remote period in the male population born and living in rural areas of Altai Krai during the first nuclear test conducted at the Semipalatinsk test site was revealed: RR=1.616, 95% CI 1.180–2.214, with the standard error of relative risk equal to 0.160.