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Objectives: The aim of this study was to present the baseline results of a pilot project conducted to evaluate the effectiveness of lung cancer screening using low-dose chest computed tomography (CT) in regions with excessive radon levels in the Republic of Kazakhstan.Methods: In total, 3671 participants were screened by low-dose chest CT. Current, former, and never-smokers who resided in regions with elevated levels of radon in drinking water sources and indoor air, aged between 40 and 75 with no history of any cancer, and weighing less than 140 kg were included in the study. All lung nodules were categorized according to the American College of Radiology Lung Imaging Reporting and Data System (Lung-RADS 1.0).Results: Overall, 614 (16.7%) participants had positive baseline CT findings (Lung-RADS categories 3 and 4). Seventy-four cancers were detected, yielding an overall cancer detection rate of 2.0%, with 10.8% (8/74) stage I and a predominance of stage III (59.4%; 44/74). Women never-smokers and men current smokers had the highest cancer detection rates, at 2.9% (12/412) and 6.1% (12/196), respectively. Compared to never-smokers, higher odds ratios (ORs) of lung cancer detection were found in smokers (OR,2.48; 95% confidence interval [CI], 1.52 to 4.05, <i>p</i><0.001) and former smokers (OR, 2.32; 95% CI, 1.06 to 5.06, <i>p</i>=0.003). The most common histologic type of cancer was adenocarcinoma (58.1%).Conclusions: Implementation of low-dose CT screening for lung cancer in regions with elevated radon levels is an effective method for both smokers and never-smokers.

INTRODUCTIONColorectal cancer (CRC) is one of the most frequently di-agnosed malignancies worldwide, in both men and women. The highest incidence rates were registered in West European countries (up to 51.2/100,000), Australia/New Zealand (36.9/100,000), and North America (31.5/100,000). 1 However, according to the International Agency for Research on Cancer (IARC), in some Asian countries (e.g., Republic of Korea, Japan, Singapore), the incidence rate might be as high as that in Western Europe. 2 In addition, a mortality rate of 17.3 cases per 100,000 people is reported in Asia, which is higher than those in North America (10.1/100,000) and Australia (10.9/100,000). High mortality rates have been reported even in some Asian countries with relatively low incidences of CRC (

Relevance: Over the years, lung cancer (LC) remains the leading cause of cancer deaths in Kazakhstan. In 2018, LC was diagnosed in 3741 people in the RK, and 2377 dies from LC. The purpose of this study was to assess the age-gender characteristics of morbidity and mortality from LC in Kazakhstan based on statistical and literature data. Results: The conducted analysis by gender and age showed a consistent and significant increase in LC mortality in the RK, starting from the age of 40-44 years. The highest incidence and mortality were registered in the age groups of 65-69 years and 70+ years. In general, in all age categories, the incidence and mortality in men exceeded the incidence and mortality in women by 4.5–5.3 times. The highest mortality in men and women of all ages was registered in 2009 (34.3‰ and 6.9‰, respectively), the lowest – in 2019 (20.8‰ in men and 4.6‰ in women). Conclusions: The results of the assessment can be used to improve early diagnosis of LC and in the preparation of national screening programs and regional pilot projects for LC prevention and the identification of risk groups. The use of the results will contribute to increasing the effectiveness of treatment, improving the five-year survival of patients, reducing the level of neglect and mortality from LC.

Relevance: With the introduction of low-dose lung cancer screening, it became necessary to study the radiological characteristics of detected nodules to determine the optimal tactics for managing patients, reduce mortality by detecting early stages, and reduce the number of false-positive results. The study aimed to investigate the radiological semiotics of lung lesions detected by low-dose lung cancer screening and classified as categories 4A and 4B according to the Lung-RADS 1.1 and establish the relationship between their characteristics and possible malignancy. Methods: We studied the results of 167 LDCT images of the chest. All LDCT examinations were performed on CT scanners with a low dose protocol that did not exceed 1 mSv. Results: Of the 167 identified lesions in the lungs, 89 (53.3%) were pathologically verified: 6 (7.1%) cases from the Lung-RADS 4A category and 83 (100%) from the Lung-RADS 4B category. According to pathomorphological examination, 74 (83.1%) out of 89 participants had malignant tumors. In the studied categories, the association between the development of lung cancer and gender Odds Ratio was statistically significant – 2.320 (95% CI 1.230-4.376). Most lung cancer cases had solid nodules (83.8%) with tuberous contours (43.2%), a density of 20-35 HU, and the reaction of the adjacent pleura (58.1%). Conclusion: The study of pathognomonic radiological characteristics of lung lesions will improve the early diagnosis of lung cancer and reduce the number of false-positive results