Breast Cancer Incidence in Kyrgyzstan: Report of 15 Years of Cancer Registry.

Objective: The epidemiological features of the breast cancer (BC) incidence in Kyrgyzstan were studied.

Methods: The retrospective study (2003-2017). Descriptive and analytical methods of oncoepidemiology were used. Crude (CR), age-specific (ASIR), age-standardized (ASR), equalized incidence rates and approximation were calculated. The method of drawing up a cartogram based on the determination of the standard deviation (σ) from the mean (x) was applied.

Results: During the study period, 7,850 new cases of BC were registered. The average annual crude and age-standardized incidence rate were 18.8±0.5 and 24.0±0.5 cases per 100,000 population of female, respectively, and their trends tended to increase (Т=+1.0%; R2=0.242 and Т=+0.2%; R2=0.015, respectively). The analysis of ASIR showed unimodal growth with a peak at 60-64 years - 85.9±4.9 cases per 100,000 population of female. ASIR trends decreased in the age groups of 40-59 years, and the most pronounced decrease was in 50-54 years (T=-1.5%; R2=0.391), in other age groups the trend increased and were most pronounced up to 30 years (T=+4.4%; R2=0.180). Trends in ASR of BС tended to grow in almost all regions, with higher levels in Osh (Т=+3.6%; R2=0.665) and Jalal-Abad (Т=+3.8%; R2=0.551) regions. The cartograms of ASR per 100,000 population of female were allocated according to the following criteria: low - up to 17.2, average - from 17.2 to 26.5, high - above 26.5. The results of the spatial analysis showed the regions with a higher levels of BC incidence rate per 100,000 population of female: Chuy (31.3), Osh city (27.1) and Bishkek city (39.2).

Conclusion: The study of the epidemiological spatio-temporal features of the incidence of breast cancer is of both theoretical and practical interest and plays an important role in monitoring and evaluating anticancer activities.