CLINICAL AND EPIDEMIOLOGICAL CHARACTERISTICS OF BONE SARCOMAS IN THE REPUBLIC OF KAZAKHSTAN IN 2010-2019

Relevance: Sarcomas are a heterogeneous group of malignant neoplasms (MNs) of mesenchymal origin. The peak incidence of bone tumors falls on a socially significant age: with osteosarcoma and Ewing’s sarcoma – 10-25 years, with chondrosarcoma – 35-40 years. Bone sarcomas are the most aggressive human MNs. This urges to determine the prognostic factors of the disease, timely assess the treatment effect, and identify possible relapses. The study aimed to improve the early diagnosis of bone sarcomas, to improve and increase the oncological alertness of doctors by establishing the trends in bone sarcoma incidence and mortality in the Republic of Kazakhstan in 2010-2019, and this disease incidence and mortality in 2019 by age, gender, bone tumor histotype and region of the country. Methods: The study included the data of patients registered at the RK National Cancer Registry in 2010-2019 with a “bone sarcoma” diagnosis (ICD-10 code: C40-C41). The incidence of bone sarcomas was presented as absolute and crude rates per 100,000 population. Absolute standardized morbidity and mortality were calculated using the World Standard. MS Excel 2016 was used to display the results graphically. Results: By the end of 2019, 1587 patients were registered with bone sarcomas in the RK. From 2010 to 2019, the incidence of bone sarcoma in the RK decreased by 39%, including 36% among men and 40% among women. Mortality decreased by 37% to 0.8% per 100,000 population. Bone sarcoma is not among the 20 most common types of cancer in the RK; it accounts for 0.7% of all new cases of MN (2010-2019). The peak incidence of bone sarcoma was observed at the age below 20 years (20%), and mortality – in the age group of 45-54 years (22%). Conclusion: The rare occurrence of bone MNs can cause misdiagnosis during the initial examination. Bone sarcomas account for 0.8% of all MNs diagnosed in the RK; however, the aggressiveness of the course and rapid hematogenous metastasis causes a high percentage of neglect of this disease during the initial visit. In addition, bone sarcomas are more common than other MNs in young adults and adolescents. The prognosis of primary bone sarcomas depends on many factors.