Prevalence and survival of patients with malignant tumors of the thymus gland (C37). (Population study at the federal district level).
Authors: Merabishvili Vakhtang M. 
Published: August 2022

The thymus gland has a scientific name thymus. The gland is located in the upper part of the chest immediately behind the sternum. During puberty, it reaches its maximum size, then its atrophy occurs, which reduces immunity in subsequent age groups. The maximum decrease in immune indicators occurs in old age.
Until now, neither in Russia nor abroad, nothing was known about the patterns of the prevalence of malignant neoplasms of the thymus due to the extremely rare occurrence of such cases.
We have attempted to establish the patterns of occurrence of malignant neoplasms of the thymus gland (C37) and get some idea of the effectiveness of its treatment at the population level. This opportunity was presented to us in connection with the creation of a cancer registry database at the level of the North-Western Federal District, numbering more than 1 million 350 thousand patients with a population of more than 13 million people.
The International Agency for Research on Cancer (IARC) publishes a monograph "Cancer incidence in Five Continents" every 5 years. In the latest edition of 2021, vol. XI, the prevalence of the thymus gland (C37) is presented together with the heart disease (C38).
Purpose. Based on the database of the newly created population cancer registry of the North-Western Federal District, to determine the prevalence, primary mortality and survival of patients with malignant neoplasms of the thymus gland (C34), taking into account gender, age characteristics and survival of patients. At the international level, try to divide the combined heading С37, 38. Select separately С37.
Methods. The material for the study was the database of the population cancer registry with a volume of more than 1 million 350 thousand observations. Standard research methods recommended by the International Association of Cancer Registries were used.
Results. The conducted research has shown the possibility to assess the prevalence and effectiveness of anticancer measures for rare malignant neoplasms. The specific weight of malignant neoplasms of the thymus gland (C37) among all tumors in the Northwestern Federal District is 0.02%, 5 times less than the occurrence of malignant neoplasms of the heart (C38). Attention is drawn to the fact that in recent years the accounting of this group of tumors has significantly improved in the North-Western Federal District. There were no sharp differences in the structure of the male and female population in the values of registered cases of the disease among people younger and older than 60 years.
It is important to note that positive dynamics of mortality rates of patients with malignant neoplasms of the thymus gland (C37) has been established for each year of follow-up. The parameters of age-specific indicators of morbidity have been determined, where the highest level is set for patients in the age group of 60-69 years. Grouped into four temporary cohorts, patients with the ventricular gland (C37) showed positive dynamics of one-year and five-year survival. A 25% decrease in the proportion of patients with an unspecified stage of the disease was revealed.
A high level (90-100%) of survival in patients with localized tumor process was noted. The five-year survival rate increased from 42.5 to 45%.