The Analysis of Basic Epidemiology and Genetic Characteristics of Prostate Cancer in Latvia. Summary of the Doctoral Thesis

Abstract

Prostate cancer is a common medical condition throughout the world. In many countries of the world, prostate cancer is the leading type of cancer by incidence and the second after lung cancer by mortality. Prostate cancer is morphologically, genetically, and clinically heterogeneous disease, and its clinical progress, response to therapy, and prognosis are directly dependent on its heterogeneous nature. Despite the multitude of studies devoted to prostate cancer worldwide, as well as some studies that were performed in Latvia, the information about its epidemiological trends in Latvia is incomplete and outdated. Even though studies were conducted about the genetic features of inherited prostate cancer in Latvia, insufficient comparative data are available about the familial and sporadic prostate cancer according to the criteria of survival rates, age, T stage, and tumour cell grade. The gene CHEK2 participates in cell repair and acts as a tumour suppressor. The del5395 mutation of CHEK2 has been linked to elevated risk of prostate cancer in several Central and Eastern European studies. There is a lack of data about the effect of del5395 mutation in CHEK2 on the development of prostate cancer in Latvian population. The goal of this study was to perform a population-based study of trends in prostate cancer epidemiology in Latvia between the years 1990 and 2014, to compare familial prostate cancer with sporadic prostate cancer in Latvia, and to investigate the effects of del5395 mutation in CHEK2 gene on the development of prostate cancer cases in Latvia. The study results indicate that the incidence, prevalence, and mortality due to prostate cancer in Latvia have increased from year 1990 to 2014. The largest increase in the incidence of prostate cancer was observed in the population under 60 years of age. Also, the largest increase in the prevalence of prostate cancer was observed in the population under 60 years of age. The mortality due to prostate cancer decreased in the populations that were 70–79 and 80 + years of age. The 5, 10, and 15 year survival rates improved in the considered time period, while the share of unspecified (TX) stage decreased, and the share of early stages (T1 and T2) increased. The mortality of patients in Latvia during the first year after diagnosis of prostate cancer has decreased in the considered time period. The familial type of prostate cancer had statistically significantly higher survival rate and earlier start of disease than the sporadic type of prostate cancer, but no differences were found in the T stages and the tumour cell grade. The del5395 mutation of CHEK2 gene is the common founder mutation in Latvia, but no statistically significant effect of this mutationon on the risk of prostate cancer development was identified in the Latvian population.