Bladder cancer trends in Latvia during 1990-2017: incidence, mortality, and survival rates.

INTRODUCTION: The aim of this article was to evaluate bladder cancer (BC) incidence, mortality and survival trends in Latvia over the past 28 years. MATERIAL AND METHODS: Our study included patients diagnosed with BC between 1990 and 2017. The data were obtained from the national population-based cancer registry. Joinpoint regression analysis was used to identify points where a significant change in incidence and mortality trends occurred, accordingly with the patient's gender and age. Relative survival (RS) was estimated by Ederer I and II methods. RESULTS: Altogether, 9589 patients with initial BC diagnosis were included in the study. The age-standardised (ASR) incidence rates (per 100,000) increased from 6.8 in 1990 to 12.5 in 2014 followed by a statistically insignificant decrease continuing up to 2017. The ASR BC mortality rates (per 100,000) also rose from 3.9 in 1990 to 4.4 in 2017. However, there was a decline in BC mortality trends in the age-group 40-59 with annual percentage change (APC) -1.1%. RS rates increased from 55.0 % in 1990-2000 to 59.0% in years 2013-2017. CONCLUSIONS: This study revealed that the incidence and mortality rates have been gradually increasing over the past 28 years. The exception being cancer-specific mortality in the age group 40-59, which tends to decrease. Although the 5-year RS rates improved over the reviewed period, there is still plenty of room for improvement.

Prostate cancer trends in Latvia during 1990-2012: incidence, prevalence, mortality, and survival rates.

BACKGROUND AND OBJECTIVE: Prostate cancer (PCa) is one of the most common form of cancer in males worldwide. One of the highest PCa-related mortality rates in the world is observed in Latvia. MATERIALS AND METHODS: Our study included male patients diagnosed with PCa between 1990 and 2012. We analyzed incidence, prevalence and mortality trends using joinpoint analysis. Kaplan-Meier analysis was performed for 5-, 10-, 15- and 20-year overall survival and cancer-specific survival rates. RESULTS: A total of 14,083PCa patients with a mean age of initial PCa diagnosis being 70.1 (SD 8.6) was registered. The standardized incidence rates (per 100,000) increased from 18.9 in 1990 to 74.7 in 2012, while the standardized prevalence rates (per 100,000) increased from 69.9 in 1990 to 437.6 in 2012. Standardized PCa mortality rates (per 100,000) also rose from 13.2 in 1990 to 27.2 in 2006 followed by statistically insignificant decrease continuing up to 2012. The mean 5-year cancer-specific survival rates increased from 43.6% in 1990 to 70.7% in 2007, and the mean 10-year cancer-specific survival rates from 32.9% in 1990 to 40.5% in 2001. CONCLUSIONS: This study revealed that the incidence, prevalence and mortality rates increased between 1990 and 2012, and although the 5- and 10-year overall and cancer-specific survival rates improved over the reviewed period they still needed to get better.

Telomere length in Chernobyl accident recovery workers in the late period after the disaster.

The outcome of the Chernobyl nuclear power plant (CNPP) accident was that a huge number of people were exposed to ionizing radiation. Previous studies of CNPP clean-up workers from Latvia revealed a high occurrence of age-associated degenerative diseases and cancer in young adults, as well as a high mortality as a result of cardiovascular disorders at age 45-54 years. DNA tandem repeats that cap chromosome ends, known as telomeres, are sensitive to oxidative damage and exposure to ionizing radiation. Telomeres are important in aging processes and carcinogenesis. The aim of this study was to investigate the long-term effect of protracted ionizing radiation exposure on telomere length in CNPP clean-up workers. Relative telomere length (RTL) was measured in peripheral blood leukocytes of 595 CNPP clean-up workers and 236 gender- and age-matched controls using real-time quantitative polymerase chain reaction (q-PCR). Close attention was paid to participation year and tasks performed during the worker's stay in Chernobyl, health status, and RTL differences between subgroups. Telomere shortening was not found in CNPP clean-up workers; on the contrary, their RTL was slightly greater than in controls (P = 0.001). Longer telomeres were found in people who worked during 1986, in those undertaking 'dirty' tasks (digging and deactivation), and in people with cancer. Shorter telomeres appeared frequently in those with cataract, osteoporosis, atherosclerosis, or coronary heart disease. We conclude that the longer telomeres revealed in people more heavily exposed to ionizing radiation probably indicate activation of telomerase as a chromosome healing mechanism following damage, and reflect defects in telomerase regulation that could potentiate carcinogenesis.