RESUMO
Over the past few years, a number of studies have revealed that a significant number of men with prostate cancer had genetic defects in the DNA damage repair gene response and mismatch repair genes. Certain of these modifications, notably gene alterations known as homologous recombination (HRR) genes; PALB2, CHEK2 BRCA1, BRCA2, ATM, and genes for DNA mismatch repair (MMR); MLH1, MSH2, MSH6, and PMS2 are connected to a higher risk of prostate cancer and more severe types of the disease. The DNA damage repair (DDR) is essential for constructing and diversifying the antigen receptor genes required for T and B cell development. But this DDR imbalance results in stress on DNA replication and transcription, accumulation of mutations, and even cell death, which compromises tissue homeostasis. Due to these impacts of DDR anomalies, tumor immunity may be impacted, which may encourage the growth of tumors, the release of inflammatory cytokines, and aberrant immune reactions. In a similar vein, people who have altered MMR gene may benefit greatly from immunotherapy. Therefore, for these treatments, mutational genetic testing is indicated. Mismatch repair gene (MMR) defects are also more prevalent than previously thought, especially in patients with metastatic disease, high Gleason scores, and diverse histologies. This review summarizes the current information on the mutation spectrum and clinical significance of DDR mechanisms, such as HRR and MMR abnormalities in prostate cancer, and explains how patient management is evolving as a result of this understanding.
RESUMO
BACKGROUND: Late diagnosis of prostate cancer is common in low and middle income countries and contributes to high morbidity and mortality of the disease. Utilization of prostate cancer screening services plays a major role in prevention of adverse outcomes. However, there is limited information on the knowledge about, the perceived risk of, and the utilization of prostate cancer screening in Tanzania. OBJECTIVE: To determine knowledge and perceived risk of prostate cancer, and the utilization of prostate cancer screening services, and associated factors, among men in Dar es Salaam, Tanzania. DESIGN: A population-based cross-sectional study involving men aged 40 years and above living in Dar es Salaam was conducted between May and August, 2018. METHODOLOGY: Participants were recruited through multistage random sampling and took part in structured face-to-face interviews. Categorical variables were summarized using proportions while continuous variables were summarized as medians and inter-quarterly range (IQR). Chi square test was used to compare differences between proportions, and logistic regression modelling was used to determine factors associated with utilization of prostate cancer screening. Both crude and adjusted odds ratios (OR), with corresponding 95% confidence intervals, are reported. All analyses were two-tailed and the significance level set at 5%. RESULTS: A total of 388 men with a median age of 53 years (IQR 44-55) participated. Half (52.1%) had poor knowledge about prostate cancer and prostate cancer screening. A third (32.3%, n = 125) perceived the risk of prostate cancer to be low. Only 30 respondents (7.7%) had ever been screened for prostate cancer. Utilization of prostate cancer screening services was independently associated with age above 60 years [AOR = 21.46, 95% CI: 6.23, 73.93], monthly income above 305 US Dollars [AOR = 15.68, 95% CI: 4.60, 53.48], the perceived risk of prostate cancer [AOR = 16.34, 95% CI: 7.82, 14.92] and knowledge about prostate cancer [AOR = 67.71, 95% CI: 8.20, 559.57]. CONCLUSIONS: Knowledge about prostate cancer and prostate cancer screening services was low among men in Dar es Salaam with a third perceiving themselves to be at no risk for the disease. Utilization of screening services was low and associated with low income, younger age, low perceived risk of prostate cancer and low knowledge about the disease. Intervention measures aiming to increase knowledge about prostate cancer and screening services, and affordable provision of services, are urgently called for.
RESUMO
Hundred unrelated father-son buccal swab sample pairs collected from consented Tanzanian population were examined to establish mutation rates using 17 Y-STRs loci DYS19, DYS389I, DYS389II, DYS390, DYS391, DYS392, DYS393, DYS385a, DYS385b, DYS437, DYS438, DYS439, DYS448, DYS456, DYS458, DYS635, and Y-GATA-H4 of the AmpFlSTRYfiler kit used in forensics and paternity testing. Prior to 17 Y-STRs analysis, father-son pair biological relationships were confirmed using 15 autosomal STRs markers and found to be paternally related. A total of four single repeat mutational events were observed between father and sons. Two mutations resulted in the gain of a repeat and the other two resulted in a loss of a repeat in the son. All observed mutations occurred at tetranucleotide loci DYS389II, DYS385a, and DYS385b. The locus specific mutation rate varied between 0 and 1.176 x10-3 and the average mutation rate of 17Y-STRs loci in the present study was 2.353x10-3 (6.41x10-4 - 6.013x10-3) at 95% CI. Furthermore the mean fathers' age with at least one mutation at son's birth was 32 years with standard error of 2.387 while the average age of all fathers without mutation in a sampled population at son's birth was 26.781 years with standard error of 0.609. The results shows that fathers' age at son's birth may have an effect on Y-STRs mutation rate analysis, though this age difference was statistically not significant using unpaired samples t-test (p = 0.05). As a consequence of observed mutation rates in this study, the precise and reliable understanding of mutation rate at Y-chromosome STR loci is necessary for a correct evaluation and interpretation of DNA typing results in forensics and paternity testing involving males. The criterion for exclusion in paternity testing should be defined, so that an exclusion from paternity has to be based on exclusion constellations at a minimum of two 17 Y-STRs loci.