Tobacco smoking, polymorphisms in carcinogen metabolism enzyme genes, and risk of localized and advanced prostate cancer: results from the California Collaborative Prostate Cancer Study

Genetic mutations in smoking-associated prostate cancer

OBJECTIVES

Tobacco smoking is known to cause cancers potentially predisposed by genetic risks. We compared the frequency of gene mutations using a next generation sequencing database of smokers and nonsmokers with prostate cancer (PCa) to identify subsets of patients with potential genetic risks.

MATERIALS AND METHODS

Data from the American Association for Cancer Research Project Genomics Evidence Neoplasia Information Exchange (GENIE) registry was analyzed. The GENIE registry contains clinically annotated sequenced tumor samples. We included 1832 men with PCa in our cohort, categorized as smokers and nonsmokers, and compared the frequency of mutations (point mutations, copy number variations, and structural variants) of 47 genes with more than 5% mutation rate between the two categories and correlated with overall survival using logistic regression analysis.

RESULTS

Overall, 1007 (55%) patients were nonsmokers, and 825 (45%) were smokers. The mutation frequency was significantly higher in smokers compared to nonsmokers, 47.6% and 41.3%, respectively (p = 0.02). The median tumor mutational burden was also significantly higher in the samples from smokers (3.59 mut/MB) compared to nonsmokers (1.87 mut/MB) (p < 0.001). Patients with a smoking history had a significantly higher frequency of PREX2, PTEN, AGO2, KMT2C, and a lower frequency of adenomatous polyposis coli (APC) and KMT2A mutations than compared to nonsmokers. The overall mortality rate (28.5% vs. 22.8%) was significantly higher among smokers (p = 0.006). On a multivariate logistic regression analysis, the presence of metastatic disease at the time of diagnosis (OR: 2.26, 95% CI: 1.78-2.89, p < 0.001), smoking history (OR: 1.32, 95% CI: 1.05-1.65, p = 0.02), and higher frequency of PTEN somatic gene mutation (OR: 1.89, 95% CI: 1.46-2.45, p < 0.001) were independent predictors of increased overall mortality among patients with PCa. Patients with PTEN mutation had poorer overall survival compared to men without PTEN mutations: 96.00 (95% CI: 65.36-113.98) and 120.00 (95% CI: 115.05-160.00) months, respectively (p < 0.001) irrespective of smoking history although the G129R PTEN mutation was characteristically detected in smokers.

CONCLUSIONS

PCa patients with a tobacco smoking history demonstrated a significantly higher frequency of somatic genetic mutations. Whereas mutations of PREX2, KMT2C, AGO2, and PTEN genes were higher in smokers, the APC and KMT2A mutations were higher in nonsmokers. The PTEN somatic gene mutation was associated with increased overall mortality among patients with PCa irrespective of smoking history. We found that G129R PTEN mutation known to reduce the PTEN phosphatase activity and K267Rfs*9 a frameshift deletion mutation in the C2 domain of PTEN associated with membrane binding exclusively detected in smokers and nonsmokers, respectively. These findings may be used to further our understanding of PCa associated with smoking.

Association of NAT2, GSTT1, and GSTM1 gene polymorphisms withprostate cancer risk in Bangladeshi population

One of the leading causes of cancer-related mortality in males is prostate cancer. The latest molecular studies revealed the interconnection of genetic polymorphism of N acetyltransferase (NAT) and Glutathione-S-transferase (GST) gene in the genesis of prostate cancer. The study's aim was to find out the association of NAT2, GSTT1, and GSTM1 gene polymorphisms with the risk of prostate cancer in the Bangladeshi population. This case-control study included 207 histopathologically diagnosed cases of prostate cancer and 200 age-matched healthy controls. After taking informed written consent, 5.0 ml of venous blood was collected to extract genomic DNA for genetic analysis ofNAT2, GSTT1& GSTM1 by PCR-RFLP by multiplex PCR methods. In this study, the mean±SD age of cases and control was 67.3±8.3, and 62.2±6.8 years, respectively. A higher frequency of mutant NAT2*5A, NAT2*6A, and NAT2*7A in prostate cancer cases was observed in this study, in comparison to controls. Prostate cancer risk was found considerably increased in patients with NAT2 slow genotypes, GSTT1 and GSTM1 null genotypes, compared to control. Furthermore, Prostate cancer risk was found very significantly associated with the presence of combined genotypes that included NAT2 (slow), GSTT1 (null), and GSTM1 (null), and the risk rose 9.64-fold when compared to the wild genotype for NAT1, GSTT1, and GSTM1. Again, it was observed that individuals with positive smoking history/family history of cancer along with NAT2 slow genotype had significantly increased risk for prostate cancer. Moreover, the likelihood of developing a moderate to a high-grade tumor (Gleason score 7), as well as locally progressed or metastatic prostate cancer was considerably greater in persons with NAT2 slow genotypes, GSTT1, and GSTM1 null genotypes. This study established the association of genetic polymorphisms of NAT2, GSTT1, and GSTM1 genes with prostate cancer risk in the Bangladeshi population.

Polymorphisms in the gene encoding CYP1A2 influence prostate cancer risk and progression

The role of the cytochrome P450 1A2 (CYP1A2) rs2472299, rs2470890 and rs11072508 polymorphisms in prostate cancer risk, disease progression and tumour development remains unclear. The potential associations of these three CYP1A2 polymorphisms and haplotypes with prostate cancer susceptibility and its clinicopathological characteristics were therefore investigated. The present case-control study consisted of 522 patients with prostate cancer and 554 healthy controls. High-resolution melting analysis was used to determine the CYP1A2 polymorphisms. No significant association in prostate cancer risk was seen for CYP1A2 rs2472299 and rs11072508. However, a significantly decreased risk of prostate cancer was found for CYP1A2 rs2470890 [odds ratio (OR), 0.67; P=0.02] in the recessive model. After analysis of the associations of clinical status and these three CYP1A2 polymorphisms, the CYP1A2 rs2470890 and rs11072508 polymorphisms showed a positive association with a higher Gleason score (rs2470890 OR, 1.36, P=0.04 in the allelic model; rs11072508 OR, 1.37, P=0.04 in the allelic model and OR, 1.60, P=0.03 in the dominant model). All three polymorphisms showed a significant positive association with pathological T stage in the additive, allelic and dominant genetic models (P<0.05). Haplotype analysis revealed that the most common haplotypes 'GTT' and 'ACC' were significantly associated with pathological T stages 3 and 4 (OR, 0.62; P=0.02 and OR, 1.54; P=0.03, respectively). A significant association was found between the 'GTT' haplotype and the Gleason score (OR, 0.71; P=0.03). In conclusion, these CYP1A2 polymorphisms and haplotypes have the potential to predict prostate cancer disease progression.

The Impact of Lifestyle on Prostate Cancer: A Road to the Discovery of New Biomarkers

Prostate cancer (PCa) is one of the most common cancers among men, and its incidence has been rising through the years. Several risk factors have been associated with this disease and unhealthy lifestyles and inflammation were appointed as major contributors for PCa development, progression, and severity. Despite the advantages associated with the currently used diagnostic tools [prostate-specific antigen(PSA) serum levels and digital rectal examination (DRE)], the development of effective approaches for PCa diagnosis is still necessary. Finding lifestyle-associated proteins that may predict the development of PCa seems to be a promising strategy to improve PCa diagnosis. In this context, several biomarkers have been identified, including circulating biomarkers (CRP, insulin, C-peptide, TNFα-R2, adiponectin, IL-6, total PSA, free PSA, and p2PSA), urine biomarkers (PCA3, guanidine, phenylacetylglycine, and glycine), proteins expressed in exosomes (afamin, vitamin D-binding protein, and filamin A), and miRNAs expressed in prostate tissue (miRNA-21, miRNA-101, and miRNA-182). In conclusion, exploring the impact of lifestyle and inflammation on PCa development and progression may open doors to the identification of new biomarkers. The discovery of new PCa diagnostic biomarkers should contribute to reduce overdiagnosis and overtreatment.

Prostate cancer mortality in Brazil 1990-2019: geographical distribution and trends

INTRODUCTION:

To analyze the trend of prostate cancer mortality in the Brazilian population of 40 years of age and above.

METHODS:

Time series ecological study of the mortality rates due to prostate cancer in men of 40 years of age and above, using data from the Global Burden of Disease 2019 (GBD). Age-standardized mortality rates were calculated, as well as the age-standardized rates by the GBD for the global population, per 100,000 inhabitants, for Brazil and its States, from 1990 to 2019. The annual average percent change (AAPC) was calculated to identify the mortality trends in Brazil, through linear regression using the Joinpoint Regression Program.

RESULTS:

The standardized rates of prostate cancer mortality in Brazil were 76.89 in 1990 and 74.96 deaths for every 100 thousand men ≥ 40 years of age in 2019, with a stability trend. By age group, it was observed a decreasing trend up to 79 years of age, and an increasing trend as of 80 years of age. The state of Bahia showed the highest increase in mortality in the period (1.2%/year), followed by Maranhão and Pernambuco (1.0 and 0.9%/year). A decrease of prostate cancer mortality was found in the Federal District, Goiás, Minas Gerais, Rio de Janeiro, Rio Grande do Sul, Roraima, Santa Catarina, São Paulo, and Sergipe.

CONCLUSIONS:

In Brazil, the standardized mortality rates show a trend toward stability from 1990 to 2019 and no pattern was observed for the trends according to the Brazilian States.

Association between coffee consumption and overall risk of being diagnosed with or dying from cancer among >300 000 UK Biobank participants in a large-scale Mendelian randomization study

BACKGROUND

Previous observational studies have suggested that coffee intake may be associated with a reduction in cancer risk. Mendelian randomization (MR) studies can help clarify whether the observed associations are likely to be causal. Here we evaluated whether coffee intake is associated with: (i) overall risk of being diagnosed with/dying from any cancer; and (ii) risk of individual cancers.

METHODS

We identified 46 155 cases (of which 6998 were fatal) and 270 342 controls of White British ancestry from the UK Biobank cohort (UKB), based on ICD10 diagnoses. Individuals with benign tumours were excluded. Coffee intake was self-reported and recorded based on cup/day consumption. We conducted both observational and summary data MR analyses.

RESULTS

There was no observational association between coffee intake and overall cancer risk [odds ratio (OR) per one cup/day increase = 0.99, 95% confidence interval (CI) 0.98, 1.00] or cancer death (OR = 1.01, 0.99, 1.03); the estimated OR from MR is 1.01 (0.94, 1.08) for overall cancer risk and 1.11 (0.95, 1.31) for cancer death. The relationship between coffee intake and individual cancer risks were consistent with a null effect, with most cancers showing little or no associations with coffee. Meta-analysis of our MR findings with publicly available summary data on various cancers do not support a strong causal relationship between coffee and risk of breast, ovarian, lung or prostate cancer, upon correction for multiple testing.

CONCLUSIONS

Taken together, coffee intake is not associated with overall risk of being diagnosed with or dying from cancer in UKB. For individual cancers, our findings were not statistically inconsistent with earlier observational studies, although for these we were unable to rule out a small effect on specific types of cancer.

Latest Evidence on the Impact of Smoking, Sports, and Sexual Activity as Modifiable Lifestyle Risk Factors for Prostate Cancer Incidence, Recurrence, and Progression: A Systematic Review of the Literature by the European Association of Urology Section of Oncological Urology (ESOU)

CONTEXT

Smoking, sexual activity, and physical activity (PA) are discussed as modifiable lifestyle factors associated with prostate cancer (PCa) development and progression.

OBJECTIVE

To evaluate the available evidence concerning the association of smoking, sexual activity, and sports and exercise on PCa risk, treatment outcome, progression, and cancer-specific mortality.

EVIDENCE ACQUISITION

A systematic review of studies published between 2007 and 2017 using MEDLINE (via PubMed), Cochrane Central Register of Controlled Trials, and Web of Science databases according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis statement criteria was conducted.

EVIDENCE SYNTHESIS

While data concerning the impact of smoking on PCa development remain conflicting, there is robust evidence that smoking is associated with aggressive tumor features and worse cancer-related outcome, which seems to be maintained for 10 yr after smoking cessation. Less convincing and limited evidence exists for the association of sexual activity with PCa risk. The findings related to PA and PCa support the inference that exercise might be a useful factor in the prevention of PCa and tumor progression, while it is not finally proved under which specific conditions PA might be protective against disease development.

CONCLUSIONS

Smoking is associated with aggressive tumor features and worse cancer-related prognosis; as this negative impact seems to be maintained for 10yr after smoking cessation, urologists should advise men to quit smoking latest at PCa diagnosis to improve their prognosis. As several studies indicate a positive impact of exercise on tumor development, progression, and treatment outcome, it is certainly reasonable to advocate an active lifestyle. Least convincing evidence is available for the interaction of sexual activity and PCa, and well-conducted and longitudinal studies are clearly necessary to evaluate whether the suggested associations between PCa risk and sexual behavior are real or spurious.

PATIENT SUMMARY

In this systematic review, we looked at the impact of smoking, sexual activity, and sports and exercise on prostate cancer risk and outcome after treatment. While the evidence for sexual activity is not overall clear, we found that smoking might lead to more aggressive cancers and result in worse treatment outcome. Physical activity might prevent prostate cancer and improve cancer-related outcomes as well. Hence, it is certainly reasonable to advocate an active lifestyle and advise men to quit smoking.

Food Habits, Lifestyle Factors, and Risk of Prostate Cancer in Central Argentina: A Case Control Study Involving Self-Motivated Health Behavior Modifications after Diagnosis

Cancer is the second most important non-communicable disease worldwide and disproportionately impacts low- to middle-income countries. Diet in combination with other lifestyle habits seems to modify the risk for some cancers but little is known about South Americans. Food habits of Argentinean men pre- and post-diagnosis of prostate cancer (n = 326) were assessed along with other lifestyle factors. We studied whether any of the behaviors and risk factors for prostate cancer were found in men with other cancers (n = 394), compared with control subjects (n = 629). Before diagnosis, both cases reported a greater mean consumption of meats and fats and lower intakes of fruits, green vegetables, cruciferous vegetables, legumes, nuts, seeds, and whole grains than the controls (all p < 0.001). After diagnosis, cases significantly reduced the intake of meats and fats, and reported other dietary modifications with increased consumption of fish, fruits (including red fruits in prostate cancer), cruciferous vegetables, legumes, nuts, and black tea (all p < 0.001). Additional lifestyle aspects significantly predominant in cases included a reduced quality of sleep, emotional stress, low physical activity, tobacco smoking, alcohol consumption, living in rural areas, and being exposed to environmental contaminants. Argentinian men were predisposed to modify their unhealthy dietary habits and other lifestyle factors after cancer diagnosis.

Lack of association between polymorphisms in the CYP1A2 gene and risk of cancer: evidence from meta-analyses

BACKGROUND

Polymorphisms in the CYP1A2 genes have the potential to affect the individual capacity to convert pre-carcinogens into carcinogens. With these comprehensive meta-analyses, we aimed to provide a quantitative assessment of the association between the published genetic association studies on CYP1A2 single nucleotide polymorphisms (SNPs) and the risk of cancer.

METHODS

We searched MEDLINE, ISI Web of Science and SCOPUS bibliographic online databases and databases of genome-wide association studies (GWAS). After data extraction, we calculated Odds Ratios (ORs) and 95% confidence intervals (CIs) for the association between the retrieved CYP1A2 SNPs and cancer. Random effect model was used to calculate the pooled ORs. Begg and Egger tests, one-way sensitivity analysis were performed, when appropriate. We conducted stratified analyses by study design, sample size, ethnicity and tumour site.

RESULTS

Seventy case-control studies and one GWA study detailing on six different SNPs were included. Among the 71 included studies, 42 were population-based case-control studies, 28 hospital-based case-control studies and one genome-wide association study, including total of 47,413 cancer cases and 58,546 controls. The meta-analysis of 62 studies on rs762551, reported an OR of 1.03 (95% CI, 0.96-1.12) for overall cancer (P for heterogeneity < 0.01; I(2) = 50.4%). When stratifying for tumour site, an OR of 0.84 (95% CI, 0.70-1.01; P for heterogeneity = 0.23, I(2) = 28.5%) was reported for bladder cancer for those homozygous mutant of rs762551. An OR of 0.79 (95% CI, 0.65-0.95; P for heterogeneity = 0.09, I(2) = 58.1%) was obtained for the bladder cancer from the hospital-based studies and on Caucasians.

CONCLUSIONS

This large meta-analysis suggests no significant effect of the investigated CYP1A2 SNPs on cancer overall risk under various genetic models. However, when stratifying according to the tumour site, our results showed a borderline not significant OR of 0.84 (95% CI, 0.70-1.01) for bladder cancer for those homozygous mutant of rs762551. Due to the limitations of our meta-analyses, the results should be interpreted with attention and need to be further confirmed by high-quality studies, for all the potential CYP1A2 SNPs.

In vitro and in vivo model systems used in prostate cancer research

New incidence of prostate cancer is a major public health issue in the Western world, and has been rising in other areas of the globe in recent years. In an effort to understanding the molecular pathogenesis of this disease, numerous cell models have been developed, arising mostly from patient biopsies. The introduction of the genetically engineered mouse in biomedical research has allowed the development of murine models that allow for the investigation of tumorigenic and metastatic processes. Current challenges to the field include lack of an animal model that faithfully recapitulates bone metastasis of prostate cancer.