Smoking and Risk of Prostate Cancer and Prostate Cancer Death: A Pooled Study

Association between polyphenol subclasses and prostate cancer: a systematic review and meta-analysis of observational studies

Background

The effect of polyphenol subclasses on prostate cancer (PCA) is controversial. Therefore, the purpose of this study was to investigate the relationship between polyphenol subclasses and PCA incidence.

Methods

From the establishment of the database to December 2023, a systematic search was conducted on PubMed, Web of Science, Embase, and Cochrane Library to identify relevant observational studies. The adjusted odds ratio (OR) and corresponding 95% confidence interval (95% CI) were used to assess the association.

Results

A total of 38 studies (11 were cohort studies and 27 were case-control studies), composing 824,933 participants, were included in this meta-analysis after excluding irrelevant records. The findings of the study revealed that men who consumed dietary polyphenols had a significantly higher risk of PCA compared to those who never or rarely consumed dietary polyphenols (OR = 1.01, p = 0.023), especially dietary flavonol (OR = 1.05, p = 0.042), flavanol (OR = 1.03, p = 0.026) and anthocyanin (OR = 1.06, p = 0.001). Neither total nor subclasses of dietary polyphenols have an effect on non-localized or high-grade PCA (OR = 1.01, p = 0.518). Dietary isoflavones tended to reduce the incidence of local or low-grade PCA, although there was no statistically significant difference (OR = 1.00, p = 0.081). Regarding serum/plasma polyphenol, total polyphenol (OR = 0.95, p = 0.002), genistein (OR = 0.92, p = 0.029) and enterolactone (OR = 0.92, p = 0.022) can reduce the incidence of PCA. No association was observed between total/subclasses of urinary polyphenols and PCA risk.

Conclusion

Polyphenols seem to generally increase the risk of PCA in the male population. The effect of polyphenols on PCA is affected by factors such as polyphenol subclasses, their forms (serum/plasma, urinary, dietary), and PCA-related factors (like PCA stage).

Systematic review registration

identifier: CRD42022322699.

The association between methylmalonic acid, a biomarker of mitochondrial dysfunction, and risk of prostate cancer

BACKGROUND

The aim of the study was to investigate the association between methylmalonic acid (MMA), a biomarker of mitochondrial dysfunction, and the risk of prostate cancer (PCa).

METHODS AND MATERIALS

The relevant data were collected from the National Health and Nutrition Examination Survey (NHANES). Weighted univariable and multivariable logistic regression analyses were performed to investigate the association between MMA and risk of PCa. A stratified analysis was also carried out. The dose-response relationship was elucidated by conducting a restricted cubic spline function.

RESULTS

A total of 2451 participants were included, of which 95 were PCa participants. The fully-adjusted model 2 constructed by weighted multivariable logistic regression analysis showed that the risk of PCa decreased by 53% when every MMA unit was added [OR: 0.47 (0.22-1.00), P = 0.049]. And a decrease in PCa risk was associated with a higher MMA level in MMA subgroups [OR: 0.34 (0.15-0.82), P = 0.02]. The results from a stratified analysis showed that participants in subgroups of other race, BMI (> 30 kg/m2), smoking (former and now), and hypertension (yes), an increase in every MMA unit was linked to a decrease in PCa risk. MMA and the risk of PCa were negatively correlated in a linear manner.

CONCLUSION

It was discovered in the study that an increase in MMA level is connected to a decrease in PCa risk. The serum MMA level may be helpful in assessing PCa risk.

Cigarette smoking and prostate cancer aggressiveness among African and European American men

PURPOSE

Smoking is a modifiable lifestyle factor that has not been established as a prostate cancer risk factor, nor emphasized in prostate cancer prevention. Studies have shown that African American (AA) smokers have a poorer cancer prognosis than European Americans (EAs), while having a lower prevalence of heavy smoking. We examined the relationship between cigarette smoking and prostate cancer aggressiveness and assessed racial differences in smoking habits on the probability of high-aggressive prostate cancer.

METHODS

Using data from the North Carolina-Louisiana Prostate Cancer Project (n = 1,279), prostate cancer aggressiveness was defined as high or low based on Gleason scores, serum prostate-specific antigen levels, and tumor stage. Cigarette smoking was categorized as current, former, or never smokers. Multivariable logistic regression was used to estimate adjusted odds ratios (OR) and 95% confidence intervals (CI).

RESULTS

Self-reported current (OR = 1.99; 95% CI 1.30-3.06) smoking was associated with high-aggressive prostate cancer relative to never smokers. When stratified by self-reported race, the odds of having high-aggressive cancer increased among AA current (OR = 3.58; 95% CI 2.04-6.28) and former smokers (OR = 2.21; 95% CI 1.38-3.53) compared to AA never smokers, but the odds were diminished among the EA stratum (Pself-reported race x smoking status = 0.003).

CONCLUSION

Cigarette smoking is associated with prostate cancer aggressiveness, a relationship modulated by self-reported race. Future research is needed to investigate types of cigarettes smoked and metabolic differences that may be contributing to the racial disparities observed.

Dysregulation of immunity by cigarette smoking promotes inflammation and cancer: A review

Smoking is a serious global health issue. Cigarette smoking contains over 7000 different chemicals. The main harmful components include nicotine, acrolein, aromatic hydrocarbons and heavy metals, which play the key role for cigarette-induced inflammation and carcinogenesis. Growing evidences show that cigarette smoking and its components exert a remarkable impact on regulation of immunity and dysregulated immunity promotes inflammation and cancer. Therefore, this comprehensive and up-to-date review covers four interrelated topics, including cigarette smoking, inflammation, cancer and immune system. The known harmful chemicals from cigarette smoking were summarized. Importantly, we discussed in depth the impact of cigarette smoking on the formation of inflammatory or tumor microenvironment, primarily by affecting immune effector cells, such as macrophages, neutrophils, and T lymphocytes. Furthermore, the main molecular mechanisms by which cigarette smoking induces inflammation and cancer, including changes in epigenetics, DNA damage and others were further summarized. This article will contribute to a better understanding of the impact of cigarette smoking on inducing inflammation and cancer.

Therapeutic, diagnostic and prognostic values of TRIM proteins in prostate cancer

Prostate cancer is the second most prevalent cancer in men worldwide. The TRIM (tripartite motif) family of proteins is involved in the regulation of various cellular processes, including antiviral immunity, apoptosis, and cancer progression. In recent years, several TRIM proteins have been found to play important roles in prostate cancer initiation and progression. TRIM proteins have indicated oncogenic activity in prostate cancer by enhancing androgen or estrogen receptor signaling and promoting cancer cell growth. Inhibition of TRIM proteins has been raised as a potential therapeutic strategy for the treatment of prostate cancer. Overall, these studies suggest that TRIM family proteins exert tumor-promoting effects in prostate cancer, and targeting these proteins can provide a promising therapeutic strategy for prostate cancer treatment. On the other hand, some TRIM proteins can be differentially expressed in prostate cancer cells compared to normal cells, thus providing novel diagnostic/prognostic biomarkers for prostate cancer.

The Risk Factors and Screening Uptake for Prostate Cancer: A Scoping Review

OBJECTIVES

The purpose of this scoping review was to identify the risk factors and screening uptake for prostate cancer.

DESIGN

Scoping review.

METHODS

Arksey and O'Malley's framework guided this review; five databases (Cumulative Index to Nursing and Allied Health Literature (CINAHL), MEDLINE, PsycINFO, Academic Search Complete and Cochrane Library) and grey literature were searched. Screening was undertaken against predetermined inclusion criteria for articles published before July 2023 and written in English. This review is reported in line with PRISMA-Sc.

RESULTS

10,899 database results were identified; 3676 papers were removed as duplicates and 7115 papers were excluded at title and abstract review. A total of 108 papers were full-text reviewed and 67 were included in the review. Grey literature searching yielded no results. Age, family history/genetics, hormones, race/ethnicity, exposure to hazards, geographical location and diet were identified as risk factors. Prostatic antigen test (PSA), digital rectal examination (DRE), transrectal ultrasound (TRUS), magnetic resonance imaging (MRI), magnetic resonance spectroscopic imaging (MRSI) and prostate biopsy were identified as screening/diagnostic methods. The evidence reviewed highlights moderate knowledge and screening uptake of prostate cancer with less than half of men reporting for PSA screening. On the other hand, there is a year-to-year increase in PSA and DRE screening, but factors such as poverty, religion, culture, communication barriers, language and costs affect men's uptake of prostate cancer screening.

CONCLUSION

As prostate cancer rates increase globally, there is a need for greater uptake of prostate cancer screening and improved health literacy among men and health workers. There is a need to develop a comprehensive prostate cancer awareness and screening programme that targets men and addresses uptake issues so as to provide safe, quality care.

STRENGTHS AND LIMITATIONS OF THIS STUDY

(1) A broad search strategy was utilised incorporating both databases and grey literature. (2) The PRISMA reporting guidelines were utilised. (3) Only English language papers were included, and this may have resulted in relevant articles being omitted.

A Large Genetic Causal Analysis of the Gut Microbiota and Urological Cancers: A Bidirectional Mendelian Randomization Study

BACKGROUND

Several observational studies and clinical trials have shown that the gut microbiota is associated with urological cancers. However, the causal relationship between gut microbiota and urological cancers remains to be elucidated due to many confounding factors.

METHODS

In this study, we used two thresholds to identify gut microbiota GWAS from the MiBioGen consortium and obtained data for five urological cancers from the UK biobank and Finngen consortium, respectively. We then performed a two-sample Mendelian randomization (MR) analysis with Wald ratio or inverse variance weighted as the main method. We also performed comprehensive sensitivity analyses to verify the robustness of the results. In addition, we performed a reverse MR analysis to examine the direction of causality.

RESULTS

Our study found that family Rikenellaceae, genus Allisonella, genus Lachnospiraceae UCG001, genus Oscillibacter, genus Eubacterium coprostanoligenes group, genus Eubacterium ruminantium group, genus Ruminococcaceae UCG013, and genus Senegalimassilia were related to bladder cancer; genus Ruminococcus torques group, genus Oscillibacter, genus Barnesiella, genus Butyricicoccus, and genus Ruminococcaceae UCG005 were related to prostate cancer; class Alphaproteobacteria, class Bacilli, family Family XI, genus Coprococcus2, genus Intestinimonas, genus Lachnoclostridium, genus Lactococcus, genus Ruminococcus torques group, and genus Eubacterium brachy group were related to renal cell cancer; family Clostridiaceae 1, family Christensenellaceae, genus Eubacterium coprostanoligenes group, genus Clostridium sensu stricto 1, and genus Eubacterium eligens group were related to renal pelvis cancer; family Peptostreptococcaceae, genus Romboutsia, and genus Subdoligranulum were related to testicular cancer. Comprehensive sensitivity analyses proved that our results were reliable.

CONCLUSIONS

Our study confirms the role of specific gut microbial taxa on urological cancers, explores the mechanism of gut microbiota on urological cancers from a macroscopic level, provides potential targets for the screening and treatment of urological cancers, and is dedicated to providing new ideas for clinical research.

Causal Effects of Modifiable Behaviors on Prostate Cancer in Europeans and East Asians: A Comprehensive Mendelian Randomization Study

OBJECTIVE

Early evidence is disputable for the effects of modifiable lifestyle behaviors on prostate cancer (PCa) risk. No research has yet appraised such causality in different ancestries using a Mendelian randomization (MR) approach.

METHODS

A two-sample univariable and multivariable MR analysis was performed. Genetic instruments associated with lifestyle behaviors were selected based on genome-wide association studies. Summary-level data for PCa were obtained from PRACTICAL and GAME-ON/ELLIPSE consortia for Europeans (79,148 PCa cases and 61,106 controls), and ChinaPCa consortium for East Asians (3343 cases and 3315 controls). Replication was performed using FinnGen (6311 cases and 88,902 controls) and BioBank Japan data (5408 cases and 103,939 controls).

RESULTS

Tobacco smoking was identified as increasing PCa risks in Europeans (odds ratio [OR]: 1.95, 95% confidence interval [CI]: 1.09-3.50, p = 0.027 per standard deviation increase in the lifetime smoking index). For East Asians, alcohol drinking (OR: 1.05, 95%CI: 1.01-1.09, p = 0.011) and delayed sexual initiation (OR: 1.04, 95%CI: 1.00-1.08, p = 0.029) were identified as risk factors, while cooked vegetable consumption (OR: 0.92, 95%CI: 0.88-0.96, p = 0.001) was a protective factor for PCa.

CONCLUSIONS

Our findings broaden the evidence base for the spectrum of PCa risk factors in different ethnicities, and provide insights into behavioral interventions for prostate cancer.