Periodontal disease and the risk of prostate cancer: a meta-analysis of cohort studies

ABSTRACT Background: Periodontal disease is reportedly associated with the risk of various systemic diseases, including pancreatic and lung cancers. However, its association with prostate cancer remains inconclusive. Herein, we explored the association of periodontal disease with the risk of prostate cancer through a meta-analysis. Materials and Methods: MEDLINE, Embase, Web of Sciences and Cochrane Library databases were searched for eligible publications up to April 2020. Multivariate adjusted risk estimates with corresponding 95% confidence intervals (CIs) were extracted and calculated using random- or fixed-effect models. Results: Nine cohort studies involving 3.353 prostate cancer cases with 440.911 participants were identified and included in the meta-analysis. We found that periodontal disease significantly increased the risk of prostate cancer by 1.40-fold (hazard ratio [HR]=1.40, 95% CI: 1.16-1.70; P=0.001; I2=76.1%) compared with normal condition. Interestingly, the risk of developing prostate cancer was not significant in patients treated with periodontal therapy (HR=1.22, 95% CI: 0.86-1.73; P=0.272; I2=65.2%). The results of subgroup analyses were also consistent and significant when stratified by study design and follow-up period, whereas conflicting results were observed in periodontal disease ascertainment stratification. These findings were robust as indicated by sensitivity analyses. Conclusions: Periodontal disease was associated with the increased risk of prostate cancer, whereas no significant association was observed in patients treated with periodontal therapy. Hence, the awareness and importance for maintaining oral health should be improved, and the underlying mechanisms linking periodontal disease and prostate cancer should be fully explored in future research.

Periodontal disease and the risk of prostate cancer: a meta-analysis of cohort studies.

BACKGROUND: Periodontal disease is reportedly associated with the risk of various systemic diseases, including pancreatic and lung cancers. However, its association with prostate cancer remains inconclusive. Herein, we explored the association of periodontal disease with the risk of prostate cancer through a meta-analysis. MATERIALS AND METHODS: MEDLINE, Embase, Web of Sciences and Cochrane Library databases were searched for eligible publications up to April 2020. Multivariate adjusted risk estimates with corresponding 95% confidence intervals (CIs) were extracted and calculated using random- or fixed-effect models. RESULTS: Nine cohort studies involving 3.353 prostate cancer cases with 440.911 participants were identified and included in the meta-analysis. We found that periodontal disease significantly increased the risk of prostate cancer by 1.40-fold (hazard ratio [HR]=1.40, 95% CI: 1.16-1.70; P=0.001; I2=76.1%) compared with normal condition. Interestingly, the risk of developing prostate cancer was not significant in patients treated with periodontal therapy (HR=1.22, 95% CI: 0.86-1.73; P=0.272; I2=65.2%). The results of subgroup analyses were also consistent and significant when stratified by study design and follow-up period, whereas conflicting results were observed in periodontal disease ascertainment stratification. These findings were robust as indicated by sensitivity analyses. CONCLUSIONS: Periodontal disease was associated with the increased risk of prostate cancer, whereas no significant association was observed in patients treated with periodontal therapy. Hence, the awareness and importance for maintaining oral health should be improved, and the underlying mechanisms linking periodontal disease and prostate cancer should be fully explored in future research.

Incidence and risk factors of suicide among patients diagnosed with bladder cancer: A systematic review and meta-analysis.

BACKGROUND: Patients with bladder cancer have a high risk of suicide. This study aimed to assess how bladder cancer increases suicide risk and to identify the demographic and clinical factors associated with suicidal death among patients with bladder cancer. METHODS: Literature search of MEDLINE, PsycINFO, Embase, Web of Sciences and Cochrane Library databases was conducted up to April 2020 to identify eligible studies related to the incidence and risk factors of suicide after bladder cancer diagnosis. Summary multivariate-adjusted risk estimates and their associated 95% confidence intervals (CIs) were calculated using inverse variance method with random or fixed-effect modeling. RESULTS: Five retrospective cohorts comprising 563,680 patients with bladder cancer were included. Higher risk of suicide by 1.90-fold was observed among patients with bladder cancer (hazard ratio, HR = 1.90, 95% CI: 1.29-2.81; P = 0.001; I2 = 81.2%), especially in those aged 70 years or older (HR = 1.36, 95% CI: 1.29-1.43; P < 0.001; I2 = 0%), unmarried (HR = 1.72, 95% CI: 1.61-1.83; P < 0.001; I2 = 0%), and those with regional bladder cancer (HR = 1.88, 95% CI: 1.10-3.21; P = 0.021; I2 = 96.3%), compared with those without bladder cancer. Furthermore, gender and race were not associated with increased suicide risk among patients with bladder cancer. CONCLUSIONS: Suicide risk is increased among patients with bladder cancer, particularly those aged 70 years or older, unmarried and those with regional bladder cancer. Hence, early psychological support must be provided during the follow-up period of these special populations with a high suicide risk.

Association between Marital Status and Prognosis in Patients with Prostate Cancer: A Meta-Analysis of Observational Studies.

PURPOSE: The impact of marital status on the prognosis amongst patients diagnosed with prostate cancer remains controversial. Thus, a meta-analysis was performed to determine whether marital status can influence the prognosis in patients with prostate cancer. MATERIALS AND METHODS: Literature search of the MEDLINE, PsycINFO, Embase and Cochrane Library databases was conducted to identify eligible studies published before April 2020. Multivariate adjusted risk estimates and corresponding 95% confidence intervals (CIs) were extracted and calculated using the random effects model. RESULTS: A total of 11 observational studies comprising 1,457,799 patients diagnosed with prostate cancer were identified. Results indicated that unmarried status (separated, divorced, widowed or never married) was associated with an increased risk of all-cause mortality (hazard ratio, HR = 1.39, 95% CI: 1.30-1.50; P < .001; I2 = 92.2%) compared with married status, especially for divorced and never-married patients. Similarly, being unmarried had an elevated risk of cancer-specific mortality (HR = 1.29, 95% CI: 1.17-1.41; P < .001; I2 = 82.5%) in patients with prostate cancer. A significant difference was also observed between unmarried status and shorter overall survival (HR = 1.37, 95% CI: 1.20-1.56; P < .001; I2 = 94.5%). CONCLUSION: Results demonstrated that unmarried status is associated with a worse prognosis regarding mortality and survival in patients diagnosed with prostate cancer, particularly in divorced and never-married patients. Hence, further research should explore the potential mechanisms which can benefit the development of novel, more personalised management methods for unmarried patients with prostate cancer.

Sarcopenia as a predictor of postoperative outcomes after urologic oncology surgery: A systematic review and meta-analysis.

AIM: Sarcopenia as a reliable prognostic predictor in urologic oncology surgery remains controversial, and no consensus amongst researchers exists regarding the management of patients with sarcopenia. This meta-analysis was conducted to investigate the association between sarcopenia and postoperative outcomes after urologic oncology surgery. METHODS: A systematic search in MEDLINE (via PubMed), Embase, Web of Science and Cochrane Library databases was conducted to identify the potential studies published before August 2019. Odds ratios and hazard ratios (HRs) with 95% confidence intervals (CIs) were calculated through inverse variance with random or fixed effects models. RESULTS: Seventeen retrospective cohorts comprising 3,948 patients were included with sarcopenia prevalence between 25% and 68.9%. Patients with sarcopenia had significantly shorter overall survival (OS; HR = 2.06, 95% CI: 1.44-2.95; P < 0.001; I-square (I2) = 86%) and cancer-specific survival (HR = 2.16, 95% CI: 1.60-2.92; P < 0.001; I2 = 49.4%) than those without sarcopenia. Sarcopenia was independently associated with increased all-cause mortality (HR = 1.50, 95% CI: 1.26-1.80; P < 0.001; I2 = 0%) and cancer-specific mortality (HR = 1.50, 95% CI: 1.12-2.01; P = 0.006; I2 = 0%). No prognostic difference was observed in the postoperative risk of total complications and systemic progression except lymphovascular invasion status. CONCLUSIONS: Sarcopenia is an independent poor prognostic factor for patients undergoing urologic oncology surgery, particularly postoperative risks of short survival and increased mortality. Thus, preoperative sarcopenia evaluation can provide clinicians with important information to guide and individualise patient management and improve surgical outcomes.

Incidence and risk factors of suicide after a prostate cancer diagnosis: a meta-analysis of observational studies.

BACKGROUND: Whether the diagnosis of prostate cancer is a contributory psychological stress that causes excess risk of suicide among affected men remains controversial. We performed a meta-analysis of previous studies to investigate suicide incidence and associated risk factors among men diagnosed with prostate cancer. METHODS: The MEDLINE, Embase, Cochrane Library, and PsycINFO databases were searched to identify eligible studies published before April 2018. The inverse variance method with random-effects modeling was used to calculate summary relative risks (RRs) and their associated 95% confidence intervals (CIs). RESULTS: Eight observational studies involving 1,281,393 men diagnosed with prostate cancer and 842,294 matched prostate cancer-free men were included. An overall increased RR of suicide of 2.01 (95% CI: 1.52-2.64; P < 0.001; I2 = 91.8%) was observed among men diagnosed with prostate cancer compared with those without prostate cancer during the first year, especially during the first 6 months (RR = 2.24, 95% CI: 1.77-2.85; P < 0.001; I2 = 61.1%) after diagnosis. Moreover, prostate cancer patients were at an increased risk of suicide among men aged 75 years or older (RR = 1.51, 95% CI: 1.04-2.18; P = 0.028; I2 = 91.5%) and treated with hormonal therapy (RR = 1.80, 95% CI: 1.54-2.12; P < 0.001; I2 = 0%). Furthermore, marital status, race, disease risk category, and socioeconomic status were not associated with increased suicide risk in men with prostate cancer. CONCLUSIONS: Current evidence indicates that the risk of suicide is increased among men diagnosed with prostate cancer, particularly those aged 75 years or older, <12 months after diagnosis, and treated with hormonal therapy. Healthcare providers should be aware of these special populations considered at high risk of suicide. Hence, further research should be conducted to refine suicide risk assessment with detection tools and to develop the best practices for prevention.

Serum C-peptide concentration and prostate cancer: A meta-analysis of observational studies.

BACKGROUND: The association between serum C-peptide concentration and prostate cancer remains unexplored. Therefore, we conducted a meta-analysis to assess whether C-peptide serum concentrations are associated with increased prostate cancer risk. METHODS: Several databases were searched to identify relevant original research articles published before November 2017. Random-effects models were used to summarize the overall estimate of the multivariable-adjusted odds ratios (ORs) with 95% confidence intervals (CIs). RESULTS: Nine observational studies involving 11,796 participants were identified. The findings of the meta-analysis indicated that the association between serum C-peptide concentration and prostate cancer was not significant (OR: 1.15, 95% CI: 0.85-1.54; for highest versus lowest category C-peptide concentrations, P = .376). The associations were inconsistent, as indicated by subgroup analyses. CONCLUSION: Although our findings provided no support for the hypothesis that serum C-peptide concentration is associated with excess risk of prostate cancer, people must pay attention to this aspect and increase physical activity or modify dietary habits to constrain insulin secretion, which possibly lead to decreased incidence of prostate cancer. Hence, well-designed observational studies involving different ethnic populations are still needed.

Association of androgen deprivation therapy with thromboembolic events in patients with prostate cancer: a systematic review and meta-analysis.

BACKGROUND: Whether androgen deprivation therapy (ADT) causes excess thromboembolic events (TEs) in men with prostate cancer (PCa) remains controversial and is the subject of the US Food and Drug Administration safety warning. This study aims to perform a systematic review and meta-analysis on previous studies to determine whether ADT is associated with TEs in men with PCa. METHODS: Medline, Embase, and Cochrane Library databases were searched for relevant studies. These studies comprised those that compared ADT versus control to treat PCa, reported TEs as outcome, and were published before January 2018. Multivariate adjusted hazard ratios (HRs) and associated 95% confidence intervals (CIs) were calculated using random- or fixed-effects models. RESULTS: Five retrospective population-based cohort studies involving 170,851 ADT users and 256,704 non-ADT users were identified. Deep venous thrombosis (DVT) was found significantly associated with gonadotropin-releasing hormone (GnRH) agonists alone (HR = 1.47, 95% CI: 1.07-2.03; P = 0.017; I2 = 96.3%), GnRH agonists plus oral antiandrogen (AA) (HR = 2.55, 95% CI: 2.21-2.94; P < 0.001; I2 = 0.0%), and AA alone (HR = 1.49, 95% CI: 1.13-1.96; P = 0.004; I2 = 0.0%), but not with orchiectomy (HR = 1.80, 95% CI: 0.93-3.47; P = 0.079; I2 = 94.8%). In addition, pulmonary embolism (PE) was significantly associated with GnRH agonists alone (HR = 2.26, 95% CI: 1.78-2.86; P < 0.001; I2 was unavailable) and orchiectomy (HR = 2.12, 95% CI: 1.44-3.11; P < 0.001; I2 = 57.2%). This relationship was also supported with subgroup analyses based on different continents and races. CONCLUSIONS: GnRH agonists alone, GnRH plus AA, and AA alone cause excess DVT in men with PCa after controlling the demographic and disease characteristics and other confounding factors, although statistically significant difference was not observed in orchiectomy group. Additionally, GnRH agonists alone and orchiectomy can increase the incidence of PE.

Association between cadmium exposure and urolithiasis risk: A systematic review and meta-analysis.

BACKGROUND: We performed a meta-analysis to determine whether a consistent relationship exists between cadmium exposure and urolithiasis in humans. Accordingly, we summarized and reviewed previously published quantitative studies. METHODS: Eligible studies with reference lists published before June 1, 2017 were obtained from searching several databases. Random effects models were used to summary the overall estimate of the multivariate adjusted odds ratios (ORs) with 95% confidence intervals (CIs). RESULTS: Six observational studies involving 88,045 participants were identified and stratified into the following categories according to cadmium assessment results: occupational (n = 4) and dietary (n = 2). The findings of the meta-analysis suggested that the risk of urolithiasis increases significantly by 1.32 times at higher cadmium exposure (OR = 1.32; 95% CI = 1.08-1.62; for highest vs lowest category urinary cadmium values). The summary OR in occupational exposure (OR = 1.56; 95% CI = 1.13-2.14) increased at the same condition. Meanwhile, no association was observed between cadmium exposure and urolithiasis risk in dietary exposure (OR = 1.13; 95% CI = 0.87-1.47). A significant association remained consistent, as indicated by subgroup analyses and sensitivity analyses. CONCLUSIONS: The meta-analysis indicated that increased risk of urolithiasis is associated with high cadmium exposure, and this association is higher in occupational exposure than in dietary exposure. Nevertheless, well-designed observational studies with different ethnic populations are still needed.

Association between butchers and cancer mortality and incidence: A systematic review and meta-analysis.

BACKGROUND: In this study, we evaluated whether increased risks of mortality and cancer incidence exist among butchers worldwide. To achieve this goal, we conducted a systematic review and meta-analysis to investigate the correlations of the risks of cancer death and incidence with male and female butchers. METHODS: We obtained data by performing a comprehensive literature search in several databases for eligible studies published before March 2017. Multivariable-adjusted standardized mortality ratios (SMRs) and odds ratio (OR), as well as associated 95% confidence intervals (CIs) and those by subgroups, were extracted and pooled. RESULTS: A total of 17 observational studies comprising 397,726 participants were included in the meta-analysis. The butcher occupation was not associated with all-cancer mortality risk, with pooled overall SMRs of 1.07 (95% CI 0.96-1.20). However, the pooled ORs revealed that butchers hold an elevated risk of total cancer incidence (OR, 1.51; 95% CI, 1.33-1.73). No proof of publication bias was obtained, and the findings were consistent in the subgroup analyses. CONCLUSION: Our results suggest that working as butchers did not significantly influence all-cancer mortality risk but significantly contributed to elevated all-cancer incidence risk. Nevertheless, well-designed observational studies on this topic are necessary to confirm and update our findings.