Medical history, body size, and cigarette smoking in relation to fatal prostate cancer

Risk of urinary tract cancers following arsenic exposure and tobacco smoking: a review

Bladder cancer, prostate cancer, and kidney cancer, due to their high morbidity and mortality rates, result in significant economic and health care costs. Arsenic exposure affects the drinking water of millions of people worldwide. Long-term exposure to arsenic, even in low concentrations, increases the risk of developing various cancers. Smoking is also one of the leading causes of bladder, prostate and kidney cancers. Accordingly, this research reviews the relationship between arsenic exposure and smoking with three kinds of urinary tract cancers (bladder cancer, prostate cancer, and kidney cancer) due to their widespread concern for their negative impact on public health globally. In this review, we have gathered the most current information from scientific databases [PubMed, Scopus, Google Scholar, ISI web of science] regarding the relationship between arsenic exposure and tobacco smoking with the risk of bladder, prostate, and kidney cancer. In several studies, a significant relationship was determined between the incidence and mortality rate of the above-mentioned cancers in humans with arsenic exposure and tobacco smoking. The decrease or cessation of smoking and consumption of arsenic-free water significantly declined the incidence of bladder, prostate, and kidney cancers.

Vasectomy and Risk of Prostate Cancer: A Systematic Review and Meta-analysis

Context

Previous reports have shown an association between vasectomy and prostate cancer (PCa). However, there exist significant discrepancies between studies and systematic reviews due to a lack of strong causal association and residual confounding factors such as prostate-specific antigen (PSA) screening.

Objective

To assess the association between vasectomy and PCa, in both unadjusted and PSA screen-adjusted studies.

Evidence acquisition

We performed a systematic review according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses. The PubMed, Scopus, and Web of Science databases were searched in January 2022 for studies that analyzed the association between vasectomy and PCa.

Evidence synthesis

A total of 37 studies including 16 931 805 patients met our inclusion criteria. A pooled analysis from all studies showed a significant association between vasectomy and any-grade PCa (odds ratio [OR] 1.23; 95% confidence interval [CI], 1.10–1.37; p < 0.001; I² = 96%), localized PCa (OR 1.08; 95% CI, 1.06–1.11; p < 0.00001; I² = 31%), or advanced PCa (OR 1.07; 95% CI, 1.02–1.13; p = 0.006; I² = 0%). The association with PCa remained significant when the analyses were restricted to studies with a low risk of bias (OR 1.06; 95% CI, 1.02–1.10; p = 0.02; I² = 48%) or cohort studies (OR 1.09; 95% CI, 1.04–1.13; p < 0.0001; I² = 64%). Among studies adjusted for PSA screening, the association with localized PCa (OR 1.06; 95% CI, 1.03–1.09; p < 0.001; I² = 0%) remained significant. Conversely, vasectomy was no longer associated with localized high-grade (p = 0.19), advanced (p = 0.22), and lethal (p = 0.42) PCa.

Conclusions

Our meta-analysis found an association between vasectomy and any, mainly localized, PCa. However, the effect estimates of the association were increasingly close to null when examining studies of robust design and high quality. On exploratory analyses including studies, which adjusted for PSA screening, the association for aggressive and/or advanced PCa diminished.

Patient summary

In this study, we found an association between vasectomy and the risk of developing localized prostate cancer without being able to determine whether the procedure leads to a higher prostate cancer incidence.

Association between vasectomy and risk of prostate cancer: a meta-analysis

BACKGROUND

The debate over the association between vasectomy and prostate cancer has been lasted about 40 years and there is no sign of stopping. In the present study, we aimed to evaluate whether vasectomy is associated with prostate cancer based on the most comprehensive and up-to-date evidence available.

METHODS

The PubMed, Cochrane Library, and EMBASE databases were systematically searched inception to March 14, 2021 without year or language restriction. Multivariable adjusted risk ratios (RRs) were used to assess each endpoint. Risk of bias was assessed using the Newcastle-Ottawa scale.

RESULTS

A total of 58 studies involving 16,989,237 participants fulfilled inclusion criteria. There was significant association of vasectomy with risk of any prostate cancer (risk ratio, 1.18, 95% CI, 1.07-1.31). Association between vasectomy and advanced prostate cancer (risk ratio, 1.06, 95% CI, 1.01-1.12), low-grade prostate cancer (risk ratio, 1.06, 95% CI, 1.02-1.10), and intermediate-grade prostate cancer (risk ratio, 1.12, 95% CI, 1.03-1.22) were significant. There was no significant association between vasectomy and prostate cancer-specific mortality (risk ratio, 1.01, 95% CI, 0.93-1.10).

CONCLUSIONS

This study found that vasectomy was associated with the risk of any prostate cancer and advanced prostate cancer. From the current evidence, patients should be fully informed of the risk of prostate cancer before vasectomy.

Impact of Vasectomy on the Development and Progression of Prostate Cancer: Preclinical Evidence

Some observational studies have implied a link between vasectomy and an elevated risk of prostate cancer. We investigated the impact of vasectomy on prostate cancer outgrowth, mainly using preclinical models. Neoplastic changes in the prostate were compared in transgenic TRAMP mice that underwent vasectomy vs. sham surgery performed at 4 weeks of age. One of the molecules identified by DNA microarray (i.e., ZKSCAN3) was then assessed in radical prostatectomy specimens and human prostate cancer lines. At 24 weeks, gross tumor (p = 0.089) and poorly differentiated adenocarcinoma (p = 0.036) occurred more often in vasectomized mice. Vasectomy significantly induced ZKSCAN3 expression in prostate tissues from C57BL/6 mice and prostate cancers from TRAMP mice. Immunohistochemistry showed increased ZKSCAN3 expression in adenocarcinoma vs. prostatic intraepithelial neoplasia (PIN), PIN vs. non-neoplastic prostate, Grade Group ≥3 vs. ≤2 tumors, pT3 vs. pT2 tumors, pN1 vs. pN0 tumors, and prostate cancer from patients with a history of vasectomy. Additionally, strong (2+/3+) ZKSCAN3 expression (p = 0.002), as an independent prognosticator, or vasectomy (p = 0.072) was associated with the risk of tumor recurrence. In prostate cancer lines, ZKSCAN3 silencing resulted in significant decreases in cell proliferation/migration/invasion. These findings suggest that there might be an association between vasectomy and the development and progression of prostate cancer, with up-regulation of ZKSCAN3 expression as a potential underlying mechanism.

A Systematic Review and Meta-analysis of Associations between Clinical Prostatitis and Prostate Cancer: New Estimates Accounting for Detection Bias

BACKGROUND

Previous meta-analyses have estimated summary positive associations between clinical prostatitis and prostate cancer. However, none have accounted for detection bias, the possibility for increased prostate cancer screening and detection in men with clinical prostatitis, in their pooled estimates.

METHODS

We searched for studies that investigated the relation between clinical prostatitis and prostate cancer through November 2018. Random effects meta-analysis was used to calculate summary odds ratios (OR) among all studies and in strata defined by methods used to reduce detection bias.Results: Although an increased odds of prostate cancer was seen among men with a history of clinical prostatitis in all 38 eligible studies combined [OR, 2.05; 95% confidence interval (CI), 1.64-2.57], this estimate attenuated to null among studies that performed the most rigorous analyses to limit detection bias (OR, 1.16; 95% CI, 0.77-1.74).

CONCLUSIONS

Our findings indicate that previously reported positive associations between clinical prostatitis and prostate cancer are likely due to detection bias.

IMPACT

Studies using rigorous detection bias methods are warranted to replicate these findings, as well as to examine the possible relation between prostate inflammation and prostate cancer directly, rather than indirectly through the diagnosis of "prostatitis," which includes a large proportion of men without evidence of prostate inflammation.

Association between blood pressure and risk of cancer development: a systematic review and meta-analysis of observational studies

With the exception of renal cell carcinoma, studies assessing the association between hypertension and other cancers are inconsistent. We conducted a meta-analysis to assess this evidence. We included observational studies investigating the association between any definition of hypertension or systolic and diastolic blood pressure and risk of any cancer, after searching PubMed until November 2017. We calculated summary relative risks (RR) and 95% confidence intervals (CI) using inverse-variance weighted random effects methods. A total of 148 eligible publications were identified out of 39,891 initially screened citations. Considering only evidence from 85 prospective studies, positive associations were observed between hypertension and kidney, colorectal and breast cancer. Positive associations between hypertension and risk of oesophageal adenocarcinoma and squamous cell carcinoma, liver and endometrial cancer were also observed, but the majority of studies did not perform comprehensive multivariable adjustments. Systolic and diastolic blood pressure were positively associated with risk of kidney cancer but not with other cancers. In addition to the previously well-described association between hypertension and risk of kidney cancer, the current meta-analysis suggested that hypertensive individuals may also be at higher risk of colorectal and breast cancer. However, careful interpretation is required as most meta-analyses included relatively small number of studies, several relative risks had weak or moderate magnitude and maybe affected by residual confounding.

The Association Between Vasectomy and Prostate Cancer: A Systematic Review and Meta-analysis

Importance

Despite 3 decades of study, there remains ongoing debate regarding whether vasectomy is associated with prostate cancer.

Objective

To determine if vasectomy is associated with prostate cancer.

Data Sources

The MEDLINE, EMBASE, Web of Science, and Scopus databases were searched for studies indexed from database inception to March 21, 2017, without language restriction.

Study Selection

Cohort, case-control, and cross-sectional studies reporting relative effect estimates for the association between vasectomy and prostate cancer were included.

Data Extraction and Synthesis

Two investigators performed study selection independently. Data were pooled separately by study design type using random-effects models. The Newcastle-Ottawa Scale was used to assess risk of bias.

Main Outcomes and Measures

The primary outcome was any diagnosis of prostate cancer. Secondary outcomes were high-grade, advanced, and fatal prostate cancer.

Results

Fifty-three studies (16 cohort studies including 2 563 519 participants, 33 case-control studies including 44 536 participants, and 4 cross-sectional studies including 12 098 221 participants) were included. Of these, 7 cohort studies (44%), 26 case-control studies (79%), and all 4 cross-sectional studies were deemed to have a moderate to high risk of bias. Among studies deemed to have a low risk of bias, a weak association was found among cohort studies (7 studies; adjusted rate ratio, 1.05; 95% CI, 1.02-1.09; P < .001; I2 = 9%) and a similar but nonsignificant association was found among case-control studies (6 studies; adjusted odds ratio, 1.06; 95% CI, 0.88-1.29; P = .54; I2 = 37%). Effect estimates were further from the null when studies with a moderate to high risk of bias were included. Associations between vasectomy and high-grade prostate cancer (6 studies; adjusted rate ratio, 1.03; 95% CI, 0.89-1.21; P = .67; I2 = 55%), advanced prostate cancer (6 studies; adjusted rate ratio, 1.08; 95% CI, 0.98-1.20; P = .11; I2 = 18%), and fatal prostate cancer (5 studies; adjusted rate ratio, 1.02; 95% CI, 0.92-1.14; P = .68; I2 = 26%) were not significant (all cohort studies). Based on these data, a 0.6% (95% CI, 0.3%-1.2%) absolute increase in lifetime risk of prostate cancer associated with vasectomy and a population-attributable fraction of 0.5% (95% CI, 0.2%-0.9%) were calculated.

Conclusions and Relevance

This review found no association between vasectomy and high-grade, advanced-stage, or fatal prostate cancer. There was a weak association between vasectomy and any prostate cancer that was closer to the null with increasingly robust study design. This association is unlikely to be causal and should not preclude the use of vasectomy as a long-term contraceptive option.

The role of prostatitis in prostate cancer: meta-analysis

Objective

Use systematic review methods to quantify the association between prostatitis and prostate cancer, under both fixed and random effects model.

Evidence Acquisition

Case control studies of prostate cancer with information on prostatitis history. All studies published between 1990-2012, were collected to calculate a pooled odds ratio. Selection criteria: the selection criteria are as follows: human case control studies; published from May 1990 to July 2012; containing number of prostatitis, and prostate cancer cases.

Evidence Synthesis

In total, 20 case control studies were included. A significant association between prostatitis and prostate cancer was found, under both fixed effect model (pooled OR=1.50, 95%CI: 1.39-1.62), and random effects model (OR=1.64, 95%CI: 1.36-1.98). Personal interview based case control studies showed a high level of association (fixed effect model: pooled OR=1.59, 95%CI: 1.47-1.73, random effects model: pooled OR= 1.87, 95%CI: 1.52-2.29), compared with clinical based studies (fixed effect model: pooled OR=1.05, 95%CI: 0.86-1.28, random effects model: pooled OR= 0.98, 95%CI: 0.67-1.45). Additionally, pooled ORs, were calculated for each decade. In a fixed effect model: 1990’s: OR=1.58, 95% CI: 1.35-1.84; 2000’s: OR=1.59, 95% CI: 1.40-1.79; 2010’s: OR=1.37, 95% CI: 1.22-1.56. In a random effects model: 1990’s: OR=1.98, 95% CI: 1.08-3.62; 2000’s: OR=1.64, 95% CI: 1.23-2.19; 2010’s: OR=1.34, 95% CI: 1.03-1.73. Finally a meta-analysis stratified by each country was conducted. In fixed effect models, U.S: pooled OR =1.45, 95%CI: 1.34-1.57; China: pooled OR =4.67, 95%CI: 3.08-7.07; Cuba: pooled OR =1.43, 95%CI: 1.00-2.04; Italy: pooled OR =0.61, 95%CI: 0.13-2.90. In random effects model, U.S: pooled OR=1.50, 95%CI: 1.25-1.80; China: pooled OR =4.67, 95%CI: 3.08-7.07; Cuba: pooled OR =1.43, 95%CI: 1.00-2.04; Italy: pooled OR =0.61, 95%CI: 0.13-2.90.CONCLUSIONS: the present meta-analysis provides the statistical evidence that the association between prostatitis and prostate cancer is significant.

Smoking and prostate cancer in a multi-ethnic cohort

BACKGROUND

Prostate cancer (PCa) and smoking-related morbidity disproportionately burdens African American (AA) men. Smoking is associated with high-grade PCa and incidence, but few studies have focused on AA men. This study aims to determine the effect of tobacco-use on odds of PCa and of high-grade PCa in a population of predominantly AA men.

METHODS

This is a cross-sectional study evaluating smoking and PCa status in men with incident PCa and screened healthy controls. Altogether, 1,085 men (527 cases and 558 controls), age ≥ 40 years were enrolled through outpatient urology clinics in two US cities from 2001 to 2012. Validated questionnaires were used to gather clinical and socioeconomic data.

RESULTS

The cases and controls were predominantly AA (79.9% and 71.3%, respectively, P = 0.01). AA men smoked more frequently (53.4% vs. 47.9%, P < 0.001) and quit less frequently than European American (EA) men (31.5% vs. 40.4%, P = 0.01). AA heavy smokers had increased odds of PCa diagnosis (OR 2.57, 95% CI 1.09, 6.10) and high-grade cancer (OR 1.89, 95% CI 1.03, 3.48) relative to never smokers and light smokers. Among AAs, heavy smokers had lower odds of NCCN low PCa recurrence risk stratification. AA former smokers had a trend for increased odds of high-grade cancer compared to never smokers. The associations between smokings, cancer diagnosis and cancer grade did not reach statistical significance in EA men.

CONCLUSION

We found ethnic differences in smoking behavior. Heavy smoking is associated with increased odds of PCa and of higher Gleason grade in AA men.

How can I help myself? A critical review of modifiable behaviors, medications, and complementary alternative medicine for men receiving radiotherapy for prostate cancer

Men receiving radiation for prostate cancer frequently want to know what steps they can take to optimize their chance of cure and reduce their risk of side effects. A variety of modifiable behaviors, medications, and complementary alternative medicine interventions have been investigated in this regard. In this review, we summarize data on tobacco use, exercise, statins and aspirin, and vitamins. There is limited randomized data supporting any of the interventions and additional studies are needed before clinicians can confidently inform their patients regarding what steps to take to improve their outcomes.

Smoking and the risk of prostate cancer in the European Prospective Investigation into Cancer and Nutrition

BACKGROUND

Smoking is not associated with prostate cancer incidence in most studies, but associations between smoking and fatal prostate cancer have been reported.

METHODS

During 1992 and 2000, lifestyle information was assessed via questionnaires and personal interview in a cohort of 145,112 European men. Until 2009, 4623 incident cases of prostate cancer were identified, including 1517 cases of low-grade, 396 cases of high grade, 1516 cases of localised, 808 cases of advanced disease, and 432 fatal cases. Multivariable Cox proportional hazards regression models were used to examine the association of smoking status, smoking intensity, and smoking duration with the risk of incident and fatal prostate cancer.

RESULTS

Compared with never smokers, current smokers had a reduced risk of prostate cancer (RR=0.90, 95% CI: 0.83-0.97), which was statistically significant for localised and low-grade disease, but not for advanced or high-grade disease. In contrast, heavy smokers (25+ cigarettes per day) and men who had smoked for a long time (40+ years) had a higher risk of prostate cancer death (RR=1.81, 95% CI: 1.11-2.93; RR=1.38, 95% CI: 1.01-1.87, respectively).

CONCLUSION

The observation of an increased prostate cancer mortality among heavy smokers confirms the results of previous prospective studies.

Poly (AT) polymorphism in the XPC gene and smoking enhance the risk of prostate cancer in a low-risk Chinese population

We investigated two polymorphisms of xeroderma pigmentosum complementary group C (XPC) in 202 subjects with prostate cancer (PCa) and 221 healthy controls in a Chinese Han population. Genotyping was performed using a polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) technique. Our results indicated that smoking is associated with an increased risk for PCa (odds ratio [OR]: 1.51; 95% confidence interval [CI]: 1.02-2.22). Subjects carrying the XPC-PAT+/+ genotype exhibited a significantly increased risk for PCa (OR: 2.11; 95% CI: 1.12-3.99). The combined subjects with either the PAT+/+ or PAT+/- genotype also exhibited a 1.54-fold increased risk associated with PCa (OR: 1.54; 95% CI: 1.04-2.26). Moreover, smokers with PAT+/- or PAT+/+ had a higher risk for PCa (OR: 1.98; 95% CI: 1.08-3.64; P = 0.026 and OR: 3.56; 95% CI: 1.45-8.76; P = 0.004, respectively) compared with never smokers with the PAT-/- genotype. Analyses of the XPC Lys939Gln polymorphism did not show an association with PCa risk. Our findings support the hypothesis that XPC-PAT polymorphisms may contribute to the risk of developing PCa. More important, an elevated risk of PCa associated with a gene-environment (smoking) interaction was determined in a Chinese population.