Smoking is a predictor of adverse pathological features at radical prostatectomy: Results from the Shared Equal Access Regional Cancer Hospital database

Ambient air exposures to arsenic and cadmium and overall and prostate cancer-specific survival among prostate cancer cases in Pennsylvania, 2004 to 2014

BACKGROUND

Exposures to arsenic (As) and cadmium (Cd) have been associated with higher prostate cancer (PC) mortality; however, these associations have been inconsistent. The authors investigated whether higher ambient air concentrations of As and Cd are associated with lower overall and PC-specific survival among PC cases in Pennsylvania.

METHODS

Incident PC cases of patients, aged 40 years or older, with a clinical diagnosis and nonmetastatic disease were identified in the 2004 to 2014 Pennsylvania Cancer Registry. Demographic, clinical, and pathologic information were extracted from the Pennsylvania Cancer Registry. The 3- and 5-year average and cumulative air concentrations of As and Cd were extracted from the Environmental Protection Agency's Toxics Release Inventory database. Spatial-temporal hierarchical accelerated failure time models were used to examine the associations between air concentrations of As and Cd and overall and PC-specific survival for the total population and stratified by geographical region defined by rurality and Appalachia status, after adjusting for confounders.

RESULTS

There were 78,914 PC cases included. Increasing 3- and 5-year average and cumulative air concentrations of As and Cd were significantly associated with lower overall and PC-specific survival among cases, after adjusting for confounders, for the total population, and stratified by geographical region for most of the estimates.

CONCLUSIONS

Data suggest that increasing ambient air exposures to As and Cd may play a role in overall and PC-specific mortality risk among PC cases. Exposures to As and Cd are modifiable and may provide insight into potential strategies to improve PC health outcomes.

LAY SUMMARY

Arsenic and cadmium exposures linked to increased prostate cancer deaths remain unclear. We investigated whether air levels of arsenic and cadmium reported to be released from industries decrease overall and prostate cancer-specific survival among prostate cancer cases identified in the 2004 to 2014 Pennsylvania Cancer Registry. Among the 78,914 prostate cancer cases, increasing air levels of arsenic and cadmium are found to be associated with lower overall and prostate cancer-specific survival for the total population and within rural and urban Appalachia and urban non-Appalachia counties in Pennsylvania. Reducing exposures to arsenic and cadmium have the potential to decrease prostate cancer deaths.

Prostate Cancer Incidence and Aggressiveness in Appalachia versus Non-Appalachia Populations in Pennsylvania by Urban-Rural Regions, 2004-2014

BACKGROUND

Few studies have examined prostate cancer incidence and aggressiveness in urban-rural Appalachian populations. We examined these rates in urban-rural Appalachia and non-Appalachia Pennsylvania (PA), and the association between these areas and more aggressive prostate cancer at diagnosis.

METHODS

Men, ages ≥ 40 years with a primary prostate cancer diagnosis, were identified from the 2004-2014 Pennsylvania Cancer Registry. Age-adjusted incidence rates for prostate cancer and more aggressive prostate cancer at diagnosis were calculated by urban-rural Appalachia status. Multivariable Poisson regressions were conducted. Multiple logistic regressions were used to examine the association between the geographic areas and more aggressive prostate cancer, after adjusting for confounders.

RESULTS

There were 94,274 cases, ages 40-105 years, included. Urban non-Appalachia had the highest 2004-2014 age-adjusted incidence rates of prostate cancer and more aggressive prostate cancer (293.56 and 96.39 per 100,000 men, respectively) and rural Appalachia had the lowest rates (256.48 and 80.18 per 100,000 men, respectively). Among the cases, urban Appalachia were more likely [OR = 1.12; 95% confidence interval (CI) = 1.08-1.17] and rural Appalachia were less likely (OR = 0.92; 95% CI = 0.87-0.97) to have more aggressive prostate cancer at diagnosis compared with urban non-Appalachia.

CONCLUSIONS

Lower incidence rates and the proportion of aggressive disease in rural Appalachia may be due to lower prostate cancer screening rates. More aggressive prostate cancer at diagnosis among the cases in urban Appalachia may be due to exposures that are prevalent in the region.

IMPACT

Identifying geographic prostate cancer disparities will provide information to design programs aimed at reducing risk and closing the disparity gap.

Association of Smoking Status With Recurrence, Metastasis, and Mortality Among Patients With Localized Prostate Cancer Undergoing Prostatectomy or Radiotherapy: A Systematic Review and Meta-analysis

Importance

Studies investigating the association of cigarette smoking with prostate cancer incidence and outcomes have revealed controversial results.

Objective

To systematically review and analyze the association of smoking status with biochemical recurrence, metastasis, and cancer-specific mortality among patients with localized prostate cancer undergoing primary radical prostatectomy or radiotherapy.

Data Sources

A systematic search of original articles published between January 2000 and March 2017 was performed using PubMed, MEDLINE, Embase, and Cochrane Library databases in March 2017.

Study Selection

Observational studies reporting Cox proportional hazards regression or logistic regression analyses were independently screened.

Data Extraction and Synthesis

This systematic review and meta-analysis was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement and the Cochrane Handbook for Systematic Reviews of Interventions. Available multivariable hazard ratios (HRs) and corresponding 95% CIs were included in quantitative analysis. A risk-of-bias assessment was completed for nonrandomized studies.

Main Outcomes and Measures

Prespecified outcomes of interest were biochemical recurrence, metastasis, and cancer-specific mortality.

Results

A total of 5157 reports were identified, of which 16 articles were selected for qualitative analysis and 11 articles were selected for quantitative analysis. All included studies were observational and nonrandomized and comprised a total of 22 549 patients. Overall, 4202 patients (18.6%) were current smokers. The overall median follow-up was 72 months. Current smokers had a statistically significantly higher risk of biochemical recurrence (HR, 1.40; 95% CI, 1.18-1.66; P < .001 [10 studies]), as did former smokers (HR, 1.19; 95% CI, 1.09-1.30; P < .001 [7 studies]). Current smokers were also at a higher risk of metastasis (HR, 2.51; 95% CI, 1.80-3.51; P < .001 [3 studies]) and cancer-specific mortality (HR, 1.89; 95% CI, 1.37-2.60; P < .001 [5 studies]), whereas former smokers were not (metastasis: HR, 1.61; 95% CI, 0.65-3.97; P = .31 [2 studies]; cancer-specific mortality: HR, 1.05; 95% CI, 0.81-1.37; P = .70 [4 studies]).

Conclusions and Relevance

Current smokers at the time of primary curative treatment for localized prostate cancer are at higher risk of experiencing biochemical recurrence, metastasis, and cancer-specific mortality.

Circulating microRNAs in plasma among men with low-grade and high-grade prostate cancer at prostate biopsy

BACKGROUND

MicroRNAs (miRNAs or miR-) have been linked to factors associated with aggressive prostate cancer such as biochemical recurrence and metastasis. We investigated whether circulating miRNAs in plasma could be used as diagnostic biomarkers for more aggressive prostate cancer at prostate biopsy.

METHODS

Men, aged 40 years and above, newly diagnosed with prostate cancer were categorized into two risk groups, low-grade (Gleason score, 6 or 7 [3 + 4] and serum prostate-specific antigen [PSA], <20 ng/mL) and high-grade (Gleason score, ≥7 (4 + 3) and serum PSA, ≥20 ng/mL) prostate cancers. The limma R package was used to compare the expression of miRNAs in plasma between the two risk groups, adjusting for age.

RESULTS

There were 66 men, aged 46-86 years, included: 40 men with low-grade and 26 men with high-grade prostate cancers. There were lower expressions of miR-28, miR-100, miR-942, and miR-28-3p, and higher expressions of miR-708, miR-1298, miR-886-3p, miR-374, miR-376c, miR-202, miR-128a, and miR-185 in high-grade compared to low-grade prostate cancer cases at biopsy, after adjusting for age (P < 0.05). These differences were no longer statistically significant after adjusting the P values for multiple comparisons.

CONCLUSION

There was no circulating miRNA associated with high-grade prostate cancer at biopsy after adjusting for age and multiple comparisons. Nevertheless, relationships between these circulating miRNAs and high-grade prostate cancer were observed, which suggest them as promising prostate cancer biomarkers. Further investigation in a larger cohort may provide insight into their diagnostic potential for aggressive prostate cancer.

Functional role and tobacco smoking effects on methylation of CYP1A1 gene in prostate cancer

Cytochrome P450 (CYP) 1A1 is a phase I enzyme that can activate various compounds into reactive forms and thus, may contribute to carcinogenesis. In this study, we investigated the expression, methylation status, and functional role of CYP1A1 on prostate cancer cells. Increased expression of CYP1A1 was observed in all cancer lines (PC-3, LNCaP, and DU145) compared to BPH-1 (P < 0.05); and was enhanced further by 5-aza-2′-deoxycytidine treatment (P < 0.01). Methylation-specific PCR (MSP) and sequencing of bisulfite-modified DNA of the xenobiotic response element (XRE) enhancer site XRE-1383 indicated promoter methylation as a regulator of CYP1A1 expression. In tissue, microarrays showed higher immunostaining of CYP1A1 in prostate cancer than normal and benign prostatic hyperplasia (BPH; P < 0.001), and methylation analyses in clinical specimens revealed significantly lower methylation levels in cancer compared to BPH at all enhancer sites analyzed (XRE-1383, XRE-983, XRE-895; P < 0.01). Interestingly, smoking affected the XRE-1383 site where the methylation level was much lower in cancer tissues from smokers than non-smokers (P < 0.05). CYP1A1 levels are thus increased in prostate cancer and to determine the functional effect of CYP1A1 on cells, we depleted the gene in LNCaP and DU145 by siRNA. We observe that CYP1A1 knockdown decreased cell proliferation (P < 0.05) and increased apoptosis (P < 0.01) in both cell lines. We analyzed genes affected by CYP1A1 silencing and found that apoptosis-related BCL2 was significantly down-regulated. This study supports an oncogenic role for CYP1A1 in prostate cancer via promoter hypomethylation that is influenced by tobacco smoking, indicating CYP1A1 to be a promising target for prostate cancer treatment.

[What do prostate cancer patients know about smoking? : Results of a bicentric questionnaire study (KRAUT study)]

BACKGROUND

According to the results of a recent meta-analysis, cancer-specific mortality of prostate cancer (PCA) patients is enhanced by 24 % in case of a positive smoking history with a dose-dependent impact of smoking. Until now it is unknown whether this information actually reaches the patients and how extensively an informational discussion about this topic is pursued by physicians.

OBJECTIVE

Three study hypotheses were defined: (1) the knowledge of PCA patients about the potential relationship between tumor progression and cigarette consumption is low, (2) only in rare cases has a clear statement been provided by treating physicians including the explicit advice to stop smoking, and (3) there was a direct association between tumor stage and the extent of cigarette consumption.

MATERIALS AND METHODS

A questionnaire comprising 23 items was developed and validated with 25 uro-oncological patients prior to study start. Between September 2013 and December 2014 a total of 124 PCA patients (median age 65 years) from two urology departments were included in this questionnaire-based survey.

RESULTS

The study population comprised 43 % (n = 54), 39 % (n = 48), and 18 % (n = 22) nonsmokers, former smokers and active smokers, respectively. Active and former smokers differed insignificantly in the number of pack-years only (24.8 vs. 23.7 years, p = 0.995). Of the patients, 56 % regarded an influence of cigarette consumption on the PCA-specific prognosis as possible. However, because a significant (p < 0.001) number of patients wrongly suspected smoking to be causative for PCA development, their knowledge about PCA prognosis is supposedly not based on adequate knowledge. Two of 22 active smokers (9.1 %), 5 of 48 former smokers (10.4 %), and 2 of 54 nonsmokers (3.7 %) had an informational discussion with their urologist about the association of cigarette consumption and PCA-related prognosis (a further 9.1, 4.2 and 3.7 %, respectively, received this information solely from other medical specialties). Only 1 of 22 active smokers (4.5 %) was offered medical aids for smoking cessation by the general practitioner; none of the patients received such support by an urologist. There was no association between a positive smoking history or number of pack-years and PCA tumor stage.

CONCLUSIONS

Education of PCA patients about the relationship between cigarette consumption and cancer-related prognosis is currently inadequate. Following the latest findings on this topic, urologists should pursue informational discussions with their patients, thereby strengthening their position as the primary contact person for decision making in PCA management.