Modeling the Complex Exposure History of Smoking in Predicting Bladder Cancer: A Pooled Analysis of 15 Case-Control Studies

A prospective study of smoking-related white blood cell DNA methylation markers and risk of bladder cancer

Bladder cancer, a common neoplasm, is primarily caused by tobacco smoking. Epigenetic alterations including DNA methylation have the potential to be used as prospective markers of increased risk, particularly in at-risk populations such as smokers. We aimed to investigate the potential of smoking-related white blood cell (WBC) methylation markers to contribute to an increase in bladder cancer risk prediction over classical questionnaire-based smoking metrics (i.e., duration, intensity, packyears) in a nested case-control study within the prospective prostate, lung, colorectal, and ovarian (PLCO) Cancer Screening Trial and the alpha-tocopherol, beta-carotene cancer (ATBC) Prevention Study (789 cases; 849 controls). We identified 200 differentially methylated sites associated with smoking status and 28 significantly associated (after correction for multiple testing) with bladder cancer risk among 2670 previously reported smoking-related cytosine-phosphate-guanines sites (CpGs). Similar patterns were observed across cohorts. Receiver operating characteristic (ROC) analyses indicated that cg05575921 (AHHR), the strongest smoking-related association we identified for bladder cancer risk, alone yielded similar predictive performance (AUC: 0.60) than classical smoking metrics (AUC: 0.59-0.62). Best prediction was achieved by including the first principal component (PC1) from the 200 smoking-related CpGs alongside smoking metrics (AUC: 0.63-0.65). Further, PC1 remained significantly associated with elevated bladder cancer risk after adjusting for smoking metrics. These findings suggest DNA methylation profiles reflect aspects of tobacco smoke exposure in addition to those captured by smoking duration, intensity and packyears, and/or individual susceptibility relevant to bladder cancer etiology, warranting further investigation.

Molecular Markers for Bladder Cancer Screening: An Insight into Bladder Cancer and FDA-Approved Biomarkers

Bladder cancer is one of the most financially burdensome cancers globally, from its diagnostic to its terminal stages. The impact it imposes on patients and the medical community is substantial, exacerbated by the absence of disease-specific characteristics and limited disease-free spans. Frequent recurrences, impacting nearly half of the diagnosed population, require frequent and invasive monitoring. Given the advancing comprehension of its etiology and attributes, bladder cancer is an appealing candidate for screening strategies. Cystoscopy is the current gold standard for bladder cancer detection, but it is invasive and has the potential for undesired complications and elevated costs. Although urine cytology is a supplementary tool in select instances, its efficacy is limited due to its restricted sensitivity, mainly when targeting low-grade tumors. Although most of these assays exhibit higher sensitivity than urine cytology, clinical guidelines do not currently incorporate them. Consequently, it is necessary to explore novel screening assays to identify distinctive alterations exclusive to bladder cancer. Thus, integrating potential molecular assays requires further investigation through more extensive validation studies. Within this article, we offer a comprehensive overview of the critical features of bladder cancer while conducting a thorough analysis of the FDA-approved assays designed to diagnose and monitor its recurrences.

Assessment of the Ecological Association between Tobacco Smoking Exposure and Bladder Cancer Incidence over the Past Half-Century in the United States

BACKGROUND

Since tobacco smoking represents the most established risk factor for bladder cancer, we sought to assess the ecological association between tobacco smoking prevalence and bladder cancer incidence and to contrast it with lung cancer.

METHODS

The annual overall tobacco smoking prevalence rates were extracted from the Report of the Surgeon General and the Center for Disease Control between 1953 and 1983. The overall age-adjusted incidence rates for bladder and lung cancers were derived from the Surveillance, Epidemiology, and End Results database between 1983 and 2013 (30-year latency period). Weighted least square regression models were used to assess bladder and lung cancer incidence rate differences (IRD) related to trends in tobacco smoking prevalence. A Wald test was used to compare whether the prevalence of tobacco smoking, as an explanatory variable, differentially predicts bladder versus lung cancer incidence rates.

RESULTS

The associations between tobacco smoking prevalence and bladder cancer incidence were not significant in the overall (IRD = +0.04; 95%CI (-0.14; +0.22); p = 0.63), male (IRD = +0.07; 95%CI (-0.09; +0.23); p = 0.37), or female (IRD = +0.12; 95%CI (-0.01; +0.25); p = 0.06) populations. There was an association between tobacco smoking prevalence and lung cancer incidence in the overall (IRD: +3.55; 95%CI ( +3.09; +4.00); p < 0.001), male (IRD: +4.82; 95%CI (+4.44; +5.20); p < 0.001), and female (IRD: +3.55; 95%CI (+3.12; +3.99); p < 0.001) populations. The difference between the observed associations of tobacco smoking prevalence with bladder versus lung cancer incidence was also significant in all examined populations (p < 0.001).

CONCLUSIONS

Variations in tobacco smoking prevalence only partially explained the trends in the incidence of bladder cancer, indicating that its etiology is complex.

Epidemiology, Screening, and Prevention of Bladder Cancer

CONTEXT

Bladder cancer (BC) represents a significant health problem due to the potential morbidity and mortality associated with disease burden, which has remained largely unaltered over time.

OBJECTIVE

To provide an expert collaborative review and describe the incidence, prevalence, and mortality of BC and to evaluate current evidence for BC screening and prevention.

EVIDENCE ACQUISITION

Data on the estimated incidence and mortality of BC for 2020 in 185 countries were derived from the International Agency for Research on Cancer GLOBOCAN database. A review of English-language articles published over the past 5 yr was conducted using PubMed/MEDLINE to identify risk factors in addition to contemporary evidence on BC screening and prevention.

EVIDENCE SYNTHESIS

BC is the tenth most common cancer worldwide, with 573 278 cases in 2020. BC incidence is approximately fourfold higher in men than women. Tobacco smoking remains the principal risk factor, accounting for approximately 50% of cases. There is insufficient evidence to recommend routine BC screening. However, targeted screening of high-risk individuals (defined according to smoking history or occupational exposure) may reduce BC mortality and should be the focus of prospective randomized trials. In terms of disease prevention, smoking cessation represents the most important intervention, followed by a reduction in exposure to occupational and environmental carcinogens.

CONCLUSIONS

BC confers a significant disease burden. An understanding of BC epidemiology and risk factors provides an optimal foundation for disease prevention and the care of affected patients.

PATIENT SUMMARY

Bladder cancer is the tenth most common cancer worldwide and is approximately four times more common among men than among women. The main risk factors are tobacco smoking, followed by exposure to carcinogens in the workplace or the environment. Routine screening is not currently recommended, but may be beneficial in individuals at high risk, such as heavy smokers. Primary prevention is extremely important, and smoking cessation represents the most important action for reducing bladder cancer cases and deaths.

Urinary bladder cancer as a late sequela of traumatic spinal cord injury

BACKGROUND

Traumatic spinal cord injury (SCI) is also a combat-related injury that is increasing in modern warfare. The aim of this work is to inform medical experts regarding the different course of bladder cancer in able-bodied patients compared with SCI patients based on the latest medical scientific knowledge, and to present decision-making aids for the assessment of bladder cancer as a late sequela of traumatic SCI.

METHODS

A study conducted between January 1998 and December 2019 in the BG Trauma Hospital Hamburg formed the basis for the decision-making aids. Urinary bladder cancer was diagnosed in 40 out of 7396 treated outpatient and inpatient SCI patients. General patient information, latency period, age at initial diagnosis, type of bladder management and survival of SCI patients with bladder cancer were collected and analysed. T category, grading and tumour entity in these patients were compared with those in the general population. Relevant bladder cancer risk factors in SCI patients were analysed. Furthermore, relevant published literature was taken into consideration.

RESULTS

Initial diagnosis of urinary bladder cancer in SCI patients occurs at a mean age of 56.4 years (SD ± 10.7 years), i.e., approximately 20 years earlier as compared with the general population. These bladder cancers are significantly more frequently muscle invasive (i.e., T category ≥ T2) and present a higher grade at initial diagnosis. Furthermore, SCI patients show a significantly higher proportion of the more aggressive squamous cell carcinoma than that of the general population in areas not endemic for the tropical disease schistosomiasis. Consequently, the survival time is extremely unfavourable. A very important finding, for practical reasons is that, in the Hamburg study as well as in the literature, urinary bladder cancer is more frequently observed after 10 years or more of SCI. Based on these findings, a matrix was compiled where the various influencing factors, either for or against the recognition of an association between SCI and urinary bladder cancer, were weighted according to their relevance.

CONCLUSIONS

The results showed that urinary bladder cancer in SCI patients differs considerably from that in able-bodied patients. The presented algorithm is an important aid in everyday clinical practice for assessing the correlation between SCI and bladder cancer.

Alcohol drinking and head and neck cancer risk: the joint effect of intensity and duration

BACKGROUND

Alcohol is a well-established risk factor for head and neck cancer (HNC). This study aims to explore the effect of alcohol intensity and duration, as joint continuous exposures, on HNC risk.

METHODS

Data from 26 case-control studies in the INHANCE Consortium were used, including never and current drinkers who drunk ≤10 drinks/day for ≤54 years (24234 controls, 4085 oral cavity, 3359 oropharyngeal, 983 hypopharyngeal and 3340 laryngeal cancers). The dose-response relationship between the risk and the joint exposure to drinking intensity and duration was investigated through bivariate regression spline models, adjusting for potential confounders, including tobacco smoking.

RESULTS

For all subsites, cancer risk steeply increased with increasing drinks/day, with no appreciable threshold effect at lower intensities. For each intensity level, the risk of oral cavity, hypopharyngeal and laryngeal cancers did not vary according to years of drinking, suggesting no effect of duration. For oropharyngeal cancer, the risk increased with durations up to 28 years, flattening thereafter. The risk peaked at the higher levels of intensity and duration for all subsites (odds ratio = 7.95 for oral cavity, 12.86 for oropharynx, 24.96 for hypopharynx and 6.60 for larynx).

CONCLUSIONS

Present results further encourage the reduction of alcohol intensity to mitigate HNC risk.

Smoking and bladder cancer: review of the recent literature

PURPOSE OF REVIEW

This review summarizes the current knowledge regarding the relationship between smoking and bladder cancer (BCa), especially with respect to treatment outcomes for muscle and nonmuscle-invasive BCa (MIBC/NMIBC).

RECENT FINDINGS

PubMed/Medline databases were searched for recent reports investigating the association of smoking with BCa. Smoking is associated with an increased risk of recurrence in patients with NMIBC and may impair Bacillus Calmette-Guerin treatment efficacy. Moreover, smoking is associated with poor responses to neoadjuvant chemotherapy, poor survival outcomes and high complication rates in patients undergoing radical cystectomy. Smoking cessation mitigates these negative effects, especially. However, the amount of patient counselling provided regarding this important matter and patient knowledge regarding smoking and BCa risk are inadequate. Currently, the impact of secondhand smoke on BCa risk remains uncertain.

SUMMARY

Tobacco smoking is responsible for approximately half of BCa cases, and is associated with poor oncological outcomes for both NMIBC and MIBC. Despite smoking being a well known risk factor, counselling and knowledge in this area are insufficient. Appropriate smoking cessation interventions and patient information are required to improve patient health and optimize BCa survival.

Prognostic Impact of Smoking Period in Patients with Surgically Resected Non-small Cell Lung Cancer

BACKGROUND

The pack-year index, which is calculated by multiplying a smoking period by the number of cigarette packs smoked per day, is frequently used to investigate the risk of developing lung cancer. Notably, however, whether the smoking period or the number of packs per day is more predictive of postoperative prognosis remains unclear in non-small cell lung cancer (NSCLC) patients who receive curative lung resection.

PATIENTS AND METHODS

Initial screening included 2055 consecutive lung cancer patients who had underwent curative lung resection between 2000 and 2016 at a single center in Japan. Data from 1134 NSCLC patients with smoking history were ultimately analyzed. Time-dependent areas under the curve (AUCs) were used to compare diagnostic accuracy.

RESULTS

On univariate analysis, the number of packs smoked per day was not a significant predictor of disease-free survival (DFS; p = 0.2387) or overall survival (OS; p = 0.1357). On multivariable analysis, smoking period was an independent predictor of DFS and OS (both p < 0.0001). Time-dependent smoking period AUCs were superior to those of number of packs smoked per day. On subgroup analyses, patients with a smoking period ≥ 40 years had significantly shorter DFS and OS than those with a smoking period of < 40 years, independent of sex, clinical stage, and histological type.

CONCLUSIONS

Smoking period was a significant prognostic indicator in NSCLC patients who underwent curative lung resection, which should be validated in further prospective and/or multicenter studies with large sample sizes.