Risk Factors Involved in the High Incidence of Bladder Cancer in an Industrialized Area in North-Eastern Spain: A Case-Control Study.

Bladder cancer (BC) is the most common of the malignancies affecting the urinary tract. Smoking and exposure to occupational and environmental carcinogens are responsible for most cases. Vallès Occidental is a highly industrialized area in north-eastern Spain with one of the highest incidences of BC in men. We carried out a case-control study in order to identify the specific risk factors involved in this area. Three hundred and six participants were included (153 cases BC and 153 controls matched for age and sex): in each group, 89.5% (n = 137) were male and the mean age was 71 years (range 30-91; SD = 10.6). There were no differences between groups in family history, body mass index, or dietary habits. Independent risk factors for CV were smoking (OR 2.08; 95% CI 1.30-3.32; p = 0.002), the use of analgesics in nonsmokers (OR 10.00; 95% CI 1.28-78.12; p = 0.028), and profession (OR: 8.63; 95% CI 1.04-71.94; p = 0.046). The consumption of black and blond tobacco, the use of analgesics in nonsmokers, and occupational exposures are risk factors for the development of BC in this area, despite the reduction in smoking in the population and the extensive measures taken in the last few decades in major industries to prevent exposure to occupational carcinogens.

Systematic review of population-based bladder cancer registries: How criteria heterogeneity affects the comparison of incidences.

BACKGROUND: The population-based registry of bladder cancer (BC) raises specific problems intrinsic to the tumor, as the inclusion of noninfiltrating, potentially malignant and multiple tumors. We performed a systematic review (PRISMA guidelines) of population-based BC registries to obtain information on their geographic areas involved, last dates of real incidence of BC, and rules coding used in BC for uncertain behavior, in situ and multiple tumors. METHODS: Using MEDLINE and Google Scholar, we identified scientific publications of in the last 10 years in English or Spanish, whether they were related to a national or international cancer registry, provided information on registry rules, and provided data on the incidence of BC. RESULTS: After the first screening, a total of 194 references were obtained. After a second analysis, three registries were selected: International Agency for Research on Cancer (IARC) is a world registry providing real incidence of BC in the period 2008-2012. Surveillance, Epidemiology, and End Results (SEER) Program registered incidence until 2017 in more than 90% of the US population. Spanish Network of Cancer Registries (REDECAN) unifies 14 Spanish registries (27.4% of the population) with real incidence data from 2010 to 2015. The coding and inclusion rules have been modified, but currently, most registries include BC in situ and uncertain behavior tumors. Whenever a new case occurs 36 months after a previous diagnosis, SEER registers those as multiple incident cancers in the same location, while IARC and REDECAN only allow one cancer per location during the lifespan of the patient. CONCLUSIONS: Comparison of the incidence of BC among different population-based cancer registries is prone to bias due to the methodological differences regarding the inclusion of carcinomas in situ, indeterminate, and multiple tumors. A good cancer registry could provide better surveillance strategies for BC patients.

Environmental Factors Involved in the High Incidence of Bladder Cancer in an Industrialized Area in North-Eastern Spain.

Background: Bladder cancer (BC) is the most common of those affecting the urinary tract, and a significant proportion of the cases are attributable to tobacco use as well as occupational and environmental factors. Objective: The aim of this study is to estimate the current incidence of BC in an industrialized area in northeastern Spain and to analyze its time trends over three decades from an ecological perspective. Methods: Patients diagnosed with histologically confirmed primary BC, during 2018-2019, in an area in northeastern Spain (430,883 inhabitants) were included. Crude and age-standardized incidence rates were estimated per 100,000 person-years based on the number of individuals getting their first diagnosis. An exploratory time trend analysis was carried out to describe the evolution in tobacco use and occupational or environmental risk factors and the incidence of BC in the same area from the 1990s. Results: 295 patients were included (age 72.5 ± 10.3 years; 89.8% men). The crude rate was 62.6 (95% CI: 51.9-73.2) for men and 6.8 (95% CI: 3.4-10.3) for women. The annual rate adjusted to the European Standard Population was 85.3 (95% CI:75.0-95.5) for men and 7.0 (95% CI:4.5-9.5) for women. From 1994 to 2018, the prevalence of smokers decreased in men (42.3% to 30.9%) as well as in the active population working in the industry (44.36% to 22.59%). Nevertheless, the car fleet, especially diesel, has increased considerably. The annual mean concentrations of air (PM10, PM2.5, O3, and NO2) and water (nitrates, arsenic, trihalomethanes) pollutants were within the regulatory limit values, but not the maximum levels. Conclusions: The incidence of BC is one of the highest in men but not in women, despite the decrease in tobacco use and industrial activity (perhaps related to high latency after carcinogen exposure cessation) and despite the control of environmental pollution (the maximum regulatory limit probably needs to be lowered). Finally, a similar exposure to the carcinogen would result in a gender-specific differential incidence.