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

Abstract

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.

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

“…The textile industry constituted the economic base of the Vallès Occidental region from the mid-19th century to the 1970s. This fact justified the performance of BC incidence and population-based case–control studies whose objectives were to assess occupational risk factors for BC in this area [ 5 , 13 , 17 ]. These studies demonstrated that tobacco consumption was strongly associated with BC [ 13 ].…”

“…The incidence of BC in Vallès Occidental remains one of the highest in men and one of the lowest in women, at a European and global level, despite the decline in tobacco consumption and industrial activity over the years [ 6 ]. Compared to data published during the period 1992–1994, both the crude annual incidence and age-adjusted incidence have increased in both sexes, although the increase in men is notably higher [ 5 , 13 ]. The high incidence of BC in men, some 25 years later, could be related to a high prevalence in this area of well-known risk factors such as smoking, residence in industrialized areas, and occupational exposure to certain carcinogenic products [ 13 , 14 ].…”

“…Vallès Occidental is a region of Catalonia located in the northeast of Spain with an extended industrial tradition, mainly textiles, in which a markedly elevated incidence of BC was detected in men in the 1990s [ 4 ]. This trend remains at present [ 5 ], with a crude rate of 62.6 (95% CI 55.0–70.1) in men and 6.8 (95% CI 4.4–9.3) in women, and an annual rate adjusted for the standard European population of 85.3 (95% CI 75.0–95.5) in men and 7.0 (95% CI 4.5–9.5) in women. In addition, although we do not have specific data on other types of cancer, the crude rate per 1000 inhabitants of active neoplasia in West Vallès Occidental in 2015 was significantly higher than that of the rest of Catalonia (29.17 vs. 21.85, respectively) [ 6 ].…”

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

“…We have recently carried out a study on the high incidence of BC in an industrialized Mediterranean area, which has led us to consider the comparability of the incidence of BC between the different registries. 32 …”

“…In addition, not only BC has a high rate of recurrence, but also generally presents as multicentric, and in some cases with a strong potential for infiltration, even if the invasion of the submucosa is not observed in the anatomopathological sample. We have recently carried out a study on the high incidence of BC in an industrialized Mediterranean area, which has led us to consider the comparability of the incidence of BC between the different registries 32 …”