Doctoral dissertation

Occupational exposure and risk of kidney and renal pelvis cancer

Cancers of kidney and renal pelvis are an important component of the overall cancer burden. Their causes are of interest both to urological oncologists and epidemiologists. Previous research on the subject has been mostly restricted to limited study populations, and its generalizability is problematic.

In her doctoral thesis, Irmina Michalek aimed at identifying work-related agents associated with the risk of kidney and renal pelvis cancer.
 
The research was based on a large cohort study called the Nordic Occupational Cancer Study (NOCCA). It includes all Nordic working-age population who participated in at least one population census between 1960 and 1990, altogether about 15 million individuals. Census records contributed data on employment history and were linked with data on cancer cases obtained from national cancer registries. The follow-up began from the earliest census and continued up to 2005. In this time, nearly 85,000 cases of kidney cancer and 11,000 cases of renal pelvis cancer were identified in Nordic countries.
 
The risk of kidney cancer was significantly higher than the average for the dentists (32% higher), journalists (20% higher), and physicians (19% higher). The significantly lower risk was found among forestry workers (18% below average). The risk of renal pelvis cancer was substantially higher than the average among physicians (63% higher) and public safety workers (38% higher). The significantly lower risk was found among forestry workers (49% below average), farmers (24% lower), and unskilled construction workers (22% lower).
 
Additionally, Michalek et al. evaluated the relationship between exposure to heavy metals at workplaces and the risk of kidney and renal pelvis cancer in three Nordic countries (Finland, Sweden, and Iceland). Census-based job titles of the cancer cases and controls were linked to a job-exposure matrix (NOCCA-JEM) to estimate the quantitative cumulative exposure. This study showed marked increase in risk of kidney and renal pelvis cancer among those aged 59-74 years and in the past exposed to high levels of iron (41% higher risk than unexposed group), moderate levels of welding fumes (27% higher than unexposed group), and high levels of welding fumes (43% higher than unexposed group).
 
This doctoral research supports the view that occupation is associated with the risk of kidney and renal pelvis cancer, and smoking is an important risk factor for these tumors. Additionally, exposure to iron and welding fumes at the workplace appear to play an important role.

A large number of cancer cases with a decade-long occupational history of the participants yielded an unprecedented opportunity for this doctoral research to identify the association between occupation and risk of kidney and renal pelvis cancer.

The doctoral dissertation of MD Irmina Maria Michalek in the field of Epidemiology titled Occupational exposures and risk of kidney and renal pelvis cancer in the Nordic countries will be publicly examined in the Faculty of Social Sciences at Tampere University at 12 o’clock on Thursday, 31.10.2019 in the auditorium F114 of the Arvo building, Arvo Ylpön katu 34, Tampere. The Opponent will be Adjunct Professor France Labrèche, University of Montreal. The Custos will be Professor Eero Pukkala, Faculty of Social Sciences, Tampere.

The dissertation is available online at http://urn.fi/URN:ISBN:978-952-03-1239-8

Photo: Florentino Luciano Caetano dos Santos