Testicular cancer cases have been steadily increasing over the last several decades [1]. Approximately 1,200 Canadian men will be diagnosed with testicular cancer in 2022 [2]. Even though testicular cancer is rare, it is the most prevalent cancer in men aged 15 to 35 years [3].
Risk factors associated with testicular cancer include undescended testicle (cryptorchidism), family history of testicular cancer, personal history of testicular cancer, calcium deposits in the testicle, and tall adult height [1]. Occupational exposures, such as some pesticides and work as a firefighter, may also play an important role in the development of testicular cancer [1,4].
Possible occupational risk factors
Increased risk of testicular cancer was observed in firefighters and police in the ODSS. It is well documented that firefighters are exposed to various known and suspected carcinogens in fire and smoke [8]. Firefighters may have been exposed to PFOA, which was used in fire-fighting foam in the past [4]. Occupational exposures related to risk of testicular cancer in police is less understood. There is some evidence that microwave emissions from radar guns may be a risk factor due to the proximity of hand-held radar guns to the testicles [5,9-11].
Elevated risk of testicular cancer was observed in workers involved in aircraft manufacturing, assembly, and repair, which has been observed in previous studies [5,12-13]. Product fabrication and manufacturing occupations may have been exposed to PCBs present in older electrical products and equipment manufactured prior to the 1977 ban on PCB, as the legislation allowed for continued use of PCB equipment until the end of its service life [14]. Electrical product industry workers may have been exposed to PCBs through handling electrical equipment and cable insulation [14-16]. Construction workers in power lighting and wire communications may have been exposed to materials containing PCBs, such as electrical equipment, cable insulation, and adhesives [14-16], and PFOAs, found in electrical wire casing [17]. Workers in other product fabricating, assembling, and repairing occupations may have been exposed to PCBs through oils used in motors and hydraulic systems [14-16]. There is also limited evidence for exposure to hydrocarbon carcinogens and glycol ethers in aircraft handling occupations [5,12-13].
Increased risk of testicular cancer was observed in various transportation occupations and industries in the ODSS. Whole body vibration [18] and diesel engine exhaust [4,19] have been linked to other cancer sites and may be potential risk factors in transportation workers. However, there is a lack of evidence supporting associations of these exposures with testicular cancer.
Figure 1. Risk of testicular cancer diagnosis among workers employed in each industry group relative to all others, Occupational Disease Surveillance System (ODSS), 1999-2020
The hazard ratio is an estimate of the average time to diagnosis among workers in each industry/occupation group divided by that in all others during the study period. Hazard ratios above 1.00 indicate a greater risk of disease in a given group compared to all others. Estimates are adjusted for birth year and sex. The width of the 95% Confidence Interval (CI) is based on the number of cases in each group (more cases narrows the interval).
Figure 2. Risk of testicular cancer diagnosis among workers employed in each occupation group relative to all others, Occupational Disease Surveillance System (ODSS), 1999-2020
