I am grateful to Wereld Kanker Onderzoek Fonds and World Cancer Research Fund International for funding our project.
Night shift work is prevalent, but its relationship with cancer is understudied. We will conduct a novel investigation on the relationship between night shift work and testicular cancers, along with analyses of ovarian cancer. Our results will be informative for the global workforce, general public and policymakers for primary prevention, as occupational exposures can be regulated.
– Dr Felix Onyije
Background
Approximately 30-50% of cancer cases can be prevented, with those linked to occupation and lifestyle risks being at the higher end. It is crucial to prioritise cancer prevention research that is impactful, providing reliable information to support policy changes and make a global difference in reducing cancer burden. Night shift work exposure is common and has not been thoroughly studied in relation to testicular germ cell tumours, and there is limited research on its relationship with ovarian cancer despite potential implications.
Aims and objectives
The purpose of this proposed project is to assess the relationship between working night shifts, which can disrupt sleep patterns, and the likelihood of developing testicular germ cell tumours in men and ovarian cancer in women.
How it will be done
The ON-Shift project will use data from two sources. The first source is a nationwide study called TESTIS, conducted in France between 2015 and 2018. This study involved 454 cases of testicular germ cell tumours in individuals aged 18 to 45 years. These cases were referred to the regional sperm bank for semen preservation. The study also included 670 controls, who were either sperm donors or partners of women seeking assisted reproduction treatment or high-risk pregnancy services. The cases and controls were matched based on the hospital centre administrative region and year of birth. The second data source is a Danish nested case-control study. This study involved 4,600 cases of ovarian cancer in individuals aged 18 to 70 years. The controls consisted of 115,000 individuals without ovarian cancer, identified through the Central Population Registry, which has collected individual information on Danish residents since 1968.
Potential impact
This study will be the first to assess night shift work exposure and testicular germ cell tumours risk, and the largest for ovarian cancer. If the results are confirmed in future studies with better exposure assessment, it could lead to recommendations for prevention, such as adding a “work-sleep balance” section to regional cancer prevention guidelines.