Night Function and Breast Cancer: French Court Recognizes Occupational Link

A landmark ruling in France has established a direct link between a nurse’s breast cancer and her long-term night shift work. The administrative court of Marseille acknowledged the connection, a decision that could pave the way for increased recognition of occupational diseases related to shift work.

The Case

The case centers on a nurse at the Martigues hospital center in Bouches-du-Rhône, who worked night shifts for nearly 25 years, from 1991 to 2016. She was diagnosed with breast cancer in January 2014 at the age of 55 and subsequently sought recognition of her cancer as an occupational illness. Her initial request to the hospital director in October 2021 was denied, as was a subsequent appeal to the administration in November 2021. She then brought the case before the administrative court of Marseille.

Court’s Decision and Reasoning

On March 3, 2026, the administrative court ruled in favor of the nurse, overturning the previous denials. The court determined that a direct link between her working conditions and the development of breast cancer was sufficiently probable. This decision highlights a growing understanding of the health risks associated with disrupting the body’s natural circadian rhythm through night work.

The court’s reasoning was based on several factors. Medical experts noted that recent scientific literature suggests a possible link between night work and an increased risk of breast cancer, even though data remains somewhat contradictory. Importantly, the experts found that the nurse had few pre-existing risk factors for the disease, making her work schedule a more significant potential contributor. The court emphasized that establishing a direct link doesn’t require certainty, only a demonstration that working conditions could have contributed to the development of the cancer.

Scientific Basis for the Link

Research indicates that night work can disrupt hormonal functions in women, potentially increasing the risk of breast cancer. Studies dating back to 2007 have highlighted these effects [2]. The court acknowledged this body of evidence in its ruling.

Implications and Compensation

This ruling sets a precedent for similar cases in France and may lead to greater awareness of the health risks associated with night shift work. The nurse is now eligible for compensation in the form of an annuity, calculated based on her disability rating. While such decisions remain relatively rare, several other hospital staff exposed to night work have initiated similar claims in recent years [2].

Further Resources

• Justice Recognizes a “Direct Link” Between a Nurse’s Breast Cancer and Her Night Work
• The administrative court of Marseille has recognized a direct link between the breast cancer developed by a nurse and her nearly 25 years of working night shifts