Night work is linked to an increased risk of breast, gastrointestinal and skin cancers in women, according to several studies published in “Cancer Epidemiology, Biomarkers and Prevention” on Monday.
This study consists of an analysis of 61 studies covering 114,628 cancer cases and 3.9 million participants in North America, Europe, Australia and Asia.
These researchers, including oncologist Xuelei Ma from China’s Sichuan University in Chengdu, investigated whether working at night for long years could increase the risk of eleven types of cancer in women. Another analysis was done on the effects of night work for six types of cancer among nurses.
The findings of this study show a 19% increase in risk cancer for women working nights for several years. This risk is greatest for skin cancer (41%), followed by breast cancer (32%) and gastrointestinal cancer (18%) compared with women who have not performed night work for a long period of time.
The researchers also reported that breast cancer growth was only found in women working at night in North America and Europe. According to them, this could indicate that these women had higher levels of sex hormones which increases the risk of breast cancer.
Among female nurses, those who worked at night had a significantly higher risk of breast cancer (58%) as well as gastrointestinal cancer (35%) and lung cancer (28%).
Of all professions, nurses are the group of women with the highest risk of breast cancer. But this increased frequency could also be explained by the medical knowledge of nurses and the fact that they submit more frequently to medical examinations, report the authors.
Another explanation lies in the constraints of nursing work, which can often be more intense at night. The researchers determined that night work increases the risk of breast cancer by 3.3% per five-year age group in a night shift.
“The results of this study suggest the need for programs to protect the health of women working at night, with regular medical examinations,” say the researchers.