Night-shift work increases risk for various cancers in women

Cancer risks can fluctuate depending on where you live, what you eat, what’s in your genes and what you do for work. Now, according to new research, when you work may also have an impact.

A meta-analysis from researchers in China published in Cancer Epidemiology, Biomarkers & Prevention found that women working night shifts face a 19 percent higher risk of cancer, including breast, skin and gastrointestinal varieties.

“We were surprised to see the association between night shift work and breast cancer risk only among women in North America and Europe,” said Xuelei Ma, PhD, oncologist at West China Medical Center of Sichuan University in Chengdu, China. “It is possible that women in these locations have higher sex hormone levels, which have been positively associated with hormone-related cancers such as breast cancer.”

The study examined 61 articles with 114,628 cases of cancer in North America, Europe, Australia and Asia. Women who performed long-term night shift work had a 41 percent higher risk of skin cancer, 32 percent higher risk of breast cancer and 18 percent higher risk of gastrointestinal cancer. Ma and colleagues discovered the breast cancer risk was higher only in women in North America and Europe.