Don't Sleep? You Can Get Cancer

Yet one more reason to feel stressed about not sleeping.

It can give you cancer.

Poor-quality sleep marked by frequent awakenings can speed cancer growth, increase tumor aggressiveness and dampen the immune system’s ability to control or eradicate early cancers, according to a new study, as reported by newswise.com.

The Web site notes that the study is the first to demonstrate, in an animal model, "the direct effects of fragmented sleep on tumor growth and invasiveness, and it points to a biological mechanism that could serve as a potential target for therapy."

“It’s not the tumor, it’s the immune system,” said study director David Gozal, MD, chairman of pediatrics at the University of Chicago Comer Children’s Hospital, at newswise.com. “Fragmented sleep changes how the immune system deals with cancer in ways that make the disease more aggressive.”

He adds, "(The gene) appears to be a lynchpin for the cancer-promoting effects of sleep loss. The effects of fragmented sleep that we focused on were not seen in mice that lacked this protein.”

The good news is that science may have found the gene that can make this happen, and a way to target treatment. 

In the study, researchers interrupted the sleep of a select group of mice while the group slept through the night. They found that tumors from mice with fragmented sleep were twice as large as those from mice that had slept normally. A follow-up experiment found that when tumor cells were implanted in the thigh muscle, which should help contain growth, the tumors were much more aggressive and invaded surrounding tissues in mice with disrupted sleep.

“In that setting, tumors are usually encased by a capsule of surrounding tissue, like a scar,” Gozal said. “They form little spheres, with nice demarcation between cancerous and normal tissue. But in the fragmented-sleep mice, the tumors were much more invasive. They pushed through the capsule. They went into the muscle, into the bone. It was a mess.”

"The difference appeared to be driven by cells from the immune system, called tumor-associated macrophages, which cluster at the site of tumors," newswise.com points out. "These are a hallmark of the immune system’s response to cancer, but they can respond in a variety of ways, depending on chemical signals they receive."

Tumors which suppress the immune response and instead promote the growth of new blood vessels—which encourages tumor growth -- were found in the mice who were woken repeatedly through the night.

“This study offers biological plausibility to the epidemiological associations between perturbed sleep and cancer outcomes,” newswise.com quoted Gozal. “The take home message is to take care of your sleep quality and quantity like you take care of your bank account.”