Scientists may have figured out how to prevent hair loss in cancer patients undergoing chemo. And it could be as easy as holding off on your treatment until after the sun goes down. Discovering that mouse hair has a 24-hour cycle of growth followed by restorative repair, researchers from the Salk Institute for Biological Studies, the University of Southern California (USC) and the University of California, Irvine (UCI) suspect that hair loss in humans from toxic chemotherapy and radiotherapy might actually be minimized, if not totally eradicated, if these treatments are given late in the day.
Yes, you read that right. Getting chemo at night could allow cancer patients to keep most if not all of their hair. In a new study appearing in the online edition of the Proceedings of the National Academy of Sciences (PNAS), scientists found that mice lost 85 percent of their hair if they received radiation therapy in the morning, compared to just a 17 percent loss when treatment occurred in the evening. And they think this could apply to humans, too.
Which begs the question: Where were these good guys in lab coats when I needed them? If only we'd known this when I did my CHOP chemo regimen. I would've insisted on getting treatment while watching David Letterman!
Researchers worked out the precise timing of the mice hair's so-called circadian clock, and also uncovered the biology behind the clockwork - that is, the molecules that tell hair when to grow and when to repair damage. They then tested the clock using radiotherapy.
The study’s co-lead investigator, Satchidananda Panda, an associate professor in Salk’s Regulatory Biology Laboratory and expert on circadian rhythm, explains the process exclusively to The Reno Dispatch.
"Clocks are everywhere in our body, but one new function of the clock we just learned is how cells repair their own DNA at certain times of the day," he says. "This has practical implications in cancer radiation therapy and chemotherapy, which often intend to damage the tumor DNA. However, the bystander normal cells are also damaged. The outcome is adverse effects such as hair-loss and upset stomach."
Panda says the difference in DNA repair ability in normal cells based on the time of day is "quite remarkable. It clearly shows that time-of the day specific cancer treatment might reduce side effects - allowing clinicians to potentially increase the dose for effective treatment with tolerable side effects."
Maksim Plikus, assistant professor of developmental and cell biology at UCI and the study’s first author, said in a statement today that these findings are "exciting" because they present a significant step towards developing new radiation therapy protocols that include minimizing negative side effects on normal tissues, such as hair or bone marrow, while maintaining the desired effects on cancer cells.
"We will now apply our findings to design novel circadian rhythm-based approaches to cancer therapy," he said.
It remains to be seen how this will work in humans. But scientists are optimistic. Meanwhile, I know this isn't a cure for cancer. But hair loss is a very stressful part of cancer treatment for millions of people. I can only speak for myself: I wasn't at all happy about being bald for six months.
Panda adds that while we don’t yet know if human hair follows that same clock they found in mice hair, "it is true that facial hair in men grows during the day, resulting in the proverbial 5 o’clock shadow. There's no 5 a.m. shadow if you shave at night."
Hmm. I never thought about that. Maybe I'd better start shaving at night, too. But wait, there's more. There are all kinds of clinical implications for all these internal clocks, beyond the timing of drug therapy. For example, some researchers suspect that obesity and diabetes occurs when an organ or organs — perhaps the liver or stomach or pancreas — should be sleeping, but is awakened by food that needs to be processed.
“These local clocks do a lot more things than the central clock in the brain, which primarily regulates sleeping,” Panda says. “This field of research is exciting and may, someday, contribute to human health.”