Cancer patients who are tearing their hair out over a common side effect of radiation treatment may have some good news. Researchers say they have found a way to significantly reduce—in some cases even eliminate—hair loss as a result of radiotherapy. Taking advantage of the latest discoveries about the science of hair growth, doctors will be able to help keep the temporary hair loss characteristic of chemotherapy and radiation therapy to a minimum.
These treatment techniques work by destroying cancer cells in the body, with chemicals or radiation, as the case may be. However, in some patients, this can entail doing some damage to healthy cells, particularly fast-growing ones—such as hair follicles. This isn’t necessarily a characteristic of the specific chemotherapy drugs administered. The same drug can cause different degrees and patterns of hair loss in different patients; some may lose head hair, some eyebrows and eyelashes, some body hair, various combinations, and some patients lose no hair at all.
It has historically been difficult to predict the effects in a particular patient, but it is usually temporary—though when it does grow back, usually between shortly before the end of the treatment period and a few weeks afterward, it may come back different from what it was like before. What the researchers have found is that when treatments are administered has an effect on how much hair is lost. Hair growth appears to be tied to the circadian rhythm, or body clock, which keeps various autonomous functions keyed to an approximately 24-hour cycle. In laboratory animals, hair growth is fastest early in the day, while evening hours are generally given over to repairing DNA errors that cropped up.
When radiation is administered during this repair period, it seems to have a smaller effect on hair than when it’s administered during the morning growth period. That suggests that the best time to treat humans is likewise when hair growth is slowest, the next task being to determine when that is. This may prove to be the first effective way to prevent hair loss from cancer treatment. Other attempts have not met with success; even the pattern baldness treatment minoxidil appears to have no effect for cancer patients.