A Spanish study has revealed an unexpected side effect of immunotherapy treatment for lung cancer: patients' grey hair spontaneously darkened during treatment with checkpoint inhibitor drugs. The finding, published in JAMA Dermatology, represents the first documented case of hair repigmentation associated with immunotherapy for lung cancer.
Study Details and Patient Population
Researchers at Autonomous University of Barcelona followed 52 patients with non-small cell lung cancer (NSCLC) who were receiving immunotherapy treatments. Of these, 14 patients experienced significant hair darkening while being treated with one of three checkpoint inhibitors: Keytruda (pembrolizumab), Opdivo (nivolumab), or Tecentriq (atezolizumab). The average age of affected patients was 65 years.
The patients were being monitored by dermatologists specifically to track potential cutaneous toxic side effects, as these are common adverse effects of immunotherapy treatments. However, the hair repigmentation came as a complete surprise to the research team.
"This was totally unexpected, so it was exciting," said Dr. Noelia Rivera, a dermatologist at the Hospital Universitari Germans Trias i Pujol and one of the study's authors. "We thought it could be an isolated case when it happened with the first patient. But the research team found the same thing when they asked other patients for photographs of themselves from before treatment."
Hair Color Changes and Treatment Response
In 13 of the 14 patients, hair turned darkish brown or black, returning to shades similar to what patients had before their hair turned grey. One patient experienced black hair growth in patches. The transformation represented a return to more youthful-looking hair colors across the affected patient group.
Notably, 13 of the 14 patients who experienced hair repigmentation also demonstrated superior treatment responses compared to other patients in the study. These patients reported either partial response or stable disease states. Only one patient had to discontinue therapy after four cycles due to life-threatening disease progression.
"All but one of the 14 patients in the Spanish study responded better to treatment than other patients, suggesting that hair darkening might be an indication that the drugs are working," the researchers noted.
Mechanism and Previous Reports
The underlying mechanism responsible for the hair repigmentation remains unclear and requires further investigation. Hair repigmentation is considered very rare, though it has been reported previously with other drugs such as Thalomid. However, this represents the first documentation of the phenomenon in relation to immunotherapy treatment for lung cancer.
Interestingly, the same checkpoint inhibitor drugs have been previously linked to hair losing color in patients with melanoma, suggesting these medications may have variable effects on hair pigmentation depending on the cancer type or patient population.
Clinical Implications and Future Research
The dual positive implications of this study could have far-reaching effects for both cancer treatment and cosmetic applications. The correlation between hair darkening and improved treatment response suggests this visible change might serve as a potential biomarker for therapeutic efficacy.
"The high rates of good response to therapy in these patients was also an exciting finding. We are surprised at the results, and we are encouraged to keep on with the study," Dr. Rivera stated.
However, researchers emphasize caution regarding potential cosmetic applications. Dr. Rivera noted that the immunotherapy drugs used in the study have serious side effects that make them unsafe for healthy individuals. Any cosmetic application would require development of different, safer compounds.
Expert Commentary and Historical Context
Dr. June Robinson, a Northwestern University research professor in dermatology and editor of JAMA Dermatology, called the findings "a fascinating report – one of those things that comes out of the blue." While acknowledging the results deserve deeper investigation, she cautioned that it was too soon to suggest they might lead to new treatments for unwanted grey hair.
The pharmaceutical industry has previously capitalized on unexpected drug side effects to develop new treatments. Examples include Propecia for male pattern baldness, Latisse for eyelash growth, and Botox for anti-wrinkle applications, all of which originated from drugs initially approved for other medical conditions.
Dr. Rivera emphasized the need for extensive additional research: "A lot of research is yet required, first to come up with a study, and after that, to get funding to develop the project." The research team continues their investigation to search for an explanation for this unexpected phenomenon.
