Losing one’s hair due to chemotherapy treatment can be an extremely emotional experience.
Even if the treatment successfully eradicates the cancer, many patients still don’t feel 100 percent back to normal until their hair grows back fully, which can take months or even years, said Hope S. Rugo, MD, professor of Medicine and director of Breast Oncology and Clinical Trials Education at the University of California San Francisco Helen Diller Family Comprehensive Cancer Center.
That’s why Rugo helped lead the FDA clearance process for the DigniCap Scalp Cooling System—cleared by the FDA in December 2015—a cold, temperature regulated cap that a patient can wear during chemotherapy to reduce the chance of hair loss.
“Preventing hair loss is a very important quality-of-life issue for our patients,” said Rugo. “It makes people feel like they are well sooner because they are not wearing a head covering or worrying about their appearance for so much longer after their treatment.”
The cap’s reduced temperature results in a reduced blood flow to the scalp area so that less of the chemotherapy reaches the hair cells, therefore slowing down the hair cells cellular metabolism. Hair cells are therefore not exposed to the full dose of chemotherapy and may be able to survive the treatment.
The FDA clearance was based on a clinical study comparing hair loss in 117 breast cancer patients with either stage I or stage II breast cancer who underwent at least four cycles of specific chemotherapy regimens.
Of the patients that used the DigniCap Scalp Cooling System in the study, 66.3 percent lost less than half of their hair when followed for a month after the last chemotherapy cycle. In comparison, 100 percent of women in the control group who did not use the system lost more than half of their hair.
In an interview with R&D Magazine, Rugo discuss the benefits of the system for hair loss prevention, how it works and barriers to it becoming commonly used.
R&D Magazine: How does the Dignicap system work?
Rugo: “The way the scalp cooling was theorized to work was that if you cool the scalp you would reduce the delivery of chemotherapy through the blood vessels to the scalp, simply by causing vasoconstriction. Subsequent research has found that there is a reduced delivery of chemotherapy, although certainly chemotherapy is still delivered, and the cooling doesn’t go down very far, so it only effects the scalp. The real reason why scalp cooling is effective is because the cooling really reduces the metabolism of the hair follicle cells. The hair follicle is squeezed off where it exits from the follicle when chemotherapy is causing hair loss, and they get really, really thin at that spot because the follicle is busy speeding up its metabolism to try and make do with the toxin. In this case, we reduce that effect by cooling the cells.
We try and enhance the cooling by having patients wet their hair right before they put the cap on; no one has ever done randomized studies to show that this is necessary, but it has always been part of scalp cooling.
The way it works is you start the system before receiving chemotherapy, which works out really well because almost all chemotherapy is preceded by pre-medication. Then you want the cooling device to be at the requisite temperature once you start the chemotherapy infusion. Then you get the chemotherapy and there is a post-cooling time afterwards. The idea is, right after the chemotherapy ends, which is all intravenous, the levels in the blood are quite high and you want those levels to decrease. You won’t clear all of the drug, of course for some time, but it appears, depending on the strength of the chemotherapy agent and the half-life, you can design a reasonable post-cooling time. That time usually lasts between 90 to 120 minutes. It is quite possible that shorter post-cooling time is just as effective, and that is being evaluated in some settings now.”
How does Dignicap compare to other types of scalp cooling?
“There are basically two different types of scalp cooling systems. There is a manual type, where you freeze a gel cap and then put it on your head. That gel cap has to be replaced because it keeps warming up, so it has to start out at a much colder temperature. In fact, you have to be very cautious about not damaging the scalp from the cold temperature, although that is a rare event.
There is another type of manual cold cap that is a flat gel material that then is molded to the head. But those do require somebody that is not the patient to change the cap every half an hour. It also requires either the presence of a freezer and then refrigeration, or a cooler that is specifically designed for that cap.
There is a second type of scalp cooling system which is automatic. Within this space, there are two devices, one is Dignicap, and the other, which is not approved yet, is Paxman Scalp Cooling. These devices are a machine that circulates a coolant through a cap that looks like a swimming cap. The cap has little channels inside it where the coolant circulates. For the Dignicap, there are actually temperature sensors in both the back and front of the cap, and the machines continually readjusts the temperature of the coolant that is circulating through the cap, based on what the temperature sensors are telling the machine. The cap is covered with an insulating material to prevent the heat from escaping.
The advantage of these automated machines is that they are small; both types can cool two patients at the same time on either side of the machine. They don’t require any intervention on the part of the patient or a family member. We do suggest that people still bring someone to help them with a variety of things with the chemotherapy, but it is a much less active process so it’s easier for patients.”
Are there any risks or downsides that patients should be aware of with this technology?
“We found that the treatment was very tolerable. The side effects were exactly what you would expect if you put a really cold cap on your head; a headache, a sense of being cold. We allow patients to ask for pain medication right before their start to deal with that initial cooling or the ‘brain freeze’ that they feel at the start. Then they adjust to the cold, and it doesn’t bother them so much anymore.
People were initially worried that there would be an increased risk of scalp metastasis by reducing blood flow to the scalp and reducing the delivery of chemotherapy. Theoretically that doesn’t really make any sense because we know that the scalp is not a privileged site that holds cancer cells for growing back. Where we know they hide out is places where they can get a foothold, a structure to sit on, and where they can get nutrition, for example in the bone marrow.
But obviously we needed to prove this. We are following our patients out and we now have more than two years of follow-up data with no evidence of scalp metastasis. The paper that we just published in Breast Cancer Research and Treatment, for which I am the first author, is a meta-analysis of all trials that reported the incidence of scalp metastasis in both cooled and non-cooled patients. What we showed is that the risk of scalp metastasis in breast cancer is exceedingly low and it is no way increased in patients that have scalp cooling. “
This system was studied in early-stage breast cancer patients. Is there potential for its use in other settings or other cancers?
“For patients with metastatic breast cancer, one thing we know for sure is that eventually they are going to die of their cancer. If they don’t want to lose their hair and that is stopping them from getting treatment, I’d rather have them get effective treatment and use the cap than not get treatment. That is an issue for patients that know that they are going to die of their cancer and they are putting off death by using chemotherapy. It is a very different approach than for people with curable disease. We do bring it up to metastatic patients and allow them to use scalp cooling, but it’s a very individualized decision.
For other cancers, we have not discouraged the use of cooling caps, except in certain settings where patients are receiving chemotherapy for liquid-type tumors, where cells are circulating everywhere at the same time, like leukemia or lymphoma. We don’t recommend that. We also don’t recommend it at this time for other types of hair loss treatment because it hasn’t been shown to work.
For other types of cancers, like ovarian cancer, lung cancer, ect., these are very reasonable options.”
Are there any barriers preventing scalp cooling from becoming more widely used?
“One of the things that is a shame about this is the fact that it costs money and insurance doesn’t cover it yet. We are hoping that these trials and the safety data will help to get insurance coverage for scalp cooling. It is a very important goal for the future to try and get insurance coverage, or at least partial insurance coverage for scalp cooling so that it is not a technique that can only be used by people who can afford it. Bethany Hornthal, who got us the original philanthropic funding, is working with an organization that she helped to create called Hair to Stay. They are working to raise money to help fund patients that are low income that want to use scalp cooling. They’ve already helped quite a number of patients. That is a hard thing to sustain for every patient that wants scalp cooling forever, so we really want insurance to kick in for patients and still have that philanthropic funding that is so important.”
This interview was edited for length and clarity