Cancer cold caps

For some people losing their hair whilst undergoing treatment for cancer can be as, if not more, traumatic than the cancer diagnosis itself. Hair loss can make a patient feel vulnerable, it's an obvious sign they are unwell and they may worry about other people's reactions.

Cold caps, also called scalp coolers, can reduce head hair loss for patients undergoing certain types of chemotherapy. They're not new, they've been around since the 1970s, but not all NHS hospitals use them or have enough to go round.

What is a cancer cold cap?

It's a lightweight, tight fitting, silicone cap which looks a bit like a cycle helmet. It is worn before, during and after chemotherapy drugs are administered. The total time it is worn ranges from 1½ to 5 hours, with the average time being 2 to 2½ hours. Correct fitting is important.

Having an icy cold head can feel very uncomfortable at first, but patients report that once the cap reaches its target temperature, they go numb. Painkillers may also help.

How does it work?

Cold caps dramatically reduce the temperature of the scalp making the blood vessels in the scalp contract, which in turn restricts the amount of blood containing concentrated chemotherapy drugs reaching the hair follicles. This increases the chances of retaining head hair. Hair elsewhere on the body will still be affected by the chemotherapy.

There are several cold cap models available and two methods of scalp cooling:

• A refrigerated, computerised, cooling system, which constantly pumps liquid coolant into a cap
• A cap filled with a chilled gel (a number of these may be used during one session as they can begin to warm up).

What's the evidence for scalp cooling reducing hair loss?

A number of small studies claim the caps are highly effective in 50% to 60% of the women who have used them.

One cold cap, the DigniCap used in some UK hospitals, was tested on 122 early-stage breast cancer patients receiving standard chemotherapy. More than two-thirds of those who used it kept their hair. According to the regulator FDA in the US, common side effects were cold-induced headaches, neck and shoulder discomfort, chills and pain.

Another study of 1,411 patients carried out in The Netherlands, from 2006 until 2009 in 28 hospitals using the Paxman scalp cooling systems found that overall 50% of the patients with scalp cooling had good hair preservation.

Two US studies published in JAMA in 2017 found that scalp cooling was associated with stopping significant hair loss in approximately 50% of women in trials.

Scalp cooling doesn't work for everyone and there's no way to tell in advance if it will work for you or not.

Some people who use a cancer cold cap will retain their hair (this can happen anyway, with or without the cap), some will still lose most of their hair, others will lose some and other patients may experience thinning of their hair.

Some doctors have concerns about scalp cooling as they believe it may prevent uncommon cancer cells near the scalp from being killed. Cancer Research UK says in theory there is a risk this could happen, but there has been very little research done into this possibility.

Hair loss due to chemotherapy is usually temporary, and hair should begin to grow back once treatment is over or for some people even before it has ended.