Hair loss is a common side effects of some cancer treatments.
It's a common side effect of some chemotherapy drugs. Hormone therapy and targeted drugs are more likely to cause hair thinning, although hair loss can sometimes happen.
Radiotherapy makes the hair fall out in the treatment area. Hair on other parts of the body is not affected.
Whether you lose your hair depends on:
- the type of drug or combination of drugs you are taking
- the dose
- your individual sensitivity to the drug
- your drug treatment in the past
These drugs can cause:
- mild thinning of your hair
- partial hair loss, or loss of patches of hair
- complete hair loss (alopecia)
Complete hair loss can happen gradually. Or hair may fall out fairly quickly, in clumps.
You might also have thinning or loss of eyelashes, eyebrows and other body hair. For example, pubic hair, underarm hair and chest hair in men.
Chemotherapy drugs work by killing growing cells such as cancer cells. But normal body tissues such as the hair follicles, also have lots of growing cells. This is what makes your hair fall out.
Not all chemotherapy drugs cause hair loss. Some don't cause any hair loss at all, or only slight thinning. If your hair is going to fall out, it usually begins within 2 to 3 weeks after treatment starts.
Hair almost always grows back once your treatment has finished. In very rare cases, it does not grow back. This usually only happens with very high doses of particular drugs.
It might take several months for hair to grow back. It might look the same as before, or it may be thicker or thinner. Sometimes it can be a different colour or curlier.
Other cancer drugs
There are different types of targeted drugs and these cause hair problems to different degrees. Some of these drugs cause hair thinning, slower hair growth and dry, brittle hair. Some can cause hair loss on the head and body. These problems tend to develop 2 to 3 months after starting treatment.
Hormone therapies are more likely to cause hair thinning. This usually slows down or stops within the first year of starting treatment.
Your hair should start to thicken a few weeks after finishing targeted drugs or hormone therapies. But it may take a couple of months before you really notice the difference.
Radiotherapy to the head always causes some hair loss. Your hair will fall out in where the radiotherapy beams enter your head.
You can also lose some hair on the opposite side, where the radiotherapy beams pass through.
It might take more than 6 months after radiotherapy for your hair to grow back.
Hair regrowth may be patchy at first, and it might stay patchy for some people.
But for most people, hair usually grows back completely in time.
Reducing hair loss from chemotherapy
Some people want to look into ways of reducing hair loss from their treatment. There is no known way to prevent hair loss from radiotherapy, hormonal therapies or targeted medicines. For chemotherapy, it might be possible to try scalp cooling to reduce hair loss.
Scalp cooling can sometimes reduce the amount of hair loss.
Scalp cooling lowers the temperature of your scalp and reduces the blood flow in the scalp. This reduces the amount of drug reaching the hair follicles on your head. With less of the cancer drugs getting to the hair follicles, the hair is less likely to die off and fall out.
There are different types of scalp cooling, these include the:
- cold cap – a hat filled with gel that is chilled before you put it on
- refrigerated cooling system – you wear a cap that is attached to a machine, the machine pumps liquid coolant into the cap
When not to use scalp cooling
Scalp cooling is not suitable for use in all types of cancer or situations. You won’t normally have scalp cooling if there is too high a risk that there might be cancer cells in your scalp blood vessels. This is because the cells in the scalp blood vessels might survive the treatment.
So for example, scalp cooling is not recommended in people:
- with cancers such as leukaemia and lymphoma
- whose cancer has spread to the scalp
- who are due to have radiotherapy to their scalp
You would not have scalp cooling with continuous chemotherapy through a pump or with chemotherapy tablets. This is because you would have to wear the cold cap for 24 hours a day.
Some doctors are not happy about their patients using scalp cooling for any type of cancer. They worry about the risk of cancer cells being left in the scalp, leading to cancer spread in the skin of the scalp (scalp metastases).
In theory there is a risk, but there is not enough evidence to know this for sure. Research in this area has mainly looked at women with breast cancer.
One study looked at the number of scalp metastases in women who had scalp cooling and women who did not. There was no significant difference. Scalp metastases is very rare in women with breast cancer.
Things to think about
Scalp cooling only blocks certain drugs and does not work for everyone. You might still have hair thinning, or lose your hair completely. You can't tell whether it will work for you until you try it.
You spend longer at hospital having your treatment if you have scalp cooling. You need to wear the cap before, during and after you have the chemotherapy drugs into your bloodstream.
The time varies depending on the drug. For example, you might wear the cap:
- about 30 minutes before treatment
- during treatment – this could be anything from 10 minutes to a couple of hours
- 1 to 2 hours following treatment
Research suggests that scalp cooling with Afro Caribbean hair is not as successful. So your nurse might recommend you have longer periods of scalp cooling if this applies to you.
Scalp cooling can make you feel cold all over. And it can make you feel uncomfortable and give you a headache. Take lots of layers to put on and ask for a blanket if you need it. Hot drinks will help you feel warmer