Cryotherapy for skin cancer is the use of liquid nitrogen to destroy a lesion. Cryotherapy may be a good option for benign lesions, such as actinic keratosis. It also treats thin non-melanoma skin cancer. Cryotherapy is used when there are only a few lesions to treat, and the lesions have clear borders.
How is cryotherapy performed?
Cryotherapy is a quick and simple procedure that your doctor can do in the office. Your doctor may draw an outline (margin) around the lesion. Liquid nitrogen is often sprayed, although a swab or cryoprobe also could be used.1
The sprayer is held about 1 centimeter above the lesion. As your doctor sprays the area, an iceball will form around the lesion and margin.1,2 Your doctor will continue to spray the area for up to 30 seconds after the iceball forms. This keeps the area frozen for long enough to destroy the tissue. Depending on the lesion, your doctor may allow the area to thaw for 2 to 3 minutes and then re-freeze the area.1 For actinic keratosis, re-freezing may not be necessary.1
The spray or probe reaches temperatures as low as -13ºF to -58ºF.1 This causes cells to freeze immediately. Inflammation develops in the area within 24 hours, causing further destruction.1
What types of skin cancer is cryotherapy used to treat?
Cryotherapy is one of the most common treatments for actinic keratosis.3 Actinic keratosis is a precancer, or a skin abnormality that may develop into skin cancer. Up to 10% of actinic keratoses become squamous cell carcinoma (SCC).4 For this reason, your doctor may recommend treating actinic keratoses. Cryotherapy cures between 75% and 99% of actinic keratoses.3
Cryotherapy is occasionally used to treat basal cell carcinoma (BCC) or SCC that only affects the top layer of skin.5,6 Other terms used for these types of lesions are:
- Thin BCC
- SCC in situ, which is when the cancer cells are only in the top layer of skin
- Bowen’s disease
Surgery is preferred for thin skin cancers. However, if surgery is not possible, cryotherapy may be an alternative. About 15% of BCC return within 1 year of cryotherapy, and 20% return within 5 years.5 Up to 20% of SCC in situ treated with cryotherapy return within 1 year.7
Small Kaposi sarcoma lesions on the face can be treated with cryotherapy.8
What should I expect before, during, and after cryotherapy treatment for skin cancer?
For actinic keratoses, your doctor may prescribe fluorouracil topical medication to use before cryotherapy.4 Fluorouracil reduces the number of lesions that need to be treated. It also reduces the risk of recurrence.
Cryotherapy can be painful.7 You may feel burning or discomfort in the place that was treated.3
Your doctor will tell you how to care for the wound after cryotherapy. You should follow your doctor’s instructions and talk to your doctor if you have any questions. A blister will form in the treated area within a day. A few days later, a scab will form. Your doctor may instruct you to apply an ointment to the surface. The scab will peel off within a few weeks, depending on the location. You can cover the scab with a bandage if your clothes rub the area. Do not pick at the scab. Do not apply make-up to the area until it has healed.9
What are the risks of cryotherapy?
Serious side effects are rare.3 Cryotherapy does not usually leave a scar. It can cause discoloration in the treated area. The discoloration may improve over several months, but it can be permanent.1 You also may have permanent hair loss in the area. Loss of sensation in the treated area is rare. If it does occur, it can take up to 18 months to regain sensation.1
Other possible risks during or immediately after cryotherapy include:
- Bleeding at the freeze site
- Headache after treatment of lesions on the forehead
- Fainting (rare)1
What questions should I ask before cryotherapy for skin cancer?
- What options do I have for treating this lesion?
- Why do you think cryotherapy is a good option for me?
- How should I prepare for cryotherapy?
- How is cryotherapy performed?
- How should I care for the wound?
- How long does it usually take for the wound to heal?
- How often should I have follow-up exams with my dermatologist to check for cancer recurrence or a second skin cancer?