Therapies for Precancerous or Early Basal & Squamous Cell Skin Cancers

NYU Langone doctors use several therapies to treat an actinic keratosis, a precancerous lesion that can turn into a squamous cell skin cancer. Some of these treatments may also be used for very early basal cell or squamous cell carcinoma.

Which therapy you undergo is largely a matter of personal preference. You and your doctor can discuss the right treatment option for you.


With cryotherapy, doctors spray liquid nitrogen on a growth to freeze and destroy it. You may feel a burning sensation for several seconds. The treated area turns pink and forms a blister, which peels off. This procedure can be performed in the doctor's office.

Cryotherapy is a very effective treatment in more than 85 percent of people.

Topical Medications

Doctors may use a cream called 5-fluorouracil, a form of topical chemotherapy, to destroy numerous actinic keratoses. For example, the cream may be useful for people who have precancerous growths covering the entire back of their hands or a section of their face. This medication may also be used to treat a very early basal cell cancer.

It can be applied daily at home for a number of weeks and may cause skin irritation, redness, blisters, or open sores. Side effects subside after treatment.

Another cream contains the immune-boosting medication imiquimod. It may be prescribed to treat an actinic keratosis or a very early basal cell cancer. You apply imiquimod to the lesion several times a week at home. Imiquimod may also cause skin irritation and redness, but this is temporary.

A gel containing a medication called diclofenac, a nonsteroidal anti-inflammatory drug (NSAID), may be used to treat actinic keratosis. You apply it to your skin twice a day for two to three months. Skin irritation, which may include redness, swelling, and tingling, occurs less frequently with diclofenac than with other topical medications.

Ingenol mebutate is a cytotoxic gel, meaning it destroys fast-growing cells. It’s usually used for only two to three days, but it can irritate the skin, causing redness, swelling, or crusting, which eventually goes away after treatment.

Photodynamic Therapy

Doctors at NYU Langone may use an outpatient procedure known as photodynamic therapy to treat actinic keratosis on areas such as the scalp and face.

In this procedure, a doctor applies a topical medication to the skin, which collects in precancerous cells, making them sensitive to light. He or she activates the medication with a laser, which destroys the lesion. This therapy can cause redness, irritation, and sun sensitivity, and so our doctors suggest covering up and wearing sunscreen. Side effects usually subside after a few weeks.