Topical Treatment of Basal Cell Carcinoma

If you have been diagnosed with basal cell carcinoma (BCC), the most common type of skin cancer, your doctor will discuss treatment options with you. One treatment that may be offered is topical medication, which is most commonly used in situations where surgical removal of the tumor may yield a poor cosmetic result or when many tumors are present in a small area or are superficial, such as superficial basal cell carcinoma.

There are two different medications that may be used to treat BCCs. Each of these medications has a different mode of action, but they both work with your body to fight and eliminate the cancerous lesion. Unlike other skin cancer treatments, such as surgical removal, Mohs Micrographic Suregry, or electrodessication and curettage, treatment with topical medication is done at home under physician supervision.

Types of Topical Medication

There are two primary topical medications that are used to treat basal cell carcinomas and, less commonly, other forms of skin cancer.


Imiquimod, available as Aldara 5% or Zyclara 3.75% and 2.5% creams uses your immune system to eliminate skin cancer cells. While only the 5% cream is FDA approved to treat superficial basal cell carcinoma, the 3.75% cream has also been used off label. When the cream has been applied to the lesion, it activates an inflammatory cascade that increased a molecule called interferon.

Interferon then activates the immune system and points it to the direction of abnormal cells. Since one of the functions of the immune system is cancer surveillance and destruction, inflammation results in destruction of abnormal cancer cells. Interferon is also used to treat many other types of cancer with a similar mechanism of action.

Imiquimod is also FDA approved to treat actinic keratosis, a precancerous skin lesion that may eventually turn into squamous cell carcinoma. Imiquimod has also been used off label to treat squamous cell carcinoma, in situ (not invasive) and superficial types, with many reports of success in the literature.


5-Fluorouracil (5FU), the active ingredient in many formulation, including Carac 0.5% cream, Flouroplex 1% cream, Efudex 5% cream, is a chemotherapy drug that is applied directly to a basal cell carcinoma to destroy it. The drug interferes with the formation of DNA and RNA, which are critical to cell division and growth. Cancerous cells divide more rapidly than normal tissue and more readily absorb 5-fluorouracil than surrounding healthy cells. When abnormal cells take up 5FU,  the medication does not allow them to divide. Like imiquimod, fluorouracil can also be used to treat actinic keratosis and squamous cell carcinoma (off label).

When Should Topical Medication Be Used?

Topical creams may be used for small or superficial basal cell carcinomas. In some instances, when surgery is not appropriate or the patient is a poor surgical candidate, topical treatment may be considered. Topical medications are less effective than other forms of skin cancer treatment. Surgical removal, cryotherapy, electrosurgery, and photodynamic therapy all offer higher cure rates than either imiquimod or fluorouracil. Despite this, there are many reasons why topical medications may be recommended over other treatments. Unlike other methods, topical medications are less likely to leave a large scar or cause permanent changes to the skin. The medications can also be used to treat several lesions at once. Surgery and anesthesia isn’t necessary. As such, if a patient presents with a slow-growing or superficial BCC, a topical medication may be used as a first line of treatment. If treatment fails, a surgical removal can always be tried later.

Risks and Benefits

There are many risks and benefits to consider when choosing a topical versus a surgical treatment of basal cell carcinoma. This should be discussed carefully with your dermatologist.


  • At home treatment under physician supervision
  • Anesthesia is not needed
  • Less possibility for scarring


  • Failure to eliminate the tumor completely
  • Recurrence of skin cancer
  • Pain or soreness in treatment area during course of treatment
  • Unsightly wound during treatment and while the skin heals afterwards
  • Discomfort caused by scabbing or crusting during treatment
  • Long duration of treatment
  • Lack of histologic control
  • Possible high medication cost

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