Topical chemotherapy is a medical treatment that involves applying anti-cancer agents directly to the skin. This localized approach targets and eliminates abnormal cells on the skin’s surface. It is primarily used for treating specific skin cancers and precancerous lesions. This article will explain how topical chemotherapy functions, the conditions it addresses, the common medications used, and what individuals can expect during treatment.
Understanding Topical Chemotherapy
Topical chemotherapy delivers therapeutic agents directly to the affected skin, killing cancer cells. These medications typically target rapidly dividing cells, a characteristic of cancerous and precancerous cells. This method differs from systemic chemotherapy, which circulates throughout the entire body and can affect healthy cells. The localized action of topical chemotherapy minimizes systemic side effects, focusing its impact on superficial skin conditions.
Conditions Treated with Topical Chemotherapy
Topical chemotherapy treats several superficial skin conditions and early-stage cancers. It is frequently prescribed for actinic keratosis, precancerous lesions appearing as scaly patches on sun-exposed skin. These can develop into squamous cell carcinoma if untreated.
The therapy is also effective for superficial basal cell carcinoma (BCC), the most common type of skin cancer, which typically remains on the skin’s surface. Additionally, squamous cell carcinoma in situ, or Bowen’s disease, can be treated. This form of squamous cell carcinoma is confined to the top layer of the skin.
Common Medications and Their Application
Two frequently used agents in topical chemotherapy are 5-fluorouracil (5-FU) and imiquimod. 5-FU, often known by brand names like Efudex or Carac, is an antimetabolite that inhibits DNA synthesis in rapidly dividing cells. This action prevents cancer cells from reproducing and leads to their destruction.
Imiquimod, sold as Aldara or Zyclara, works differently by stimulating the body’s immune system to attack abnormal cells. It modifies the immune response, leading to the release of cytokines that help fight tumor cells.
Both medications are available as creams or solutions and are applied directly to the affected skin. For 5-FU, application typically involves a thin layer applied once or twice daily, with treatment durations ranging from 2 to 6 weeks, depending on the condition being treated.
Imiquimod is often applied a few times a week, usually at bedtime, for several weeks, such as 5 days a week for 6 weeks for superficial BCC or 2 days a week for 16 weeks for actinic keratosis. Patients are usually instructed to wash their hands before and after application, and to apply the cream sparingly, rubbing it into the skin until it disappears.
What to Expect During Treatment
During topical chemotherapy, patients can expect visible skin reactions in the treated areas. These common reactions, such as redness, swelling, blistering, and crusting, indicate the medication is actively destroying abnormal cells. The skin may also become sore, tender, itchy, or experience a burning sensation.
The intensity of these reactions can vary among individuals and typically progresses, often worsening before improving. For 5-FU, irritation usually begins within 5 to 10 days, with sores and crusts appearing as treatment continues. Imiquimod can also cause similar local skin reactions, and in some cases, flu-like symptoms such as fever, headache, or muscle aches may occur, though these are usually mild.
Managing these side effects often involves gentle skin care, such as washing the treated area with mild soap and water, and applying petroleum jelly or prescribed moisturizers after the medication has been on the skin for the recommended duration. It is important to protect the treated areas from sun exposure, as the skin can become more sensitive to UV light.
The skin generally begins to heal within a few weeks after treatment concludes, though full resolution of redness and sensitivity can take longer. Healthcare providers will offer guidance on managing discomfort and will advise when to seek further medical attention if symptoms are severe.