Chemo Cream for Skin Cancer: When Should You Consider This Noninvasive Option?

A skin cancer diagnosis can be tough to deal with. It doesn’t help that some of the treatments have potentially life-changing consequences, such as severe scarring and function loss.

The good thing is that not everything about this condition is a downer. For example, early intervention has an excellent chance of eliminating cancer and bringing patients back to full health.

Additionally, not all skin tumors require aggressive therapy. Some can be dealt with using a special chemo cream for skin cancer.

When are topical skin cancer treatments appropriate to use? How do skin-applied cancer creams work? Do they have the same benefits and side effects as other skin cancer treatment options? Read on to learn more if you have the same questions about skin cancer chemotherapy creams.

What Are the Types of Skin Cancer, and Why Should That Matter?

Skin cancer is characterized by the abnormal or destructive growth of skin cells. There are numerous skin cell types, any of which can become malignant once triggered.

Keratinocytes are the tiny brick-like cells that comprise the skin barrier. Melanocytes are the skin cells that form the pigment melanin. Fibroblasts are collagen-producing cells. The nerves, hair follicles, oil glands, blood vessels, and many other skin tissue types are also made up of tiny cells that can give rise to cancer when overexposed to carcinogens.

However, the 3 skin cancer types of particular importance are the keratinocyte cancers, basal cell carcinoma and squamous cell carcinoma, and the melanocyte tumor, melanoma. Basal cell skin cancer is the most prevalent skin cancer type, followed by squamous cell skin cancer. Melanoma, though much rarer than keratinocyte cancers, is the top cause of death from skin cancer due to its aggressive nature.

Basal cell carcinoma comprises about 75% of all nonmelanoma skin cancer cases and 25% of all malignancies in the US. This slow-growing tumor rarely “metastasizes,” meaning distant spread is uncommon. Basal cell carcinoma arises from the deep portions of the epidermis, the superficial skin layer.

Squamous cell cancer of the skin accounts for around 20% of nonmelanoma skin cancers in the US. This tumor type is generally slow-growing but more likely to metastasize than basal cell carcinoma. The tumor cells can span the entire epidermis. Squamous cell carcinoma in situ grows strictly within this superficial layer. By comparison, invasive squamous cell carcinoma grows into the deeper skin layer, the dermis.

Melanoma constitutes only 4% of all skin cancers in the US but causes 75% of all skin cancer deaths. This condition affects white populations more than people with skin of color. Tumors arise from malignant melanocytes that may be unusually colored or devoid of pigmentation.

Of these cancer types, superficial basal cell carcinoma, noninvasive squamous cell skin cancer, and some cases of nodular basal cell carcinoma may be treated with chemotherapy cream formulations. Aggressive tumors, such as invasive squamous cell carcinoma and melanoma, should be removed by more rigorous therapies like surgery.

The biggest risk factor for skin cancer formation is chronic, excessive UV light exposure. That’s why people with outdoor jobs or recreations and individuals who undergo UV phototherapy or tanning beyond the recommended levels have an increased risk.

UV rays destroy the skin’s DNA, triggering abnormal growth processes that lead to cancer. Actinic keratosis, a precancerous skin condition, can develop after years of excessive UV exposure. Actinic keratosis can become malignant without treatment.

Heredity also greatly contributes to skin cancer risk, with some skin tumors affecting families. Other significant skin cancer factors include the following:

• Chronically excessive exposure to physical or chemical carcinogens like x-rays, arsenic, and cigarette smoke
• Poor immunity, whether inborn or acquired
• Drugs, including cancer chemotherapy medications, photosensitizers, and immunosuppressants
• Persistent skin inflammation, as happens in chronic burns, psoriasis, and lupus
• Infection with a high-risk human papillomavirus (wart) subtype

Skin cancer lesions can appear as a lump or open sore, depending on the type. These lesions tend to bleed with minimal trauma and do not improve with ordinary anti-inflammatory skincare products.

How Do You Treat Skin Cancer?

The goals of skin cancer therapy are to remove malignant cells completely, prevent recurrence, preserve the treated area’s appearance and function, and minimize side effects. Modern science has created several ways to accomplish these goals, explained below.

Surgical Excision

The gold standard of cancer treatment is surgical excision. The two most widely used surgical techniques for skin cancer are Mohs surgery and wide local excision.

Mohs surgery is a procedure only a Mohs surgeon, a specially trained, board-certified dermatologist, can perform. The Mohs technique is the most highly recommended for skin-confined cancers, rendering superior cosmetic and functional outcomes and cure rates.

The tumor is removed stepwise, sparing as much of the surrounding healthy tissue as possible. The Mohs surgeon examines each excised piece using a microscope, ensuring that no cancer cells are left after the session.

Wide local excision may be performed by a non-Mohs specialist, such as a general surgeon or an otolaryngologist. The entire tumor is cut out together with a fairly large portion of the surrounding skin. The surgeon submits the tissue sample afterward to a laboratory to check for cancer cells in the tumor edges, the presence of which indicates incomplete cancer removal.

This procedure has high success rates in treating deep tumors but does not always result in complete cancer tissue removal. Wide local excision may also ruin the treated area’s appearance or function.

Both procedures are recommended for various skin cancer types, including melanoma. Recurrence rate after treatment is generally low. You may read our previous article comparing Mohs surgery and wide local excision to learn more.

Minimally Invasive Procedures

Minimally invasive surgical procedures that have been tried for skin cancer treatment include cryotherapy and electrodesiccation with curettage. Cryotherapy uses liquid nitrogen to freeze the tumor. Electrodesiccation with curettage burns the lesion and its blood vessels, after which the doctor scoops the charred tissues out.

These procedures are relatively inexpensive and available in many geographical locations. Both are highly effective in removing small basal cell skin cancer lesions. However, recurrence is as high as 39% after cryotherapy and 20% after electrodesiccation with curettage. The cosmetic results are also inferior to surgical excision.

Light-Based Treatments

Light-based technologies that may be used for removing skin cancer are photodynamic therapy and laser ablation. Photodynamic therapy entails the application of a photosensitizer on the treatment area before blasting it with powerful blue or red light. Laser surgery often involves burning the cancer cells with pulses of highly energized infrared light.

Photodynamic therapy and laser ablation may be offered as alternatives to patients who refuse surgical excision for small, early-stage basal cell carcinoma and squamous cell carcinoma. However, these treatments have been tested only in clinical trials involving small groups of patients. The risk of recurrence is similar to those of minimally invasive procedures. Photodynamic therapy and laser ablation are relatively costly and do not consistently produce good esthetic outcomes.

Radiation Therapy

Radiotherapy, a common procedure, may be used to remove various types of skin cancer if surgery is contraindicated due to the following:

• Inoperability, as in cases when the mass is very close to a major blood vessel or nerve
• Patient refusal
• The presence of serious comorbidities

Radiotherapy produces less discomfort and may be used on areas that pose physical challenges during surgery, such as the back of the ears and the sides of the nose. Radiotherapy is as effective as surgery and also has comparably low recurrence rates. This treatment is often used when cancer cells remain after surgery or tumors multiply or spread remotely, making surgery impractical.

However, the skin can deteriorate after radiation exposure. This treatment option is generally offered only to older patients, as they have a lower life expectancy and less concern for long-term cosmetic effects.

Electrochemotherapy

Electrochemotherapy uses electricity to sensitize cancer cells to the effects of a chemotherapy drug like bleomycin or cisplatin. This cancer treatment provides good tumor control, causes minimal side effects, and is cost-effective. Success rates are as high as 96% in basal cell carcinoma and 80.6% in advanced melanoma.

Electrochemotherapy may cause pigmentation problems and skin sores. Surgical excision is still preferred because it achieves longer remission periods and is more widely available than electrochemotherapy.

Systemic Chemotherapy

Oral and injectable medications, which have effects on various body organs besides the skin, are not the standard of care for skin cancer. However, physicians may recommend the systemic approach for widespread tumors. Drugs include dacarbazine and immunotherapy medications like nivolumab and pembrolizumab. Systemic chemotherapy can have serious side effects, so it is usually reserved for widespread, fast-growing skin cancer types.

Can Skin Cancer Be Treated Topically?

The short answer is yes, skin cancer may be treated topically. However, this approach has limited applications in skin cancer therapy. Surgery is still preferred in most cases.

When Is Topical Chemo Used for Skin Cancer?

Topical chemotherapy is considered only for patients with superficial skin cancer, usually low-risk basal cell carcinoma and noninvasive squamous cell carcinoma. A low-risk skin tumor has the following attributes:

• Lesion size less than 2 centimeters
• Located in the trunk or extremities, which are areas where skin cancer is less likely to spread to other sites
• Primary tumor, when the malignancy occurs for the first time
• Lacks aggressive features based on microscopic examination
• Does not involve nerves

Other reasons for choosing topical chemotherapy over skin cancer surgery include the following:

• Lesions appearing in multiples, increasing the patient’s risk for complications like infection and disfigurement
• Refusal to consent to surgery
• Advanced age
• Severe health risks, such as poor immunity, blood sugar control, blood clotting, or wound healing
• Logistical challenges when getting surgical treatment

If topical treatment is a suitable option and the patient consents to it, the benefits include a low risk of severe side effects, low cost, and good esthetic results.

When Should You Avoid Topical Skin Cancer Treatment?

Topical chemotherapy is generally not recommended when the skin cancer has aggressive features. Recurrent tumors, metastatic lesions, melanoma, and invasive squamous cell carcinoma are some examples of aggressive, fast-spreading skin cancers. Other contraindications are drug-specific, discussed below.

What Drugs Do Topical Chemotherapy Creams Contain, and How Do They Compare?

The drugs most widely used in chemo cream formulations are imiquimod and 5-fluorouracil. Both are approved by the US FDA for actinic keratosis and low-risk skin cancer treatment.

Imiquimod modifies the skin’s immune response and is available as a 5% cream. The medication is applied once daily 5 times a week for 6 weeks. Patients using imiquimod immunotherapy cream must be adults with good immunity.

Malignant tumors considered suitable for treatment are smaller than 2 centimeters in size, confirmed as the primary superficial basal cell carcinoma type on biopsy, and located in a low-risk area, such as the trunk, limbs, and neck. Patients with nodular basal cell skin cancer may also try this drug but only with a specialist’s recommendation as the FDA does not advise it.

The most frequent side effects of imiquimod chemotherapy cream include moderate-to-severe redness, swelling, open sores, scabbing, irritation, and itching in the treated skin area. Some patients also experience flu-like symptoms.

The cancer drug 5-fluorouracil resembles DNA building blocks, acting as a molecular decoy that ultimately stops skin cancer growth and kills off tumors. Topical 5-fluorouracil cream is available as a 5% formula applied twice a day for 3 to 6 weeks. This drug has similar indications to imiquimod. The side effects of these drugs are also comparable, except 5-fluorouracil does not cause flu-like symptoms. Topical 5-fluorouracil cream is not recommended during pregnancy.

Studies show that imiquimod 5% chemotherapy cream is more effective than 5-fluorouracil 5% cream and photodynamic therapy in treating superficial basal cell skin cancer. Topical 5-fluorouracil and photodynamic therapy have comparable effectiveness in treating such lesions.

Which Specialist Should You Ask About Skin Cancer Creams?

The best medical specialist to help you deal with skin cancer is a board-certified dermatologist. These skin disease experts are highly trained to identify skin malignancies and create an effective and safe personalized treatment plan. They can help you decide whether topical skin chemo creams are a suitable option for you.

During your first consultation, your dermatologist will ask you questions about your skin lesion, such as when it appeared, how it evolved, and if you experience other symptoms. They may inquire about possible risk factors that can help with diagnosis, such as any past health problems, family members with similar skin conditions, or significant sun exposure.

After noting your medical history, they will take a look at the lesion and give you a full-body skin check. A complete physical examination enables your dermatologist to assess your problem accurately. Your skin specialist shall conduct their examination professionally, with utmost consideration for your privacy.

After completing their evaluation, dermatologists typically recommend a biopsy to confirm the diagnosis and properly classify the tumor. They may also order other diagnostic tests to assess the severity of the problem, such as blood tests, x-rays, CT, and MRI.

How Do Skin Cancer Specialists Choose a Skin Cancer Treatment?

Factors that can help skin cancer specialists formulate your treatment regimen include the following:

• Anatomic location: High-risk zones for skin cancer include the areas around the eyes, the smile lines, and the sites behind the ears. Low-risk zones, as mentioned, include the trunk, neck, and extremities. Malignancies in high-risk zones are generally treated more proactively than those in low-risk zones.
• Tumor type: Aggressive tumor types include any recurrent or metastatic skin cancers, melanoma, and invasive squamous cell carcinoma. These lesions typically warrant more intensive therapies.
• Primary vs. recurrent: A primary tumor is generally more responsive to therapy and less aggressive than a recurrent malignancy.
• Benefits vs. risks: Physicians will consider surgical alternatives if they are comparably effective, safer for patients, and able to improve quality of life after skin cancer treatment. For example, radiation may be chosen in tumor locations where surgical excision can cause disfigurement or function loss.
• Patient tolerance: Patients with severe medical conditions or of advanced age may have poor tolerance for surgical or anesthetic side effects. Less invasive treatments, such as radiotherapy and topical immunotherapy, may be recommended instead.
• Patient preference: Patients who refuse surgical treatment should be offered less invasive alternatives, such as chemo cream use.
• Accessibility of the treatment: Mohs surgery is the best option for skin-deep cancers. However, not all geographic locations have Mohs surgeons available, and this treatment can be pricey. Alternatives to this gold-standard procedure range from topical chemo to wide local excision, with the choice depending on tumor status and patient factors.

Ensure you provide all pertinent information to your skin cancer specialist to help them tailor your therapy exactly according to your needs.

What Is the Outlook for Skin Cancer Treated Topically?

Skin cancer has an excellent prognosis if treated appropriately and promptly. If you prefer chemo cream over surgery, working with a bona fide skin cancer specialist and applying the cream as instructed help ensure your chosen treatment is indeed safe and effective.

About 40-50% of patients with first-time basal cell skin cancer experience a recurrence within 5 years from treatment. The outlook is poorer if the primary tumor has grown extensively upon diagnosis. The average survival time for metastatic basal cell skin cancer is 8-10 months without therapy. Factors that help improve skin cancer prognosis include good posttreatment care, adequate intake of antioxidant vitamins like nicotinamide, and good immune resistance.

How Do You Prevent Future Skin Cancer Recurrences?

Measures that can keep skin cancer from coming back include religious sun protection and skin care, regular full-body skin exams, a balanced diet high in antioxidants, and treatment of precancerous growths like actinic keratosis. People who may have a hereditary skin tumor may require genetic counseling and testing of other family members for cancer prevention or early detection.

Topical Skin Cancer Chemotherapy: Weighing the Choices

To eliminate skin cancer successfully, you must ensure that your chosen treatment is effective and safe. The first-line skin cancer therapy is surgery. However, low-risk skin malignancies respond well to less invasive remedies, giving you alternatives if you’re not a good surgical candidate or you simply prefer other options.

Topical chemotherapy is one recourse you may explore due to its potential benefits, such as preservation of quality of life and ease of use. Still, you must ensure that you know all the facts before making a skin cancer treatment decision. If you’re seriously considering topical chemotherapy, guidance from a board-certified skin disease specialist is an absolute must!

Frequently Asked Questions

How Long Does Skin Cancer Cream Take to Work?

That depends on the cream’s active drug component and your treatment response. Imiquimod’s standard treatment course is 6 weeks long, while topical 5-fluorouracil is prescribed for 3-6 weeks. Some patients require longer regimens before the tumor being treated disappears.

How Do You Know If Your Chemo Cream Works?

A skin reaction, such as redness or itchiness, is normal during treatment and is a sign that your chemo cream works. You may see scabbing as your skin heals. Your dermatologist may advise you to still complete the regimen as instructed if you do not see a strong response.

Your skin specialist can determine whether your treatment response is adequate using special exam techniques or instruments like a dermoscope. Regular follow-ups with your dermatologist can help track your treatment progress properly.

What Should You Do If Your Skin Cancer Chemo Cream Doesn’t Work?

Your dermatologist may recommend extending your treatment duration or exploring other options if your response to your chemo cream is inadequate. Results vary from patient to patient. Close monitoring is important to ensure that therapeutic adjustments are made in a timely fashion if necessary.

Not Sure If Chemo Creams Are for You? Ask LA’s Top Skin Cancer Specialists

Deciding on a skin cancer treatment is difficult and should not be taken lightly. Treading in the wrong direction can worsen the lesion and may have dire consequences. But you need not worry as long as you have a trusted skin disease expert in your corner.

At BHSkin Dermatology, our board-certified dermatologists are some of the best in California. They have helped many patients get rid of skin cancer safely and effectively. Visit us at our Glendale or Encino clinic or use our virtual platform for your first consultation.

Book your appointment today!

References:

1. American Academy of Dermatology. (2024). Imiquimod: Skin Cancer Treatment FAQs. Retrieved September 15, 2024, from https://www.aad.org/public/diseases/skin-cancer/imiquimod-skin-cancer-treatment-faqs
2. Christensen, S. R., & Leffell, D. J. (2019). Chapter 204: Mohs Micrographic Surgery. Fitzpatrick’s Dermatology, 9th ed. https://accessmedicine.mhmedical.com/content.aspx?bookid=2570&sectionid=210446129
3. Combalia, A., & Carrera, C. (2020). Squamous Cell Carcinoma: An Update on Diagnosis and Treatment. Dermatology Practical & Conceptual. 10(3), e2020066. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7319751/
4. Decker, R. H., & Wilson, L. D. (2019). Chapter 200: Radiotherapy. Fitzpatrick’s Dermatology, 9th ed. https://accessmedicine.mhmedical.com/content.aspx?bookid=2570&sectionid=210445568
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8. Peris, K., Fargnoli, M. C., Kaufmann, R., Arenberger, P., Bastholt, L., Seguin, N. B., Bataille, V., Brochez, L., Del Marmol, V., Dummer, R., Forsea, A. M., Gaudy-Marqueste, C., Harwood, C. A., Hauschild, A., Höller, C., Kandolf, L., Kellerners-Smeets, N. W. J., Lallas, A., Leiter, U., … EADO”A, EDF”B, ESTRO”C, UEMS”D and EADV”E (2023). European Consensus-Based Interdisciplinary Guideline for Diagnosis and Treatment of Basal Cell Carcinoma-Update 2023. European Journal of Cancer. 192, 113254. https://www.sciencedirect.com/science/article/pii/S0959804923003568#sec0225
9. Tan, I. J., Pathak, G. N., & Silver, F. H. (2023). Topical Treatments for Basal Cell Carcinoma and Actinic Keratosis in the United States. Cancers. 15(15), 3927. https://www.mdpi.com/2072-6694/15/15/3927
10. Tang, J. Y., Epstein, Jr. E. H., & Oro, A. E. (2019). Chapter 111: Basal Cell Carcinoma and Basal Cell Nevus Syndrome. Fitzpatrick’s Dermatology, 9th ed. https://accessmedicine.mhmedical.com/content.aspx?bookid=2570&sectionid=210434418
11. U.S. Food and Drug Administration. (October 2021). Prescribing Information: Fluorouracil. Retrieved September 15, 2024 from https://www.accessdata.fda.gov/drugsatfda_docs/label/2021/016831Orig1s063lbl.pdf
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Author: Don Mehrabi

Don Mehrabi, MD, FAAD, is LA’s leading board-certified dermatologist who treats patients, builds the BHSkin clinics, and raises three kids. This blog builds on medical studies combined with Dr. Mehrabi's first-hand experiences from practicing in Encino-Tarzana, Glendale, and online