Current Clinical Trials

Localized squamous cell carcinoma of the skin is a highly curable disease.[1] The traditional methods of treatment involve the use of cryosurgery, radiation therapy, electrodesiccation and curettage, and simple excision. Each of these methods may be useful in specific clinical situations.

Of all treatment methods available, Mohs micrographic surgery has the highest 5-year cure rate for both primary and recurrent tumors. This method uses microscopic control to evaluate the extent of tumor invasion. Lymphadenectomy is indicated when regional lymph nodes are involved.

Treatment options:

1. Mohs micrographic surgery.[2] Although this method is complicated and requires special training, it has the highest cure rate of all surgical treatments because the tumor is microscopically delineated until it is completely removed. It is indicated for the treatment of:
   • primary squamous cell carcinomas when they occur at sites known to have a high initial treatment failure rate following traditional methods;
   • primary tumors with poorly defined clinical borders, primary tumors with diameters more than 2 cm; or
   • primary tumors arising in regions where the maximum preservation of uninvolved tissue is desirable such as the face, head, and genitalia.

   Mohs micrographic surgery should be used for squamous cell carcinomas that show perineural invasion since tumor transit along nerves may extend many centimeters away from the primary or recurrent tumor site.[3] Recurrent squamous cell carcinomas can also be treated with this technique.




2. Simple excision with frozen or permanent sectioning for margin evaluation. This traditional surgical treatment usually relies on surgical margins ranging from 3 mm to 10 mm, depending on the diameter of the original tumor.[4] Tumor recurrence is not uncommon because only a small fraction of the total tumor margin is examined pathologically.



3. Electrodesiccation and curettage. This is a quick method for destroying the tumor, but the adequacy of treatment cannot be assessed immediately since the surgeon cannot visually detect the depth of microscopic tumor invasion. It should be reserved for very small primary tumors since this disease has metastatic potential.



4. Cryosurgery. Cryosurgery is used for patients with clinically well-defined in situ tumors. It is especially useful for debilitated patients with medical conditions that preclude other types of surgery.

   Absolute contraindications for cryosurgery include abnormal cold tolerance, cryoglobulinemia, cryofibrinogenemia, Raynaud disease, and platelet deficiency disorders. Relative contraindications to cryosurgery include tumors of the scalp, ala nasi, nasolabial fold, tragus, postauricular sulcus, free eyelid margin, upper lip vermillion border, and lower legs. Caution should also be used before treating nodular ulcerative neoplasia more than 3 cm, carcinomas fixed to the underlying bone or cartilage, tumors situated on the lateral margins of the fingers and at the ulnar fossa of the elbow, or recurrent carcinomas following surgical excision. Significant morbidity is associated with the use of cryosurgery.

   Edema is common following treatment, especially around the periorbital region, temple, and forehead. Treated tumors usually exude necrotic material after which an eschar forms and persists for about 4 weeks. Permanent pigment loss at the treatment site is unavoidable. Atrophy and hypertrophic scarring have been reported as well as instances of motor and sensory neuropathy.




5. Radiation therapy. Radiation therapy is a logical treatment choice, particularly for patients with primary lesions requiring difficult or extensive surgery (e.g., eyelids, nose, or ears).[5] Radiaiton therapy eliminates the need for skin grafting when surgery would result in an extensive defect. Cosmetic results are generally good to excellent with a small amount of hypopigmentation or telangiectasia in the treatment port. Radiation therapy can also be utilized for lesions that recur after a primary surgical approach.[6]

   Radiation therapy is contraindicated for patients with xeroderma pigmentosum, epidermodysplasia verruciformis, or the basal cell nevus syndrome because it may induce more tumors in the treatment area.




6. Topical fluorouracil (5-FU). This method may be helpful in the management of selected in situ squamous cell carcinomas (Bowen disease). Careful and prolonged follow-up is required since deep follicular portions of the tumor may escape treatment and result in future tumor recurrence.[7]



7. Carbon dioxide laser. This method may be helpful in the management of selected squamous cell carcinoma in situ. It may be considered when a bleeding diathesis is present, since bleeding is unusual when this laser is used.



8. Interferon alpha. Clinical trials are ongoing to treat squamous cell carcinoma with intralesional interferon alpha.[8] The results should be available in several years. One report shows the combination of interferon alpha and retinoids is effective treatment for squamous cell carcinoma.[9]

Follow-up:

• Since squamous cell carcinomas have definite metastatic potential, patients should be re-examined every 3 months for the first several years and then followed indefinitely at 6-month intervals.

Check for U.S. clinical trials from NCI's PDQ Cancer Clinical Trials Registry that are now accepting patients with squamous cell carcinoma of the skin. The list of clinical trials can be further narrowed by location, drug, intervention, and other criteria.

General information about clinical trials is also available from the NCI Web site.

References

1. Preston DS, Stern RS: Nonmelanoma cancers of the skin. N Engl J Med 327 (23): 1649-62, 1992.  [PUBMED Abstract]
   
   
2. Thomas RM, Amonette RA: Mohs micrographic surgery. Am Fam Physician 37 (3): 135-42, 1988.  [PUBMED Abstract]
   
   
3. Cottel WI: Perineural invasion by squamous-cell carcinoma. J Dermatol Surg Oncol 8 (7): 589-600, 1982.  [PUBMED Abstract]
   
   
4. Abide JM, Nahai F, Bennett RG: The meaning of surgical margins. Plast Reconstr Surg 73 (3): 492-7, 1984.  [PUBMED Abstract]
   
   
5. Caccialanza M, Piccinno R, Moretti D, et al.: Radiotherapy of carcinomas of the skin overlying the cartilage of the nose: results in 405 lesions. Eur J Dermatol 13 (5): 462-5, 2003 Sep-Oct.  [PUBMED Abstract]
   
   
6. Lovett RD, Perez CA, Shapiro SJ, et al.: External irradiation of epithelial skin cancer. Int J Radiat Oncol Biol Phys 19 (2): 235-42, 1990.  [PUBMED Abstract]
   
   
7. Dabski K, Helm F: Topical chemotherapy. In: Schwartz RA: Skin Cancer: Recognition and Management. New York, NY: Springer-Verlag, 1988, pp 378-389. 
   
   
8. Padovan I, Brodarec I, Ikić D, et al.: Effect of interferon in therapy of skin and head and neck tumors. J Cancer Res Clin Oncol 100 (3): 295-310, 1981.  [PUBMED Abstract]
   
   
9. Lippman SM, Parkinson DR, Itri LM, et al.: 13-cis-retinoic acid and interferon alpha-2a: effective combination therapy for advanced squamous cell carcinoma of the skin. J Natl Cancer Inst 84 (4): 235-41, 1992.  [PUBMED Abstract]
   
   

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