Diagnosis & Treatment at Memorial Sloan Kettering
Most suspected skin cancers are often first noticed by the patient or a family member before they are brought to the attention of a doctor.
To diagnose skin cancer, the doctor will take a complete medical history and ask the patient about his or her past exposure to the sun and other known causes of skin cancer, and whether he or she has a personal or family history of skin conditions. The doctor will probably ask when the mark appeared and whether it has changed in size or appearance. He or she will perform a skin examination and may check for enlarged lymph nodes.
If the doctor believes there is any cause for concern about a particular patch of skin, he or she will perform a biopsy, during which all or part of the growth is surgically removed. This is usually done in the doctor’s office using a local anesthetic. A pathologist will examine the removed skin under a microscope to determine if any cancer is present. If there is, the doctor will discuss with the patient the different management options and recommendations, based on the cancer features, to select the best possible treatment.
Most squamous cell carcinomas can be cured if detected and treated early. But because this type of skin cancer can grow quickly, delaying treatment could make it more difficult to cure and increase the risk of cosmetic damage and functional difficulties. In addition, larger, deeper squamous cell carcinomas that appear on the lips and ears, or in people who are immunocompromised, are more likely to spread (metastasize).
Squamous cell carcinomas are classified based on the risk of recurrence and the risk of spreading, which depends primarily on anatomical location. Cancers on the central part of the face — including the eyelids, nose, lips, and ears are considered high-risk and have the potential to metastasize. Recurrent cancers and those greater than two centimeters in diameter on the trunk or extremities are categorized similarly. Squamous cell carcinomas that are small, superficial, have a well-defined edge, and have not been treated before are at a low risk of recurring. These are defined as low-risk cancers.
Numerous treatment options are available, and most are easily performed in the doctor’s office. The treatment decision is based on whether the squamous cell is high- or low-risk, which is based on the risk of recurrence. Other considerations include the patient’s age, general health, medical history, and cosmetic preferences.
This is a very common treatment for squamous cell carcinoma and is most effective for low-risk tumors. After numbing the area with a local anesthetic, the surgeon uses a semi-sharp instrument with a spoon-shaped edge (called a curette) to scrape away cancerous tissue. The area is then treated with an electric needle to control bleeding and destroy any cancer cells that may remain around the edge of the wound. The wound usually heals within a few weeks.
This treatment involves applying liquid nitrogen to freeze the abnormal tissue, which then sloughs off as the underlying skin heals.
Surgery is often recommended to remove squamous cell tumors, particularly those classified as high-risk. Surgical excision involves injecting a local anesthetic and removing the tumor from the skin along with a “safety margin” to ensure that all cancer cells have been removed. The wound is then closed with sutures. Surgery is most effective for tumors with well-defined borders and can be performed virtually anywhere on the body. An advantage of surgery is that the tissue can be sent to a laboratory for microscopic evaluation by a pathologist, who will verify whether the entire tumor has been removed along with a sufficient safety margin.
For tumors with a high risk of recurrence, doctors at Memorial Sloan Kettering offer a highly specialized technique called Mohs surgery. In this procedure, a surgeon removes tumor tissue layer by layer, mapping and freezing each layer, and examining the tissue for tumor cells under a microscope before proceeding to the next layer. A precise, complex, but time-consuming process, Mohs surgery ensures that the entire tumor is removed and minimizes scarring by preserving as much normal skin as possible.
Mohs surgery has the highest cure rate of all therapies for squamous cell carcinomas and is particularly effective for high-risk squamous cell carcinomas, such as large, deep tumors, tumors that have recurred after other treatments, and tumors in areas such as the face that require preservation of as much normal skin as possible.
Radiation therapy with x-rays or high-energy particles can be useful for treating tumors in areas that are difficult to treat surgically, or in patients who are at higher risk for surgical complications. Radiation is sometimes used after surgery to destroy tumor cells that may have been missed, or to treat tumors with a higher risk of recurrence. Radiation is usually delivered in small doses over a period of three to four weeks to avoid burning the skin and to improve the cosmetic outcome. Radiation therapy is often reserved for older patients who cannot tolerate surgery.
Less Common Treatments
Tumor tissue is vaporized with a highly focused beam of light. Because laser surgery only kills tumor cells on the surface of the skin, its use is limited and close follow-up is essential.
This therapy is most commonly used for actinic keratoses. A strong light activates a photosensitizing chemical that is applied to the lesion, which destroys abnormal tissue while causing minimal damage to the surrounding skin.
Topical chemotherapy treatment targets damaged skin without touching surrounding normal tissues. Because the tissue is unable to be tested, and cure rates are typically lower than other therapies, these are usually reserved for low-risk, small lesions. And because topical chemotherapy does not kill cells under the surface of the skin, close follow-up is essential after therapy.
One treatment is fluorouracil (5-FU). Available in a cream or lotion, it is applied by the patient at home for three to six weeks. The patient’s skin may become irritated and red during treatment with 5-FU.
Another topical treatment is imiquimod, a topical lotion applied by the patient at home that causes local immune cells to attack abnormal tissue. It may be used to treat actinic keratosis.
Chemical peels may also be used to slough off actinic keratoses.
Our doctors are evaluating a new, non-invasive imaging technique called confocal reflectance microscopy. This research advance allows doctors to rapidly image tissue removed during Mohs surgery, speeding up the detection of remaining tumor cells without the need for complex frozen tissue processing. In the future, the technique may also help in diagnosis, determining safety margins, and identifying any remaining tumor cells after topical therapy,
Any form of surgery may leave a scar, some more noticeable than others. When removal of a squamous cell carcinoma leaves a wound that is too large to close with simple sutures, skin grafts and flaps, and other reconstructive procedures performed by Memorial Sloan Kettering surgeons can help heal the skin and restore its appearance.