Squamous cell carcinomas detected at an early stage and removed promptly are almost always curable and cause minimal damage. However, the larger and deeper a tumor grows, the more dangerous and potentially disfiguring it may become, and the more extensive the treatment must be.
If left untreated, SCCs may spread (metastasize) to local lymph nodes, distant tissues and organs and can become life-threatening. Therefore, any suspicious growth should be seen by a physician without delay. A tissue sample (biopsy) will be examined under a microscope to arrive at a diagnosis. If tumor cells are present, treatment is required.
Fortunately, there are several effective ways to eradicate squamous cell carcinoma. The choice of treatment is based on the tumor’s type, size, location and depth of penetration, as well as the patient's age and general health.
Treatment can almost always be performed on an outpatient basis in a physician's office or at a clinic. A local anesthetic is used during most surgical procedures. Pain or discomfort is usually minimal, and there is rarely much pain afterwards.
Mohs surgery is the gold standard for treating many SCCs (as well as many basal cell carcinomas and some melanomas). This includes those in cosmetically and functionally important areas around the eyes, nose, lips, ears, scalp, fingers, toes or genitals. Mohs is also recommended for skin cancers that are large, aggressive or growing rapidly, that have indistinct edges, or have recurred after previous treatment.
The procedure is done in stages, all in one visit, while the patient waits between each stage. After removing a very thin layer of tissue, the surgeon sections, color-codes and maps the tissue, then examines it under a microscope in an on-site lab. If any cancer cells remain, the surgeon knows the exact area where they are and removes another layer of tissue from that precise location, while sparing as much healthy tissue as possible. The doctor repeats this process until no cancer cells remain.
The wound may be left open to heal or the surgeon may close it with stitches. This depends on its size and location. In some cases, a wound may need reconstruction with a skin flap, where neighboring tissue is moved into the wound, or possibly a skin graft.
This technique examines 100 percent of the tumor margins and leaves the smallest scar possible. The cure rate is up to 99 percent for a skin cancer that hasn’t been treated before, and up to 94 percent for a skin cancer that has recurred after previous treatment.
The physician uses a scalpel to remove, or excise, the entire cancerous tumor along with a surrounding border of presumably normal skin as a safety margin. The physician closes the skin around the surgical site with stitches and sends the tissue specimen to a lab to verify that all cancerous cells have been removed. If the lab finds evidence of skin cancer beyond the safety margin, the patient may need to return for another surgery.
Excisional surgery can be used for squamous cell carcinomas as well as basal cell carcinomas and melanomas. For tumors discovered at an early stage that have not spread beyond the tumor margin, excisional surgery is frequently the only treatment required.
Curettage and Electrodesiccation (Electrosurgery)
This technique is usually reserved for small lesions. The physician scrapes off the lesion with a curette (an instrument with a sharp, ring-shaped tip), then burns the tumor site with an electrocautery needle to stop the bleeding and kill any remaining cancer cells. The physician typically repeats this procedure a few times, scraping and burning a deeper layer of tissue each time to help ensure that no tumor cells remain. The technique can produce cure rates approaching those of surgical excision for superficially invasive squamous cell carcinomas without high-risk characteristics. However, it is not recommended for any invasive or aggressive SCCs, those in high-risk or difficult sites, such as the eyelids, genitalia, lips and ears, or other sites that would be left with cosmetically undesirable results, since the procedure leaves a sizable, hypopigmented scar.
This procedure is used for superficial SCCs. The physician destroys the tumor tissue by freezing it with liquid nitrogen, using a cotton-tipped applicator or spray device. Later, the lesion and surrounding frozen skin may blister or become crusted and fall off, usually within weeks. There is no cutting or bleeding, and no anesthesia is required. The physician may repeat the procedure several times at the same session to help ensure destruction of all malignant cells. Redness, swelling, blistering and crusting can occur following treatment, and in dark-skinned patients, some pigment may be lost. Inexpensive and easy to administer, cryosurgery may be the treatment of choice for patients with bleeding disorders or intolerance to anesthesia. However, it has a lower overall cure rate than the surgical methods. Depending on the physician's expertise, the five-year cure rate can be quite high with selected, superficial squamous cell carcinoma; but cryosurgery is not often used today for invasive SCC because it may miss deeper portions of the tumor and because scar tissue at the cryotherapy site might obscure a recurrence.
Laser therapy is not yet approved for SCC, but is sometimes used as a secondary therapy for superficial SCCs when other techniques are unsuccessful. The physician uses a beam of light of a specific wavelength to destroy certain superficial SCCs. Some lasers vaporize (ablate) the skin cancer, while others (nonablative lasers) convert the beam of light to heat, which destroys the tumor.
The physician uses low-energy X-ray beams to destroy the tumor, with no need for cutting or anesthesia. Destruction of the tumor may require several treatments over a few weeks or daily treatment for a month. Average cure rates are about 90 percent, since the technique does not provide precise control in identifying and removing residual cancer cells at the margins of the tumor. The technique can involve long-term cosmetic problems and radiation risks, as well as multiple visits. For these reasons, though this therapy limits damage to adjacent tissue, it is mainly used for tumors that are hard to treat surgically, as well as patients for whom surgery is not advised, such as the elderly or those in poor health. In some more advanced cases of SCC, radiation may be needed after surgery.
Photodynamic Therapy (PDT)
PDT may be used for some superficial SCCs on the face and scalp but is not recommended for invasive SCC. The physician applies a light-sensitizing topical agent to the lesion and the area surrounding it. The patient waits for an hour or more to let this absorb into the skin. The doctor then uses a strong blue or red light or laser to activate this medicated area. This selectively destroys the lesion while causing minimal damage to surrounding healthy tissue. Some redness, pain, peeling, flaking and swelling can result. After the procedure, patients must strictly avoid sunlight for at least 48 hours, as UV exposure will increase activation of the medication and may cause severe sunburns.
5-fluorouracil (5-FU) and imiquimod, both FDA-approved for treatment of actinic keratoses and superficial basal cell carcinomas, are also being tested for the treatment of some superficial squamous cell carcinomas. Successful treatment of Bowen's disease, a noninvasive SCC, has been reported. However, invasive SCC should not be treated with 5-FU. Some trials have shown that imiquimod may be effective with certain invasive SCCs, but it is not yet FDA-approved for this purpose. Imiquimod stimulates the immune system to produce interferon, a chemical that attacks cancerous and precancerous cells, while 5-FU is a topical form of chemotherapy that has a direct toxic effect on cancerous cells.
Treatments for Recurrent and Advanced Squamous Cell Carcinoma
Squamous cell carcinomas usually remain confined to the epidermis (the top skin layer) for some time. However, the larger these tumors grow, the more extensive the treatment needed. They eventually penetrate the underlying tissues, which can lead to major disfigurement, sometimes even the loss of a nose, eye or ear, and they sometimes result in nerve or muscle injury.
“Advanced” is a broad term for cutaneous SCCs that may have spread extensively or have resisted multiple treatments and recurred. These include locally advanced SCCs – primary tumors that are very large, or have burrowed down into nearby subcutaneous tissue, muscles or along nerves – as well as tumors that have metastasized to the nearby lymph nodes or other parts of the body. About 50,000 cases a year, or about 1 out of every 20 cases, either become locally advanced or spread (metastasize) to distant tissues and organs. When this happens, SCCs can become life-threatening.
Metastases most often arise on sites of chronic inflammatory skin conditions and on the ear, nose, lip and mucosal regions, including the mouth, nostrils, genitals, anus and the lining of the internal organs.
For SCCs that recur, become locally advanced or metastasize, the doctor may use a combination of treatments, including surgery, radiation and experimental targeted therapies and immunotherapies. First, however, he or she may recommend an evaluation by a multidisciplinary team of specialists. The team, which may include your dermatologist or Mohs surgeon, plus additional physicians and surgeons from other specialties, can discuss the various treatment options that could be considered, including participation in a clinical trial.
Today, the field is rapidly advancing, and clinical trials may be available investigating combinations of two or more established therapies such as radiation, surgery and some kind of systemic therapy, as well as newer approaches like immunotherapies, which harness the power of your own immune system to fight the cancer. If you have advanced CSCC, it’s important to stay up to date on clinical trial developments with your doctor or team, and stay optimistic.