Treatment of Squamous Cell Carcinoma

Squamous cell carcinoma is the second most common skin cancer and is increasing at an alarming rate, particularly in the elderly. Squamous cell carcinoma without question is related directly to sun exposure and also to age. The more sun and sunburns you have had and the longer you live the higher your risk of developing squamous cell carcinoma. They often come from precancerous lesions called actinic or solar keratoses which fair-haired, fair-eyed patients suffer from who have had sunburns as a child and have had chronic sun exposure. These red, raw, itchy, sometimes tender scaly spots on the scalp, face, ears, back of the hands and arms can convert to squamous cell carcinoma. Squamous cell carcinoma can also develop on its own and grow rapidly often fooling patients thinking they are bug bites, boils or infected hairs. These types of squamous cell carcinomas can be dangerous; they present as a nodule that hurts, grow rapidly and have between a 5%-25% risk of spreading or becoming metastatic depending on their depth of invasion and location.

Metastatic squamous cell carcinoma can be lethal and requires aggressive surgery by our head and neck surgical colleagues. This most often happens when squamous cell carcinoma occurs on the scalp, ears, or lips. Squamous cell carcinoma in these areas would usually spread first to the lymph nodes of the neck or in front of or behind the ear. The goal in treating all skin cancers is to treat them early before they become dangerous and that is particularly true of squamous cell carcinoma because if they are not very deeply invasive the risk of them spreading is probably close to zero.

There are superficial forms of squamous cell carcinoma which are called in situ or Bowen’s disease (SCC in situ). There is a specialized form of squamous cell carcinoma in situ that can occur on the genitalia called Bowenoid papulosis which is induced by the wart virus, not by sun exposure. Just as in superficial forms of basal cell carcinoma, superficial squamous cell carcinoma can be treated with the scraping and burning procedure (curettage and electrodesiccation), excision or sometimes Aldara or imiquimod. Aldara or imiquimod has not been studied nearly as thoroughly for superficial squamous cell carcinoma as it has for basal cell carcinoma. Aldara’s cure rates for SCC in situ are supposed to be 80% based upon less reliable studies. We have seen a number of cases of squamous cell carcinoma in situ that have failed rather spectacularly from superficial treatment with Aldara or Efudex, which is called 5-fluorouracil. Solano Dermatology Associates does not recommend Efudex or 5-fluorouracil for cancers, only for the precancerous lesions called actinic keratoses despite its use by other practices for cancer. We do not recommend Efudex because its use is actually quite weak when compared to even the limited research done using Aldara for skin cancer. Aldara for squamous cell carcinoma in situ causes a severe reaction and it needs to be continued for ten weeks thus it is, just as is with basal cell carcinoma, infrequently used. For very large areas that have been resistant to superficial forms of treatment we will perform wide excision or Mohs micrographic surgery. This superficial form of squamous cell carcinoma is becoming alarmingly common and is actually difficult to treat adequately without significant surgery, particularly in hair bearing skin. It is always problematic to recommend aggressive surgery for a non-invasive, not very dangerous cancer but these can become very large and eventually invasive and need to be treated properly to avoid a much worse procedure down the road when it can become many times the size it was early on.

Invasive squamous cell carcinoma can be quite dangerous particularly if it is over 2 mm in depth or involves the muscle, the lip, the cartilage of the ear, or down to the bone of the scalp. Patients who have suppressed immune systems, such as transplant patients on drugs to keep their transplant healthy, patients with leukemias and lymphomas, and HIV infected patients who are immunosuppressed can get virulent forms of squamous cell carcinoma that can become metastatic and are often difficult to manage. These patients who have problems with their immune systems need to have their squamous cell carcinomas managed promptly and completely.

For squamous cell carcinomas of the face, full-thickness excision down to the fat and a layered closure is the treatment of choice. Mohs micrographic surgery can be used for squamous cell carcinomas of the central face, scalp or on the shins where they are increasingly common. Mohs is quite useful on areas like the shins and scalp because we can keep the wound smaller and allow a direct or primary closure as opposed to taking skin in from somewhere else as a skin graft, which is frequently needed for regular surgery in these areas because regular surgery takes larger margins. We try to avoid skin grafts which create a second wound and take a long time to heal particularly when over bone of the skull or over the tight, often swollen skin of the shins.

There is some evidence that Vitamin D3 deficiency might accelerate the growth of squamous cell carcinoma which might explain partly why elderly patients, even those in nursing homes who are getting no sun exposure, are developing these cancers at an alarming rate and are sometimes not being managed until they are quite aggressive. Any patient who has skin cancer, who then stays out of the direct sunlight as much as possible with hats, clothing and sunscreen should be taking Vitamin D3. We recommend 4,000-5,000 unites per day. If you have Vitamin D deficiency and are followed by your regular doctor then he or she should manage your Vitamin D dosage.