Basal cell carcinoma is the most common skin cancer. There are millions of these every year in this country alone, much less worldwide. They are usually not very dangerous although they can be quite invasive, destructive and disfiguring. Most of these occur on the face but they can occur anywhere, even in areas where the sun does not shine. Most patients who get basal cell carcinoma have had sunburns, but they also have a genetic predisposition. There may be other co-factors that are not well understood at this time that are contributing to the epidemic of skin cancer.
The treatment of basal cell carcinoma partly hinges upon the pathology. Basal cell carcinoma has different pathologic subtypes grouped into non-aggressive and aggressive forms.
Non-aggressive or circumscribed basal cell carcinoma includes the nodular and superficial types. These can occur anywhere but they are common on the trunk.
The most common treatment for these low-risk, less aggressive basal cell carcinomas is an ablative procedure call curettage and electrodessication. Non-aggressive basal cell cancers are soft and mushy compared to normal skin. An experienced clinician can use a semi-sharp circular spoon-like tool called a curette to scoop out the obvious cancer, leaving behind normal skin. This is often, but not always, followed by a burning procedure called electrodessication to obtain an extra margin of safety. For the worst types of non-aggressive basal cell carcinomas the curettage followed by electrodesiccation is done three times. For the least aggressive types, such as superficial basal cell carcinoma on the trunk, sometimes curettage alone is adequate without using the burning which allows these to heal with better scars. These can also be removed with excisional surgery where the affected areas are cut out and then sewn in a layered fashion with absorbable sutures underneath the skin and some sort of stitching in the skin.
There are some non-surgical treatments for these non-aggressive basal cell carcinomas, primarily Aldara or imiquimod cream. Dr. Geisse authored the two major papers that led to the approval of Aldara or imiquimod cream to treat basal cell carcinomas in the United States. He was the principal investigator for 3M Pharmaceuticals who at that time owned the drug and sponsored the large double blind placebo controlled studies to get it approved. Drs. Beutner and Geisse did the very first study proving that this cream would work for basal cell carcinoma, which led to the larger studies, mentioned above. Despite Solano Dermatology Associates’ long history with Aldara or imiquimod, it is in fact rarely used for basal cell carcinoma. It is costly and creates a significant rash and has to be used for six weeks and only yields an 80% cure rate for small superficial basal cell carcinomas of the trunk. That compares to 90% cure rates for curettage and electrodesiccation or excision and thus, unless there is an extremely apprehensive patient who does not want surgery or the cancer is in an area where any scar would be emotionally devastating (such as on the central chest in a young woman), Aldara is not often used to treat basal cell carcinoma.
Mohs micrographic surgery is the treatment of choice for central facial tumors including so-called non-aggressive or circumscribed tumors. Mohs micrographic surgery, explained elsewhere, provides 98-99% certainly of removal; thus if the cancers are located on the nose, ears, lips or close to the eyes using lesser forms of surgery would not be in the patient’s best interest. The worst cases the Mohs surgeon sees are often the ones that have been previously incompletely removed by lesser forms of treatment. Sometimes many years can go by before incompletely treated basal cell carcinomas show up around or underneath the scar. By that time patients can lose their entire noses, eyelids and ears to this sometimes-destructive cancer.
Aggressive or non-circumscribed forms of basal cell carcinoma include infiltrative, micronodular and sclerosing or morpheaform basal cell carcinomas.
These variants of basal cell carcinoma are usually on the central face and can be much larger than they appear from the surface. They often have what is called “subclinical extension”. What that means is that the cancer has branches and roots that go out well beyond the small area that may be visible on the surface. These cancers are often incompletely removed by regular forms of surgery, thus Mohs micrographic surgery is the treatment of choice for these more aggressive cancers, particularly on that face. Wide and aggressive excision can be done on the trunk for aggressive basal cell carcinoma without doing Mohs since the scar is not as noticeable or as concerning to the patient and there is usually enough extra skin to close even large wounds.
Radiation therapy is rarely used for the treatment of basal cell carcinoma. It is expensive, requires multiple trips to the radiation oncologist and has some significant short term and more importantly long term side effects. The side effects include short term redness, swelling and sometimes bleeding and open areas of skin in the area that has been treated with radiation. Long term scarring and dilated blood vessels can occur and rarely second malignancies can occur in irradiated skin many years later. Around the eyes, nose or the glands of the face radiation can cause quite severe side effects such as dryness of the nose, bloody noses, dry eyes, loss of vision and loss of saliva formation from the parotid gland, which is the major gland in the cheek that forms saliva.
Solano Dermatology Associates rarely recommends radiation therapy and usually only for terrible cases where the surgery would be disfiguring in an elderly patient as a form of palliation, which means we shrink the tumor and keep it from bleeding or leaking on their beds, but do not necessarily cure it since these are slow growing cancers as a rule. Rarely, when basal cell cancers are deeply invasive or involve nerves, we use radiation after Mohs surgery to help ensure it does not return. If these cancers are large and deep on the face and involve the nerves of the face and if they are not completely removed they can lead to invasion of the brain through the cranial nerves. Radiation therapy as primary treatment of basal cell carcinoma providers somewhat over 90% cure rates, based upon fairly limited studies when compared to Mohs micrographic surgery which has a great deal of data to support its use and confirm its much higher cure rate.