Squamous cell carcinoma in situ or Bowen’s disease can be treated with superficial treatments as these cancers have not invaded past the most superficial layer of the skin, the epidermis. Superficial treatments include
- Cryotherapy- using a cold liquid or tool to freeze cancer cells
- Photodynamic therapy(PDT)- using light energy to activate a drug that is applied to the area
- Topical medications- Imiquimod and fluorouracil(5-FU)
- Electrodesiccation & Curettage – scraping away the visible tumor with a sharp tool followed by cauterization of the base of the wound with an electric needle.
Surgery [Wide local excision]: Traditional surgery, also referred to as a wide local excision (WLE), removes the cancer with a rim of normal tissue around the cancer, called a margin. Having a complete margin removed with the cancer decreases the chances of the cancer coming back. The thickness of the margin is dependent on the type of cancer and the cancer’s features that indicate how aggressive the cancer is. The thickness of the margin may also be selected by your surgeon based on the exact location of the cancer and its proximity to important delicate structures of the face (for example, the eyelids). Surgery can sometimes be performed in the office but if the cancer is large or in a sensitive area, this may need to be done in the operating room with anesthesia.
MOHS micrographic surgery [MOHS surgery]: a technique that allows a specially trained dermatologist or surgeon to remove the least amount of normal tissue possible in the removal of your skin cancer. This is especially advantageous in aesthetically sensitive areas on the face, such as around the eyes, nose, mouth or ears. In MOHS surgery, after all the visible tumor is removed with a scalpel, a thin rim of normal tissue is removed from the wound and checked under the microscope while you are waiting to look for any residual cancer cells. This is a slow process that continues while you wait until the final layer shows no residual cancer cells. This creates the smallest possible wound while still removing all of the cancer cells. After MOHS surgery, the wound is sewn back together, leaving a scar. MOHS is effective for the treatment of basal cell carcinoma and squamous cell carcinoma. The usefulness of MOHS surgery in melanoma, merkel cell carcinoma and sebaceous cell carcinoma is debated.
The Role of MOHS Micrographic Surgery and Standard Surgery Excision [WLE]: For basal cell carcinoma both MOHS and standard surgery [WLE] have very high success rates for treating the cancer. MOHS may allow the cancer to be completely removed while taking a smaller margin, thus leaving a smaller scar. Wide excision is necessary when the basal cell cancer extends to structures deeper than the skin.
For squamous cell carcinomas, MOHS has been shown to have a lower rate of recurrence. However, if the cancer is very large or has invaded deep structures under the skin, MOHS may not be possible and traditional surgery [WLE] would be advised instead.
Neck Dissection: Lymph nodes are small structures that collect and filter material for the lymphatic system (which is a body-wide network drainage system that filters body fluids of infectious foreign particles). The lymphatic system can also collect and filter cancer cells. Therefore, cancer cells can spread to lymph nodes and grow. A Neck Dissection is a surgery to remove the lymph nodes of the neck that may contain cancer cells. This surgery is done under general anesthesia to allow detailed work around the delicate nerves and structures of the neck. A neck dissection attempts to remove all of the lymph nodes in the area of which the cancer has the ability to spread. After a neck dissection, despite the absence of lymph nodes in the specific area of surgery, your lymph generally finds and uses other lymph pathways to move through the neck.
Parotidectomy: The parotid gland is the large saliva gland that lies in front of the ear lobe over the side of the face and overlying the jawbone. This gland makes saliva but also contains lymph nodes. A parotidectomy is removal of part or all of the parotid gland and may be part of the treatment when lymph nodes have to be removed in that area for skin cancer. Your mouth has 800-1000 other saliva glands so you will not miss the saliva made by the parotid gland after it is removed.
The facial nerve runs through the parotid gland and splits the gland into a superficial and a deep lobe. Parotid surgery requires identifying the very thin nerve as it travels through the parotid gland,and the surgeon’s goal is to keep all of the nerve branches safe during parotidectomy. When the parotid or the lymph nodes in the parotid contain cancer, the cancer can grow and invade these nerves, destroying them and thus causing weakness of the face.
Radiation: Radiation therapy is the use of high-energy waves to kill cancer cells. Radiation can be given in several forms such as external beam radiation therapy (EBRT) or directly applied via electronic brachytherapy).
Brachytherapy delivers radiation directly to the cancer via a miniaturized x-ray source. This allows treatment of the cancer without surgery and is useful when surgery is not an option or not desirable. However, brachytherapy only penetrates the skin to a short depth and therefore can only be used for certain small cancers which do not invade deeply.
Patients receiving traditional radiation therapy (EBRT) will need several radiation treatments, and the schedule will depend on the regimen selected by the radiation oncologist. This is often more cumbersome than having surgery or MOHS. Side effects of radiation are temporary and include redness, skin changes, skin breakdown and fatigue. Permanent side effects of radiation are less common, but include an unfavorable appearance of the skin, non-healing ulcers and cataracts if given near the eye. There is also a small risk of cancer recurring in the radiated area and the radiation itself can cause skin cancers to form, usually several years after treatment. Generally, radiation is not as effective as surgery in the primary treatment of skin cancer and the same area should only be treated once with radiation.
Surgery is usually the best way to treat skin cancers but, in some cases, radiation therapy can be used as the main (primary) treatment and thereby avoid surgery. There can be good results for certain basal cell carcinomas and squamous cell carcinomas. This may also be true for merkel cell cancer but generally surgery is preferred. Radiation is very rarely used as primary treatment for sebaceous cell carcinoma ormelanoma.
Radiation can also be used as an added treatment after surgery to treat cancer that was not completely removed or to decrease the likelihood of the cancer returning. Radiation is sometimes needed for cancers that have grown into larger nerves or skin cancer that is invading very deeply even if the cancer was entirely removed by surgery.
What is systemic therapy?
Systemic therapy is a medicine that affects the entire body and has the potential to treat cancer cells throughout the body. Most systemic treatments are given by an IV infusion, however some can also be given as a pill.
The most common types of systemic therapies are chemotherapy, immunotherapy, and targeted therapy.
Chemotherapy is a drug therapy that is put into the bloodstream to kill fast-growing cells in your body. Since cancer cells grow more quickly than other cells, these drugs preferentially kill cancer cells over other non-cancerous cells.
Immunotherapy is a drug therapy that can either educate the immune system to recognize and
attack a certain type of cancer cell, or enhance the performance of the body’s immune system to fight cancer.
Targeted therapy is a drug therapy that targets specific genes and proteins that regulate the growth and survival of cancer cells. This indirectly kills the cancer cells or slows down its growth.
Chemotherapy has very little effect on skin cancers and is generally only used in the following situations:
- When surgery, radiation, and immunotherapy are not options
- When patients have a metastatic Merkel cell carcinoma and immunotherapy is not available.
- When radiation is being given after surgery, chemotherapy may be given with it to make it more effective.
Immunotherapy is the primary systemic treatment for skin cancers. Immunotherapies are methods that use the patient’s own immune system to kill cancer cells.nThere are several types of immunotherapy, but the most common group are called “immune checkpoint inhibitors”. These medicines are highly effective for melanoma, Merkel cell carcinoma, and squamous cell carcinoma. This type of treatment is commonly used when the cancer has spread somewhere else in the body and cannot be removed with surgery. These medicines are generally very well tolerated and have less side effects than traditional chemotherapy. Sometimes this medicine may be given after surgery, as well in hopes of decreasing the likelihood of the cancer coming back.
Targeted therapy is currently used for both melanoma and basal cell carcinoma. For melanoma the common target is the BRAF signaling pathway – mutations that cause this genetic pathway to be overactive are present in about 30% of head and neck melanomas. Much like immunotherapy, targeted therapy is typically used for melanoma that has spread somewhere else in the body or after surgery for a high-risk melanoma. The hedgehog inhibitor is a targeted therapy useful for basal cell carcinomas. This can be used for basal cell skin cancers that spread elsewhere in the body but also for cancers that continue to recur after surgery or radiation.