What Is Basal Cell Carcinoma?
Sun exposure damages the DNA in the skin. The body continually repairs this damage. Skin cancers arise where the body has been unable to repair the damage.
Although sun exposure causes skin cancer, there are also other factors involved. The lighter the skin color, the more easily the sun damages its DNA. The more you are out in the sun, the more damage you sustain. There is also an inherited component.
Some bodies are better able to repair the DNA damage than others and this ability, or the lack of it, can be inherited. Unrepaired damage to the basal or bottom layer of the epidermis of the skin results in the formation of Basal Cell Carcinomas, abbreviated BCCs.
What Happens If Basal Cell Carcinoma Isn't Treated?
Left untreated, BCCs continue to grow larger in diameter and to penetrate deeper and deeper into the skin and the structures beneath the skin. It is extremely rare for BCCs to spread, or metastasize, to other parts of the body. This usually only happens if it has gone untreated for many, many years or if the person has a severely compromised immune system from another medical problem.
Once you have had one BCC, you have about a 15-30% chance of getting another one in the next 3 years. If you have had more than one BCC, that risk goes up.
There are several different subtypes of BCCs. Some of these include superficial, nodular, ulcerated, pigmented, infiltrative, sclerosing (also known as morpheaform), infundibulocystic, and basosquamous cell carcinoma (which is a combination of a BCC and a squamous cell carcinoma).
It is important for the provider to know the subtype of BCC that you have, because some are more aggressive than others and the more aggressive ones need to be treated in a more aggressive fashion.
What Are My Treatment Options?
There are various treatments available to treat BCCs. Some of these are outlined below.
- Electrodesiccation and curettage (ED&C, also called C&D for curettage and desiccation): Skin cancers are often softer than normal skin. With this technique, the soft material is scraped off (curettage) and what remains is treated with an electric current to destroy the tissue (electrodesiccation). This is usually repeated once or twice and is done under local anesthesia in our office.
- Excision: The skin cancer is cut out with a margin of normal surrounding skin, since BCCs can have microscopic extensions that cannot be seen with the naked eye. Additional skin is then usually removed, so that the remaining skin can be sewn back together in a straight line. This is all done under local anesthesia in our office. The removed skin is sent to a pathology lab for processing and then read by a dermatopathologist to determine if it has been completely removed or if there is some BCC remaining in the patient.
- Mohs surgery:The skin cancer is cut out and the patient waits while the removed tissue is processed to ensure its complete removal. It may be removed completely on the first attempt, or it may take several attempts to ensure that the cancer is completely removed.
Once the skin cancer is completely removed, the hole, or defect, created by its removal is repaired. There are several options for reconstruction: sometimes the defect is allowed to heal in on its own (this is called second intention healing), sometimes the defect is stitched into a straight line, and sometimes the surgeon needs to do a more complex repair such as a flap or graft (this is more common on certain body parts such as the nose or ear). This is all done under local anesthesia in our office by one of our Mohs surgeons.
Mohs surgery offers the highest cure rate of all treatment options due to the way that the tissue is processed on the day of surgery. This technique is typically reserved for BCCs on the head, neck, groin, hands, or feet, or BCCs elsewhere on the body that have a more aggressive subtype.
- Imiquimod: This cream is FDA approved to treat only the superficial subtype of BCC. It is typically applied 5 times a week for 6 weeks and stimulates an immune reaction against the tumor.
- 5-Fluorouracil (5-FU): This cream is also FDA approved to treat only the superficial subtype of BCC. It is typically applied twice a day for one month and blocks DNA replication in the tumor cells and also stimulates an inflammatory reaction.
The cure rates with either cream are lower than with surgery. If the BCC does not resolve or recurs after a topical cream, then surgical treatment is indicated.
Other Treatment Options
- Cryotherapy: this non-invasive treatment option freezes the tumor enough to kill it. This is usually done under local anesthesia with liquid nitrogen. The cure rates are not as high as surgical treatment.
- Photodynamic therapy (PDT): A liquid is applied to the skin cancer and left in place from minutes to hours depending on which liquid is needed. Then a specific wavelength of light is applied to the site for at least several minutes. The liquid and the light work together to kill the skin cancer. Afterwards, you may have a sunburn-like reaction and should avoid sun exposure.
- Radiation Therapy: There are several radiation protocols that can may be used, including electron beam therapy and superficial brachytherapy. The radiation oncologist would choose which method is best suited to treat your BCC. Radiation therapy typically involves several treatments per week for several weeks.
- Oral Pills (hedgehog inhibitors): These are usually reserved for patients with a large number of BCCs, or individual BCCs that are too large or dangerous to treat by surgery or have spread (metastasized) to other parts of the body. These medications work by blocking a pathway (the hedgehog pathway) that contributes to BCC development. They have many side effects including muscle pain, changes in taste, and hair loss. The two commercially available hedgehog inhibitors are vismodegib (Erivedge) and sonidegib (Odomzo).
- Immunotherapy Infusion: BCCs that have metastasized (spread to other parts of the body) or are very large and aggressive and have failed the previously mentioned oral hedgehog inhibitors may be treated with immunotherapy infusions with cemiplimab (Libtayo). These infusions are typically administered in collaboration with an oncologist and stimulate your body’s immune system to attack the cancer.
If you have been diagnosed with a Basal Cell Carcinoma in our office your provider will discuss the various options that are appropriate for your situation. You will then decide together how to proceed.