Once you have gone over the pathology report and staging information with your doctor, it’s time to plan the treatment strategy. This section discusses the different types of therapy that are available for squamous cell skin cancer and their advantages and disadvantages.
Surface/Destructive Therapy
These treatments are applied directly to your skin to treat squamous cell skin cancer.
Curettage & Cautery (C&C)
In this procedure, the doctor scrapes the cancer from your skin (curettage). Then s/he applies heat to destroy any remaining cancer cells (cautery), which also stops any bleeding.
Advantages:
- It’s quick, often completed in one office visit
- It does not require stitches (or a follow-up appointment to remove them)
- It’s a less-invasive option for people who don’t want or can’t tolerate a more-invasive procedure
- For high-risk groups who have multiple squamous cell skin cancers, C & C allows rapid treatment of multiple cancers at the same time. It’s just important to check the pathology to make sure there are no high-risk features
Disadvantages:
- It does not work well on areas that have hair
- It may not heal as well as an excision, so it probably should not be used on an area where you are concerned about the appearance
- If the tumour is deeper than expected, it may still need to be surgically removed
- It is not as effective as surgery
Cryosurgery
This procedure involves applying a cold substance, such as liquid nitrogen, to the tumour and freezing it off. It may be considered for low-risk squamous cell skin cancer when more effective therapies are either not advised or impractical. It can also be considered in individuals with conditions that cause them to form large numbers of tumours.
DEBATABLE. Topical medications such as Aldara are used for actinic keratosis and basal cell carcinoma, but respected medical organisations do not agree on their use in squamous cell skin cancer. Aldara is not generally recommended for patients with squamous cell skin cancer, except in some in situ (non-invasive) cases. Similarly, topical 5-fluorouracil (5-FU), which is a type of chemotherapy, is not recommended as a treatment for invasive squamous cell skin cancer.
Surgery
There are two general types of surgery for squamous cell skin cancer:
Wide Local Excision
A dermatologist (or specialised surgeon) cuts out the cancer and an area around the tumour. Removing an extra part of skin (a wide margin) assures that s/he got all the cancer. If there is a big enough margin of normal skin around the cancer cells, your treatment is complete. If not, your doctor may need to go back and take more. The specimen is normally sent for histological testing.
Mohs Micrographic Surgery (MMS)
Mohs (rhymes with nose) micrographic surgery is sometimes recommended for squamous cell skin cancer that is likely to recur (come back) or is in an area where you don’t want to remove a lot of skin (such as the face). Mohs surgery is named after Dr Mohs, who invented the technique.
In Mohs (also called microscopic controlled excision) surgery, you are awake while the surgeon removes the smallest amount of tissue needed to treat the cancer. In the UK, Mohs surgery is normally performed in a hospital as an outpatient.
The surgeon removes the skin cancer that can be seen. Then a thin layer of surrounding skin is cut away and examined under a microscope. If cancer cells are found in that additional layer, the process will be repeated until no cancer cells can be seen. The surgeon will then decide the best way to treat the wound.
Radiation Therapy
Radiation therapy is used if you can’t undergo surgery or if you really don’t want it. Radiation therapy can also be used in addition to surgery to help prevent the cancer from coming back (adjuvant therapy). Smaller and thinner tumours may respond well to this type of therapy. Finally, if the skin cancer has grown deep or spread, radiation therapy may help you feel more comfortable because it can control some of the symptoms associated with the cancer.
The different types of radiation therapy used to treat squamous cell skin cancer are:
- Superficial radiation therapy: Radiation beams are sent just beneath the skin, treating only the tumour
- External beam radiation therapy: High-energy beams of radiation are directed into the tumour in order to kill cancer cells, but no radioactive sources are placed inside your body
- Brachytherapy: Radioactive implants are placed directly inside (or near) the cancer. Also called internal radiation, this therapy is also used to treat prostate cancer
Photodynamic therapy is a treatment that uses light-activated radiotherapy. Although this type of therapy is used for some basal cell carcinomas, it is not considered effective for squamous cell skin cancer. Similarly, laser therapy is also not considered effective for squamous cell skin cancer.
Adjuvant therapy: Additional cancer treatment given after the primary treatment to lower the risk that the cancer will come back. For squamous cell skin cancer, the primary treatment is usually surgery. Adjuvant therapy may include chemotherapy, radiation therapy, hormone therapy, targeted therapy, biological therapy, or immunotherapy.
Systemic Therapy
Systemic therapy is therapy given throughout your body. Currently, one immunotherapy drug, cemiplimab, is available for treating squamous cell skin cancer.
Cemiplimab
Cemiplimab (Libtayo®) is available for treatment of advanced squamous cell skin cancer, which includes locally advanced or unresectable (which means it can’t be removed with surgery) squamous cell skin cancer as well as squamous cell skin cancer that has metastasised (spread) to the lymph nodes or distant regions. It is given in the vein (IV, intravenously) every three weeks, usually in a hospital or cancer centre. Cemiplimab belongs to a class of drugs called programmed cell death protein 1 (PD-1) inhibitors. PD-1 inhibitors reactivate part of the immune system (the T-cell system) that has been suppressed by cancer cells. When this T-cell system is reactivated, it can then do its job and seek out and kill cancer cells.
In clinical trials, cemiplimab shrank tumours in about half the patients with squamous cell skin cancer. This shrinking lasted six months or longer in 61% of the patients who responded to cemiplimab. A small proportion (about 4%) of patients had their tumours disappear completely. Cemiplimab caused side effects that are typically seen with PD-1 inhibitors, which are mostly related to the immune system being activated. These side effects included lung problems, intestinal problems, liver problems, hormonal issues, kidney problems, and skin issues such as rash, blistering, and sores in the mouth.
Pembrolizumab
Pembrolizumab (Keytruda®) is available for the treatment of squamous cell skin cancer that is (1) locally advanced and unresectable (which means it can’t be removed with surgery) or can’t be treated with radiation; or (2) recurrent (that has come back); or (3) metastatic (spread to the lymph nodes or distant parts of the body). Pembrolizumab is given in the vein (IV, intravenously), every three weeks or every six weeks, typically at a hospital or an infusion center. The drug is a PD-1 inhibitor. In clinical trials, over a third of patients with squamous cell skin cancer responded to pembrolizumab. The majority of these responders did well long term. Pembrolizumab had side effects that are typically seen with PD-1 inhibitors, many of which are associated with immune-system activation. These include lung problems, intestinal problems, liver problems, hormonal issues, kidney problems, and skin issues such as rash and blistering.