When selecting a therapy for your squamous cell skin cancer, you and your doctor will discuss the stage of your disease, any other medical conditions you may have, and your personal preferences for different types of therapy. This section reviews recommendations for therapy by stage and provides some guidance on how to weigh the efficacy, safety, convenience, and other treatment factors that are important to you.
Actinic Keratoses
Since actinic keratoses are considered precancers, your doctor (GP/dermatologist) may recommend aggressively treating them. The decision for a therapeutic approach depends on your health, how many actinic keratoses you have, where they are, and what they look like. They can be treated in the office by cryotherapy, curettage and cautery, photodynamic therapy, or laser resurfacing (for cancers on the lip). Separately or in addition, your dermatologist may recommend topical therapies you can apply at home, such as 5-fluorouracil (5-FU) cream, diclofenac sodium gel, imiquimod, or itirbanibulin. Be sure to have a conversation about these options with your dermatologist to determine the best approach for you. The topical treatments work by inducing an aggressive inflammatory reaction, so the skin can look sore and blistered whilst you are applying them. Please talk to your doctor about the best option for you.
Bowen’s Disease, Cancer in Situ
For Bowen’s disease, the treatments are:
- Topical treatment (5 fluorouracil)
- Cryotherapy
- Photodynamic therapy
- Excision
Low-Risk, Local Squamous Cell Skin Cancer
For low-risk, local squamous cell skin cancer, standard approaches include:
- Curettage and cautery (most commonly used for squamous cell skin cancer in situ)
- Wide local excision
- Radiation therapy (if surgery is not appropriate/feasible)
- What happens if your surgery doesn’t remove all the cancer? Typically, another surgery will be performed. If that’s not possible, then radiotherapy will be considered
High-Risk or Very High-Risk Local Squamous Cell Skin Cancer
If your tumour is high risk, then you may be a candidate for the following treatments:
- Wide local excision
- Mohs surgery
- Radiation therapy
- Systemic therapy (if curative radiotherapy is not feasible)
What happens if the surgery does not get it all or your doctor finds additional concerning features in the tumour? If the surgery does not remove all the cancer, another surgery may be an option. If that’s not possible, radiation therapy, systemic therapy, or a clinical trial may be considered. Also, if additional high-risk features are found, your doctor may alter the treatment plan.
Advanced Squamous Cell Skin Cancer
Locally Advanced Squamous Cell Skin Cancer
If you have locally advanced squamous cell skin cancer, recommended treatment options include:
- Wide local excision
- Mohs surgery
- Radiation therapy
- Systemic therapy (if curative surgery or radiotherapy is not feasible)
Regional Disease
If your doctor takes a sample of the lymph node through fine needle aspiration, or core biopsy and finds positive nodes, a number of steps will be taken:
- CT with contrast of the entire lymph node area to figure out size, number of nodes that have cancer, and location
- CT or PET/CT to rule out other metastases elsewhere in your body
- Once scanning is complete, your doctors will determine if surgery is possible. If surgery is possible they will remove the affected lymph nodes in a process called lymph node dissection. You will most likely receive radiotherapy to kill any leftover cancer cells and prevent them from coming back (in this case, radiotherapy is a type of adjuvant therapy)
- If the surgery cannot be completed, your team may provide radiotherapy (if possible) and systemic therapy, most likely with cemiplimab or pembrolizumab
Distant Metastatic Disease
For that small subgroup of patients with squamous cell skin cancer who have distant disease, the recommendation is systemic therapy or a clinical trial. Surgery or radiotherapy can be considered for symptomatic sites as palliation.
- Is sentinel lymph node biopsy used in squamous cell skin cancer?”
Not routinely.
There are different ways of classifying lymph nodes that contain cancer. Some are visible to the naked eye or palpable (which means they can be felt by the hand). Some involved nodes are not visible or palpable and are only found by a sentinel lymph node (SLN) biopsy. SLNs are the first nodes (or a single node) to which lymph fluid flows and to which cancer may move when it leaves the skin. To perform an SLN biopsy, a doctor will inject a radioactive tracer or dye (marker) into the area near the primary tumour location; the marker will travel via the lymphatic system to the sentinel node(s), and this will help the surgeon visualise/identify them. The SLN(s) will then be removed and examined for cancer cells. Lymph nodes that are identified as having squamous cell skin cancer cells in them only by performing a SLN biopsy are classified as occult, since they are not palpable or visible to the naked eye. Generally speaking, when lymph node involvement is occult vs visible or palpable, it marks a better disease course.
Recent studies suggest that SLN biopsy may help identify patients with squamous cell skin cancer and high-risk features who have small metastases to their regional lymph nodes before they become apparent to touch and sight. Patients with palpable or visible cancer generally have a worse prognosis than patients who have “microscopic nodes.” However, to date it is not clear whether finding patients with a positive SLN and doing a complete lymph node dissection (removing all the lymph nodes in the nodal area) or adjuvant radiotherapy actually improves outcomes for these patients in terms of recurrence or metastases. For this reason, the role of SLN biopsy remains controversial in squamous cell skin cancer.
Lymph node dissection: A procedure to remove lymph nodes affected by cancer or lymph nodes in which there is a high chance that cancer has spread. If only some of the lymph nodes are removed, it is called a regional lymph node dissection. If most or all of the lymph nodes are removed, it is called a radical lymph node dissection. Lymph node dissection is major surgery and there are potential short-term and long-term side effects.
Palliation: Relief of symptoms and suffering caused by cancer and other life-threatening diseases. Palliation helps a patient feel more comfortable and improves the quality of life but does not cure the disease. For 95% of squamous cell skin cancer cases, your expert dermatologist or surgeon can manage the disease surgically. After the lesion has been biopsied (or fully removed), the slides created from the biopsy tissues are normally discussed in a multidisciplinary team (which may include other dermatologists, pathologists, plastic surgeons, and clinical oncologists) who will discuss whether the tumour has been fully treated or whether further treatment is needed.
If your dermatologist can’t cure you surgically, other specialties may be needed to treat your squamous cell skin cancer. Typical situations that warrant this approach include:
- Surgically challenging (or high-risk) tumours in the head-and-neck region Progressive growth of the tumour
- Tumours arising in immunosuppressed patients
- Tumours arising in skin within a chronic trauma/ulcer
- Disease that has spread to the regional lymph nodes
- Disease that has spread (metastasized) to bone, liver, lung, etc.
Note: Patients who are immunocompromised after solid organ transplantation have special considerations in terms of reducing their immunosuppression therapy and/or switching to a mammalian target of rapamycin (mTOR) inhibitor when they have a life-threatening skin cancer or rapid development of multiple tumours. In these settings, the transplant team should be consulted as part of the multidisciplinary squamous cell skin cancer management team.
A Special Case for Head-and-Neck Squamous Cell Skin Cancer
Squamous cell skin cancer on the head and neck requires a specialised multidisciplinary approach given the surgical challenges in this region. Typically, a head-and-neck surgeon will be consulted. Currently, for patients with only one small lymph node involved (less than 3 cm in diameter), that lymph node should be removed as well as any others on that side of the neck that look suspicious for squamous cell skin cancer. Additionally:
- If there is a larger lymph node involved or if more than one lymph node is involved, then all the lymph nodes on that side should be removed
- If cancer is found in lymph nodes on both sides of the neck, then all lymph nodes on both sides should be taken out
- If cancer is in the parotid lymph nodes, the recommendation is to also remove part of the parotid gland that drains into those lymph nodes as well as some of the other lymph nodes
For a discussion of lymph node dissection for head and neck cancer and how to prepare for that surgery, see https://www.mskcc.org/cancer-care/patient-education/neck-dissection . Once you know the options based on the stage of your disease, you can weigh the efficacy, safety, convenience, and other treatment factors that are important to you.