Squamous Cell Carcinoma (SCC)
What is Squamous Cell Carcinoma (SCC)?
- Squamous Cell Carcinoma (SCC) a sub-type of NON-MELANOMA skin cancer. It is usually not life-threatening, but in some cases it can spread if left untreated.
- SCC is the 2nd most common type of skin cancer following behind basal cell carcinoma, the other type of non-melanoma skin cancer.
- It arises in the epidermis (top layer of skin) but if left untreated can penetrate and invade into deeper tissues.
- It usually occurs in areas of sun exposure, but can also be found in mucous membranes such as the lip and tongue, where there is higher risk of spreading.
- Transplant patients taking immunosuppressant medications have a much higher risk of developing SCC as their immune system cannot effectively fight off the cancer cells.
What does it look like?
- A scar like area that is white, yellow or waxy with poorly defined borders.
- A wart-like growth that crusts and occasionally bleeds.
- A persistent, reddish, irritated scaly patch with irregular borders that sometimes crusts or bleeds, usually located on the back, shoulders, chest, arms or legs.
- An open sore that bleeds and crusts and persists for weeks.
- A “crater-like” elevated growth with a central depression or core that occasionally bleeds. A growth of this type may rapidly increase in size.
Images from: www.canadianskincancerfoundation.com
How it is diagnosed?
If your doctor suspects that the lesion could be a skin cancer, they will initially proceed with a biopsy to confirm the diagnosis. This is necessary to determine the sub-type and choose the appropriate treatment plan. A local anesthetic will be administered through a small needle and three different types of biopsies could be performed:
- Shave Biopsy – for smaller lesions, a flat scalpel blade is used to remove the bulk of the lesion. A Co2 Laser can be used to cauterize the base so that no sutures are required.
- Punch Biopsy – for larger or deeper lesions, a small circular blade is used to cut a portion of the tissue out. The opening will be closed with a few sutures that will need to be removed.
- Excisional Biopsy – in some cases, the entire lesion will be removed with the biopsy. An incision will be made in an elliptical (eye shape fashion) with a narrow margin of normal skin around the tissue. The opening will be closed with sutures that will need to be removed.
What will the biopsy results tell us?
Biopsy results take approximately 2-3 weeks to be processed. Regardless of your results, we will contact you with your final results. At this point, the dermatopathologist will have determined which sub-type of SCC it is. This will help us determine the most appropriate treatment. It is not unusual that the biopsy has not taken the entire lesion and that further surgery is required. Even if the area has healed well and there does not appear to anything remaining, there is often a small component that is still present which may not be visible with the naked eye. If untreated, it can cause the lesion to recur and potentially grow even larger.
Squamas Cell Carcinoma Treatment
There are two main types of SCC:
- Squamous Cell Insitu (SCCIS) or Bowen’s is a superficial SCC that is localized to the very top layers of the skin.
- Invasive Squamous Cell Carcinoma indicates that the tumor has started to penetrate into the deeper levels of skin. Invasive SCC are usually graded as well differentiated, moderately differentiated and poorly differentiated, depending on how well organized the cells are when examined microscopically. As they become less differentiated, there is a greater risk of them spreading.
Depending on the type of squamous cell carcinoma, several treatment options may be recommended.
SCCIS or Bowen’s
– because this is localized to the superficial layers of skin, less invasive treatments can be performed.
- Co2 Laser Ablation
- Removes several layers of damaged skin with laser to reach normal skin
- No sutures are required, but because there is a larger defect, it often takes 2-4 weeks to completely heal. Lower legs may take even 6-8 weeks to completely heal
- Topical Imiquimoid (Aldara 5% or Zyclara 3.75%)
- This is an immune-stimulating medication that when applied to the site stimulates your body to repair the damaged tissues
- A small amount of cream is applied 5 nights/week x 6 weeks
- Some local irritation and crusting is expected during the treatment process
- In some high risk sites, wide local excision in our office or referral for MOHS surgery for SCCIS may be indicated
Invasive Squamous Cell Carcinoma
– as this has started to spread into the deeper tissues, complete excision is usually required. However, there are exceptions such as patients of advanced age or with medical conditions that may preclude them from surgery. In these cases, less invasive treatment options can be considered.
- Wide Excision in our office:
- an elliptical shape of tissue is used to remove the skin cancer as well as a margin of healthy tissue. Both internal (absorbable) and external sutures are usually required to close the incision.
- The surgical specimen is sent to the lab to be analyzed. Our goal is to obtain “clear margins”, confirming that the cancer has been removed with an adequate margin of healthy skin. Results will be received in approximately 2-3 weeks.
- MOHS Surgery – This is recommended for skin cancers that are located on high risk areas such as the face, scalp and ears where there is little excess skin and there is a higher risk of spreading.
- MOHS surgery is the most effective method to remove the entire skin cancer while sparing as much tissue as possible.
- Once the area has been frozen with a local anesthetic the visibly apparent skin cancer is removed. While you remain in the office, the tissue is examined under a microscope.
- If cancer cells are still present, additional skin will be removed and analyzed again. This process will be repeated until no cancer cells remain.
- Once no skin cancer cells are present, the tissue is sutured together. Some larger defects may require a skin graft for closure.
- This process gives the advantage of knowing that the tumor has been completely excised without having to wait 2-3 weeks for biopsy results.
Sunscreen and Sun Protection
As this type of skin cancer develops from exposure to the damaging UV rays from the sun, it is essential that you wear a daily sunscreen of 30 SPF or greater to minimize the risk of developing more. In addition to sunscreen, sun protective clothing and a hat is the best way to protect yourself. Even in our cold Calgary climate, the daily exposure to UV radiation can cause unseen damage.
The cure rate for SCC that have been properly treated is over 95%. However, because you have the genetic pre-disposition, skin type, or sun exposure that allowed you to get one skin cancer, you are at a higher risk of developing another one in the future. We will continue to monitor your skin every 6-12 months for any new or recurrent lesions for the first few years. If now new lesions have developed, we will return you for your family physician for ongoing surveillance. You are often more aware of changes in your skin than your health care professional, so we recommend that you perform a monthly skin examination and notify your physician if you have any new or suspicious lesions.
Remember… the best treatment for skin cancer is PREVENTION! SO WEAR YOUR SUNSCREEN DAILY!!
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