Why is Mohs surgery so important?
Mohs surgery is the worldwide “Gold Standard” in skin cancer removal and is based on a "common sense" approach to removing skin cancer. By design, it ensures that only your skin that contains tumor cells is removed during surgery, which limits the sacrifice of unnecessary healthy tissue that is commonly excised when the Mohs surgery is not utilized to surgically remove a cancer. Additionally, the precise systematic tracking of the cancer roots in real time using Mohs surgery, ensures that a skin cancer is removed with the highest possible cure rate for that cancer prior to any reconstruction being performed. When a cancer is removed in this way, the patient is ideally positioned to also receive the best surgical reconstruction outcome from their cancer treatment.
Unfortunately, due to the cost of performing Mohs surgery, only cancers on the face, neck and in specific sites that are hard to surgically repair or where there is limited tissue, like the wrist and hands, ankles and feet, or in the genital region are typically treated in this manner. Out of these anatomic zones, only cancers that are histologically more “aggressive / complex”, or cancers resistant to prior treatment are eligible for this care.
Unfortunately, due to the cost of performing Mohs surgery, only cancers on the face, neck and in specific sites that are hard to surgically repair or where there is limited tissue, like the wrist and hands, ankles and feet, or in the genital region are typically treated in this manner. Out of these anatomic zones, only cancers that are histologically more “aggressive / complex”, or cancers resistant to prior treatment are eligible for this care.
Who Performs Mohs surgery?
In Canada there are only approximately 30 practitioners certified by the current world regulatory body, the American College of Mohs Surgery, to perform Mohs Micrographic Surgery. Most practitioners are Fellows of the Royal College of Physicians certified in Dermatology and subspecializing in Mohs surgery. Dr. Bryce Cowan was the first plastic surgeon to perform this procedure in Canada and is a Fellow of the Royal College of Surgeons of Canada. He remains one of only 2 plastic surgeons in the country certified in this procedure. There are less than 8 plastic surgeons ACMS certified to perform Mohs surgery worldwide.
What cancers is Mohs Surgery used to treat?
Basal cell cancer, squamous cell cancer, in-situ melanoma, extramammary Paget's disease, atypical fibroxanthoma, dermatofibrosarcoma protruberans, sebaceous carcinoma, and other rare skin cancers are best treated by Mohs surgery.
All of these tumors essentially grow in a contiguous form, like roots growing connected to a tree trunk. The tumor and roots continue to grow and invade tissue until removed. Other cancers, like invasive melanoma, grow discontinuously (or break up into pieces) and are much less suitable for Mohs surgery and may be better treated by other methods. The roots of skin cancers can extend from the skin to include underlying fat and surround nerves and eventually invade into muscle. Some tumors also extending and erode into cartilage and bone. Just like the analogy of the root system on a tree, the majority of the tumor is typically hidden from site and can only be identified by a clear precise systematic tracking of each root by Mohs surgery. Unfortunately, it is impossible to predict the exact size of the root system by visual examination of the cancer alone. For that reason, the precise size of your tumor will be unknown prior to the removal and it is impossible to accurately predict the extent of reconstructive surgery that may be required before you undergo surgery.
All of these tumors essentially grow in a contiguous form, like roots growing connected to a tree trunk. The tumor and roots continue to grow and invade tissue until removed. Other cancers, like invasive melanoma, grow discontinuously (or break up into pieces) and are much less suitable for Mohs surgery and may be better treated by other methods. The roots of skin cancers can extend from the skin to include underlying fat and surround nerves and eventually invade into muscle. Some tumors also extending and erode into cartilage and bone. Just like the analogy of the root system on a tree, the majority of the tumor is typically hidden from site and can only be identified by a clear precise systematic tracking of each root by Mohs surgery. Unfortunately, it is impossible to predict the exact size of the root system by visual examination of the cancer alone. For that reason, the precise size of your tumor will be unknown prior to the removal and it is impossible to accurately predict the extent of reconstructive surgery that may be required before you undergo surgery.
How is Mohs performed?
Mohs surgery is performed through a precise step-by-step tumor excision and systematic mapping process using tangential frozen histology sections to identify and track cancer roots on a biopsy proven cancer.
Performed under local anaesthesia, the visible tumor is excised, and orientation nicks placed for subsequent reorientation. Removed specimens are colour coded, mapped, and prepared into histologic slides by tangential frozen sectioning. Specific histologic dyes are used for specific tumors and the slides analyzed to identify the precise location of any remaining tumor. The location of any remaining roots is mapped, and patients are brought back into the operating room for an additional “level”. This process is repeated indefinitely until the entire cancer has been removed. As the location of residual tumor roots can be seen on each level, but the length of the remaining root cannot be known, it may take multiple levels, and significant time, to clear your cancer before your tumor site can be reconstructed.
Performed under local anaesthesia, the visible tumor is excised, and orientation nicks placed for subsequent reorientation. Removed specimens are colour coded, mapped, and prepared into histologic slides by tangential frozen sectioning. Specific histologic dyes are used for specific tumors and the slides analyzed to identify the precise location of any remaining tumor. The location of any remaining roots is mapped, and patients are brought back into the operating room for an additional “level”. This process is repeated indefinitely until the entire cancer has been removed. As the location of residual tumor roots can be seen on each level, but the length of the remaining root cannot be known, it may take multiple levels, and significant time, to clear your cancer before your tumor site can be reconstructed.
Intro to Mohs Surgery |
THE ADVANTAGES OF MOHS SURGERY |
| To learn more about Mohs Surgery and its advantages watch the informational videos above with Dr. Cowan |