Skin Cancer Treatment
How are early-stage melanoma skin cancers treated?
Early stage melanoma skin cancers, or those melanomas which are localized just to the skin are treated by excision. You remove the melanoma and some adjacent skin and then you sew up the normal skin. That is virtually the only way early stage melanoma skin cancers are treated and it's extremely effective in removing what we call the primary tumour. When the melanoma has invaded into the skin, perhaps greater than 2 millimetres, the margin of skin around it that we remove is usually two centimetres. Anywhere short of two millimetres, the margin of skin is usually around one centimetre on both sides of the tumour and then when that is removed, the skin is brought together. If the lesion is totally removed, then that lesion is gone. Our concern then shifts to whether or not any of the cells in that lesion had already metastasised either to lymph nodes or to other parts of the body, and then treatment needs to be directed towards that problem. The original primary lesion, though, has already been removed surgically. When the lesion is very superficial, a superficial excision with a very narrow margin is virtually 1% curative.
How are later-stage skin cancers treated?
When a malignant melanoma has already invaded deeply into the dermis, it has a high possibility, not probability, a high possibility, of already having metastasised to other organs or to lymph nodes. The original primary lesion is easily removed surgically, with some margin usually around 1 to 2 centimetres depending on the nature of the lesion. The skin is then brought together and sewn together and that lesion is gone. However, if the cells have gone elsewhere; if they have been found in the nose or been found in the adjacent skin, or in some of the organs inside the body, then additional, more aggressive treatment is necessary for this skin cancer. Radiation, for instance, is not very effective in malignant melanoma; chemotherapy is variably effective but certainly not as effective as it is in other fields. That, of course, is a constantly changing field whereby new chemotherapeutic agents and new approaches are being derived all the time. Also, immunotherapy, where the immune system is marshalled in order to kill some of these cells which are left in the primary tumour, is a major interest in malignant melanoma, as well as vaccines. These are all potentially on the horizon.
How often will I need to follow up with my doctor after being treated for skin cancer?
The rule of thumb in my office is that once someone's had a skin cancer, I generally see them anywhere from every 4 to every 6 months for a cutaneous exam to see if whether or not other skin cancer lesions have occurred. Malignant melanoma needs follow up both at the dermatologist, and if invasive with high risk, this type of skin cancer requires follow up at their oncologist as well, but the dermatologist visit is to look for new, separate melanomas. Again, the chance of a patient with a malignant melanoma developing a second unrelated malignant melanoma is 20 times greater than a patient developing their first one, and so in follow-up sessions we do complete skin exams both looking at the cancerous lesion that has now been removed as well as all the other cancerous lesions on the skin.
What are "margins" and how are they related to cancer treatment?
When a skin cancer is discovered, it needs to be removed, usually surgically. When a basal cell or a squamous cell carcinoma is removed surgically we have margins of normal skin that need to be taken along with the abnormal skin where the skin cancer is. That margin is anywhere from 2-5 millimetres usually depending on the size of the skin cancer. The bigger the skin cancer, the more irregular its growth pattern, and the wider the margin. In malignant melanoma, on the other hand, there are standards which are used which have to do with how invasive the melanoma is into the skin. When the melanoma is in situ or within the epidermis, generally a 0.5 centimetre or 1 centimetre margin is used. When the melanoma is less than 2 millimetres invasive into the skin, a 1 centimetre margin is usually used, and with anything above that a 2 centimetre margin is used. This is merely to ensure that the tumour is removed in total with some normal skin as a buffer for some abnormal cells which may be present in that area.
Is chemotherapy effective in treating skin cancer?
The efficacy of chemotherapy in treating skin cancer varies. The use of chemotherapy in basal cell carcinomas is completely ineffective and completely unnecessary. Basal cell carcinomas do not metastasise or do so at an infinitesimal rate. They do not require chemotherapy and are destructive locally, and therefore they merely need to be removed locally. In some very rare instances squamous cell carcinomas can metastasise when they are large or under certain clinical circumstances, such as on mucous membranes or on patients who are immunosuppressed. Chemotherapy may have some role as well as radiation in those patients. In malignant melanoma, which is the skin cancer which does metastasise, chemotherapy is adjunctive. It is something that is used along with other things. It can, in certain cases, slow down growth, but is rarely, if ever, curative.
Can cancer be treated with creams or solutions?
There are some basal cell carcinomas, as well as superficial squamous cell carcinomas, that we now have access to removing by the use of an immunostimulant cream known as Imiquimod (brand name Aldara). Aldara brings the immune system over to the tumour and in so doing the immune system has the capability of destroying the abnormal cells. Aldara or Imiquimod is extraordinarily effective in multiple superficial basal cell carcinomas. It is not, however, a "free lunch" because it causes a fair amount of irritation. It can cause crusting and inflammation. You have to use it for 6 weeks to 12 weeks. It is non-surgical so it is appealing to patients, and there are certain clinical situations where it is extremely valuable but it is not primary treatment for skin cancers; either basal cells or squamous cell carcinomas.
What types of radiation therapy are used to treat skin cancer?
Skin cancer's basal cell carcinomas and squamous carcinomas are sometimes treated by radiation therapy, in particular radiation therapy is used to treat small lesions in very cosmetically sensitive areas or on small lesions in patients who are too sick or have too many complications to undergo surgery. I usually send somewhere in the neighbourhood of five to ten patients a year for radiation therapy for small basal cell carcinomas on the tip of the nose, in elderly patients in particular, because this is such a high cosmetic area, and cancer surgery does leave some cosmetic deficit. The problem with radiation therapy is that it is very time consuming – you have to go four to five times a week for about three to five weeks – and that it does change the texture of the skin surrounding the tumour. Radiation therapy may also lead to additional skin cancers 10 to 15 years later so it is not an appropriate treatment for young people. Radiation therapy is relatively bloodless, it is painless, and again, those people who are too senescent or ill to undergo surgery, radiation therapy is one of the alternatives that we have. Radiation therapy is not appropriate for primary malignant melanoma, and it is not used whatsoever to remove the atypical cells. That is always done by surgery.
What is an "excisional biopsy"?
When someone presents to our office with a possible skin cancer, we need to do some sort of tissue analysis to find out under the microscope first whether it is a skin cancer, then what kind of skin cancer it is, and then under certain circumstances what the features of that skin cancer are. There are numerous ways of doing a biopsy or a tissue sampling. Perhaps the most involved way of doing that is an incisional biopsy whereby the entire lesion is removed and usually the normal skin is then sewn together. That is usually not necessary with a basal cell carcinoma and a squamous cell carcinoma. In certain circumstances, it may be necessary if a malignant melanoma is suspected, because it is the only way we can get both the breadth and depth of the entire lesion in order to find out some of those features for which we are looking. Those features may offer both diagnostic as well as prognostic significance.
What is "curettage" and "electrodessication"?
When a patient is diagnosed with a basal cell carcinoma or a superficial scremiso carcinoma we have an option of removing the diseased skin by a very simple method called curettage and electrodessication. That is a procedure by which the lesion is locally anesthetized. It is scooped out and then curetted or scraped. The reason why scraping is so effective is the tumor cells do not stick together and the normal cells do. So, it'd be somewhat like removing the brown spot in a banana. There's a different texture that's palpable to the operator. When that is done, the lesion is then hyphercated or lesion is burned by an electrical current which gives another margin of cells that are destroyed to give another margin of certainty to removal. Often that procedure is repeated two times or sometimes even three times. It is again, only really valuable on superficial lesions not very invasive lesions and has in appropriate circumstances an approximately 90 to 95 percent sucess rate in removing the tumor. It does however, leave a noticeable scar and so for a cosmetic standpoint is often not the best choice that we can use.
How are basal and squamous cell cancers removed?
Basal cell and squamous cell carcinomas are routinely removed surgically in an office setting, usually in a very non-traumatic way. There are multiple ways of removing the abnormal cells. Destroying them is one way and removing them and bringing the skin together would be another way. Destruction can occur by a process called curette and electro-desiccation, whereby the lesion is cut out, then scraped out and burned. The tissue can also be destroyed by using deep liquid nitrogen treatment which is not the normal way we use liquid nitrogen (which is for superficial destruction) but is rather a sophisticated way of removing the cells that are deeper than the surface of the skin. The standard way we remove skin cancers is by removing the skin which harbours the abnormal cells. The standard way is to cut out the abnormal skin and bring normal skin together. That is known as excisional surgery. There is another method known as a Mohs surgery. Mohs is a method used for very specific tumours in high risk areas or very specific tumours in which it is important to preserve normal skin. It has a very high rate of success, usually approaching 95-98% in terms of removing the skin cancer. It is done in stages where the tissue is removed, looked at under the microscope, and then the physician comes back and looks at it again under the microscope, until all the abnormal cells are removed. Although radiation is used in many other cancers, it is rarely used in skin cancers apart from in rather selective cases, and it is another way of destroying tissue.
What is "skin grafting" and "reconstructive surgery"?
As the number one way of removing skin cancer is to cut out the skin which has the abnormal cells in it, the second responsibility of the physician is to bring the skin back together, for both a functional and cosmetic repair. Probably in ninety to ninety-five percent of the cases, that can be done by just bringing the two pieces of skin together adjacent to the tumour, whereby there's a small thin line resultant after the correction of the defect. However, sometimes the defect is so large, or is in such a fragile, anatomic area, that skin cannot be brought directly together in order to repair the defect. There are two other processes, then, that are available to us. One is to use flaps, whereby you take adjacent skin and rotate it in to close the defect. The other is to use grafts, where you take skin, usually from a anatomically similar area, such as behind the ear, etc., put it into the defect, and then have that close the area where the tumour was removed. When possible, an adjacent closure, or a flap closure, is the most cosmetically acceptable. When necessary, a graft would be the next choice. All these things are done by very, very skilled dermatologic surgeons, and actually, the results can be remarkable.
What is a "topical chemotherapy" and is it effective in treating skin cancer?
In very superficial basal cell carcinomas and in superficial squamous cell carcinomas, we do have an ability to, on occasion, treat with a topical agent which can destroy the tumour cells. There are two topical agents that are used. One is 5% 5-Fluorouracil. 5% 5-Fluorouracil kills the cancer cells as they divide. Its limitation is it works topically, and so only superficially. It is nowhere near as effective as using surgery to remove the lesion, but it of course is non-surgical, so there's less bleeding, etc. However, it is a long treatment option. You have to use it for a period of time. The second alternative, which is relatively new, is Aldara, or Imiquimod. This is a medication which is an immune stimulant. Any time there is a cancer of any kind, there are two components to the cancer. One is the cells have to be abnormal, and two is they have to camouflage themselves from the body's own immune system. What Aldara does is it brings the body's immune system over to the area to offset that camouflage, and as a result, the immune system very selectively will destroy the cancer cells. This is a long, drawn out procedure, whereby the Aldara has to be put on once twice a day for sometimes as much as twelve weeks. It causes a fair amount of inflammation, irritation, crusting, and oozing, and the cosmetic result can range anywhere from very good to average. It is of some value for those patients who do not have the capability of surgery, or patients who have multiple lesions at any given time.
Does laser therapy have a role in treating skin cancer?
When a patient presents with a skin cancer, that area of the skin needs to be removed. It can be removed by multiple modalities but surgery is by far the most common. A cutting tool such as a scalpel is the most prevalent way of removing that tissue. Lasers can be used as a cutting tool. It works no better by any means than a scalpel. Although it does limit some blood loss during the surgery, it is not a standard way of removing skin cancers and is probably not as accurate in most hands as a scalpel in those of us that are used to using as a scalpel. There is no laser per se that removes skin cancer without surgery. It is merely a surgical cutting device when used appropriately.
What is "chemical peeling" and how does it help treat skin cancer?
Chemical peels are various different varieties depending on how deep the peel penetrates into the epidermis and dermis. Superficial chemical peels and medium chemical peels are cosmetic peels and have no value whatsoever- preventative or therapeutically in terms of skin cancer. However, very deep chemical peels can obliterate some of those abnormal cells: which will either become skin cancer or are early pre-cancers. That can be done by both laser and by chemical; for deep peel and has some value. There is a new type of therapy called photodynamic therapy or PDT, whereby a chemical substance is put on the skin, it sits of the skin for some period of time and then a special light is applied to the skin which causes a deep peel throughout the skin. This is extraordinarily valuable for multiple actinic keratosis, or legions that called “pre-cancers”. In obliterating all those actinic keratosis, the incidences of skin cancer would go significantly down. The role of peels for skin cancer, however, is not really appropriate and is not done in any capacity.
What is "photodynamic therapy" or "PDT"?
Photodynamic therapy or "PDT" is a relatively new modality we have in treating the skin. "Photodynamic therapy" occurs when you put a chemical on the skin and let it sit for several hours. That chemical seeps into the skin and the skin cells and is absorbed by the skin cells. If there are multiple pre-cancers on the skin, they actually preferentially take in the chemical. That chemical is stimulated by light, and so after several hours the patient is put into a light box; that light is not effective on normal skin but on all the skin where the chemical has been absorbed, it causes tremendous reaction and cell death and in so doing can selectively kill multiple actinic keratosis at one time. In so doing, the incident and risk of skin cancers is markedly diminished in the future for that patient.
