Guest: Dr. Bruce H. Thiers – Dermatology
Host: Dr. Linda Austin – Psychiatrist
Announcer: Welcome to an MUSC Health Podcast.
Dr. Linda Austin: I am Dr. Linda Austin. I am talking today with Dr. Bruce Thiers, who is Professor in Chair of Dermatology at the Medical University of South Carolina. Dr. Thiers, skin cancer is an umbrella term that covers a number of different entities. What are some of the most common forms of skin cancer?
Dr. Bruce H. Thiers: We usually divide skin cancer into two general categories. One is nonmelanoma skin cancer and the other is melanoma or some people say malignant melanoma, which is really a redundant term since all melanoma is malignant. Nonmelanoma skin cancer includes basal cell carcinoma, which is the most common kind of skin cancer and squamous cell carcinoma. Melanoma speaks for itself. It’s a tumor involving the pigmented cell of the skin and the most feared tumor that we see in dermatology.
Dr. Linda Austin: Let’s do a separate podcast on each one, but let’s start then with basal cell carcinoma. What is a basal cell carcinoma?
Dr. Bruce H. Thiers: Basal cell carcinoma is a skin cancer that evolves from the basal cell of the epidermis. The epidermis is of course the outer layer of the skin. The basal cell lies along the lower layer of the epidermis. When this cell grows uncontrollably, we call it a basal cell carcinoma. Basal cell carcinoma, if you got to have a skin cancer, the best one to have because it has no potential to metastasize or spread beyond the skin.
Dr. Linda Austin: What does a basal cell carcinoma look like? How do you know to biopsy it?
Dr. Bruce H. Thiers: Well, first is the location. All skin cancers are related to sun exposure and the vast majority of them are seen in sun exposed areas; for example the face and the arms. Basal cell carcinoma looks like a pearly papule. It looks a lot different from many of the benign lesions we see in the skin and it often has some dilated blood vessel overlying it, which we call telangiectasia.
Dr. Linda Austin: Describe that a little bit more please?
Dr. Bruce H. Thiers: Well, what does pearly mean? Pearly mean shiny like a pearl. Basal cell often has a shiny appearance almost the translucent appearance as opposed to be many of the other benign lesions we see on the skin, which tend to be brown and scaly.
Dr. Linda Austin: And papule -- what does a papule look like?
Dr. Bruce H. Thiers: A papule is any elevated skin lesion. If you run your hand along the skin and you can feel the lesion, then it’s a papule, which simple again means that it is elevated above the surface of the skin.
Dr. Linda Austin: So, how often should a person take a look at their own body, a beloved one, take a look or have their physician take a look to see if they might have a basal cell carcinoma?
Dr. Bruce H. Thiers: That’s actually an excellent question and it probably depends on number one, the degree of sun exposure you have had in your life. Number two, whether you have a family history of skin cancer. In patients, who have never had a skin cancer and do not have excessive sun exposure, probably a yearly examination by their primary care physician is sufficient. On the other hand, if they have had a great deal of sun exposure, either occupational, or recreational, or they have a personal or family history of skin cancer, they probably should come in either yearly or twice yearly for examination by a dermatologist.
Dr. Linda Austin: Now, if these lesions then -- these basal cell carcinomas don’t spread to distant sites or metastasize, why do they cause problems? Why do they have to be removed?
Dr. Bruce H. Thiers: Like any cancer, basal cell carcinoma exhibit unrestrained growth and if not excised, they will continue to grow on the skin and eventually ulcerate. Even more importantly, basal cell carcinomas in certain critical locations such as the eye, around the ear, or really anywhere on the face can cause these figuring sores either from their own growth or secondary to the surgery, the excision that’s necessary to remove them. Any skin cancer whether it would be basal cell carcinoma or any other skin cancer is much easier to remove when it’s small than when it’s large and any skin cancer, if allowed to grow can become a real problem down the road.
Dr. Linda Austin: So, in another words you are going to have to get it taken off sooner or later and it is much smarter to do when it’s small.
Dr. Bruce H. Thiers: Exactly, many people know that something is amiss, but they weren’t denial and they let these lesions grow to the point where they really have to have aggressive surgery to remove them and I think patients who has skin biopsies as long as 20 years ago and don’t have these tumors removed and they didn’t, and when they come in, these tumors are really quite large.
Dr. Linda Austin: What’s the largest, you have seen?
Dr. Bruce H. Thiers: I have seen a single basal cell carcinoma covering the whole back and one covering whole face.
Dr. Linda Austin: Let’s take the more common scenario of a small basal cell carcinoma that’s may be half an inch in diameter or a quarter inch in diameter. After you have surgically removed it, does the person need to be treated?
Dr. Bruce H. Thiers: The first procedure we do on a suspected skin cancer is a biopsy and a biopsy by definition is removal of a small piece of the lesion in order to send some skin to the pathologist to get a diagnosis. Once the pathologist diagnoses basal cell carcinoma, the question remains what’s the best way to treat the lesion that remains? Depending on where it is, we may recommend what we call simply curettage of the lesion, which means we scrape it off with a curette. We may recommend excision of the lesion with sutures, we may recommend micrographic surgery, in which the lesion is taken off in layers with each layer checked under the microscope or we may recommend a topical therapy, a cream called Nicomide that has some curative powers in terms of getting rid of basal cell carcinoma. The treatment has to really match the lesion. Any basal cell carcinoma near a vital structure such as the eye, the ear, or the mouth is usually treated by micrographic surgery because we really need as much assurance is possible that the whole lesion is removed without any residual, which could cause recurrence. Lesions in less critical areas such as the back are sometimes treated non-surgically with a topical cream that I mentioned called the Nicomide because here even though the cure rate is less if the lesions reoccurs down the road, we can always excise it at that time. So, the treatment is really designed to match the location and the size of the tumor.
Dr. Linda Austin: Now, you mentioned earlier that like other skin cancer basal cell carcinoma is associated with sun exposure. How long does it take that process to unfold? Let’s imagine a child who has spend a lot of time at the beach, what’s the youngest age then that you might first start to see basal cell carcinomas?Bruce H. Thiers:Well, in the south as opposed to a higher latitudes, we often see basal cell carcinomas in young people especially women in their twenties. It is thought that the -- what we call the incubation period. It is thought that the incubation period for basal cell carcinoma is probably 10, 15, or 20 years and stated differently what this means is that when we see skin cancer develop, the patient is probably paying the price of their indiscretion with the sun one or two decades previously. We often see patients who are middle aged, who say they have stayed out of the sun since they were teenagers, who developed many skin cancers and it’s exactly that sun exposure as a teenager that they are probably paying the price for later in life.
Dr. Linda Austin: So, then it must be a very slow growing tumor if evidently the damage is done pretty early and then it just takes that long to come to for a vision. Why does it take so long from that excessive sun exposure for the basal cell carcinoma to show up?
Dr. Bruce H. Thiers: Well, that probably has to do with a lot of more scientific concepts such as initiation and promotion of tumor growth. The sun exposure probably initiates the process towards the development of the tumor and there may be other factors later in life that actually promotes the growth of the tumor. So, again, if you were a real beachcomber when you were a teenager that may kind of plant the seed for the tumor, which evolves one or two decades later as what we recognize as a basal cell carcinoma.
Dr. Linda Austin: Dr. Thiers, thank you so much for talking with us today.
Dr. Bruce H. Thiers: My pleasure.
Announcer: If you have any questions about the services or programs offered at the Medical University of South Carolina or if you would like to schedule an appointment with one of our physicians, please call MUSC Health Connection at 1-843-792-1414.