Melanoma Knowledge Starts With Dermatologists, Expert Says

Christopher R. Shea, MD

The eighth edition of the American Joint Committee on Cancer (AJCC) Cancer Staging System is going into effect January 1, 2018, with the goal to educate clinicians on 12 new staging systems and revised staging definitions—an area likely to help physicians treating patients with melanoma.

The updated AJCC edition, as well as other changes in the melanoma field, should be absorbed beyond researchers, experts say. Dermatologists and pathologists must also familiarize themselves with the evolving landscape, especially for their patients.

“It is important for dermatologists to know more than only about the skin aspects, because many patients will view their dermatologists as their primary care physician for their melanoma,” explained Christopher R. Shea, MD. “It is important to know something about the revolution in the molecular biology of melanoma. Obviously, we are not in a position to perform—in most cases—the sentinel lymph node surgeries or to prescribe and manage these checkpoint inhibitors and so forth. But, we need to know about them.”

OncLive: What did you discuss on your lecture on pathology in melanoma?

Shea, the Eugene J. Van Scott Professor of Medicine, chief of the Section of Dermatology at The University of Chicago Medicine, discussed the pathology and dermatologic management of melanoma during the 2017 OncLive^® State of the Science Summit on Melanoma and Immuno-Oncology. In an interview during the meeting, he expressed the importance of expanding melanoma knowledge to more specialists as well as the advancements in pathology over the last several years.Shea: Pathology is actually extremely important because that’s where it all begins; that is how we get the diagnosis. More importantly, we can also get a lot of information about prognosis. We get the diagnosis, which is what it is, and prognosis, which is what it may do.

What advances have we seen in pathology over the last few years?

What are the biggest differences between the seventh and eighth editions?

Over the years, pathologists have developed a more refined understanding of what to look for under the microscope to get that information, which is used for staging. Clinical and pathologic staging dictates the treatment, and it’s also very important for predicting survival.Most importantly, there’s going to be a new AJCC Cancer Staging System that’s actually being published now; it’s in a period now in which we’re learning about it and people can get ready for it. It will be in effect in January 2018. This incorporates some changes from the seventh edition. Again, it has to do with particulars of the pathologic changes, like the importance of the mitotic figures and the ulcerations in the tumors.Most importantly, it has to do with thin melanomas—which were thought to be 1 millimeter or less. They were thought to be stage Ia unless they had either mitotic figures or ulcerations. The presence of either or both would upgrade the disease to stage Ib, which means that it is a worse prognosis. It is still stage I, but it’s a worse subset of that.

What major questions still exist with staging melanoma?

It’s been discovered that the mitotic figures, although they’re still very important, are not the best way to classify the staging. Therefore, that’s actually been dropped as a criterion for stage Ia and stage Ib. After only being in the AJCC classification for one go around—the previous edition—it’s now been dropped. Instead, they are looking at 1-millimeter thickness but also 0.8 millimeters as a breakpoint. The point of this is that, previously, very thin melanomas that might have had 1 mitotic figure were automatically considered to be a higher risk and undergo sentinel lymph node biopsies. It was very rare that those were found to be metastatic melanomas. That is the rationale for that change.As with all kinds of staging, staging is a general prediction for a population and not for a single individual patient. There is always an element of probability to it. The refinements we’re going to see going forward will likely be related to novel markers of the biology of the tumor that hopefully are going to be validated. However, right now, they are still not reflected in the official staging classifications.

You also spoke on dermatologic management of melanoma. What is important to note here?

There are molecular kinds of characterizations of individual patients’ tumors. Those same kind of molecular characterizations are going to be very important for directing therapy as we go forward.I am actually both a dermatologist and a pathologist, which is not that rare of a combination. As clinical dermatologists, we use our pathologic knowledge to imagine what’s going on under the surface. The dermatologist actually has a very critical role in melanoma; although not in the management of metastatic disease, but they are kind of the gatekeepers of the entry point for a lot of patients.

We have several rules. One is to diagnosis melanoma in its earliest stage, when it’s confined to and presenting in the skin, because that’s the stage in which it can be cured—in most cases.

After the diagnosis of melanoma, we also have a very important role in monitoring for local recurrence of tumor within the skin or within the lymph nodes. It is also very important to look out for secondary primary melanomas. This is simply because having 1 melanoma does increase the risk of another one independently.

There is a very important role in terms of early surgical management and, most importantly, diagnosis and monitoring. But, we also have a major role for education because patients come to us with concerns about melanoma. Oftentimes, we can allay that concern, or we sometimes have to confirm the concern. However, in doing so, we can educate the patients and their families. Sometimes, the families will require screening, as well.

We can certainly educate the community, too. It’s interesting; now, there is probably greater interest in educating other kinds of skin care providers aside from doctors and nurses. This includes beauty parlors, barbershops, and—yes—tattoo artists, as well. All of them are kind of serving in the area of the skin and should know something about how to recognize melanoma and to simply refer them to a professional who would be able to handle that.

What advice can you give to dermatologists on discussing a potential diagnosis of melanoma?

A goal of the education is prevention, because prevention is much better than cure in this case. These include things like practicing safe sunscreen usage, avoiding sunburns, and certainly avoiding tanning salons. In Illinois, we are very proud as dermatologists that, because of the Illinois Dermatologic Society, the state outlawed the use of tanning salons for minors as has been done elsewhere. This is because this young skin is particularly susceptible to the effects of those rays, which are carcinogenic and involved in melanoma formation.One never wants to say it without the pathologic diagnosis, which sort of brings the circle around to where we started. That is collaboration between the clinician and the pathologist. It is most important for the dermatologist to give the pathologist the correct specimen.

What ongoing research in this field are you excited about?

I always would tell the patients to await the pathology report. I’m happy to say that most of the patients we see in dermatology can be cured and have an excellent prognosis. We have the much more fortunate side of the disease spectrum to deal with because we are in a position to see many cases that are in the early, curable stage.The most important ones have to do with the checkpoint inhibitors. These very powerful drugs are showing remarkable changes in survival.

I’ve seen 2 revolutions in medicine in my career over the last 40 years. The first was the HIV/AIDS epidemic where we had a disease that was uniformly lethal and extremely miserable that is now manageable. Many people are living for decades with HIV disease. The hope is that the same is coming true for melanoma.

Examine the skin; it’s the unknown, unseen organ. It’s hard to believe because it is hiding in plain sight. A lot of general practitioners—not dermatologists in the community—don’t have much dermatologic knowledge. You don’t need to know that much in order to know when to refer. We wouldn’t expect anyone to get far out on a limb to making decisions they’re not comfortable with. But, understanding the basics of morphology and the appearance of skin lesions can go a long way toward a sense of basic confidence.