From Basal Cell Carcinoma to Melanoma: What to Know About Skin Cancer

Skin cancers range from potentially lethal, in the case of metastatic melanoma, to far more common skin cancers, such as squamous cell and basal cell carcinomas, most of which are detected early and removed. Early detection is one of the best defenses against skin cancer, while prevention is the best overall.

“I tell people it should be like brushing your teeth in the morning—make sure you're getting sunblock on,” says Kelly Olino, MD, a Yale Medicine surgical oncologist who specializes in treating skin cancer at Yale Cancer Center and Smilow Cancer Hospital.

In addition to applying sunblock of SPF 30 or higher, and reapplying every two hours, Dr. Olino advises having a dermatologist examine any concerning lesions or moles.

“If you're [someone] who notices something that started off small and innocuous, marble-like, and you're looking at it a month, or a few months, later and you say, ‘Man, this has doubled in size,’ or there really is a change in the color pattern, those are the ones you really need to get in and see the doctor about,” she says.

Even clinicians with decades of experience assessing skin issues still need to get a biopsy analysis to determine if a suspicious lesion is cancerous, making it all the more important to seek attention for any concerns about a change in a skin lesion.

Dr. Olino considered more skin cancer questions and offered answers.

Skin cancer is the most common cancer worldwide.

A lot of that is due to lower-risk skin cancers such as squamous cell cancer and basal cell carcinoma. The overwhelming majority of these are taken care of locally by your dermatologist, sometimes even by some primary care doctors. Most of these carry a good prognosis and are local problems that get dealt with in a small procedure where the lesion is removed. It's difficult to track the numbers, or to see trends, for these nonaggressive skin cancers because so many people just take care of them in their local doctor’s office.

For more serious issues such as melanoma, merkel cell carcinoma, and cutaneous sarcomas, those are usually treated by a more specialized group of clinicians, so it's easier to track that incidence rate.

Of skin cancers, melanoma is the one people worry about the most. “In situ” means it is very early stage and that the cancerous cells are confined to the outer layer of the skin and have not penetrated lower layers of the skin.

For invasive, more dangerous melanomas, we're looking at anywhere from about 90,000 to 100,000 people who will get a new diagnosis of an invasive melanoma in this country annually. And we think, although it's not tracked as closely, a similar number of people will get a noninvasive melanoma diagnosis, which is melanoma in situ.

If you look at the layers of our skin, there are two. A more superficial layer that we look at all the time, that is called our epidermis. That’s the location—the surface of the skin—of in situ melanoma.

Cells that turn into invasive melanoma are deeper in the skin, in the layer called the dermis. That's the layer where we have blood channels and lymph channels that allow the cancer to spread.

We're not sure exactly how many melanomas in situ would turn into invasive melanomas. I tell my patients that, frankly, we're not smart enough yet to know that if we left these atypical cells alone, whether they would be OK. Or would it be 10 years later, or a year later, that they would transform? That's hotly debated.

But I have not yet met a patient who wants to enroll in a 20-year observation program to see what happens. Most doctors just recommend that we remove the melanoma in situ and eliminate any risk for the patient.

So many people have these lesions (that can look like a red, scaly spot, or even like a wart), and thankfully a very small proportion of squamous cell cancers are aggressive. But they should be checked out.

There are some people who are, frankly, a bit ashamed that they let something get to be the size that it is. We always want to greet those patients with a big “thank you for coming in and seeing us.” As a surgeon, those are some of the most rewarding people I get to take care of because it can take a lot of courage for them to come in, and their surgery could be life-changing.

Use the acronym ABCDE for what to watch for. Look for lesions that are asymmetrical, or with blurred borders, and with a difference in the color, and a growing diameter. See if it’s bigger than the tip of a pencil eraser, if it’s evolving. Evolution is the most important, as in something that is changing over three months and if it's growing, changing either in color, or how it feels, or if it’s more raised. I think those are really the most important characteristics that help us determine whether it requires a biopsy to determine if it’s cancer.

Again, most of these cancers are fairly noninvasive. But the only way we can diagnose it is underneath a microscope with the assistance of a pathologist.

At this point in my medical career, I’m pretty good. If you asked me the same question when I was a medical student, the answer would be ‘I’m terrible at that.’ But you learn to recognize the patterns over time. It’s best to have something checked if you are concerned; don’t make an assessment yourself. Dermatologists know when to biopsy and remove it or when it’s OK to leave it alone.

Anytime a patient's worried and advocating for themselves, it should warrant more discussion. There's been some work on combining primary care practices with tele-dermatology to assist in decision-making.

Yes, for smaller areas, such as melanoma in situ.

Sometimes melanomas can actually take over quite a large area. We have a patient who has one that encompasses nearly the entirety of the top of the scalp. These can be cosmetically challenging. They can also then lead to some deformity if really left unchecked for long enough, even though it may not have a risk of spreading to other organs.

Mohs surgery is a combination of surgery done by a highly trained dermatologist who’s able to look underneath a microscope, in real time, to determine all of your cancer margins to ensure that all of it is removed. For squamous cell and basal cell, that's something that can be done quickly, on site, at your Mohs surgeon’s office.

It's much harder to do for melanoma in situ because that requires a special stain for the melanoma cells, and that's not done instantaneously. It can take a longer portion of the day.

For thinner melanomas, right now our standard is to take an extra centimeter around from where we think that the melanoma has ended. But we go all the way down to the casing of the muscle, which we call fascia, because we want to make sure we're also clearing the channels within the skin that can go to lymphatics and the fatty tissue. And we want to sample those. We do the same thing for Merkel cell cancer.

For melanoma, we actually have an open trial now that’s looking to see, for thicker melanomas, how much of a margin we need to take. Historically, we started at five centimeters for all melanomas. And we've gotten down to either two centimeters or one centimeter.

And we're currently studying, with the MelMART clinical trial, whether we could do one centimeter for all melanomas. If you have the same end result in terms of survival outcomes and you actually have less of an area removed, it means easier healing, less need for flaps, skin grafts, and so forth. Again, we would want to choose the lesser margin if everything is equal because it's less invasive to our patients.

Yes, that standard was not based on the best data from some time ago. That's why these randomized clinical trials are so important. It was someone's best guess at the time and, thankfully, as we use evidence-based medicine, we get smarter and get better data.

If we're doing surgeries on the fingers, toes, face, or scalp, those are much, much more likely to require assistance of a plastic or reconstructive surgeon because there's less tissue that can be easily moved around. It's much more rare to need the assistance of a plastic surgeon if we're operating on arms, legs, back, or chest, just because we have a lot more flexibility. And again, we still do a beautiful reconstruction for the patient.

For people who have thicker melanomas or a risk that we've deemed to be more than 10% based upon their initial skin biopsy results, we still do recommend that patients undergo a sentinel node biopsy. It’s done by identifying, removing, and examining the sentinel, or first, lymph node for cancer cells. The surgery tells us if cancer has spread from a primary tumor, or lesion, to the nearest lymph nodes.

We have gold-standard clinical trial data that tells us how important it is for your prognosis to know the status of the lymph node. And for now, that means sentinel node biopsy. It is an operation, so it's a discussion that's really important to have with patients.

Side effects are related to surgical trauma to surrounding tissue—swelling, some fluid accumulation. We do worry, similar to breast cancer patients, about something called lymphedema. That's severe swelling that could be permanent when we alter the lymph node. For a sentinel node, typically that risk is somewhere about 2% to 3%. Thankfully, those risks are small.

This Q&A was adapted from Connecticut Public Radio’s “Yale Cancer Answers,” a weekly program that shares information on the latest cancer breakthroughs and treatments through conversations with experts from Yale Cancer Center.