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Skin cancer is the most common cancer among adults in the United States. “Skin cancer, no matter whether it's a small lesion on the nose or has spread to the liver, is often challenging to treat because of the location, size or shape of the tumor, or what it connects to,” says Roy Decker, MD, PhD, a radiation oncologist at Yale Medicine's Department of Therapeutic Radiology. “But if you have the appropriate arsenal of tools, then you can be very successful in treating skin cancer.”

Yale Medicine physicians, including the therapeutic radiology team, have both the specialized skills and advanced tools to effectively treat a full array of skin cancer conditions, from the simplest to the most complicated.

What are the types of skin cancer?

There are three major types of skin cancer, the most common of which are basal cell carcinomas and squamous cell carcinomas. Basal and squamous cells are types of cells in the skin’s top layer, which is known as the epidermis.

A less common type of skin cancer is melanoma, which forms in skin cells that produce the skin's pigment, called melanocytes. While much rarer than basal cell and squamous cell carcinomas, melanoma is much more deadly.

While basal and squamous cell carcinomas and malignant melanomas make up nearly all cases of skin cancer in the United States, there are other, even more rare forms of the disease, such as cutaneous T-cell lymphoma and Merkel cell carcinoma.

What are risk factors for skin cancer?

For basal and squamous cell carcinomas, as well as for melanoma, the major risk factor is exposure to ultraviolet (UV) light from sunlight and other sources, such as tanning beds. Other risk factors include having fair skin, being older in age and being male.

How is skin cancer diagnosed?

Typically, a skin cancer diagnosis begins with a visit to a dermatologist, a doctor who specializes in treating skin diseases. The dermatologist examines the skin and reviews the patient’s personal and family medical history.

The only way to definitively diagnose skin cancer is through a biopsy, which is an examination of a sample of suspicious tissue. The dermatologist usually can collect the sample quickly and easily during the skin exam at his or her office. 

The tissue sample from the biopsy then goes to a lab and is analyzed by a pathologist who specializes in identifying cancer cells.

How is skin cancer treated?

Due to effective skin cancer screening and a heightened awareness of the disease, most lesions caused by basal and squamous cell carcinomas are detected at a very early stage. Dermatologists generally remove those abnormalities with quick, minor surgery at the office, and often that is the only treatment needed.

A frequent technique dermatologists use is called Mohs surgery, where layers of skin are removed one by one and then instantly examined for cancer cells, a process that continues until the first cancer-free layer is found. 

Other treatments for basal and squamous cell carcinomas include photodynamic therapy (which uses light to kill cancer cells) and medicated creams.

Some early-stage melanomas are also successfully treated with surgery alone. Beyond surgery, treatments for this most serious form of skin cancer include immunotherapy (in which medicines are given to stimulate the patient’s immune system), chemotherapy, and radiation therapy.

In what ways is radiation used for different skin cancers?

In a select group of patients with basal and squamous cell carcinomas, radiation may be used as an alternative to surgery. This group includes people whose tumors are in places where surgery would be difficult—for example, in the corners of the eye, in the nostrils or on an earlobe. Additionally, some patients may be too frail, or otherwise unsuitable for surgery (due to a medication they are taking, for example). For patients with advanced basal or squamous cell carcinomas, radiation may be used after surgery to help ensure that the cancerous cells have been killed.

In patients with melanoma, radiation is mostly used for those with metastatic disease, meaning cancer that has spread from the skin to other parts of the body. These patients may be treated with radiation as a palliative measure, meaning to relieve pain and/or other symptoms (as opposed to eliminating the underlying cancer). Other melanoma patients may receive radiation in conjunction with immunotherapy.

With particular expertise in using radiation to treat rarer, more aggressive forms of skin cancer, Yale Medicine receives a large number of referrals for treatment. “We see a lot of rare tumors,” says Dr. Decker. “There are only a few hundred of some of these types of tumors diagnosed per year in the United States, but because we’re a large referral center, we see and treat a large number of them.”

How is a radiation treatment plan determined?

Several techniques are used to treat skin lesions, and the decision on which to select is largely determined by tumor size, shape and location. “Very often, there is one best way to treat a patient,” Dr. Decker says, “but sometimes, we can present a few different treatment options, and in those cases we discuss the choices with the patient in order to incorporate his or her priorities in the decision-making process.”

Each patient’s particular case also determines the amount of radiation used, as well as the the frequency of treatment sessions. “Treatment could involve a single one-hour session, or daily 15-minute sessions five days a week, for six or seven weeks,” Dr. Decker says.

What are potential side effects of the radiation therapy?

The main short-term side effect patients experience during any form of radiation therapy to treat cancerous skin tumors is skin irritation and redness at the treatment area. “Effects range from nothing at all to the appearance of a severe sunburn,” Dr. Decker says. Irritation would be confined to the treatment area, would not cause problems elsewhere in the body and would heal soon after treatment ends.

Long-term side effects of radiation also vary. Some patients do not have any, while others may experience subtle skin changes making the skin in the treated area feel different to the touch. Sometimes, months or years after therapy, patients develop additional scarring of the skin, making it fibrous and less stretchy.

What makes Yale Medicine’s approach to treating skin cancer unique?

Yale Medicine’s equipment and expertise are highly advanced, and the clinical practice receives referrals from radiation centers across the region. “We have accumulated a lot of technology specifically to treat skin cancer, and I think that has made our program much more valuable,” says Dr. Decker. “Much of this technology is not available in smaller community hospitals, where it wouldn’t make sense to own such specialized equipment because there aren't enough cases on which to use it.”

Additionally, skin cancer cases at Yale Medicine are treated by a multidisciplinary group of doctors including dermatologists, surgeons, plastic surgeons, dermatopathologists, medical oncologists and radiation oncologists. "We are one of the few institutions in the country that have a tumor board devoted solely to skin cancer," says Dr. Decker. The team discusses skin cancers, including melanomas and even rarer types, at group meetings and collaborates to devise the best treatment plan for each patient.

Yale Medicine has a world-renowned melanoma program that leads the way in treating this form of skin cancer and breaks ground in new treatment areas. “There is a large amount of research here devoted to melanoma,” Dr. Decker says. “And there are a lot of exciting things happening, such as clinical trials in skin cancer, which is quite unique. We have a lot of experience with which to work."