Melanoma has a long memory. Quite often, it is the delayed consequence of sunburns or repeated, intense sun exposures experienced as a child or teen — the coveted golden tan of youth come back to haunt.
Early sun exposure (ultraviolet radiation) can damage the DNA in skin cells called melanocytes, which give our skin its pigment or coloration, igniting and driving a process of mutations and malignancy many years later, with subtypes characterized at the molecular level by novel signatures of mutagenesis, some unrelated to sun exposure.
It typically occurs on parts of the body chronically exposed to sun, such as the arms, neck and face, but melanoma can grow or spread anywhere, from the skin beneath fingernails to the soles of feet; inside the mouth, the genitals, even the gastrointestinal tract.
The tell-tale clue is most often an irregular mole or bump or suspect patch of skin. Discoloration varies widely: black, brown, red, sometimes no color at all. Detected early, before it has spread, superficial melanomas can be relatively easy to treat with minor surgery and/or radiation. The prognosis is usually good, though the threat of recurrence is real and lifelong vigilance is essential.
Melanoma is the least common of skin cancers, but by far the most serious and the incidence is increasing faster than any other cancer. Most skin cancer deaths are due to melanoma, roughly 10,000 a year, two-thirds of them men. Survival depends greatly upon the stage of cancer at diagnosis and to what the degree the malignancy has spread to other parts of the body. A very early stage melanoma isolated to where it began has a 5-year survival rate of more than 98 percent, which means 98 percent of patients will still be alive five years after diagnosis. But if the melanoma has spread to nearby lymph nodes, the rate drops to 62 percent. If it has spread to other parts of the body, 5-year survival falls to 18 percent.
These are stark and sobering statistics, but they are not immutable. For example, the latter 18 percent figure is with traditional therapies, but the survival rate for people with metastatic melanoma has increased to 69 percent with combined immunotherapies now being offered at certain NCI-designated centers, such as Moores Cancer Center.
• Treatment advances
In recent years, treatment options for melanoma have expanded across the entire spectrum of this disease and new ones have emerged. There has been progress. It begins, appropriately, with advances in detection. Dermascopy employs a high-powered microscope to non-invasively examine lesions and other spots on the skin, boosting the accuracy of diagnoses without requiring multiple biopsies. CT scans can be used to look at internal soft tissues and organs, including assessing whether lymph nodes are enlarged, a possible sign of spreading melanoma. Genetic testing can add further information about a patient's risk of melanoma or help inform doctors about how best to proceed with treatment.
Surgery and radiation remain the most effective treatments when appropriate. If a melanoma is more advanced or has spread, adjuvant therapies may be required. Immunotherapy stimulates the body's natural immune response, to help it do the work of unmasking and killing cancer cells. As with other forms of cancer, there are new and developing immunotherapies for melanoma.
Several immune checkpoint inhibitors that block different proteins on immune cells have been approved by the FDA and are game-changers for some patients with advanced melanoma. Therapies based upon interferons, a group of signaling proteins involved in triggering a general protective immune response, can be used to delay the recurrence of melanoma in certain settings, such as tumors with ulceration.
Patients undergoing immune therapy can have serious side effects and need to be monitored closely during treatment. Newer immunotherapies are in the offing. Many are still in clinical trials, but with promising results. Indeed, Greg Daniels, M.D., Ph.D., a medical oncologist and professor of medicine at Moores Cancer Center who specializes in melanoma and immunotherapies, is principal investigator on four on-going trials.
Additionally, Sandip Patel, M.D., is a medical oncologist and assistant professor at Moores Cancer Center who specializes in novel immunotherapeutics across tumor types. He is principal investigator on a half dozen clinical trials of drugs targeting novel immune pathways of treat advanced melanoma.
Later this year, Moores Cancer Center will be one of the handful of places in the country where patients can receive cellular immunotherapy — a process by which a patient's own immune cells are selectively augmented outside of the body for their anticancer properties and reinfused back into the patient. A similar process has proven successful in treating certain leukemias.
Some of these approaches help the body's immune cells more effectively seek out cloaked cancer cells or inhibit mutated or activated genes linked to melanoma. Researchers continue to look for ways to make existing drugs work better with fewer side effects, often through new combinations of treatments.
On Aug. 13, cancer survivors and cancer research supporters will gather for the 24th annual Luau and Legends of Surfing Invitational on the beach below Scripps Pier. It's a festive occasion that includes a surfing competition and Polynesian dancing, music and food. It's also a long-standing fundraiser for Moores Cancer Center — more than $7 million has been raised over the years.
I hope to see some of you there. I'll be wearing the sunscreen.
• SURFING FOR A CURE: Cancer survivors and research supporters will gather for the 24th annual Luau & Legends of Surfing Invitational, Sunday, Aug. 13, 2017 on the beach below Scripps Pier. A surfing competition starts at 7 a.m. and then the luau follows with Polynesian dancing, music and food at 11:30 a.m. It's a long-standing fundraiser for Moores Cancer Center. Tickets at luauandlegendsofsurfing.org
— Scott M. Lippman, M.D., is director of UC San Diego Moores Cancer Center. His column on medical advances from the front lines of cancer research and care appears in La Jolla Light once a month. You can reach Dr. Lippman at email@example.com