It’s summertime! And we humans naturally want to spend more time
outdoors. While it’s tempting to underestimate your chances of getting
skin cancer, it happens to be the most common type of cancer in the United States.
According to the American Cancer Society (ACA), more people are diagnosed
with skin cancer each year than all other cancers combined. “One
in five Americans will develop it by the time they are 70,” says
Torrance Memorial Physician Network primary care physician Kalpana Hool, MD.
Although many cases of skin cancer are detected early and treatable, the
ACA estimates 7,230 people will die of melanoma in 2019. We asked Dr.
Hool to explain the causes, risks and prevention of skin cancer.
What causes skin cancer?
Dr. Kalpana Hool: Ultraviolet radiation from the sun—UVA and UVB
rays—causes skin damage and eventually can lead to skin cancer.
One of the most damaging activities is the use of tanning beds, which
have high concentrations of UV radiation. You have about a 60% higher
risk of all types of skin cancer with a history of regular tanning bed use.
Family history of skin cancer, fair skin, a history of severe sunburn especially
at a young age and multiple moles are all risk factors. A person’s
risk for melanoma—the deadliest type of skin cancer—doubles
if you have had more than five sunburns over your lifetime.
And organ transplant patients are especially at risk. They have weakened
immunity because of the anti-rejection medications they take, so they
have to be very careful in the sun.
Are there different types of skin cancer?
KH: Yes. The most common type is basal cell skin cancer, which affects
more than 4 million Americans annually. These cancers look like little
pink pearls, raised spots, in sun-exposed areas such as face, back of
hands and neck. The majority of basal cells are treatable and curable
if detected early enough.
The second most common is squamous cell, which affects approximately 1
million a year. These usually appear as a spot that’s scaly, grey
and ulcerated. They can bleed and often are painful. Again, they appear
in exposed areas such as face, hands and neck. If detected early they
are treatable and curable.
The least common—but most deadly—is melanoma. That’s
the scary one, and we expect about 192,310 cases of melanoma will be diagnosed
in the U.S. in 2019. The estimated five-year survival rate for patients
whose melanoma is detected early is about 98% and goes down to 24% if
it metastasizes to distant organs. This poor outcome is even an improvement
over just a few years ago.
Usually melanoma appears as a hyperpigmented mole that changes rapidly.
Most doctors use the ABCDE test:
A = asymmetrical—a dark, irregular spot in which the right side doesn’t
match the left.
B = borders—if the borders are irregular, it’s likely melanoma.
C = color—a mole that is dark but also has different colors within
D = diameter, or size—anything more than 6 mm, bigger than a pencil
eraser, is suspect.
E = evolving or changing—anything that changes month to month needs
to be evaluated immediately.
Are certain skin types more prone than others?
KH: Yes, we use the Fitzpatrick Skin-Type classification, which divides
skin into six types ranging from type 1, which is pale skin that doesn’t
tan and usually burns, up to type 6, which is a dark brown or black skin
with deep pigmentation. In general, types 1 and 2 are most at risk for
People with very dark skin have a lower risk, but they do get a type of
cancer—acral lentiginous melanoma—that is very dangerous and
appears in places where there is not sun exposure, such as the palms of
the hands, soles of the feet and nail beds, often as a dark streak in
the nail bed. I just saw two of these cases, and we know you have to act
fast and get diagnosed and treated quickly.
How can I prevent skin cancer?
KH: Skin cancer is all about prevention. There is a lot you can do. The
first emphasis is on the goal of reducing exposure to UV radiation by
avoiding direct sunlight. We recommend—especially for type 1 skin—not
going outdoors between 1 and 4 p.m. Best to do outdoor activities before
10 a.m. and after 4 p.m.
Avoid sunbathing and tanning beds. Wear broad-spectrum UVA and UVB sunscreen
with at least SPF 30 or greater. Even SPF 15 will block 93% of harmful
rays, but SPF 50 will block 98%. And reapply every two to four hours.
Use at least 1 teaspoon for your face and 2 tablespoons for your body.
Don’t forget your lips, especially those with fair skin. Special
lip balm can also block UV radiation.
Wear a broad-brimmed hat that covers your ears and back of neck; consider
SPF-rated clothing. And make sure to get an exam every year or if you
see a sore that is not healing. Most sores heal within a week, so if you
notice one that’s not healing or bleeds easily, it’s a concern.
Isn’t there a risk of vitamin D deficiency if I don’t get enough sun?
KH: UV radiation can cause damage within 15 minutes, so in general I don’t
recommend sunlight as the best source for vitamin D. People with type
1 skin don’t need much sun exposure at all to get the vitamin, and
skin that is more pigmented is less efficient so they have to be in the
sun much longer to absorb enough.
The recommendation is 600 to 800 IU daily and up to 2,000 IU per day for
those at risk for osteoporosis, so I believe in vitamin D3 supplements
if you are deficient (and most people are). A blood test can determine
that, and then work with your doctor. Vitamin D3 is fat-soluble, so you
should take it with food that has a little fat in it for better absorption.
What about smoking?
KH: There is some evidence that smoking leads to skin cancer; it certainly
ages your skin more quickly.
Is melanoma treatable?
KH: All skin cancers are treatable, but melanoma has to be detected early
and must be removed. If it has advanced, then the treatments include surgery,
radiation and immunobiologic therapy.
Has immunotherapy been successful?
KH: There have been significant advances with immunotherapy. It basically
stimulates the immune system and helps restore the body’s natural
defenses. These therapies can be used for other cancers as well.
Kalpana Hool, MD, is a primary care physician with the Torrance Memorial
Physician Network. She practices at 602 Deep Valley Drive Suite 300 in
Rolling Hills Estates. She can be reached at 310-517-4692.