PARDON ME FOR BEING THE SKUNK at your summer picnic, but as you’re enjoying the sun on your face, remember that overexposure to ultraviolet-B waves accounts for about half of all diagnosed cases of cancer each year. That’s one million cases of basal cell, squamous cell, and melanoma malignancies, and Texas, for obvious reasons, routinely ranks among the top three states (with California and Florida) in incidence of these. The most lethal, melanoma, took the lives of nearly eight thousand Americans and more than four hundred Texans last year and is only increasing in prevalence. This is too bad: Most skin cancers can be successfully prevented and self-monitored. You’ve just got to know a mole from a melanoma. Here’s your last-chance guide before the dog days set in.

Know your ABCD’s—and E’s. Most of your moles are going to develop in your first two decades of life; treat any that appear after that with suspicion. Think like a five-year-old and employ what the American Cancer Society calls the ABCD’s of mole examination: A stands for a melanoma’s asymmetry; B for its borders, which tend to be irregular rather than smooth; C for its variegated color; and D for a diameter greater than six millimeters (one-fourth inch), larger than the average mole. Moreover, says Ronald Rapini, the chairman of dermatology at M. D. Anderson Cancer Center, in Houston, you should add an E for evolution: While regular old moles don’t grow, melanomas do—first horizontally and then vertically, up from the skin and down into it, which is how the cancer becomes systemic and lethal.

An equal-opportunity cancer. Unlike most cancers, melanoma develops in adults in their twenties, thirties, and forties just as often as it does in the elderly; in fact, it is a leading killer cancer in the younger age groups. And only an estimated 10 percent of the cases are hereditary.

Sometimes a mole is just a mole. While only a third of melanomas start with a preexisting mole, people who are particularly “moley,” with, say, one hundred moles or so (the average is fifteen to forty, a Jeopardy question if there ever was one), or who have a profusion of dysplastic nevi (irregularly shaped moles) should have them checked more often and removed if necessary.

Get personal with yourself. Do self-exams, and check everywhere. Melanomas have been known to show up where the sun don’t shine, like on the bottoms of feet or under arms.

So how much sun is too much? Some dermatologists swear that there’s no such thing as a good tan, period. But no one wants to live like a bat in a cave, and according to some recent research, we need a daily modicum of sunshine—fifteen minutes or so—to maintain proper levels of vitamin D (which, ironically, is believed to be an endogenous defender against cancer). Your best bet? If you’re out long enough to get burned, that’s too long.

Swear by your sunscreen. It’s the average sun worshipper’s best defense against UVB rays. Stan Taylor, a professor of melanoma education and detection at the University of Texas Southwestern Medical Center at Dallas, advises an SPF of at least 30 if you’re fair-skinned. And, he adds, “Put on enough to change the color of your skin. Then let it sink in for fifteen minutes before you go out.”

Magic Bullet Watch:
A vaccine for melanoma?

A vaccine for melanoma has been a holy grail for skin cancer researchers for decades. Now there’s hope for a successful one at the Baylor Health Care System of Dallas’s Institute for Immunology Research. Under the direction of Jacques Banchereau, scientists there have developed a way to train a melanoma patient’s dendritic cells—white blood cells that direct the immune system’s response to various pathogens—to focus the immune system’s arsenal of antibodies on the malignancy. Of twenty patients with metastatic melanoma (presently a death sentence) treated two years ago with such a personalized vaccine, two are in remission and ten are still alive. Baylor officials are so encouraged by the concept that the center has created a biotech company, ODC Therapy, to further develop and ultimately produce and market the vaccine.