When you know how to protect yourself, what to look for, and what to do if you see something unusual, you can reduce your risk
By Wendy Haaf
Had Carol H., now 57, not experienced a minor mishap while scuba diving during a Caribbean vacation in the early 1990s, she probably wouldn’t be alive today. On the last day of her holiday, the Montrealer brushed against something underwater. By the time she got home, she says, “I had this massive welt—it was like a grapefruit on my ankle.”
Though the dermatologist who saw Carol the next day didn’t explain, he urged her to undergo regular skin exams. Years later, Carol found out why: her skin is liberally sprinkled with moles, a trait linked with an increased risk for melanoma, a potentially deadly form of skin cancer. If not for that doctor’s suspicions, Carol likely would eventually have been diagnosed with late-stage melanoma. Instead, a mole that had started down that path was removed when its cells were severely abnormal but still precancerous, a stage at which the cure rate is nearly 100%.
“If I hadn’t had that infection on my ankle, I never would have gone to a dermatologist,” she says. The skin is by far the most common site of cancer—skin cancers account for about one-third of new cancer diagnoses in Canada each year, according to Health Canada. While the majority of the estimated 80,000 annual cases are non-melanoma skin cancers that are unlikely to spread to other parts of the body, these do have the potential to progressively invade surrounding tissue, resulting in the need for extensive surgery and the possibility of disfigurement.
Some forms carry a high risk for recurrence. And while melanoma affects relatively fewer Canadians—11,300 new cases annually—it’s one of just a handful of cancers that’s rising in incidence, with cases tripling over the past 30 years. Caught early, it’s highly treatable, with cure rates of 90% or more, but 1,300 Canadians die of the disease each year.
Typically attributable to accumulated ultraviolet (UV) exposure over many years, skin cancers can occur in the absence of risk factors such as a blistering sunburn during childhood and fair skin—Carol, for example, has a dusky complexion, has never burned, and has scrupulously protected her skin from the sun—and don’t always match the criteria for heightened suspicion, such as a spot having a diameter greater than six millimetres. “We talk about these UV-induced cancers being less common in patients with pigmented skin, but the risk isn’t zero,” says Dr. Marissa Joseph, medical dermatology lead at Women’s College Hospital in Toronto. She’s also an endowed chair in Ethnodermatology and an associate professor at the University of Toronto.
In addition, skin cancers can crop up in areas of the body that aren’t associated with high sun exposure, such as the soles of the feet. “People think skin cancers are easy to spot, but some are surprisingly subtle,” Joseph says. “I tell patients that skin cancer doesn’t read the textbook—it’s not always scary or dramatic, and the presentation can vary.”
You can, however, take steps to improve the likelihood of early detection and to moderate your chances of developing skin cancer, regardless of your age and level of previous UV exposure. “Knowing what to look for and how to protect yourself is important for everyone, but particularly for older adults because the risk increases with age, and that’s largely related to cumulative sun exposure over time,” Joseph says.
Here’s what you need to know, starting with a primer on the three main types of skin cancer.
Basal Cell Carcinoma (BCC)
You almost certainly know someone who has had basal cell carcinoma: it’s the most common skin cancer (and indeed the most common of all cancers in humans), accounting for approximately 75% of non-melanoma skin-cancer cases. Most prevalent among those 60 and older, BCC strikes an estimated one in eight Canadians over their lifetime. Typically slow-growing, it poses a very low—0.1%—risk of metastasizing (spreading to other sites) and is highly curable, with a five-year survival rate of nearly 100%.
However, BCC can invade and penetrate surrounding tissues—and the larger and deeper the lesion, the more extensive the surgery needed to remove it and a margin of healthy cells. In such situations, the procedure can pose a risk for disfigurement, especially when BCC arises on the face or head, which it does roughly one-third of the time.
In comparison to BCCs that start elsewhere on the body, those on these areas, when examined under the microscope, often show a more aggressive growth pattern. This is also true of BCCs located on the neck, feet, shins, or anogenital area.
BCC is also more apt than other skin cancers to arise in more than one place at the same time—in the medical literature, the proportion of patients with more than one primary BCC lesion ranges from 7% to 49%.
And even if you have it in only a single spot, there’s a sizable chance it won’t be your last encounter with BCC: the three-year recurrence rate after one BCC is about 44%.
“You don’t hear a lot about basal cell, because we just tend to cut it out and that’s the end of it,” says Dr. Yuka Asai, a dermatologist at Kingston Health Sciences Centre and associate professor and chair of the Division of Dermatology in the Department of Medicine at Queen’s University in Kingston, Ont. Or at least that’s the widespread public perception, since BCC doesn’t usually require treatment beyond surgical excision.
However, a BCC diagnosis “can be quite draining if you’re having many of them and they’re all in cosmetically and functionally very sensitive areas,” she adds.
Growing up in the Okanagan, Nicki Rooker of Penticton, B.C., never worried about sunburn, since her skin naturally darkened instead. “I spent a lot of time in the sun, and even as an adult, I would bake in the sun to get that perfect tan,” she recalls.
Sadly, that lack of burning didn’t translate into protection against skin cancer—a tan is visible evidence of UV damage. When a small bump appeared high on Rooker’s nose, near her eye, the lesion turned out to be a BCC. Rooker travelled to Calgary to undergo Mohs surgery, which removed all traces of cancer. (Mohs involves delicately removing a tumour one layer of skin cells at a time and checking it under the microscope for cancer cells before proceeding to the next step.)
Just two years later, Rooker’s hairdresser noticed a spot on the top of her head. “Automatically, my thoughts went to cancer,” she says. “I went to my dermatologist, and sure enough, that’s what it was.” Another Mohs surgery and 50 stitches later, Rooker again was cancer-free—until roughly three years ago. “Number three was on my cheek, just below my eye,” she says. “That one took another 50 plus stitches.” Fortunately, she says, thanks to her doctors’ skill, “you can’t even tell I’ve had surgery unless you look really closely.”
Squamous Cell Carcinoma (SCC)
Second in prevalence overall, “squamous cell carcinoma is the most common skin cancer in patients with brown or black skin,” Joseph says. And while sun exposure is one of the risk factors, “in patients with pigmented skin, SCC can also be associated with chronic wounds, such as ulcers that last a long time in people with diabetes,” she adds. “So if ulcers aren’t healing, squamous cell carcinoma is something to think about.”
Like BCC, SCC can invade surrounding tissue, although it’s unlikely to spread (the annual rate of metastasis is approximately 4%), and when it’s caught early, it’s treated successfully with removal in about 95% of cases.
Found most frequently on the face, neck, and backs of the hands, SCC is more common in men, older patients (particularly those who have weakened immune function, for example, due to taking drugs to prevent rejection of a transplanted organ), and people with a history of another type of skin growth called actinic keratosis (AK).
Also known as seborrheic keratoses or wisdom spots (“We affectionately call them barnacles on the ship of life,” Asai says), AKs may show up as patches of rough or scaly brown skin.
While the possibility that an AK lesion will develop into SCC without treatment is relatively low (2% to 10%), it’s not yet feasible to pinpoint which ones possess this potential, so the usual practice is to consider all of them precancerous and treat them as such. (The latter can be done in a variety of ways, including freezing them off with liquid nitrogen and using prescription topical medications that prompt the skin’s immune system to clear away the abnormal cells.)
Actinic keratoses, Joseph says, “are benign, and a single one has a very, very low risk of non-melanoma skin cancer. But if someone has many of them, that risk is additive, and it’s a sign they have had a lot of sun damage.”
Melanoma
According to a 2025 study by the International Agency for Cancer Research, more than 80% of cutaneous melanoma cases worldwide can be attributed to UV exposure. (Cutaneous melanoma is the most prevalent subtype of melanoma.) Risk factors include a blistering sunburn (even a single one) before age 20 and outdoor occupations (which are associated with a 2.5- to 3.5-fold increase in risk). à
More males than females develop melanoma—probably at least in part because, historically, most outdoor jobs have been held by men.
But despite the connection to UV radiation, melanomas can “arise in areas that are less sun-exposed, like the palms, the soles of the feet, and under the nails,” Joseph says, “especially in people with deeper skin tones or darker skin.” For instance, melanoma sometimes presents as a bruise-like mark or streak under a nail.
What to Watch For
You may already be familiar with the ABCDE checklist that past public-awareness campaigns have high-lighted as a guide to identifying possible signs of a spot being an early skin cancer: asymmetry, border (irregular, ragged, or uneven), colour (more than one shade or colour), diameter (greater than six millimetres), and evolution (changes over time). But since there are many different subtypes of skin cancers, and they can vary enormously in appearance—from pearly bumps and waxy scarlike areas to persistent sores or pimples that don’t heal and scaly patches that bleed—specialists like Joseph and Asai have moved to shorter, less confusing messaging.
“It can be distilled down to something changing, persisting, or looking different,” Joseph says. Asai uses a slightly different variation on that theme. “I like to teach people about what we call the ‘ugly duckling sign,’” she says. “Remember the old Sesame Street game—one of these things is not like the other? If you look at your body and there’s only one spot that looks like that, that’s the thing I want to see.
You don’t need special training or generative AI—you just need someone who’s looked at your back or your face before and says: ‘That thing is different. You didn’t have it before, and it doesn’t look like anything else.’”
(Experts recommend checking your skin monthly, ideally with a partner who can peer at places you can’t see yourself. Areas that are often overlooked include the scalp, ears, eyelids, lips, and backs of the hands.)
It’s worth noting that nowhere near all such spots will turn out to be skin cancers. Many actinic keratoses, for example, meet those same criteria. Your primary-care provider is a good resource to help sort out whether a lesion is potentially worrisome or not, Joseph says.
In the former event, he or she might remove a sample to be sent for testing or refer you to someone who is more comfortable performing such procedures—which might be another general practitioner. This strategy can help you get answers more quickly than if you try to get an appointment with a dermatologist, since Canada has only about 650 of these specialists (who also treat other serious conditions) for a population of more than 41.5 million. “A lot of this is figuring out access in your area,” Asai says.
Realistic Sun-Protection Strategies
Why go to the effort of protecting your skin now, since you can’t reverse the effects of UV exposure earlier in your life? “Sun protection at any age helps reduce further damage and lowers further risk,” Joseph says.
But if lowering your risk for a relatively uncommon deadly cancer isn’t motivation enough, consider the following. “If you photo-protect, you decrease the number of those precancerous lesions,” Asai says. That translates into fewer procedures to remove them. “Going to the doctor to get liquid nitrogen applied multiple times is unpleasant,” Asai says. “I tell people they may get some improvement just by staying out of the sun.”
While you can undoubtedly name the strategies for protecting your skin from UV exposure, figuring out how to integrate them into your routine may feel overwhelming or impractical.
Take recommendations to pursue outdoor activities during times when UV levels are lowest. “Nobody wants to garden at 9 p.m. or wakeboard at midnight,” Asai says. Ask yourself whether it’s realistic to think you’ll reapply a shot-glass-size amount of sunscreen every two hours to all skin that’s not covered by shorts and a T-shirt. No? Instead, wear tightly woven clothing that covers as much area as possible, including UV-blocking sunglasses and a broad-brimmed hat. (Ball caps leave the ears and back of the neck exposed.) When choosing a hat, “if you can’t see light through it, it’s probably good,” Asai notes.
And speaking of hats, Asai recommends buying several and stowing them in strategic spots, as you would dollar-store reading glasses. For instance, “you should have one in your car for when you end up at the farmer’s market,” she suggests.
The same principle applies to sunscreen—buy multiple containers so you always have one close at hand. Apply it as part of your morning routine, year-round: UV rays penetrate window glass (including that in your car) and clouds. Take particular care when near snow or water: UV rays reflect off of these surfaces, which can as much as double your exposure level.
When choosing a sunscreen, factors to consider include price and how the product feels on your skin—if it’s costly or you dislike the texture, you’re probably not going to apply it often enough or in sufficient quantities.
Sprays are a good option for areas of hair growth as long as you follow three key rules. “Number one, don’t breathe them in,” Asai says. Second, don’t spritz as you would perfume; instead, “think graffiti artist,” she adds. And finally, “you don’t have to rub it in, but wipe it at least once so the droplets get wiped off the hair and onto the skin.”
Sticks resembling deodorant are convenient and compact. “You can tuck one into your pocket or golf bag and it’s not going to explode,” Asai says. Another advantage: you can easily uncap the container and apply the product mess-free when your hands are covered in dirt or some other substance because you don’t have to rub it in.
Screening
While paying attention to any changes in your skin won’t prevent cancer, it will definitely improve the likelihood of detecting any that do develop at a stage when minimally invasive treatment carries the highest rate of success. “I do feel that some people think ‘I don’t want to bother my doctor,’” Asai observes. She urges people to resist that mindset—getting an odd-looking bit of skin evaluated as a precaution isn’t any more of an imposition than undergoing recommended screenings for other serious health problems.
“If something comes up and it’s new or it’s changing, it’s worth getting checked out—especially if it bleeds easily without trauma or crusting over,” Joseph stresses.
Similarly, if a medical professional deems a lesion non-suspicious but your gut tells you otherwise, Carol H. recommends pressing for a biopsy or second opinion. This was exactly how she was diagnosed with a subsequent stage 1 melanoma.
“Not all doctors are dermatologists, and even not all dermatologists are well versed in skin cancer,” she says. “You have to advocate for yourself.”
