Skin cancer: Warning signs, how to prevent it, and how to use sunscreen correctly, according to experts.

The skin is the largest organ in the human body and is composed of three layers of tissue: the epidermis, the dermis, and the hypodermis. Skin cancer is divided into two main groups: melanoma and non-melanoma, with the former being the most serious.

According to the World Cancer Research Fund, skin melanoma was the 17th most common cancer worldwide in 2022, ranking 14th in both men and women. The organization reports that 331,722 new cases of the disease were recorded. That same year, the countries with the highest number of patients were the United States, Germany, and the United Kingdom. In Latin America, the only country that appears in the top 10 is Brazil, in ninth place.

Although data in Colombia is scarce, the League Against Cancer indicates that the most common type of skin cancer nationwide is basal cell carcinoma, which accounted for 52.7 percent of cases between 1996 and 2010. It is followed by squamous cell carcinoma, with 22.6 percent, and melanoma, with 16.1 percent.

Basal cell carcinoma develops in the basal cells of the epidermis, while squamous cell carcinoma originates in the squamous cells of this same layer. Both types are the most common worldwide. Melanoma develops in melanocytes, cells responsible for producing melanin, the pigment that gives skin its color.

The World Cancer Research Fund notes that the main cause of this disease is exposure to ultraviolet (UV) rays. “ The evidence that overexposure to the sun causes skin cancer has been consistent for decades. However, many people still do not protect themselves from the sun, which increases their risk. Skin cancer is most common in people with fair skin that burns easily without tanning; blue eyes; and blond hair,” the institution says.

For its part, the Skin Cancer Foundation reports that the International Agency for Research on Cancer, a subsidiary of the World Health Organization, classifies UV tanning devices as Group 1, which includes agents with conclusive evidence of causing cancer in humans.

Sandra Malca, Regional Marketing Director for La Roche-Posay & CeraVe Central America and the Andean Region, explained to EL TIEMPO that other risk factors include: having a family history of skin cancer, the presence of many moles or atypical moles , and having suffered sunburns in childhood.

Regarding the genetic component, Malca indicates that it determines the body's ability to produce melanin and repair DNA damage. This is why some people are more susceptible to burns or skin injuries.

However, he emphasizes that prevention plays a key role: "Genetics determines the predisposition, but the way we take care of ourselves determines the outcome," he says.

It also warns that in the region, farmworkers, rural communities, and people who engage in outdoor activities frequently tend to be more exposed to the sun and have less access to sunscreen information or products.

“The myth persists that darker skin types don't burn or develop skin cancer, which is false. While melanoma rates are lower, when they do occur, they tend to be diagnosed late. Education and access to dermatological checkups are essential for all groups,” she asserts.

It's key not to demonize the sun. Dr. Giovanni Bojanini, an expert dermatologist at Pharmaderm, explains that, when properly managed, the sun can be beneficial to your health, as it stimulates the synthesis of vitamin D , essential for calcium absorption and bone strengthening.

However, it is essential that sun exposure be controlled and timed appropriately. In fact, the World Cancer Research Fund recommends avoiding exposure between 11 a.m. and 3 p.m., as well as protecting your skin with appropriate clothing, including caps or hats and sunglasses with UV protection.

It is also important to be alert to warning signs such as:

“A practical tool is the ABCDE rule: Asymmetry, Edges, Color, Diameter, and Evolution. Any suspicious changes warrant immediate consultation ,” explains Malca.

According to Bojanini, choosing the right sunscreen is essential for skin care. One aspect to consider is the SPF (sun protection factor), which indicates how much longer the skin can be protected from ultraviolet B (UVB) rays , which cause sunburn.

The expert says that sunscreens with SPF 50+ are ideal for all skin types, especially lighter skin , as they filter out approximately 97 percent of UVB radiation.

Also, opt for broad-spectrum products, meaning those that provide protection against both UVB and UVA rays. Exposure to both types of radiation has been shown to increase the risk of developing skin cancer.

Another essential factor is reapplying sunscreen. Even if a person is indoors, such as in an office, it is recommended to do so at least three times a day.

The choice of sunscreen should also be adapted to the type of skin:

“We shouldn't be guided by what works for family and friends. What works for someone else can cause side effects in us if it hasn't been formulated by a dermatologist. For example, if someone with oily skin uses an oil-based sunscreen, they're likely to experience a difficult-to-control acne reaction. Therefore, it's best to consult an expert before making this decision,” confirms the leader of Pharmaderm laboratories.

Sandra Malca adds that even on cloudy days, it's necessary to apply sunscreen. " Up to 80 percent of UV rays penetrate clouds, so the risk persists even on cold days or days without visible sun. In snowy or high mountain areas, the radiation can be even more intense due to the reflection effect. Sunscreen should be applied daily, regardless of the weather, and it's essential to reapply it."

ANGIE RODRÍGUEZ - TRENDS EDITORIAL - @ANGS0614