Skin cancer, experts call for extreme precautions against ultraviolet radiation that already reaches dangerous levels in Spain

Meteorologists have already warned: this summer is going to be one of the hottest in the last 30 years. Last year we experienced firsthand the ravages of high temperatures (it was the hottest summer in Spain and in Europe since there are records). The sun is a greater threat every day: ultraviolet radiation is already reaching dangerous levels in our country and it should be remembered on this World Skin Cancer Day.

According to data from the Spanish Academy of Dermatology and Venereology (AEDV), in Spain the incidence of skin cancer has increased by 40% in the last four years -more than 78,000 new cases are diagnosed annually-, despite the fact that it is highly preventable. : with basic prevention measures, more than 95% of cases could be avoided. The Spanish Society of Medical Oncology (SEOM) estimates that by 2023, 8,049 people will be diagnosed with skin melanoma.

The incidence for basal cell carcinoma is about 120 cases per 100,000 inhabitants, about 40 per 100,000 in the case of squamous cell carcinomas and in melanoma the figure is lower: 12 cases per 100,000 inhabitants, although it is estimated that by 2040 the Melanoma, the most aggressive and with the worst prognosis, will become the second tumor in global incidence and the first in incidence in men, ahead of colon and lung.

types of skin cancer

How is each one of them? Basal cell or basal cell carcinoma is the most frequent (represents about 20-30% of all skin cancers in the world). “It doesn't sound familiar to the population because they don't usually kill. It is a type of tumor that generally grows very slowly and is detected because it rubs and bleeds, because a wound does not heal, there is something that does not look like the rest…”, explained Eduardo Nagore, dermatologist and clinical chief of the Valencian Institute of Oncology (IVO), to this newspaper at the 50th AEDV Congress, held in mid-May in Santiago de Compostela

The second most frequent is squamous cell carcinoma, also known as epidermoid or squamous cell carcinoma.. “While the basal cell can be seen in relatively young people, the epidermoid is very typical of older people. All cancers increase with age, but the epidermoid is closely related to the amount of accumulated sun, the accumulated ultraviolet radiation damage in life. It is very typical in people who work in agriculture or construction, for example, and have premalignant lesions that can be treated, which are actinic keratoses from chronic exposure to radiation, and the tumor itself that grows rapidly.”

Melanoma is the one everyone knows because, although it is less frequent, it causes 80-90% of deaths from skin cancer. “We talk about melanoma, but in reality we should talk about melanomas because there are different types. It is one of the issues that have been discussed in a meeting at the congress. There is one that has to do with the accumulation of damage from the sun, typical of the farmer and people who work all day on the street, as in the epidermoid. It is not the most frequent, it is 15% of melanomas. Then there is a significant volume of melanomas whose relationship is intermittent powerful exposure, that is, of a vacation, recreational type, which right now is what predominates because you spend the entire year inside a building without seeing the sun and when it comes vacations we hit the beach,” Nagore continued.

The dermatologist indicated that there are other types of melanomas such as those that appear in the acral areas (soles of the feet, nails…). “They could be related to pressure, rubbing, minor trauma, and they occur more frequently in construction or field workers precisely because of the type of movements and forces they make.. In addition, there are other types that are not strictly our field, for example, mucosal melanomas, which depending on where they are, are sometimes seen by dermatologists or seen by gynecologists/urologists, or ocular melanoma, which is a matter of ophthalmologists” commented Nagore.

The dermatologist pointed out that people identify melanoma only as the vacation type and that sometimes causes late detection. “For example, the acrals, people don't think about it and they are treated like a diabetic foot or a callus, the nail like an onychomycosis…. Melanoma, both in men and women, can occur anywhere on the skin and the skin includes the soles of the feet, the nails, the appendages, the scalp, the bald spot, etc.”. Then there are other skin cancers such as sarcomas or such as Merkel cells, which is the most aggressive, although very rare, and is partly related to infection by a virus and partly by solar radiation, added Nagore.

The elderly, the most vulnerable

In addition to the genetic predisposition that some people may have, there are more vulnerable populations, not necessarily because they have been exposed to a greater amount of solar radiation in their lives.. For example, transplant recipients who have received immunosuppressive therapy. Age is another factor to take into account in skin tumors.. Melanoma is very rare in childhood (less than 1% of cases), but in the elderly it is quite common as there is a decreased immune response.

“At this age, melanoma occurs mainly on the head, neck and acral areas (hands and feet). As most cases are diagnosed in advanced stages, the prognoses are usually much worse than in other age groups: while melanomas in the elderly account for 40% of diagnosed melanomas, they cause 60.2% of deaths by the disease,” said Nagore. The dermatologist stressed that basal cell carcinomas, which should not cause problems, can become something very serious due to neglect, also more frequent in older people. “That would not happen to a young person, but to an old man who is ashamed, covers it up, does not go to the doctor…”.

“We have a problem when it comes to knowing the real incidence of skin cancer because, as with melanoma, the incidence is included in all the registries because it is the skin tumor that causes the highest mortality, basal cell carcinoma and especially squamous cell carcinoma. or epidermoid are often not included in the registries because they are considered tumors that do not cause much mortality and it is difficult to know the exact figures. But 40% is the estimated incidence percentage”, analyzed Yolanda Gilaberte, head of the Dermatology Service at the Miguel Servet Hospital in Zaragoza and president of the AEDV, also at the congress of this society.

This incidence is not only in Spain, but globally. “If we look at the map, Australia is the country in the world that has had the highest incidence for years, especially because of the people who emigrated from England and Ireland and went there, which is next to the Equator, and their organizations were not prepared to deal with it. that. Also the US and then all areas of northern Europe, especially due to the holiday periods that are more in the south,” Gilaberte said.

Higher incidence, reflection of past decades

It is worth asking why if there is increasing awareness about the danger of sun exposure, the incidence has increased by 40% in four years. Nagore explained that in one of the conference talks the epidemiology of melanoma was discussed. “Before Coco Chanel turned it around, being 'white' was a way of distinguishing oneself from the vulgar, from the farmer who worked the land, for example. The change was also, deep down, a distinction: I am rich and I can afford it, I have a good time outdoors and I am going to get tanned, on the beach, which is different from the 'worker tan'. This has gone on for decades and every generation that has lived until UV radiation was said to promote cancer has been burned going to the beach.”

The dermatologist added: “Your father told you 'even if your skin tans, in two or three days it won't happen to you' and indeed, but you took the burn with you. The consequence of the memory of the skin is that cancers are coming out. If our parents did not protect us, it is because they did not know, or they would have educated us in 'do not go out now that you are going to burn'. Now you do hear 'don't forget the protector' or you see people who go to soccer with their son and put a protector on him, or on the beach, where they also use hats and umbrellas. So the expectation is that this incidence will decrease because now there is more awareness, but that effect is seen in 20, 30 or 40 years, that on the one hand, and, on the other, awareness is that way because people know that the tobacco is bad and keep smoking, every time before. Well, if we are like this in that battle that we have been carrying on for a long time, what will not happen with the issue of sun exposure?

Gilaberte thinks like Nagore. “In a few years we will see a bit of the results of this greater current awareness to better protect yourself from photoprotection. We have just done a study in which we passed a photoprotection questionnaire among people who have been diagnosed with skin cancer and compared it with people without skin cancer.. All of them indicated that right now they use a high protection factor and on a regular basis, but when we asked them what they were doing 15 years before, those diagnosed with cancer used fewer protectors and lower factors than those who now do not have skin cancer”.

The president of the AEDV also spoke of the need to take climate change into account. “If the temperature is getting higher and higher we will be more exposed, because if it is cold you wrap up a lot and stay at home, when it is hot you take off your clothes and expose your skin more. It must be considered and also studied the effect, which is not yet known, that heat may have in enhancing or not the harmful effect of ultraviolet radiation.. We do not have protection against the infrared that gives off the heat and since the temperatures are increasingly higher, it is an unknown quantity that we have to start studying.”

Brutal jump in treatments

It's not all bad news. Although the general treatment of a skin tumor is surgery as the basis, sometimes radiotherapy cannot be performed or applied, for example. “For locally advanced basal cell carcinoma we have had vismodegib or sonidegib for a few years now, which inhibit the molecular pathway that produces basal cell carcinoma and shrink the tumor a lot, even to nothing. In advanced squamous cell carcinoma, there is a treatment that is cemiplimab, an immune checkpoint inhibitor PD-1/PD-L1 (in this case, the target is PD-1), which is approved by both the FDA and the EMA for advanced cutaneous squamous cell carcinoma, but in Spain it is indicated for lung cancer, it does not yet include this other indication,” explained Gilaberte.

The dermatologist added that in melanoma what is most used is immunotherapy, “which also inhibits above all those PD-1 and PD-L1, and there are, for example, pembrolizumab, nivolumab…. And others inhibit lymphocytes, such as ipilimumab. These immunotherapies are indicated above all in metastatic melanoma, but they are also repositioning what is called neoadjuvant therapy, that is, these treatments are introduced before that tumor produces generalized metastases and it seems that they improve the prognosis.. Or for melanomas that have BRAF mutations. Melanoma is where the most advances are being made”. Taking into account that it is the skin tumor that causes the most mortality, any progress is little.

According to Nagore, in general, in all cancers, advances are based on two main pillars: “Thanks to the fact that it is now known molecularly which are the genes that are mutated, the origin of why the tumor multiplies, drugs have been developed that block. They are all inhibitors, which are called tyrosine kinase inhibitors (TKIs), that is, drugs that act against molecules that are involved in this process of frenetic cell division.”

The other “brutal” pillar is immunotherapy. “It is the qualitative leap, colossal. In any type of cancer there is a battle between the 'alien cell' that multiplies and begins to invade and the immune system that tries to destroy that 'alien'. But the tumor generates molecules that block this immune response.. By identifying this, drugs were developed that unlock it, that is the big change with immunotherapy. To give some figures: before these drugs, in melanoma you had metastases and you died with an 85% probability in two years. Right now people survive 60% in five years. Although it has its counterpart and that is that it can trigger autoimmune diseases, but it is an immense advance, immunotherapy is the 'boom' of oncology”.