Cases of skin cancer have increased in recent years, partly due to excessive sun exposure. Carcinomas and melanomas in the form of nevi or moles are the two major types. Early diagnosis is essential for good treatment.
Prevalence of skin cancer in the population
Skin cancer has a high prevalence. It has been increasing progressively since the 1960s and the forecasts are that this trend will continue to increase in the coming years. This is due to changes in lifestyle habits, including exposure to the sun. Logically, the increase in life expectancy also implies a higher prevalence.
Types of skin cancer and diagnosis
There are different types of skin cancer that derive from the different cells that make up the skin integument. In order of frequency, according to dermatology experts, there are basically two main groups:
- Carcinomas. These are the most frequent and, among them, basal cell carcinoma and squamous cell carcinoma stand out. Basal cell carcinoma is the most frequent not only of skin cancers but of all cancers in general. Its incidence is around 400 new cases per 100,000 inhabitants in our environment. Squamous cell carcinoma has a lower incidence, but is more aggressive.
Both tumors are preferentially located in areas chronically exposed to the sun, but can also appear in areas that are not exposed to the sun. There are precancerous lesions known as actinic keratoses which, in a variable percentage, can give rise to squamous cell carcinomas. Moreover, some authors consider these to be carcinomas in situ, i.e., located only in the epidermis, and should be treated as a squamous cell carcinoma.
The incidence of actinic keratoses is very high, with a prevalence of 300 new patients per 100,000 inhabitants per year.
The clinical forms of these carcinomas are very varied: nodules, ulcers, plaques… Sometimes they are flat, poorly demarcated lesions that are difficult to treat.
- Melanomas. This tumor originates from melanocytes, which are the cells that produce melanin and cause our tan. In general, melanoma is more difficult to diagnose than carcinomas, which is why early diagnosis is important.
The most frequent melanoma with the worst prognosis is the one that occurs in areas of intermittent exposure to the sun; that is to say, the population that in summer exposes to the sun usually covered areas, such as the back or thorax. Melanoma can appear as a consequence of the malignization of a nevus or mole, but it can also appear on previously healthy skin.
Population at risk for skin cancer
The population at risk that most frequently develops skin cancer is the fair-skinned population, which burns easily and tans with difficulty, with blond or red hair. Likewise, the population that works outdoors is also at greater risk.
In the case of melanoma, the presence of nevi (moles) also plays a role, especially if they have atypical characteristics: asymmetry, different shades of color, etc.
Skin cancer treatment and prevention
The treatment of skin cancer is, nowadays, very varied, depending on the type of cancer and the stage in which it is found. The usual treatment is complete surgical excision and the anatomopathological study that provides us with a sure diagnosis and whether it has been completely extirpated. However, there are situations in which surgery is complex or results in a very aggressive method, or the aesthetic result is not acceptable; in these cases other methods can be used such as radiotherapy, photodynamic therapy, topical treatments or creams that can destroy superficial tumors, as well as cryotherapy with liquid nitrogen.
Early diagnosis of skin cancer is a reality today and thus the volume of carcinomas that are operated on today has decreased in relation to past decades. In the case of melanoma, the systematic control of nevi and the removal of suspicious lesions has considerably improved the prognosis.
The advice, logically, is oriented to sunbathing with caution, avoiding sunburn, especially in childhood, since the skin has a memory. The correct use of sunscreens is recommended. It is also important that the patient learns to self-examine and control nevi periodically.