Generality
Basal cell carcinoma is a malignant tumor of the skin, different from melanoma. As the name suggests, this neoplasm originates in the basal cells, which reside in the outermost layer of the skin, or the epidermis.
Figure: cutaneous lesion associated with basal cell carcinoma. From the site: www.myvmc.com
As with any tumor, one or more genetic mutations cause the basal cell carcinoma; these are often the result of excessive exposure to UV rays from the sun, but not only. In fact, the risk factors are different.
Basal cell carcinoma manifests itself with a mark on the skin visible to the naked eye and with particular characteristics.
With early diagnosis and timely treatment, it is possible to heal. Conversely, if the diagnosis and therapeutic treatment are late, it is possible that metastases form and that the basal cell carcinoma becomes fatal.
What is basal cell carcinoma?
Basocellular carcinoma, also known as basal cell or basalioma epithelioma, is a malignant tumor of the skin, which originates in the basal cells of the epidermis .
Belonging to the category of so-called skin cancers other than melanoma, it is not a particularly aggressive and dangerous carcinoma, but can become so when it is not diagnosed and treated in time.
What are basal cells? What tasks do they perform?
The basal cells are cubic or cylindrical cellular elements, located at the base of the epidermis, in direct contact with the underlying dermis . The epidermis is the outermost layer of the skin and is composed not only of basal cells but also of other cells.
The basal cells are considered a sort of stem cells, because, replicating themselves in a very intense way, they are able to give life to the so-called keratinocytes, that is the cellular elements most representative of the epidermis. As soon as they are formed, the keratinocytes move from the base towards the epidermal surface, going to replace the old generation ones, previously produced. With this fine mechanism, the basal cells guarantee an effective and periodic cell turnover .
WHAT ARE THE SKIN CANCERS OTHER THAN MELANOMA
Skin cancers other than melanoma (or non-melanomatous skin tumors ) are the most common neoplasms of the skin, and among the most common in general. The common element is the involvement of the most superficial layers of the skin; what differentiates them is instead the type of cell affected by the neoplasm.
The most widespread tumors of the skin other than melanoma are two carcinomas: the basal cell, which we are talking about, and the spinocellular one, also known as squamous cell epithelioma .
Epidemiology
Skin cancers other than melanoma . Spinocellular carcinoma and basal cell carcinoma represent, respectively, 20% and 75% of all skin cancers other than melanoma (the remaining 5% is shown in the table).
The remaining 5% of non-melanoma skin cancers consist of:
- Merkel cell carcinoma
- Cutaneous T-cell lymphoma
- Cutaneous B-cell lymphoma
- Carcinoma of the sebaceous glands
- Kaposi's sarcoma
- Dermatofibrosarcoma protuberans
Figure: a basal cell carcinoma compared to a spinocellular one. From the site: www.veteranstoday.com
This means that out of 10 skin cancer patients other than melanoma, 7/8 suffer from basal cell carcinoma and 2 from squamous carcinoma (the part that advances suffers from the remaining 5%). In Italy, the annual incidence of non-melanoma skin cancers is 100-105 cases per 100, 000 inhabitants.
Basal cell carcinoma . Basal cell carcinoma is the most common cancer in the white race. Usually, it occurs in the middle-advanced age, around 50-60 years, and affects males more than females.
The incidence rate depends on the geographical area considered: in the areas closest to the equator and / or at high altitudes it is higher than elsewhere. In Italy, the annual incidence is around 75-80 cases per 100, 000 people.
NB: according to some reliable sources, in Europe (therefore also in Italy), the annual incidence of non-melanoma skin cancers is increasing.
Causes
What is a tumor?
A tumor is the result of an out-of-control cellular multiplication triggered by one or more DNA genetic mutations. In other words, when DNA undergoes certain changes and these changes are irreparable, then the cells that contain it undergo excessive and unstoppable growth and division.
In the case of basal cell carcinoma, the cells that grow and multiply without control, due to one or more genetic mutations of DNA, are the basal cells of the epidermis. Thus altered, these cells no longer guarantee that fine cell replacement mechanism that distinguishes healthy counterparts.
WHAT DETERMINES GENETIC MUTATIONS IN BASAL CELLS?
In most cases, genetic mutations occur due to excessive exposure to ultraviolet ( UV ) radiation from the sun and / or tanning lamps.
In more rare cases, genetic damage is due to a depression of the immune system (ie a weak immune system) or to direct contact with certain toxic substances .
RISK FACTORS
After years of research, several conditions have been identified that can promote the appearance of basal cell carcinoma. These risk factors are:
- Light skin . Basal cell carcinoma can affect anyone, regardless of skin color. However, those with less melanin (a skin pigment that protects the skin from UV rays) are more predisposed than those who have more. Thus, fair-skinned individuals get sunburned very easily and, due to the lack of pigment, they are also at high risk of basal cell carcinoma.
- Too much sun . Exceeding exposure to the sun, even if you do not have fair skin, favors the appearance of basal cell carcinoma and, in general, of all skin cancers.
- Excessive exposure to tanning lamps . The tanning lamps give off the same ultraviolet radiation as the sun. Therefore, exceeding their use favors the possibility of getting basalioma and, in general, of any skin tumor.
- Radiation therapy (ie based on radiation) . Some therapeutic methods use ultraviolet radiation to treat dermatological diseases. An excessive dose of these radiations, due for example to a prolonged treatment, favors the appearance of skin tumors.
- Personal history of a previous skin cancer . Anyone who has already suffered from basal cell carcinoma or any other skin cancer is a person most at risk.
- Family history of basal cell carcinoma . Those who descend from a family in which one or more members have been affected by a basal cell carcinoma are predisposed to fall ill with the same disease.
- Contact with arsenic . Arsenic is a toxic chemical element, which can be found in the air, in aquifers and in the ground. Those who come into contact with high doses of arsenic are predisposed to develop various tumors, including basal cell carcinoma.
- Weak immune system . An individual's immune system is its defensive barrier against infections and other threats brought by the external environment; in people in whom it is weak ( immunosuppression ), it favors the appearance of various disorders, including skin cancers. An emblematic case, of what has just been said, is represented by patients with leukemia or lymphoma and organ transplants, who - being forced to suppress, with appropriate drugs, their own immune system - expose themselves to infectious diseases and, precisely, to skin cancer.
- Genetic predisposition . Some genetic diseases favor the appearance of basal cell carcinoma; in particular, it is the Gorlin-Goltz syndrome and the xeroderma pigmentosum .
Sufferers of xeroderma pigmentoso are extremely sensitive to sunlight, so much so that they must protect themselves from the sun's rays even inside their own homes.
- Advanced age . The people most affected are those aged 50-60.
Symptoms and Complications
To learn more: Symptoms Baso-cell carcinoma (or basalioma)
Basal cell carcinoma is characterized by a particular cutaneous sign .
This sign usually appears in the parts of the body most exposed to the sun (such as the face, back of the hands, scalp, neck and ears); however it can appear anywhere, therefore also in unexpected areas, such as the inside of the mouth, the genitals, the anus and the toes.
Initially the lesion is very small, then, with time, it can also assume considerable dimensions and extend in depth.
WHAT IS THE SKIN SIGN?
The cutaneous sign can present itself with various characteristics. In fact, it can look like:
- A protuberance of pearl white or waxy white, in which the blood vessels that cross it can be easily recognized. The basal cell carcinomas that arise on the face, neck and ears have similar features. In some cases, the protuberance tends to bleed and form a crust.
- A scaly area, not particularly noticeable, brown or flesh-colored . These features are the basal cell carcinomas that appear on the chest and back. In the long run, the lesion could grow considerably.
- A scar-colored scar-colored lesion . This aspect, which makes basal cell carcinoma difficult to recognize, is that typical of a very invasive tumor, called morphiform or sclerosing basal cell carcinoma .
Figure: a basal cell carcinoma in which it is possible to recognize the blood vessels that pass through it. From the site: www.ohniww.org
WHEN TO REFER TO THE DOCTOR
A dermatological examination is recommended, if a cutaneous sign, appearing without an obvious reason, tends to always show the same characteristics or even to worsen.
COMPLICATIONS
Basal cell carcinoma can become an aggressive and lethal neoplasm, if it is not diagnosed and treated in time. In fact, in such circumstances, it is easier to observe a spread of cancer cells ( metastasization ), which go to contaminate the neighboring tissues first, then the lymph nodes and, finally, the other internal organs (such as the liver).
NB: metastasis is the serious process that gives rise to metastases .
Metastases are the cancer cells that have moved from their original location and moved elsewhere, going to contaminate other organs and body tissues.
Special case . Individuals with a weak immune system and those suffering from xeroderma pigmentosum or Gorlin-Goltz syndrome deserve a separate discussion. These subjects, being particularly predisposed to develop a large number of skin cancers, are more difficult to treat, therefore the risk of a tumor metastatization is greater.
Diagnosis
Early diagnosis of basal cell carcinoma guarantees a greater probability of recovery, as it allows the therapeutic treatment to be started first. This is why, in the doubt that a particular skin sign may be a tumor, it is advisable not to hesitate to contact your doctor.
The diagnosis path is very simple and fast; in fact, it generally involves an objective examination and a biopsy.
EXAMINATION OBJECTIVE
During the physical examination, the dermatologist examines the suspected skin area and also analyzes the rest of the body; furthermore, by questioning the patient about his medical history, he tries to understand whether he is a person at risk of skin cancer.
BIOPSY
The physical examination provides various useful information, sometimes unequivocal, but the only way to establish with certainty the true nature of the skin sign, also identifying the type of cells affected by the tumor, is the biopsy .
It involves the taking, directly from the suspected skin area, of a small portion of tissue and its subsequent observation under a microscope. To the instrument, any tumor cells present show easily recognizable features.
Treatment
In order to recover from a basal cell carcinoma, it is necessary to undergo an operation to remove the formed cutaneous sign.
The techniques for removal are numerous and the choice of one rather than another depends on the location, size and severity of the tumor.
Below is a description of the most used therapeutic approaches in case of basal cell carcinoma:
Not recommended for skin neoplasms formed on the face, curettage and electrodissecation represent an ideal therapeutic solution for very small basal cell carcinomas (less than one centimeter) and located on the legs.
- Surgical excision (or excision) . It is the surgical removal of the tumor area, performed by surgical incision. This is a moderately invasive operation, as the surgeon, to be sure of totally eliminating the basal cell carcinoma, must also affect a part of the neighboring healthy tissue. Consequently, the possibility of a scar forming is concrete.
- Mohs surgery . It is the elimination of the neoplastic sore layer by layer. By examining each layer removed from time to time, the surgeon knows when the basal cell carcinoma has been completely eliminated. This procedure, since it ends with the observation of the first layer without tumor cells, guarantees the exclusive removal of the tumor, without unduly compromising healthy tissues.
- Cryotherapy . It is the cold therapy ("crio" comes from the Greek and means "cold"). It involves the use of liquid nitrogen, which, once applied to basal cell carcinoma, freezes and kills cancer cells. Cryotherapy is suitable for very thin and non-deep neoplasms.
- Topical treatment . It consists of applying creams or lotions containing particular anticancer drugs to the affected area, known as imiquimod and fluorouracil. Topical treatment is suitable in case of superficial and small-sized basal cell carcinomas.
- Photodynamic therapy . It involves the use of a photosensitizing drug, for topical use, and a source of luminous radiation. The photosensitizing drug is a kind of cream that, applied on the tumor area, makes it more susceptible to light; the light source, on the other hand, emits the light necessary to destroy the tumor cells, which have become photosensitive after the application of the drug. The main advantage of this method is its low invasiveness; the disadvantage is that its long-term effects are unknown (given the deleterious effects of light on healthy cells).
- Radiotherapy . By projecting a beam of very high-energy X-rays onto the tumor area, the tumor cells are definitively damaged, which are thus destined to die. It does not always provide the desired results and, if the treatment is not successful, it is necessary to change the treatment method. Its long-term effects are unknown.
Prognosis and prevention
Basal cell carcinoma is a curable tumor that can be cured, especially if it does not occur in delicate locations and / or in depth and if it is diagnosed early and treated appropriately.
This, however, does not exclude the possibility that a second skin cancer may appear (the same or other type); in fact, an individual already struck once is probably a subject predisposed to this type of cancer.
PREVENTION
Basal cell carcinoma is a cancer that can be prevented by following certain recommendations. Here are the main ones:
- Avoid exposing yourself too much to the sun in the central hours of the hottest days . In these moments, in fact, UV radiation is remarkable and highly damaging to the skin.
- Use sun protection creams . Their use is particularly advocated for fair-skinned individuals who are at sea, those who work outdoors and people at high risk of skin cancer (people with a weakened immune system, people with xeroderma pigmentosum) etc).
- Cover the parts of the body that are usually most exposed to sunlight and wear sunglasses . For both of these suggestions, the same is true in the case of sunscreens: they must be followed by everyone, but especially by certain people most at risk.
- Do not abuse tanning lamps or, better, avoid using them . Its use is not strongly recommended especially for those who have fair skin or are predisposed to skin cancer.
- Check your skin periodically . It is good to examine, from time to time, the whole body, even the most unthinkable points (genitals, between the toes, etc.). It may be useful to obtain more mirrors, so as to inspect even the most hidden or invisible parts of the body.
- Do not neglect any skin abnormality that appears suddenly, because it could be a basal cell carcinoma or any other skin cancer.
