All about skin cancer
Oncology / / August 12, 2017
Skin Cancer with basal cell carcinoma is one of the most common forms of cancer and it is the one in which obtained the best results of treatment.This position is due to a number of circumstances: the outdoor location of the tumor and the consequent early detectability and early (timely) the beginning of the treatment, the biological characteristics of basal cell carcinoma (not metastasize);good treatment results from both surgical and radiation techniques from.
Among all malignant tumors of the skin cancer is the 3-5-th place, accounting for 12-14%.It should be noted a large variability in the incidence of skin cancer in different countries and even within the same country in different geographical areas.The highest incidence of skin cancer in Australia say - 50% of all malignancies.In the US, the incidence of skin cancer is approximately 70-80 cases per 100 000 people, and the death rate - only 4.2 per 100 000 (in the United States each year about 5,000 people die from skin cancer).
main exogenous etiologic factor in the development of skin cancer is a long and continuous exposure to solar radiation in the open air.In this regard, skin cancer is much more common in people in rural areas compared to the urban population, the inhabitants of southern regions, compared with the North, on the exposed parts of the body as compared to the private.
Preventing skin cancer is the use of special headgear and clothing to protect exposed parts of the body from sun exposure.
Skin cancer occurs with equal frequency in men and women, mostly over the age of 60 years.A significant number of cases of skin cancer occurs on the background of the foregoing pathological conditions and diseases of the skin, known as obligate and facultative precancer.To obligate precancer refers xeroderma pigmentosum - genetically determined congenital skin disease, with increased sensitivity to ultraviolet radiation.In the group of facultative precancer combine a number of pathological conditions and diseases of the skin: skin damage by ionizing radiation, arsenic, tuberculosis and lupus erythematosus;long unhealed scars and fistulas (especially on the basis of gunshot wounds, followed by chronic osteomyelitis);thermal and chemical burns;senile skin atrophy;actinic keratoses, and others. The development of skin cancer on the basis of these diseases is observed in 6-10% of cases.
By histological structure are two main forms of skin cancer: basal (basal cell skin cancer) and squamous cell carcinoma.
most common basal cell carcinoma, is 70-75% of all skin cancer tumors (which largely determines favorable prognosis).Histological structure of the basal cell carcinoma varied.According to the microscopic studies have identified a number of forms:. Solid, glandular, cystic, pigmented, etc. The most common is the presence of cells that resemble the cells of the basal layer of the skin and forming a narrow, twisted strands.
Squamous skin cancer on the histological structure is divided into keratinizing and neorogovevayuschy form.Tumor cell consists of strands infiltrating the epidermis and dermis.On the periphery of the strands meet basal cells, and are located inside cells, resembling in form and structure subulate.A characteristic feature is the formation of horny masses in the form of "cancer of pearls."If squamous cancer actinic neorogovevayuschy completely absent.
Clinic Skin cancer is most common in people over the age of 60 years, from 40 to 50% of all people over the age of 65 years have or will have at least one cancerous tumor of the skin.Skin cancer is also very often the second localization of primary multiple cancer.Bazalioma occurs 2 times more often squamous cell skin cancer and is usually located on the face: the nose (more than 25% of the lesions), age (20%) of the cheeks (15% of losses).Squamous cell carcinoma can be located on any part of the body, but most often it reveals the lower extremities.
Clinically, there are three forms of squamous cell skin cancer and basal cell carcinoma: the superficial, infiltrative, or deep penetration, and papillary.Surface form appears or nodule formation spots (plaques), whitish, slightly raised above the skin surface.With the growth in the central part of the hearth surface pitting occurs.Then, in the center of the scarring occurs, and on the periphery of the growth continues to form a scalloped, valikoobrazno rising edges.Typically, the surface shape is observed on the face and body with basal cell carcinoma.
infiltrate (deep penetration) form is characterized by ulceration of the tumor site with the formation of the crater with a dense valikoobraznym edge and necrotic masses in the center.Gradually the tumor invades surrounding tissue and becomes stationary.This form is typical for squamous cell cancer and tends to metastasize.
Papillary form is a node on a broad basis, and sometimes grows larger.In appearance, it resembles a cauliflower.Rarely.It is characterized by rapid growth and frequent metastasis.
basal cell carcinoma is characterized by slow, as a rule, steady growth.In the absence of adequate treatment for the tumor can invade surrounding tissues, destroying them.Basal cell carcinoma is almost never metastasizes.Squamous cell carcinoma metastasizes lymphogenous by about 10% of cases.Hematogenous metastases to the lungs and bones are rare and late.
flows especially malignant skin cancer of the lower limbs and trunk, sometimes not inferior in this respect to other cancer sites.
Diagnosis In most cases, the diagnosis of squamous cell skin cancer and basal cell carcinoma can be established on the basis of clinical data.identification of ulcer with a characteristic valikoobraznym edge is the most important objective data.In all cases, the diagnosis should be confirmed by the data of morphological studies.It is important that when the incisional biopsy in the drug got a piece of the edge of the tumor infiltration.When neizyazvlennyh tumors should be performed excisional biopsy, t. E, complete excision of the tumor.
When infiltrative common forms of skin cancer need to produce X-rays to rule out a tumor ingrowth into the underlying bone.
I - tumor size up to 2 cm in greatest diameter surface.
II - tumor size of 2 to 5 cm in greatest diameter or minimum infiltration of the skin, regardless of tumor size.
III - tumor larger than 5 cm in greatest diameter or deep infiltration of the skin, regardless of tumor size.
IV - tumor invasion into the surrounding tissue, such as cartilage, muscle or bone.
Treatment For treatment of squamous cell skin cancer and basal cell carcinoma used radiation, surgical, medical techniques and combinations thereof.The choice of treatment should be carried out strictly individually according to detailed plans, depending on the tumor location, shape, growth stage, histological structure, comorbidities, age of the patient and others. You can not consider skin cancer as an easily curable disease and approach it routinely.
most widely received radiation therapy of squamous cell skin cancer.It is used as a blizkofokusnoy radiotherapy or radium therapy for tumors of stage I - II.When tumors of stage III (greater than 5 cm), it is advisable to use a combined radiation or combination therapy.
Surgical treatment may be used for tumors of the skin of the trunk and extremities, where there is a "stock" of the skin, as the lesion is necessary to excise some distance not less than 2 cm from the visible tumor borders (with basal cell carcinoma - less).The surgical technique is indicated for recurrent skin cancers, as well as tumors that developed on the background of scarring and sinus tracts.For large wound defects using different variants of bone grafting.In some cases (the germination of the bone, the neurovascular bundle) in the localization of squamous cell skin cancer on a limb amputation produce it.
In the early stages of basal cell carcinoma successfully used topical chemotherapy.Many forms of basal cell carcinoma successfully treated as electrocoagulation and cryodestruction.In general, given the relatively favorable course of the process, the widespread use of radiation therapy in patients with basal cell carcinoma should be considered as less justified than the various methods listed local destructive treatment (except for some of the localization process, rapidly growing tumors and elderly patients).When frequently encountered multiple superficial basal cell carcinoma radiation therapy is clearly not appropriate.
Due to the relatively rare squamous cell skin cancer metastasis to regional lymph nodes, a regional lymphadenectomy produced only in the presence of these metastases.
prognosis and treatment outcomes
Skin cancer has the best prognosis of all cancers.Particularly good prognosis for basal cell carcinoma - 95% recovery.In squamous cell carcinoma prognosis depends on the stage, form and location of the tumor growth.In the absence of metastases in regional lymph nodes of the five-year survival rate is 75-80%.The presence of metastases in regional lymph nodes and tumor ingrowth into the adjacent organs significantly worsens the prognosis - five-year survival is 24%.