Determination of the stage of melanoma, prognosis of melanoma
Before starting treatment, the doctor needs to determine the stage of the disease, if we are talking about melanoma. Determination of the stage of melanoma implies an attempt to study in more detail several important indicators at once, such as the size of the tumor, the depth of penetration into the skin, the prevalence of formation cells in the nearby lymph nodes and other parts of the body. If necessary, a specialist can dissect nearby lymph nodes to check for cancer cells. This procedure can also have a therapeutic effect, since the removal of the nodes affected by cancer cells helps in some cases to keep the disease under control.
The doctor carefully examines the patient, and if the formation is voluminous, then an X-ray examination of the chest is performed, the blood is analyzed, the liver is examined, the brain and bones are scanned.
Determining the stage of melanoma
There are several stages of melanoma: zero, first, second, third and fourth. At stage zero, tumor cells are found exclusively in the outer cell layer and do not grow into deep tissues.
At the first stage, the thickness of the tumor is no more than one millimeter, while the outer layer of the skin (epidermis) may be covered with sores. At the same time, ulceration may be absent, and the thickness of the tumor can be up to two millimeters, while melanoma cells do not affect the nearby lymph nodes.
The second stage of melanoma is characterized by a tumor at least one millimeter thick, or one to two millimeters thick with an ulcerated surface. This also includes tumors with a thickness of more than two millimeters, which may be ulcerated, or may have a surface not covered with ulcers. Melanoma in the second stage of the disease also does not spread to nearby lymph nodes.
In the third stage, tumor cells affect nearby tissues, tumor cells are found in one or more lymph nodes located in the vicinity of the affected skin area. Melanoma cells can also go beyond the boundaries of the primary formation, but without affecting the lymph nodes.
The fourth stage of melanoma is characterized by the spread of cancer cells to neighboring organs, lymph nodes, skin areas that are far from melanoma.
The correct definition of the stage of melanoma and the treatment carried out does not exclude the appearance of relapses in some cases. Cancer can return to its previous or new location, localizing to another part of the body. In this case, one of the important diagnostic facts is the clinical stage of melanoma at the time of diagnosis.
Melanoma prognosis
For the first and second stages of the disease, when the formation is located in the area of the primary focus with a relapse of the disease, the five-year survival rate is approximately 85%. For the third stage, when melanoma forms metastases in regional lymph nodes, the five-year survival rate is 50% if one lymph node is affected or 15-20% if more than four lymph nodes are affected. When distant metastases appear, which corresponds to the fourth stage of melanoma, the survival rate does not reach even five percent.
Most of the lesions are diagnosed in the first two stages, when the prognosis of melanoma depends on the thickness of the tumor, and its thickness is directly related to the mass. It is the mass of melanoma that determines the likelihood of metastases.
Melanoma up to 0.75 mm is successfully operated, and the five-year survival rate in this case reaches 96-99%. Today, in 40% of patients at the time of diagnosis, the thickness of the formation is no more than one millimeter. These patients are at low risk.
In those who are diagnosed with metastases, when conducting a histological examination of primary melanoma, either vertical tumor growth or melanoma regression that occurred spontaneously is found.
Melanomas larger than 3.64 mm in more than half of cases form metastases and cause death of the patient, such formations, as a rule, significantly rise above the surface of the skin.
The prognosis of melanoma is also associated with its location. It is more favorable when a formation occurs in the forearm and lower leg, worse when localized on the scalp, hands, feet and mucous membranes.
In the initial two stages, the prognosis of melanoma in women is more favorable than in men. This is partly due to the fact that in women, melanoma is more often diagnosed on the shins, where it is easier to find on self-examination.
In elderly patients, the prognosis is generally not so favorable, which is associated with late diagnosis and a high incidence of acral-lentiginous melanoma in elderly men.
Melanoma is prone to relapse. Approximately 10–15% of tumor recurrence occurs for the first time more than 5 years after surgical removal of the primary melanoma. The thicker the tumor, the greater the likelihood of its early recurrence.
Adverse factors in determining the prognosis of melanoma in the first two stages of the disease include ulceration of the surface of the primary tumor, its high mitotic activity and the appearance of satellites (separate islets of malignant cells, the diameter of which is 0.05 mm or more). Satellites are localized outside the main tumor in the reticular layer of the dermis or in the subcutaneous tissue; in most cases, they are combined with micrometastases and penetrate into the regional lymph nodes.
Another system for determining the prognosis of melanoma in the first two stages of the disease is based on the histological criteria proposed by Clark. At the first level of lesion, the tumor is in the epidermis, at the second level it is located in the papillary layer of the dermis, at the third level it is localized on the verge between the papillary and reticular layers of the dermis, at the fourth level it penetrates into the reticular layer of the dermis, at the fifth level it affects the subcutaneous tissue. The five-year survival rate will be 100, 95, 82, 71 and 49% for each individual case, respectively.
Article author: Mochalov Pavel Alexandrovich | d. m. n. therapist
Education: Moscow Medical Institute. IM Sechenov, specialty - "General Medicine" in 1991, in 1993 "Occupational Diseases", in 1996 "Therapy".
