Metastases in the bones.

One of the main problems of all cancer diseases is the inevitable onset of the last stage - the stages of metastasis. Metastases are the centers of malignant neoplasms, which with a current of lymph or blood are brought into distant organs and tissues, where the tumor process begins to develop .

Oncological diseases of almost any organs and tissues can give metastases to the bones. Such foci can be found in almost any bone structure. Most often - metastases in the spine, less often in the pelvic bones, ribs and extremities.

What tumors give metastases to the bone?

This process is most often observed with cancer of the thyroid gland, prostate and mammary glands.

There are two main types of pathological process in bone tissue - osteoblastic and osteolytic metastasis. The first form is characterized by a thickening of the bone tissue, especially its mineral constituent. The second form promotes the "washing away" of minerals, which inevitably entails thinning and fractures of bones.

The pathogenesis of this pathology is what cells stimulate the tumor. If metastasis of a malignant neoplasm involves osteoblasts in the process, the osteoblastic form develops. In the case when the tumor first meets bone resorptive cells (osteoclasts) in its path, metastasis of osteolysis occurs.

In most cases, the appearance of metastases in bone tissue is manifested by the pain of the latter. Pain syndrome develops as a result of damage to nerve endings by tumor growths, increased pressure inside the bone, and also as a result of irritation of the endings of nerve fibers with metastasized substances. In addition, the pain occurs when a bone fracture is caused by thinning of the latter (typical for osteolytic forms). The osteoblastic form is characterized by pronounced hypercalcemia (elevated calcium in the blood).

The risk of bone fractures is the high probability of complications - pulmonary embolism, deep vein thromboembolism (ultimately, this leads to loss of functional load of the organ or limb and its viability).

Metastases in the bone are diagnosed by X-ray examination. For this purpose, an overview radiography is used with a multiplicity of metastatic foci, as well as with osteolytic form. In the case of osteoblastic, a radionuclide scan is performed. One of the methods of detection, in which not only metastases in the bone, but also in other organs and tissues are visible - PET with 18P-deoxyglucose.

Surgical treatment of bone metastases is indicated with the possibility of a fracture of the latter. An orthopedic surgeon performs an operation to strengthen the bone, by inserting the pins and filling the tumor cavities with bone cement.

Radiation therapy at a dose of about fifteen to twenty-five Gy (attributable to four fractions) in half of the patients causes the disappearance of pain. A dose of thirty to forty-five Gy causes significant improvements in the patient's condition, in particular such improvements develop over the next two to three weeks after irradiation.

The second in effectiveness, after radiation therapy, is the use of radioactive strontium. Currently, bisphosphonate treatment is widely used. These are special acids that inhibit the activity of osteoclasts. In addition, these drugs weaken the pain in bone fractures, as well as due to the development of the tumor.

Thus, the prognosis for metastases in bone tissue may be different, depending on the localization, development of osteoblastic or osteolytic form and methods of treatment.