One of the complications of cancer is metastasis, which can spread into soft tissues and distant organs.
Metastasis occurs in the bones. In fact, bone metastases are secondary cancers of bone tissue, resulting from the transfer of atypical cells from the main focus with blood and lymph flow.
Usually, bone metastases occur already in the last stages of oncopathology. Moreover, about 80% of cases of bone metastasis occur against the background of breast and prostate cancer. Such formations are manifested by severe pain, frequent fractures and hypercalcemia.
Causes of
The most common metastasis in bone structures occurs with pulmonary and renal, prostatic and breast cancer, malignant formations in the ovaries and GIT-structures, lymphogranulomatosis, sarcomas and lymphomas.
Metastasize to bone tissue and other malignant neoplasms, only much less often.
When a person is healthy, his bone tissues are constantly updated. In general, bone structures are characterized by processes of resorption, remodeling and bone formation. These processes are carried out due to the cellular activity of osteoblasts and osteoclasts. These cellular structures are responsible for the formation, absorption and destruction of bone tissue.
If the atypical cells penetrate into bone structures, then the functioning of bones occurs. Healthy cells are displaced, processes of interaction of osteoblasts with osteoclasts are violated, which leads to dissociation of their activity.
In breast cancer
Metastasis in the bone structure of breast cancer is lymphogenous and hematogenous. This localization of metastases in breast cancer is common enough.
Cancer with such metastases is marked by severe soreness and excessive tendency to pathological fractures, especially in the thorax and pelvic bones.
Types of
Depending on the type of cell activation, oncologists distinguish several types of bone metastases:
- Osteoplastic - accompanied by the formation of seals on the bones;
- Osteolytic - when the predominant destruction of bone structures is observed.
Clean types in medical practice are relatively rare, their mixed forms are more often revealed.
Symptoms of bone metastases
At first, bone secondary tumors develop asymptomatically, but with the development of the tumor process, a definite clinical picture is formed:
- The presence of hypercalcemia;
- Propensity to pathological fractures;
- Presence of cerebrospinal compression.
Hypercalcemia is a life-threatening complication, which is found in about 30-40% of cancer patients with bone metastasis.
A similar condition occurs due to excessive activity of osteoclasts, leading to an increase in the level of calcium in the blood, which in turn causes a pathological increase in excretory renal abilities.
As a result, in cancer patients with metastatic foci in the bones, in addition to hypercalcemia, hypercalciuria develops, the inverse absorption of liquid and sodium, leading to polyuria, is impaired.
As a result of such changes, the activity of many systems and organs is disrupted in cancer patients:
- In nervous system activity, signs are noted, such as inhibition and mental disorders, confusion in the mind and affective disorders;
- In cardiovascular activity, there are abnormalities such as arrhythmias and low blood pressure, a decrease in heart rate, while the risk of cardiac arrest is high.
- The kidneys are affected by nephrocalcinosis and polyuria;
- In the gastrointestinal sphere there is a nausea-vomiting syndrome, frequent constipation and lack of appetite, bowel obstruction or pancreatitis may develop.
If bone metastasis destroys more than half of the cortical layer, then pathological fractures appear. They are usually found in the bone tissues of the spine( lumbar or thoracic region) and femur. Fracture can happen even with minor traumatic situations such as an awkward turn or a weak blow.
Often, such fractures appear without a visible external cause. In the case of a pathological fracture, fragments of bone can be displaced, which leads to functional limb infringements( if the fracture is localized on the long tubular bone) and neurological disorders( if the fracture is localized on vertebral structures), which significantly worsens the quality of life of the oncopacient.
A growing tumor and bone fragments can squeeze adjacent tissues.
In case of tumor compression, cancer pains appear on the cancer patient, muscle tissue weakness is disturbed, signs of impaired sensitivity appear, and dysfunction of pelvic localization and paralysis appear at terminal stages.
If metastasis is observed in vertebral tissues, then oncological patients sometimes experience spinal compression. Usually a similar phenomenon occurs when metastasizing to the thoracic vertebrae. The disorders caused by compression can develop gradually( if the metastasis is squeezed) or acute( when the bone is compressed or its fragment).
Symptomatic of compression occurs suddenly. If such a sign is revealed at its initial stage, then its reversibility( at least partial) is quite possible. If the compression is inactive, then the paralysis becomes irreversible.
How to identify metastases in the bones?
The most informative diagnostic method for detecting bone metastases is skeletal scintigraphy, which allows you to accurately determine the incidence and extent of metastasis.
A similar procedure is able to find metastases in any part of the human skeleton. Moreover, the detection of the spread of tumor cells is possible at the earliest stages, when obvious violations in bone structures are just beginning.
With the help of X-ray examination, bone metastasis can be detected only at the stage of sufficient maturity of secondary formation, when about half of the bone mass is already destroyed.
Photo of metastases in the hip bones on X-ray
But such a diagnosis allows differentiating a specific type of metastatic formation. Light-white spots speak of blastic metastases, and the gray-white color of the spots indicates a lytic type of metastasis.
Radioisotope diagnostics or osteoscintigraphy is performed using the Rezoscan radiopharmaceutical, which is administered to the oncology patient about a couple of hours before the scan.
Diagnostics may also include computerized tomography or MRI, the detection of resorption markers in urine, blood tests, etc. If metastasis is detected in the cranial bones, oncologists recommend that all organs be carefully examined to exclude the possibility of their destruction.
Are they treated?
Metastasis in the cranial bones is observed mainly in renal or thyroid carcinoma, and their treatment can be performed in a variety of ways:
- Surgical interventions are performed with palliative therapy and are necessary for all kinds of complications( compression, fractures, etc.).After the operation, the pain syndrome is eliminated, the bone marrow or limb functions are restored, etc.
- Radiation and chemotherapy for bone metastasis is used in complex conservative treatment, as well as in the preoperative or postoperative period. These techniques can destroy cancer cells and prevent their proliferation.
- Treatment with bisphosphonates. These medications slow down the processes of disorders in bone structures.
- Radiopharmaceuticals, when administered, lead to the destruction of active oncocells.
- Immunotherapy involves the use of special means to increase the resistance of the body, so that the immune system counteracts the spread of the tumor throughout the body.
Video about preparations for the treatment of metastases in bones:
Treatment with bisphosphonate preparations
Bisphosphonates are medications that prevent the loss of bone tissue. They are designed to suppress osteoclast activity and to prevent the destruction of bones.
At the site of the growth of the secondary tumor, bisphosphonates are absorbed by the osteoclast cells, as a result of which they slow down or stop their activity. In addition, the use of bisphosphonates prevents the synthesis of osteoclasts, which become early dying or self-destroying.
Bisphosphonates are divided into 2 groups. One group of drugs contains nitrogen compounds and is more effective against metastatic tumors. These include drugs like Ibandronate, Alendronate, Pamidronate, etc. The other group does not have nitrogen, for example, Clodronate, Tidronate, etc. These drugs have less therapeutic effect.
Prognosis and life expectancy of
The final predictions depend on the localization of primary cancers.
- If bone metastases are formed from lung cancer, the patient will live about six months.
- If the primary focus is located in the prostate, the life expectancy will be on the order of 1-3 years.
- If the source of metastasis in the bone structure has become a breast cancer, the life expectancy will be about 1.5-2 years.
- Kidney cancer with bone metastases leaves oncology for about a year of life.
- In melanoma with bone metastasis, life expectancy will not be more than six months.
- With thyroid cancer, spreading into bone tissue, life expectancy will be on the order of 4 years.
Bone metastasis is extremely dangerous. If it is identified in a timely manner, then it is likely that life will be saved for the oncology patient.