How does a tumor grow?
Osteosarcoma occurs in the metaphysis, the area of a long bone near the growth area where cells divide most actively. The tumor destroys bone tissue and at the same time forms pathological bone of irregular structure, which is why a characteristic mottled picture is visible on x-rays. Growing through the cortex, the tumor lifts the periosteum, forming typical radiological signs. Osteosarcoma spreads mainly through the bloodstream, and the most common target is the lungs, so a chest CT scan is included in the mandatory examination from the very beginning.
- The tumor occurs near the bone growth area
- Simultaneously destroys and forms pathological bone
- Raises the periosteum, giving characteristic signs
- Distributed through the bloodstream
- Most often affects the lungs
Causes and risk factors
In most cases, the cause is unknown and is not the fault of the parents or lifestyle. There is a connection with the period of rapid skeletal growth: the peak incidence coincides with the teenage growth spurt, and taller adolescents get sick somewhat more often. Radiation therapy previously performed for another disease significantly increases the risk. There are hereditary syndromes in which osteosarcoma is more common, particularly those associated with hereditary retinoblastoma. In older people, the tumor sometimes develops against the background of Paget's disease.
- Period of intense skeletal growth
- Tall teenager
- Previous radiation therapy
- Hereditary cancer syndromes
- Paget's disease in the elderly
- Trauma is not the cause but draws attention to the tumor
Symptoms
The first and main symptom is pain in the area of the affected bone, most often around the knee joint or in the shoulder. At first it occurs during exertion and is easily explained by a sports injury, but over time it becomes constant, intensifies at night and disrupts sleep, which distinguishes it from ordinary pain after a bruise. Later, swelling appears, the skin over it may be warm and with dilated veins. The mobility of the adjacent joint is limited, lameness occurs. Sometimes the first manifestation is a fracture in a bone weakened by the tumor.
- Bone pain that gets worse at night
- Swelling and hardening over the bone
- Warm skin with varicose veins
- Restricted movement and lameness
- Fracture due to minor trauma
- General weakness and weight loss in the common form
Diagnostics
The examination begins with an x-ray of the affected bone in two projections - this is often enough to suspect a tumor. Next, an MRI of the entire bone segment with joints above and below is performed to accurately determine the extent of the tumor and its relationship to the vessels and nerves; It is these data that determine the possibility of saving a limb. A CT scan of the chest is required to look for lesions in the lungs. Of the laboratory indicators, alkaline phosphatase and LDH are important. The biopsy should be performed by the surgeon of the team that will operate, since incorrect access may make it impossible to save the limb.
- X-ray of bone in two projections
- MRI of the affected segment with adjacent joints
- CT chest
- Alkaline phosphatase and LDH
- Bone scintigraphy or other skeletal assessment
- Biopsy in a specialized center
Treatment and recovery
Modern treatment follows a single scheme: first several courses of chemotherapy, then surgery, then continued chemotherapy. Preoperative chemotherapy reduces the tumor and allows for more frequent organ-preserving interventions, and the response to treatment is assessed based on the degree of tumor cell death in the removed specimen. Today, most patients are able to save a limb by replacing the removed section of bone with an endoprosthesis or bone graft. Amputation is used much less frequently. After surgery, long-term rehabilitation is required with gradual restoration of support and movements.
- Chemotherapy before surgery
- Organ-preserving tumor removal
- Endoprosthetics or bone grafting
- Chemotherapy after surgery
- Removal of single lesions in the lungs when they appear
- Long-term rehabilitation and physical therapy
- Regular monitoring with lung monitoring
