Occurrence | Osteosarcoma

Occurrence

The peak of the disease lies in puberty, which means that osteosarcomas occur very frequently in children and adolescents, mostly between the ages of 10 and 20. The disease predominantly affects male adolescents. Osteosarcomas account for about 15% of all primarily malignant bone tumors, making osteosarcoma the most common malignant bone tumor in (male) children and adolescents.

Osteosarcomas can also develop in adults. This is usually the case if previous diseases, such as Paget’s disease (=Osteodystrophia deformans Paget), have occurred. It is also possible that the disease pattern develops after chemo- or radiotherapy.

Causes

As already mentioned in the summary, the causes for the development of an osteosarcoma have not yet been sufficiently clarified. As with almost all other bone tumors, hormonal and growth-related factors are suspected to be the triggering factors. Rarely does an osteosarcoma develop from Paget’s disease or after radiotherapy or chemotherapy of another disease. Statistical data, however, have shown an increased probability of osteosarcoma development after retinoblastoma (tumor in the eye of children).

Metastasis

Due to the tendency of osteosarcoma to form metastases at an early stage, early diagnosis is of fundamental importance. The metastasis is usually hematogenous, i.e. via the bloodstream. Metastases are found above average mainly in the area of the lung, but also in the skeletal area (extension to other bones), or the lymph nodes.

Since an early diagnosis is rather rare due to the lack of directional symptoms, metastases are very often found at the time of diagnosis. Statistically, this is the case in about 20% of all osteosarcoma patients. It is suspected that micrometastases could already be detected in many more patients at diagnosis.

However, they are still too small to be detected with the currently used diagnostic methods. These micrometastases are attempted to be killed by chemotherapy as part of the two-pronged therapy (see: Therapy).

  • Chemotherapeutic pretreatment
  • Surgical removal of the tumor

Diagnosis

The symptoms are often not yet directional in the early stages. They occur first. As the disease progresses, general symptoms of a tumor disease, such as The diagnostic options include X-ray image diagnostics: Here, an X-ray examination is made in the symptomatically conspicuous area (at least 2 levels).

Sonography:Sonography is used in particular if an osteosarcoma has already been diagnosed. It is used for differential diagnosis, especially for the delimitation of a soft tissue tumor. General laboratory diagnostics (blood examination): Special tumor diagnostics: Magnetic resonance imaging (MRI): Magnetic resonance imaging (MRI) can be used in addition to the imaging procedures mentioned in the basic diagnostics.

Since MRI is particularly good at imaging soft tissue, it is possible to assess the extent of the tumor in diagnosed osteosarcoma to neighboring structures (nerves, vessels) of affected bones, and thus also to estimate the tumor volume and clarify the local tumor extent. If a malignant bone tumor is suspected, the entire diseased bone should also be imaged. If necessary, further diagnostic measures should be taken to rule out metastasis in other areas (see above).

Computed tomography (CT): With the help of a CT, the extent of the tumor can be assessed. Digital subtraction angiography (DSA) or angiography:Angiography is the diagnostic X-ray imaging of (blood) vessels after injection of an X-ray contrast medium. In digital subtraction angiography, vessels (arteries, veins and lymphatic vessels) are examined by X-ray diagnosis.

Skeletal scintigraphy (3-phase scintigraphy): This is an imaging procedure using short-lived radionuclides (e.g. gamma rays) or so-called radiopharmaceuticals.Skeletal scintigraphy is used to examine bones with regard to zones with increased bone metabolic activity or blood circulation. They can provide indications of existing osteosarcoma. Biopsy:To determine whether the tumor is malignant or not, tissue is removed and examined in a biopsy (= histopathological (= fine tissue) examination).

A biopsy is often performed if a tumor is suspected or if the type and dignity of a tumor is unclear. Such an examination could, for example, be carried out by means of incisional biopsy. In this procedure, the tumor is partially exposed surgically and a tissue sample (usually bone and soft tissue) is taken.

If a frozen section analysis is possible, the removed tumor tissue can be directly examined and assessed for dignity.

  • Pain and
  • Local signs of inflammation (redness, swelling, overheating)
  • Swelling of the lymph nodes
  • Unintentional weight reduction (more than 10% in 6 months)
  • Paralysis
  • Fracture without accident event (pathological fracture)
  • Night sweat
  • Pallor
  • Power loss
  • Blood count
  • Determination of the BSG (= blood sedimentation rate)
  • CRP (C-reactive protein)
  • Electrolytes
  • Alkaline phosphatase (aP) and bone-specific aP:
  • Prostate specific antigen (PSA) and acid phosphatase (sP). These levels are elevated in prostate carcinomas, which in turn often metastasize to bone.
  • Iron: in tumor patients, iron levels are typically low
  • Total protein
  • Protein electrophoresis
  • Urine status: paraproteins – evidence of myeloma (plasmocytoma)

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All articles in this series:

  1. Osteosarcoma
  2. Occurrence
  3. Prognosis