Osteosarcoma, also known as Osteogenic Sarcoma can be defined as a type of bone cancer where the proliferation of cancer cells happen in the cells that form bones. Although, bone cancer is more common in the long bones of the legs and arms, it can actually start metastasizing in any of the smaller bones as well and sometimes even in the soft tissues surrounding the bone. Osteosarcoma is more common in children and young adults than older people. Also Read: Bone Cancer: Causes, Symptoms And Treatment
In most cases, osteosarcoma starts metastasizing in areas where the bone is growing quickly, such as near the ends of the leg or arm bones, and also includes bones around the knee, either in the lower part of the thigh bones (i.e. distal femur) or upper part of the shinbone (i.e. proximal tibia). It can also happen in the upper arm bone close to the shoulder (i.e. proximal humerus). Apart from this, osteosarcoma can also happen in the bones of the pelvis (i.e. hips), shoulder, and jaw.
Based on the type of cell, where the cancer spreads, osteosarcoma can be classified into three main types, including:
High Grade Osteosarcoma
These are the most common and fastest growing types of osteosarcoma that don't look like normal healthy bone cells under the microscope. These include: Osteoblastic, Fibroblastic, Chondroblastic, Telangiectatic, Small cell, High-grade surface (juxtacortical high grade), Extraskeletal, Pagetoid and Post-radiation.
Low Grade Osteosarcoma
These are the slowest growing ones, exhibiting cells which are similar to that of healthier ones. It includes Parosteal (juxtacortical low grade) and Intramedullary or intraosseous well differentiated (low-grade central).
Intermediate Grade Osteosarcoma
This type of osteosarcoma falls in between the high and the low-grade ones with cells similar to both types. It includes Periosteal (juxtacortical intermediate grade).
Just like any other form of cancer, the exact cause of bone cancer is yet unknown but it usually happens when the genetic instructions within a healthy bone cell mutates or changes causing the bone cells to start dividing to form newer ones without any requirement. This abnormal and out of control growth of the bone cells keep piling up to form tumorous structures that can invade and destroy healthy body tissue and even spread on to other parts of the body. Also Read: Bone Metastasis, Sign of Cancer In Advanced Stage
Some causative factors that increase the chances of osteosarcoma include:
Age: More commonly seen in teens who have a sudden growth spurt.
Gender: Noticed more often in males than in females.
Height: Taller kids are more at risk than shorter ones.
Bone diseases: Diseases like Fibrous dysplasia, or Paget’s disease increases the risk.
Health conditions: Anomalies including Bloom syndrome, Li-Fraumeni syndrome, Hereditary retinoblastoma, Werner syndrome and Rothmund-Thomson syndrome aggravates the chances of osteosarcoma.
Treatment: Any previous treatment with radiation therapy makes one more prone to this type of bone cancer.
The common signs and symptoms of osteosarcoma include:
- Swelling or lumps around bones or the ends of bones as in the case of Osteochondritis Dissecans
- Pain in the bones
- Pain at night
- Pain after exercise
- Joint pain or soreness
- Broken bones or bone injury without a clear reason
Diagnosis And Treatment
On noticing or recognizing any of the above-mentioned signs and symptoms, do consult a doctor right away to get it analysed as early as possible. The doctor usually does a thorough physical examination to look for lumps around larger bones and acknowledges the past medical history. He may also prescribe some diagnostics including:
- Imaging tests like X-rays, CT scans, MRIs, bone scans, and PET scans
- Biopsy including needle and surgical technique
The available treatment options usually include:
- Surgery: Including limb-sparing surgery, rotationplasty and amputation to remove all the cancer cells.
- Clinical trials