Though the exact causes of the cancer are not known, there are certain risk factors that can be attributed to it. Depending upon their nature and origin, there are several types in which bone cancer can be divided.
Bone Cancer Depending Upon the Nature of Cells
Under this category, the disease can be classified in two main types:
Benign Bone Tumor
If the abnormal cells are non cancerous in nature, they are termed benign. Such cells do not replicate and remain restricted to the place where they originated. Benign types of bone tumors are not life-threatening and patients suffering from them show good prognosis.
Malignant Bone Tumor
Contrary to the benign one, malignant cancers are those that are cancerous and have the ability to replicate on a very fast rate. In doing so, they replace the healthy bone tissues and hence, reduce their numbers. Most of the malignant tumors pose a great health risk if left untreated or not treated on time.
Another classification of the bone cancer diseases can be done on the basis of their origin:
Primary Bone Tumor
Those malignant cells that originate within the bone itself are termed primary ones.
Secondary Bone Tumor
When the bone tissues receive cancer cells that originated from other body parts such as lungs, breast etc via metastasis, it is referred to as secondary bone cancer.
There are several types of primary cancers that can affect a bone tissue. Let’s have a look at some of them:
One of the most prevalent forms of primary bone tumor, Osteosarcoma mostly affects the people under the age of 25. It is more commonly found in males rather than in females. The abnormal cells originate from the mesoderm layer of connective tissue and are usually located at the upper or the lower ends of long bones like tibia and femur.
In many case, the cancer cells get accumulated in knee, shoulder, and jaw bones. The patients of Osteosarcoma experience pain in bones which becomes worse as the day advances. There is also a susceptibility of bone getting fractured. The average rate of survival for patients suffering from Osteosarcoma is just five years.
Another common type of bone cancer that affects the skeletal system is Chondrosarcoma. The tumor cells, in this disease, are derived from the connective tissues of the cartilage. Generally, old people are more prone to this soft tissue sarcomas. The body parts effected by it are joints between bones, hips, legs, and pelvis.
The disease remains unnoticeable until the patient starts feeling continuous pain or lump in bones. Fracture is another common symptom that can be seen at the site of tumor. If the abnormal cells to not replicate aggressively and the tumor is detected in earlier stages, the chances of survival increase manifold.
Named after James Ewing, this sarcoma of bone is caused by the mutations in the chromosomes 11 & 22 by the exchange of genetic material. The translocation of the chromosomes results in the formation of cancerous cells. Affecting mostly the male population, this type of malignant cancer is commonly found in people under the age of 30.
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The survival rate in the cases when the tumor is restricted to a particular portion is approximately 75% while in malignant cases, it is about 60%. Apart from bones, Ewing’s Sarcoma may also arise in parts like blood vessels, muscles, and fatty tissues.
Spindle Cell Sarcoma
It is a tumor of the connective tissues characterized by the presence of spindle-shaped cells. It is a relatively rare type of bone cancer and usually adults above 40 are prone to it. Depending on the body parts that they affect, spindle cell carcinoma can be broadly divided in 4 categories:
Present in the adults above 50 years of age, the malignancy may arrive from either the bones or the connective tissues. This rare condition normally affects the extremities. It is manifested in the form of a mass or lump that may or may not cause pain. In more advanced stages, other symptoms like weight loss and lethargy may also be observed. These can be accompanied by symptoms like fever and low levels of sugar.
It is the bone sarcoma that arises from the fibrous tissues of the bones and usually common in adults over the 35. The bones affected by it are the long ones-tibia and femur, and soon may spread to the surrounding soft tissues. The usual symptoms are pain, a lump of mass, and limping.
Sometimes, tumor cells do not show any kind of differentiation and it is hard for the specialist to tell in what type of cells did the sarcoma originated. Limp bones and pelvis are affected by them.
One of the rarest types of bone cancers, Leiomyosarcoma is most commonly found in femur, tibia, and humerus.
It is also one of the rare condition in which the cancerous cells are present at the lower portion of sacrum or spine. The tumor cells grow at a slower rate and mostly adults are susceptible to this condition. Some of the cancerous tissues also originate from skull and facial bones.
Giant Cell Carcinoma
This primary cancer is usually is present in the form of giant cells and in most cases, is benign in nature. If the cells become malignant, however, the carcinoma may spread to lungs. Of all the primary bone cancer forms, it accounts for about 5% and is more commonly found in females. The symptoms manifested in it include pain in extremities, inflammation, aches in muscles.
Some other forms of cancer are also prevalent:
lymphoma, a type of cancer that usually originates in lymph nodes and can also initiate in bones. Among the primary benign tumors, osteoid osteoma, osteochondroma, and osteoblastoma are common. Bones may also develop certain types of cysts and fibroma.
Bone cancers usually remain asymptotic till the disease reaches an advanced stage. It is desirable to have the regular check ups done.