Bone Cancer – Symptoms, Causes, Diagnosis And Treatment
There are two types of bone cancer – primary and secondary. Primary cancer is found very rarely in medical practice and few cases are recorded each year.
Primary bone cancers:
- Osteosarcoma that forms in the bone growth tissue
- Chondrosarcoma originates in cartilage tissue
- Ewing sarcoma, which is formed from the immature bone marrow tissue.
In all cases of bone cancer pain is present. Theoretically bone cancer can be located in any bone in the body, but occurs with predilection in the long bones.
Symptoms and signs of bone cancer:
- Pain and swollen joints (if the cancer is near a joint or near a joint)
- Bones without resistance with a tendency to fracture easily
- Unexplained fatigue
- Unintentional weight loss
- Anemia (usually discovered by chance after a blood test)
Secondary or metastatic bone cancer originates in other organs but metastasizes to bones. A patient with lung cancer or prostate cancer can present bone metastasis from the prostate cancer or lung cancer. The bone lesions are secondary locations of the primary cancer (in our case the lung or prostate cancer) and not primary bone cancer. Metastatic bone cancer is more common than primary bone cancer, because many cancers lead to bone metastases.
In most cases the exact causes of primary bone cancer remains unknown. In Padget’s bone disease, involving a multiplication and abnormal development of bone cells, patients are at increased risk for osteosarcoma.
There are a few cases in which bone cancer has a hereditary component:
- Hereditary Retinoblastoma. Retinoblastoma is a type of eye cancer that starts from the retina cells. These patients have an increased risk of developing primary bone tumors.
- Li Fraumeni syndrome. It is a condition that significantly increases the risk of cancer including brain cancer, breast cancer and osteosarcoma.
- Rothmund-Thomson Syndrome. Disease characterized by skeletal disorders, skin eruptions, and a very high risk for bone cancer.
- Multiple exostosis. It is a hereditary condition that predisposes to cartilage and bone tumors.
In some cases radiation may be culprit behind primary bone cancers. High doses of radiation are necessary though, as with radiotherapy or nuclear accidents. Undergoing routine radiological investigations (radiography, radioscopy) does not increase the risk of bone cancer.
In all cases of unexplained pain in the bones, medical consultation is required. Pain is a symptom that accompanies many disease and is not necessarily a sign of bone cancer. Pain may occur with trauma, limb arthritis, benign tumors. For a certainty diagnosis, a bone sample will be analyzed under the microscope.
- Imaging tests. Simple bone radiography, tomography, ultrasound allows the doctor to visualize the cancer.
- Bone scintigraphy is a procedure in which the patient is injected with a small amount of radioactive material which shall be deposited in the bones, which will be detected and transformed into images to view the bones.
- Biopsy of bone tissue. The certainty diagnosis of any tumor, including bone tumors is based on analysis of tissue samples. Two types of biposy are used – thin needle aspiration, or harvesting a greater portion of the bone using a thicker needle.
- Surgery. Surgery may be excisional (whole tumor excision along with a portion of healthy tissue around it) or incisional, when only a portion of the tumor is removed. Depending on the tumor size and location, local or general anesthesia will be necessary.
Staging of bone cancer
Following the bone tissue analysis, the doctor will determine if the tumor is malignant or benign. If a malignant tumor was found (cancer) the doctor can assess its degree of aggressiveness.
Osteosarcoma and Ewing’s sarcoma are grouped according to their expansion in two stages. If the tumor has only one location or has not spread or it has spread to other parts of the body.
The type of cancer, the stage in which the cancer was found, the presence or absence of tumor metastasis directly influences patient survival rate. A small bone tumor without distant metastases, and with poor tendency twords expanding has a better prognosis than in tumors with high tendency towards expansion.
Any type of cancer treatment is conditioned by tumor size, location, the presence of metastases and the health status of the patient.
Radiotherapy is a treatment for bone cancer that uses X-rays or gamma. This radiation affects both healthy cells and cancer cells but healthy cells can regenerate more easily. Most patients with cancer undergo radiation therapy either before surgery (for tumor shrinking) or after surgery to prevent tumor recurrence. Some doctors recommend radiation therapy for reducing symptoms and pain due to tumors that exert pressure on other organs
Surgery is a basic bone cancer treatment and involves removing the tumor along with a portion of healthy tissue around it so that doctors are sure they remove all the tumor.
In osteosarcoma, limb-sparing surgery involves replacing the bone with an artificial prosthesis or bone from another part of the body or from another person (transplant). A well-coordinated team of doctors – including surgeons, oncologists, radiotherapists and specialists in physical therapy and treatment is important to raise the chances of maintaining the limb.
Chemotherapy uses drugs that destroy and inhibit cells that are rapidly dividing. Cells that are dividing extremely fast and uncontrolled are cancer cells, and cells from other tissues like in the stomach mucosa or bone marrow. In most cases healthy cells recover well at the end of chemotherapy (eg the hair grows). The difference between chemotherapy and radiotherapy is that chemotherapy affects the entire body and that way metastatic cells can be targeted.
Chemotherapy can be used for the following cases:
- Tumor size reduction before surgery, thus facilitating surgery
- Cancer cells removal throughout the body
- Increased life expectancy by reducing the tumor size and extension
- Removal or relief of symptoms
There are cases in which chemotherapy is the only treatment used, but in most cases chemotherapy is part of complex treatment regimens that also include radiation therapy and surgery.