Bone Cancer
Bone (called metastasis). Bone cancer can begin in any bone in the body, but it most commonly affects the pelvis or the long bones in the arms and legs.
Bone cancer is rare. Most bone tumors are benign, which means they aren’t cancer and don’t spread to other areas of your body. But they may still weaken your bones and lead to broken bones or other problems.
Physiology –
Bone is the supporting framework for your body. The hard, outer layer of bones is made of compact (cortical) bone, which covers the lighter spongy (trabecular) bone inside. The outside of the bone is covered with fibrous tissue called periosteum.
Some bones have a space inside called the medullary cavity, which contains the soft, spongy tissue called bone marrow. The tissue lining the medullary cavity is called endosteum.
Most bones start out as a softer, more flexible form of tissue called cartilage. Cells in the body then lay calcium down onto the cartilage to form bone. After the bone is formed, cartilage may remain at the ends to act as a cushion between bones. This cartilage, along with ligaments and other tissues connect bones to form a joint.
Bone itself contains 2 kinds of cells.
• Osteoblasts are cells that lay down new bone.
• Osteoclasts are cells that dissolve old bone.
In some bones the marrow is only fatty tissue. In other bones it contains blood-forming cells. These cells make new red blood cells, white blood cells, and blood platelets. There are other cells in the bone marrow, too, such as plasma cells and fibroblasts.
Any of these bone cells can develop into cancer
Classification –
▪︎Cancers that form in the bone itself are called primary bone cancers.
There are four types of primary bone cancer:
• Osteosarcoma:
The most common type of bone cancer, most often occurs in young people between the ages of 10 and 30. Osteosarcoma develops in the cells where new bone tissue forms. It can start in any bone, but it usually begins at the ends of large bones such as the arms and legs. Doctors most commonly diagnose osteosarcoma in children and teenagers.
• Ewing sarcoma:
Ewing tumors are the second most common type of primary bone cancer in children, teens, and young adults. Ewing sarcoma includes many different tumors that have similar qualities and are believed to begin in the same types of cells. These tumors can form in the bones and in surrounding soft tissues. Ewing sarcoma most commonly grows in the hips, ribs and shoulder blades, or on long bones such as the legs.
• Chondrosarcoma:
Chondrosarcoma begins in tissue called cartilage. Cartilage is a soft connective tissue that allows movement between bones and joints. Some cartilage becomes bone when the body adds calcium to it. This cancer typically forms in the arm, leg or pelvis bones. Unlike osteosarcoma and Ewing sarcoma, chondrosarcoma occurs more frequently in adults than in younger people.
• Chordoma:
This rare tumor begins in the bones of the spine — usually at the base of the spine or the base of the skull. Like chondrosarcoma, chordoma occurs most often in older adults. Men are more likely than women to develop this type of bone cancer.
▪︎ Many tumors that begin in organs or other parts of the body can spread to the bones, as well as other body parts. These growths are called secondary or metastatic bone cancers. Breast, prostate and lung tumors most commonly metastasize (spread) to the bones.
Stages –
Staging is determined by the size and location of the tumor, and whether or not cancer has spread to other areas. Primary bone cancer is categorized into four stages:
• Stage 1: The tumor is low-grade, and the cancer cells are still localized.
• Stage 2: The cancer cells are still localized, but the tumor is high-grade.
• Stage 3: The tumor is high-grade and cancer has spread to other areas within the same bone.
• Stage 4: Cancer had spread from the bone to other areas of the body, such as the lungs or liver.
Symptoms –
The first symptom for a person with bone cancer is nagging, persistent pain in the affected area. Over time, the pain gets worse and more continuous.
The progression of pain with Ewing sarcoma tends to be faster than in most other bone cancers.
Common symptoms that could be noticed includes –
• swelling in the affected area
• weak bones that lead to a significantly higher risk of fracture
• unintentional weight loss
• a lump in the affected area
Although much less common, a person with bone cancer might also experience fever, chills, and night sweats.
Causes –
Experts are not certain what causes bone cancer, but they have found links between bone cancer and other factors. The most important factor is being exposed to radiation or drugs during treatment for other cancers. Some bone cancers occur due to conditions that are passed down in families (hereditary), although this is not usually the case.
Risk factors
It’s not clear what causes bone cancer, but doctors have found certain factors are associated with an increased risk, including:
• Inherited genetic syndromes.
Certain rare genetic syndromes passed through families increase the risk of bone cancer, including Li-Fraumeni syndrome and hereditary retinoblastoma.
• Paget’s disease of bone.
Most commonly occurring in older adults, Paget’s disease of bone can increase the risk of bone cancer developing later.
• Radiation therapy for cancer.
Exposure to large doses of radiation, such as those given during radiation therapy for cancer, increases the risk of bone cancer in the future.
Diagnosis –
Your doctor will ask about your symptoms and medical history and do a physical exam. They’ll look at pictures of your bones through imaging tests such as:
• X-rays. These show tumors and how big they are.
• CT scans. A computer uses X-rays to make more detailed pictures.
• MRI scans. These use a strong magnet to show inside your body.
• PET scans. A technician injects radioactive glucose (sugar) into your vein. A scanner then spots cancer cells, which use more glucose than regular cells.
• Bone scans. A technician injects a different radioactive material into your vein. It collects in your bones, where a scanner can see it.
Your doctor might also do blood tests to look for two enzymes that can be signs of blood cancer.
A procedure called a biopsy can confirm a diagnosis.
Treatment –
Bone cancer treatment typically involves a combination of approaches. The type and duration of these treatments vary depending on several factors, including the type of bone cancer, the size of the tumor and whether it has spread to other parts of the body. The treatments most commonly used include:
• Surgery:
Your surgeon removes the tumor and some healthy tissue around it. They can also repair or rebuild affected bones with real or artificial bone grafts. Sometimes, an entire limb must be removed to treat cancer.
• Radiation therapy:
This treatment shrinks the tumors with high doses of X-rays. Healthcare providers often use radiation before surgery to shrink the tumor so less tissue has to be removed.
• Chemotherapy:
This type of treatment kills cancer cells throughout the body with medicine. People usually receive this medicine by swallowing a pill or having it injected into a vein.
The outlook for a person with malignant bone cancer depends mainly on whether it has spread to other parts of the body.
The 5-year survival rate is the percentage of people with bone cancer (reported by stage) who are likely to survive to at least 5 years after diagnosis. However, if the cancer spreads to distant sites, such as the lungs, the 5-year survival rate reduces to 33%.
Early detection and treatment is key to improving the outlook.
For more informative articles on cancer and other health related issues, please visit our website www.santripty.com and also feel free to consult. Dr.Parveen, and her team has risen up to the occasion to provide online video consultations, online follow-ups to help for patients during the pandemic.