Bone Cancer
There are more than 30 types of bone cancer, also called bone sarcoma. Bone cancer is rare, accounting for less than 1% of all cancers (National Cancer Institute, 2017). The average age at diagnosis is 41 years (Evola et al., 2017).
Bone cancers can be benign (non-spreading) or malignant (may spread to other organs and tissues), with benign being more common. Bone tumours can also be categorised as being primary if they originate in the bone tissue, or secondary if they are a result of metastasis from other organs. Types of bone cancers include the following (National Cancer Institute, 2017):
Symptoms of bone cancer can include the following (Evola et al., 2017):
The risk factors of bone cancer include the following (Cancer Council Australia, 2017; National Cancer Institute, 2017):
Bone cancers can be benign (non-spreading) or malignant (may spread to other organs and tissues), with benign being more common. Bone tumours can also be categorised as being primary if they originate in the bone tissue, or secondary if they are a result of metastasis from other organs. Types of bone cancers include the following (National Cancer Institute, 2017):
- Osteosarcoma - cancer of the osteoid tissue in bone, accounting for up to 80% of primary skeletal cancers, and most common in the knee and upper arm. This type mostly occurs in children and adolescents (10-19 years).
- Chondrosarcoma - cancer begins in the cartilage at the ends of bones or joints, and most often occurs in the pelvis, upper leg and shoulder. This type mostly affects adults over 40 years.
- Ewing Sarcoma Family of Tumours - the least common type which can occur in bone but also in soft tissues such as muscle, fat, blood vessels or other supportive tissue, and mostly occur in the spine, pelvis, arms and legs. This type occurs most often in children and adolescents (10-19 years), with boys being more affected than girls.
Symptoms of bone cancer can include the following (Evola et al., 2017):
- Pain in the affected area
- Swelling over the affected part of the bone
- Stiffness or tenderness in the bone
- Reduced movement
- Unexplained weight loss
- Reduced sense of feeling in the affected limb
- Tiredness.
The risk factors of bone cancer include the following (Cancer Council Australia, 2017; National Cancer Institute, 2017):
- Age - osteosarcomas are associated with bone growth, hence the risk is higher in children and adolescents.
- Exposure to radiation - exposure to ionising radiation from medical tests or high dose radiation therapy, with growing children being particularly susceptible.
- Metal implants - people who may have had metal implants into bones are more likely to develop osteosarcoma.
- Vitamin D deficiency – some studies have shown having low levels of vitamin D can not only cause poor bone density but bone cancer too. Increasing vitamin D can regulate genes to reduce cancer cell growth and proliferation, angiogenesis (cancer blood supply), inflammation and oxidative stress, while also increasing cancer cell death, immune system function, and bone building. These benefits lead to improved survival and response to therapy (Garimella et al., 2017).
- Water fluoridation - drinking from public water supplies with added fluoride, such as sodium fluoride and other forms, have been shown in studies to increase the risk of osteosarcomas, particularly in teenage boys. Such fluorides can be stored in bone (Bassin, Wypij, Davis & Mittleman, 2006), and shown to cause oxidative stress, skeletal fluorosis, altered bone development and chronic inflammation that can lead to osteosarcoma (Gandhi , Naoghare, Bafana, Kannan & Sivanesan, 2016).
- Chemotherapy – some chemical agents used in chemotherapy for cancer and other treatments may increase the risk of osteosarcoma (Bassin, Wypij, Davis & Mittleman, 2006).
- Medical conditions – congenital conditions, or other bone conditions such as Paget's disease of the bone. Inherited conditions like Li-Fraumeni syndrome, hereditary retinoblastoma or other conditions, a family history of certain cancers, or other genetic factors or mutations can increase the risk.