Osteosarcoma

An osteosarcoma (OS) or osteogenic sarcoma (OGS) (or simply bone cancer) is a cancerous tumor in a bone. Specifically, it is an aggressive malignant neoplasm that arises from primitive transformed cells of mesenchymal origin (and thus a sarcoma) and that exhibits osteoblastic differentiation and produces malignant osteoid.

Osteosarcoma is the most common histological form of primary bone sarcoma. It is most prevalent in teenagers and young adults.

Signs and symptoms

Many patients first complain of pain that may be worse at night, may be intermittent and of varying intensity and may have been occurring for a long time. Teenagers who are active in sports often complain of pain in the lower femur, or immediately below the knee. If the tumor is large, it can present as overt localised swelling. Sometimes a sudden fracture is the first symptom because the affected bone is not as strong as normal bone and may fracture abnormally with minor trauma. In cases of more deep-seated tumors that are not as close to the skin, such as those originating in the pelvis, localised swelling may not be apparent.

Causes

Several research groups are investigating cancer stem cells and their potential to cause tumors along with genes and proteins causative in different phenotypes. Radiotherapy for unrelated conditions may be a rare cause.

• A small supernumerary marker chromosome or a giant rod chromosome is present in the tumor cells of low grade OS including low grade central OS and paraosteal OS (see below Variants section), carry various potentially pro-cancerous genes, and are thought to contribute to the development of these OS. (See Small supernumerary marker chromosomes and giant rod chromosomes in osteosarcomas)
• Familial cases where the deletion of chromosome 13q14 inactivates the retinoblastoma gene is associated with a high risk of osteosarcoma development.
• Bone dysplasias, including Paget’s disease of bone, fibrous dysplasia, enchondromatosis, and hereditary multiple exostoses, increase the risk of osteosarcoma.
• Li–Fraumeni syndrome (germline TP53 mutation) is a predisposing factor for osteosarcoma development.
• Rothmund–Thomson syndrome (i.e. autosomal recessive association of congenital bone defects, hair and skin dysplasias, hypogonadism, and cataracts) is associated with increased risk of this disease.
• Large doses of Sr-90, nicknamed bone seeker, increases the risk of bone cancer and leukemia in animals and is presumed to do so in people.

There is no clear association between water fluoridation and cancer or deaths due to cancer, both for cancer in general and also specifically for bone cancer and osteosarcoma. Series of research concluded that concentration of fluoride in water doesn’t associate with osteosarcoma. The beliefs regarding association of fluoride exposure and osteosarcoma stem from a study of US National Toxicology program in 1990, which showed uncertain evidence of association of fluoride and osteosarcoma in male rats. But there is still no solid evidence of cancer-causing tendency of fluoride in mice. Fluoridation of water has been practiced around the world to improve citizens’ dental health. It is also deemed as major health success. Fluoride concentration levels in water supplies are regulated, such as United States Environmental Protection Agency regulates fluoride levels to not be greater than 4 milligrams per liter. Actually, water supplies already have natural occurring fluoride, but many communities chose to add more fluoride to the point that it can reduce tooth decay. Fluoride is also known for its ability to cause new bone formation. Yet, further research shows no osteosarcoma risks from fluoridated water in humans.

Most of the research involved counting number of osteosarcoma patients cases in particular areas which has difference concentrations of fluoride in drinking water. The statistic analysis of the data shows no significant difference in occurrences of osteosarcoma cases in different fluoridated regions. Another important research involved collecting bone samples from osteosarcoma patients to measure fluoride concentration and compare them to bone samples of newly diagnosed malignant bone tumors. The result is that the median fluoride concentrations in bone samples of osteosarcoma patients and tumor controls are not significantly different. Not only fluoride concentration in bones, Fluoride exposures of osteosarcoma patients are also proven to be not significantly different from healthy people.

Source: Wikipedia