Bones are the structure of the entire human body. It is what allows us to stand up right, climb mountains and run marathons. They also protect our vital organs such as our lungs and the heart. Because they are such an important part of our bodies, it’s quite critical when the growth and structures of bones go haywire. We’ve heard about what happens when bones weaken and don’t grow and solidify enough, this is when we get osteoporosis. But what happens when bones start growing too much?
Two types of cells work together in maintaining bone structure. Osteoblasts, which build and create bone via intramembranous ossification, and osteoclasts which reabsorbs damaged or dead bone. We do have more types of cells in our bodies called mesenchymal stem cells and neuroectodermal cells, which can differentiate into nerve, fat, bone and cartilage cells. Now there are genes in our body that promote normal cell growth called proto-oncogenes. But these can mutate and become oncogenes, which overstimulate cell growth. To balance this out, our bodies have tumor suppressor genes, which promote cell death. When these genes mutate together this is when we get tumors. Tumors come in two types, benign and malignant. Benign tumors are usually confined and do not spread to other tissues of the body. Malignant tumors are what we consider the dangerous tumors. These tumors invade tissues and metastasize. The primary malignant tumors arise from bone cells and secondary tumors are tumors somewhere else in the body and metastasize to the bones.
Osteosarcoma is the most common malignant bone tumor. These arise from osteoblasts that produce too much osteoid tissue. These usually form in the metaphysis and growth plates of long bones because this is where the most cell growth occurs. Because of this, osteosarcoma generally affects 10-18 year olds, when the most bone growth is happening. Treatment for this tumor is generally surgery, sometimes amputation followed by chemotherapy.
Another type of adolescent cancer is Ewing Sarcoma. These tumors begin their formation in neuroectodermal cells and are caused by genetic mutations. This causes a defect in differentiation in mesenchymal stem cells. This results in the cells that cause the tumor called Ewing sarcoma tumor cells. The most common bones affected are the femur and the sacrum. Treatment usually includes surgery and radiation and chemotherapy.
Chondrosarcoma are malignant tumors, usually found on the scapula or pelvis. Unlike osteosarcoma, this type of cancer is found in mostly adults over the age of 50. These tumors develop chondrocytes, cells that develop cartilage. The tumor cells begin in the cartilage but will end up forming on top of the bone. In fact most patients aren’t even aware of the tumor until it causes a painful lump on the leg or arm. Unlike other sarcomas, chondrosarcoma is resistant to radiation and chemotherapy. Because it is so rare and hard to treat, most chondrosarcoma patients must go to a sarcoma treatment center. Surgery is the first step in treatment, starting at ablation and sometimes ending up in amputation at the shoulder or hip.
For my project, I decided to base it off the objectives knowing the stages of bone development and bone cell types. I designed a classroom poster showing and explaining the different types of sarcomas. It shows a healthy bone, and what the inside is supposed to look like. I also showed two types of sarcomas, osteosarcoma and Ewing’s sarcoma, and how they form onto the bones. I also included quick facts about each type of tumor and how they are unique from the other.