What Is The Difference Between Cancer And Sarcoma?

Cancer is a very broad term that defines an abnormal and uncontrolled multiplication of cells in any part of the body. Cells become cancerous when they lose their specialization of function like a normal cell and there is inhibition of apoptosis (programmed cell death). This inhibition leads them to grow uncontrollably into a mass or tumor.

Cancers can be benign or malignant. Benign tumors are those that do not spread or invade into nearby tissues, whereas, malignant tumors spread or invade into nearby tissues. Malignant tumors can be dangerous as they have a tendency not only to spread in the nearby tissues, but also to spread in distant tissues, known as metastasis.

Cancer is a genetic disease and genetic changes affecting proto-oncogenes (responsible for normal cell growth and division), tumor suppressor genes (control cell growth and division) and DNA repair genes (help fix damaged DNA).

Cancer is a vast term that includes both benign and malignant tumors, while sarcoma is a sub-classification or a malignant type of connective tissue cancer. The diagnosis and treatment of both cancer and sarcoma are the same which includes history, clinical evaluation, imaging and biopsy along with chemotherapy, radiation therapy and surgical excision of the tumor. However, the treatment of sarcoma is difficult than other types of cancers due to delay in its diagnosis, which makes its prognosis poorer than other types of cancers.

There are over 200 different types of cancers. Cancers can be grouped either by the organ they originate from or the type of cell they are formed from. Based on the type of cell, cancer can be grouped under five main types, namely:

Carcinomas: They, basically, originate from epithelial cells and are the most common type of cancers. Epithelial cells are either found outside the body, such as the skin or they form the lining of all the organs (such as liver, pancreas or stomach) and body cavities (abdominal cavity or chest cavity) in the body. Few examples include squamous cell carcinoma, basal cell carcinoma, adenocarcinoma and transitional cell carcinoma.

Lymphomas and myelomas: These are the cancers of the lymphatic system. Lymphatic system helps in immunity and fighting infection. Lymphoma is a cancer of lymphocytes (T-cells and B-cells) and the two main types of lymphomas are Hodgkins lymphoma and Non-Hodgkins lymphoma. Myelomas are cancers of plasma cells that are produced by the bone marrow.

Leukemia: This is the cancer of blood cells. The bone marrow forms abnormally large number of white blood cells that circulate in the blood. Increased number of abnormal cells in the blood and bone marrow leads to decreased number of normal blood cells, which causes decreased immunity, excessive bleeding and reduced oxygen supply to the tissues.

Brain and Spinal Cord Cancers: Both, brain and spinal cord form the central nervous system. The most common brain tumor is glioma that develops from glial cells. Brain and spinal cord tumor can either be benign or malignant.

Sarcomas: They are malignant tumors formed in the supporting structures of the body, such as connective tissue and soft tissues. Sarcomas are very rare type of cancers and occur in less than 1% of the population. There are more than 50 subtypes of sarcomas that exist.

They are divided into bone sarcoma or soft tissue sarcoma. These include bones, cartilage, fibrous tissues (tendons and ligaments), blood vessels, lymph vessels, nerves, fat and muscles. They can occur anywhere in the body, but most common types occur in the legs, arms and in the abdomen.

Generally, these are difficult to diagnose as they may be confused with other type of growths and tumors, being so rare. The risk factors for sarcoma include radiation exposure, chemical exposure (arsenic, dioxin and herbicides) and genetic syndromes (neurofibromatosis, retinoblastoma, Werner’s syndrome, Paget’s disease, Gardner’s syndrome, familial adenomatous polyposis and tuberous sclerosis).

Few examples include osteosarcoma, leiomyosarcoma, angiosarcoma, epithelioid sarcoma, Kaposi sarcoma, gastrointestinal stromal tumor (GIST), liposarcoma, synovial sarcoma, myxofibrosarcoma, malignant fibrous histiocytoma and dermatofibrosarcoma protuberans.