Sarcoma is a soft-tissue cancer, and doctors use grades to describe how aggressive and likely a tumor is to grow and spread. A tumor is graded by the letter G and the numbers 1, 2 and 3. Doctors also take into account the size and location of the tumor and whether it has metastasized or invaded the lymph nodes, according to the American Society of Clinical Oncology.
Grades are determined by the degree of difference between the cancer and other cells, the number of tumor cells dividing and the number that are dying. GX means the tumor cannot be evaluated. The lower the combined score for these three factors, the better the prognosis, according to the American Society of Clinical Oncology.
An MRI can show a tumor's size, depth and relation to other tissues such as muscle, fat, nerves and blood vessels. A biopsy is used to identify the type of cancer, where it originated and its grade. Sarcomas can occur in fatty or fibrous tissues; collagen; in the lower limbs; abdomen; head or neck region, especially in children; in the forearm or hand; deep thigh area; or in blood vessels. Survival rates depend on variables such as age and gender. The size, grade and stage of the tumor also affect the patient's chances of survival.