BIO 203 Lecture Notes - Lecture 17: Cancer, Dysplasia, Angiogenesis
Document Summary
All forms of cancer share one characteristic: uncontrolled cell division. One in three people in the us will develop cancer. Tumor (neoplasm)=a new and abnormal growth of cells. Abnormal mass of tissue surrounded by a capsule of connective tissue. Usually remains at the site where it forms. Often can be removed completely by surgery. Precancerous cells look different from normal cells. May have extra chromosomes or be missing parts of some chromosomes. Form a disorganized clump: carcinoma in situ ( cancer in place ) Tiny mass only a millimeter or two in diameter: tumor attracts a blood supply- angiogenesis. Blood brings nutrients and carries away wastes, allowing continued growth. Vessels form an escape route for tumor cells. As long as a tumor stays in place, it can grow quite large, and a surgeon may still be able to remove it, depending on the location: metastasis.
