It holds stool until it leaves the body through the anus. These abnormal cells continue to divide to make more cells, even though the body does not need the new cells. After a while, the accumulation of unneeded new cells results in a mass of extra tissue called a growth or tumor.
Rectal tumors can develop anywhere in the rectum.
Cancerous or malignant tumors often outgrow their original site and spread to nearby tissues or organs by entering the bloodstream or lymphatic system. The spread of cancer cells to other areas is called metastasis. Rectal cancer is uncommon, affecting about 11,000 Americans each year. The cause of rectal cancer is only partially understood. It is known that people with the following characteristics are more likely to develop rectal cancer.