Our body consists of a set of organs which in turn are composed of cells that divide regularly, in order to replace aging or dead and, thereby maintaining the integrity and smooth functioning of various organs.
This process is regulated by a number of mechanisms that tell the cell when to start to divide and when to remain stable. When these mechanisms are altered in a cell, it and its offspring begin uncontrolled division that eventually will lead to a tumor.
If these cells, they grow out of control, acquire the ability to invade tissues and organs around it (infiltration) and to move and grow in other parts of the body (metastasis), are called malignant tumor, which is what we call cancer.
When the tumor cells from an area of the anus, become malignant and are capable of invading surrounding healthy tissues and reach distant organs and implant them, we talk about anal cancer.
The lymphatic drainage of the tumor varies greatly depending on the location by referring to the dentate line. If the tumor is above the dentate line drain to the lymph node is peri-rectal and spine, as in a rectal cancer. If the tumor is located below the dentate line going lymphatic drainage to the inguinal and femoral nodes.
Anal cancer is a rare tumor, representing only 1.9% of all the tumors of the digestive tract.
However in the last 10 years the incidence has been increasing due to different causes or etiologic factors, such as infection of the human papilloma virus (HPV), sexually transmitted infection with human immunodeficiency virus or AIDS ( HIV) and greater use of Anal intercourse among both males and females.