What is cancer?
The word “cancer” was first used by Galen to describe breast cancer that resembled the animal “cancer” (crab) due to the swollen veins around the tumour that reminded him of the crab’s legs.
The body consists of various types of cells that have the ability to be divided. This happens in order to replace old or dead cells with younger ones. The creation of new skin when cut by knife is one of the classic examples, which may explain the concept and need of cell multiplication. Depending on the type of the cell, the time required for the completion of the cycle of a normal cell division varies from minutes to days. The division of a cell is controlled by various mechanisms at molecular level so that there is no rapid increase in body cells. When this control fails due to some changes in the structure of its molecules, uncontrolled cell multiplication begins (tumorigenesis). Tumours are divided into benign and malignant (cancer). As a concept, cancer defines all cases of uncontrolled body cell multiplication, which may threaten an individual’s life.
Any cell type may proceed to uncontrolled multiplication. This may happen due to change in genetic material (DNA), which may be inherited from parents (hereditary cancer) or to acquired changes in the DNA structure. Acquired changes are those that happen to the genetic material of cells during an individual’s lifetime and are not inherited.
Cancer cell is each cell that morphologically differs from a normal cell and has the ability to migrate to other parts of the body through the vascular (blood) or lymphovascular (lymphatic) pathway creating other cancer foci (metastasis). Both the primary focus (i.e. the first focus of cancer cell multiplication) and the secondary foci can be dangerous to the patient due to the occupation of vital organs by the cancer cells, preventing in this way their proper functioning.
Cancer treatment is governed by two guidelines: