First, it is important to understand the difference between a benign tumor and a malignant tumor, and what it really means for a cancer patient, since both have a significant influence on the prognosis (life expectancy) of a cancer patient. And, although both have certain similarities, they have one important difference (the difference between life and death in a late stage development).
Benign tumors are not usually life-threatening and are more bothersome than anything else (benign tumors probably do not cause the fatality of a patient since they do NOT have the ability to metastasize (spread) to other parts of the body. A benign tumor makes chemical adhesion molecules (sticky) that allow cells to stick together, so they contain the tumor at a local site (the site of origin).
Malignant tumors, on the other hand, have the ability to metastasize to other parts of the body: locally, through the bloodstream or through the lymphatic system. This is because malignant tumor cells cannot produce the same adherence since no chemical adhesion molecules are produced. Due to the lack of these molecules, the cells are easily separated from the main tumor (metastasis).
Can benign tumors become malignant?
Under normal circumstances, a benign tumor CAN NOT become malignant. However, there is a condition that is between benign and malignant (precancerous). Precancerous, is where a certain tumor may have the potential to become malignant; however, real and uncontrollable cell growth is not yet present. Therefore, a precancerous tumor is not really life threatening until this uncontrolled cell growth occurs (if it occurs) and until the precancerous (cancerous (malignant) cancer process is complete.
Benign, precancerous and malignant summary:
Benign is not cancerous (does not endanger life) and generally responds well to treatment.
The precancerous is not cancerous (does not endanger life) and generally responds well to treatment (if deemed necessary), until the tumor completes its process to become malignant (life threatening). However, precancerous tumors do not always turn into malignant growths that threaten life.
The malignant is cancerous (life-threatening) with the ability to metastasize to other parts of the body and is more difficult to respond to treatment (sometimes the response to treatment is less) (which usually results in a patient’s mortality )