First of all, it is important to understand the difference between a benign tumor, and a malignant tumor, and what it actually means to a cancer sufferer - as both have a significant bearing on the prognosis (life-expectancy) of a cancer patient. And, although both do have certain similarities, they have one major significant difference (the difference between life and death at a late-stage development).
Benign tumors - are not usually life-threatening, and are more of a nuisance than anything else (benign tumors are unlikely to cause the fatality of a patient as they do NOT have the ability to metastasize (spread) to other parts of the body. The cells of a benign tumor manufacture chemical adhesion (sticky) molecules which allow the cells to stick together, thus containing the tumor to one local site (the site of origin).
Malignant tumors - on the other-hand, DO have the ability to metastasize to other parts of the body: locally, via the bloodstream, or through the lymphatic system. This is due to the malignant tumor cells not being able to produce the same stickiness, as no chemical adhesion molecules are produced. Because of the lack of these molecules - cells easily breakaway from the main tumor (metastasis).
Can benign tumors become malignant?
Under normal circumstances, a benign tumor CANNOT become malignant. However, there exists a condition which falls between both benign and malignant (pre-cancerous). Pre-cancerous, is where a certain tumor may have the potential to become malignant; although, no actual uncontrollable cell growth is present as yet. Therefore, a pre-cancerous tumor is not actually life-threatening until this uncontrolled cell growth has taken place (if it takes place), and until the process from pre-cancerous - cancerous (malignant) is complete.
Benign, Pre-cancerous, and Malignant recap:
- Benign is non-cancerous (not life-threatening) and usually responds well to treatment.
- Pre-cancerous is non-cancerous (not life-threatening) and usually responds well to treatment (if deemed necessary), until such times when the tumor completes its process to become malignant (life-threatening). However, pre-cancerous tumors do not always transform into life-threatening malignant growths.
- 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 little or no response will be the case (usually resulting in the mortality of a patient).