The Difference Between Benign and Malignant Lung Cancer


Whether a patient’s lung cancer is diagnosed as being benign or malignant; can have a large bearing on the prognosis (life expectancy) and treatment options for that person. Although both conditions can be potentially life-threatening to a lung cancer sufferer – both are medical terms that must be fully understood (for the consequences involved) by any diagnosed cancer patient.

What is a benign lung cancer tumor?

Usually benign (a medical word used to describe a medical condition) is used to describe lung cancer tumors that are not specifically dangerous (not usually resulting in death). It is where a mass (lump) or tumor is found to be of a nuisance (an annoying problem), although not likely to cause the fatality of the patient in which it has been found (benign tumors do not have the ability to spread to other regions of the body [no metastasis – spread is present]).

What is a malignant lung cancer tumor?

When the word malignant is used (often synonymously with the word “dangerous”) for lung cancer, it usually refers to a tumor being cancerous. That is to say – the tumor has the ability to metastasize to other regions of the body (either locally, via the bloodstream, or through the lymphatic system). Although, both malignant and benign tumors do have certain similarities. For example:

(a) Both have the ability to grow large in size (size alone has no actual bearing on whether the tumor is malignant or benign).

(b) Both can be dangerous (malignant because it is cancerous, and benign because it has the ability to grow to a size that may affect the functional ability of other organs).

(c) Both have the ability to recur locally (usually after an operation has not successfully removed the tumor completely [contaminated cells are left behind]).

As with their similarities, they also have certain differences, for example:

(a) Usually benign tumors grow more slowly than those diagnosed malignant (exceptions do exist [certain benign tumors may grow more quickly than malignant tumors, and visa-versa]).

(b) Benign tumors do not metastasize to distant regions of the body as do malignant ones (malignant tumors metastasize to other regions of the body destroying important organs on their way).

(c) Malignant tumors often recur in distant regions of the body (those other than the site of origin).

So what allows malignant tumors to spread and benign ones not to?

When a benign tumor forms, the cells within manufacture chemicals (adhesion molecules) that cause them to stick together, whereas malignant tumor cells do not produce the same chemical (because of the lack of adhesion molecules [stickiness] the cells easily break away from the main tumor and float to other regions in the body).

Other differences include the following: tissue invasion (malignant), under microscopic investigation there is little likeness, benign tumors can often be removed with surgery alone, less likelihood of recurrence (benign), systemic effects such as fatigue and weight-loss are more common with malignant tumors, and benign tumors have a lower mortality rate.