Basic Cancer-Related Vocabulary
If you find that your oncologist or anyone else on your treatment team is using words that you don’t understand, ask for clarification and be sure to write it down. When you get home, you can look up that word online and familiarize yourself with what it means.
It would be impossible to outline all the cancer terms you’ll be encountering. But following is some of the terminology that you may encounter with regard to your tumor:
Benign versus malignant: A benign tumor is a mass that grows locally, does not invade surrounding tissue, and, in most cases, doesn’t spread to distant sites. Such tumors may also be referred to as noncancerous or nonmalignant. In contrast, malignant tumors can invade surrounding normal tissue and spread to distant sites.
Although most people are relieved when they hear that their tumor is benign, depending on its location, benign tumors can still cause considerable harm. For example, a benign tumor in the brain may destroy normal tissue as it grows.
In contrast, some malignant tumors may be easily removed through surgical excision and require no further treatment, such as in many cases of basal cell carcinoma of the skin. So, as you can see, benign and malignant can be relative terms.
However, in most circumstances, benign tumors can be removed surgically and don’t require subsequent external radiation, and there is no role for chemotherapy when it comes to these tumors.
Noninvasive and locally invasive versus metastatic: Noninvasive tumors are generally considered superficial cancers because the tumor cells haven’t spread into the surrounding tissue, whereas locally invasive cancer has spread beyond the confines of its own tissue space and directly into the surrounding tissues where it’s not normally present.
Metastatic cancer means the cancer has spread to sites beyond its tissue of origin. This may be to local lymph nodes or to distant organs. The method of spread may be by growth of the cancer into surrounding organs or spread to the lymph nodes or the blood.
Primary tumor versus secondary tumor: Primary tumor refers to what is believed to be the initial site of the malignancy, while secondary tumor or metastatic site(s) refers to locations where the tumor may have spread.
It may not always be easy to distinguish between the primary and secondary tumor sites. This is particularly the case when the cancer is found in multiple sites at diagnosis and one of a number of locations might have been the primary site. In general, in this situation, the most important reason to know the primary site is to determine the most effective treatment program.