GLOSSARY

The following closely related terms may be used to designate abnormal growths:

* Tumor or tumour: originally, it meant any abnormal swelling, lump or mass. In current English, however, the word tumor has become synonymous with neoplasm, specifically solid neoplasm. Note that some neoplasms, such as leukemia, do not form tumors.
* Neoplasm: the scientific term to describe an abnormal proliferation of genetically altered cells. Neoplasms can be benign or malignant:
o Malignant neoplasm or malignant tumor: synonymous with cancer.
o Benign neoplasm or benign tumor: a tumor (solid neoplasm) that stops growing, does not invade other tissues and does not form metastases.
* Invasive tumor is another synonym of cancer. The name refers to invasion of surrounding tissues.
* Pre-malignancy, pre-cancer or non-invasive tumor: A neoplasm that is not invasive but has the potential to progress to cancer (become invasive) if left untreated. These lesions are, in order of increasing potential for cancer, atypia, dysplasia and carcinoma in situ.

The following terms can be used to describe a cancer:

* Screening: a test done on healthy people to detect tumors before they become apparent. A mammogram is a screening test.
* Diagnosis: the confirmation of the cancerous nature of a lump. This usually requires a biopsy or removal of the tumor by surgery, followed by examination by a pathologist.
* Surgical excision: the removal of a tumor by a surgeon.
o Surgical margins: the evaluation by a pathologist of the edges of the tissue removed by the surgeon to determine if the tumor was removed completely ("negative margins") or if tumor was left behind ("positive margins").
* Grade: a number (usually on a scale of 3) established by a pathologist to describe the degree of resemblance of the tumor to the surrounding benign tissue.
* Stage: a number (usually on a scale of 4) established by the oncologist to describe the degree of invasion of the body by the tumor.
* Recurrence: new tumors that appear at the site of the original tumor after surgery.
* Metastasis: new tumors that appear far from the original tumor.
* Median survival time: a period, often measured in months or years, over which 50% of the cancer patients are expected to be alive.[104]
* Transformation: the concept that a low-grade tumor transforms to a high-grade tumor over time. Example: Richter's transformation.
* Chemotherapy: treatment with drugs.
* Radiation therapy: treatment with radiations.
* Adjuvant therapy: treatment, either chemotherapy or radiation therapy, given after surgery to kill the remaining cancer cells.
* Neoadjuvant therapy: treatment either chemotherapy or radiation therapy, given before surgery to shrink a tumor to make its resection easier.
* Prognosis: the probability of cure/remission after the therapy. It is usually expressed as a probability of survival five years after diagnosis. Alternatively, it can be expressed as the number of years when 50% of the patients are still alive. Both numbers are derived from statistics accumulated with hundreds of similar patients to give a Kaplan-Meier curve.
* Cure: A cancer patient is "cured" or "in remission" if they live past the time by which 95% of treated patients live after the date of their diagnosis of cancer. This period varies among different types of cancer; for example, in the case of Hodgkin's disease this period is 10 years, whereas for Burkitt's lymphoma this period would be 1 year.[105] The phrase "cure" used in oncology is based upon the statistical concept of a median survival time and disease-free median survival time.[106]