Master the vocabulary of oncology — from tumors and staging to chemotherapy and remission — with clear, exam-ready definitions.
Last updated: September 28, 2026
Oncology is the branch of medicine dedicated to preventing, diagnosing, and treating cancer. Understanding its vocabulary — from how a neoplasm is classified to how staging guides treatment — is essential for nursing students, pre-med learners, and anyone working alongside cancer patients.
| Term | Definition |
|---|---|
| Neoplasm | A neoplasm is an abnormal mass of tissue that forms when cells grow and divide beyond the normal controls of the body, and may be benign or malignant. |
| Benign tumor | A benign tumor is an abnormal growth that does not invade surrounding tissue or spread to other parts of the body. |
| Malignant tumor | A malignant tumor is a cancerous growth capable of invading nearby tissue and spreading to distant sites in the body. |
| Carcinoma | Carcinoma is a malignant tumor that arises from epithelial cells, the tissue lining organs and body surfaces. |
| Sarcoma | Sarcoma is a malignant tumor that arises from connective tissue such as bone, cartilage, fat, or muscle. |
| Metastasis | Metastasis is the spread of cancer cells from their original site to form new tumors in other parts of the body. |
| Carcinogen | A carcinogen is a substance or agent capable of causing changes in cells that lead to the development of cancer. |
| Oncogene | An oncogene is a gene that, when activated or mutated, has the potential to drive a normal cell to become cancerous. |
| Tumor suppressor gene | A tumor suppressor gene is a gene that normally restrains cell growth and division, and whose loss of function can allow cancer to develop. |
| Angiogenesis | Angiogenesis is the formation of new blood vessels, a process that tumors rely on to obtain nutrients and continue growing. |
| Tumor marker | A tumor marker is a substance found in blood, urine, or tissue that can indicate the presence or behavior of certain cancers. |
| Staging | Staging is the process of describing the extent of a cancer, including whether it has spread, to help guide treatment decisions. |
| Histologic grade | Histologic grade describes how closely cancer cells resemble normal cells under the microscope, reflecting how aggressively a tumor may behave. |
| Remission | Remission is a period during which signs and symptoms of cancer are reduced or absent following treatment. |
| Relapse | Relapse is the return of cancer after a period of remission. |
| Chemotherapy | Chemotherapy is the use of drugs to destroy or slow the growth of cancer cells throughout the body. |
| Radiation therapy | Radiation therapy is a cancer treatment that uses high-energy beams to damage and destroy cancer cells in a targeted area. |
| Immunotherapy | Immunotherapy is a cancer treatment that stimulates or enhances the body's own immune system to recognize and attack cancer cells. |
| Targeted therapy | Targeted therapy is a cancer treatment that acts on specific molecules involved in the growth and spread of cancer cells. |
| Palliative care | Palliative care is specialized medical care focused on relieving symptoms and improving quality of life for patients with serious illness, including cancer. |
| Oncologist | An oncologist is a physician who specializes in the diagnosis and treatment of cancer. |
| Lymphadenopathy | Lymphadenopathy is the enlargement of lymph nodes, which can occur when cancer cells spread through the lymphatic system. |
| Apoptosis | Apoptosis is the process of programmed cell death that normally eliminates damaged or unwanted cells, and that cancer cells often evade. |
| Cachexia | Cachexia is a syndrome of progressive weight loss, muscle wasting, and weakness that can occur in patients with advanced cancer. |
| Paraneoplastic syndrome | A paraneoplastic syndrome is a set of symptoms caused by substances released by a tumor or by the body's immune response to a tumor, occurring at a site distant from the cancer itself. |
Quizzes, flashcards and spaced repetition — free to get started.
Start learning free →This vocabulary helps you understand how tumors are classified, staged, and treated, and how healthcare teams describe cancer diagnosis and treatment plans.
Yes. This vocabulary is core to US health programs — nursing school and NCLEX prep, pre-med, and medical assistant training. MediLearn lets you drill these terms with quizzes and flashcards using spaced repetition.
Carcinoma is a malignant tumor that arises from epithelial cells, the tissue lining organs and body surfaces.
Histologic grade describes how closely cancer cells resemble normal cells under the microscope, reflecting how aggressively a tumor may behave.
An oncologist is a physician who specializes in the diagnosis and treatment of cancer.