Cancer terms: Leukaemia to Oncology

Leukaemia: When there is uncontrolled and/or abnormal growth of infection fighting white blood cells, it results in a type of cancer called leukaemia or commonly called ‘blood cancer’. Leukaemia is classified into Acute Lymphoblastic (ALL), Acute Myeloid (AML), Chronic Lymphoblastic (CLL) and Chronic Myeloid (CML). ‘Acute’ leukaemia is an aggressive cancer which affects children and older people over 65 years or age whereas ‘chronic’ leukaemia affects adults and takes months or even years to develop. Depending on the kind of cells that are affected, leukaemia is classified into ‘myeloid’ and ‘lymphoblastic’.
Leukocytes: Leukocytes (White Blood Cells or WBCs) are like soldiers of our body. They fight infections and help maintain our immunity against disease. They are characterized as granulocytes or agranulocytes. There are three types of granulocytes – Neutrophils, Eosinophil and Basophils and two types of agranulocytes – Monocytes and Lymphocytes. The number of leukocytes may decrease due to chemotherapy during cancer treatment making a person more susceptible to infections.
Lung cancer: Cigarette smoking is a major predisposing factor for lung cancer. Symptoms like persistent cough, pus or blood filled sputum, shortness of breath, chest pain, etc usually indicate lung cancer. Cancers affecting the lungs are usually far advanced before being diagnosed and may be of two main types – small cell lung cancer and non-small cell lung cancer.
Lymphocyte: It is a type of white blood cell that originates in the bone marrow as T cells and B cells. B cells mature into B lymphocytes in the bone marrow while T cells mature into T lymphocytes in the thymus. Lymphocytes can be found in the blood and in lymph tissue. There are three major types of lymphocyte – T cells, B cells and natural killer (NK) cells. T lymphocytes help control immune responses and help kill tumour cells. B lymphocytes make antibodies.
Lymphoma: Lymphatic system is a network of thin vessels and nodes in the body. It helps to fight infections. Cancer of the lymphatic system is called lymphoma. It involves lymphocytes. There are two main types of lymphoma – Hodgkin lymphoma and non-Hodgkin lymphoma. Both these types behave and respond to treatment differently.
Magnetic resonance imaging (MRI): A diagnostic procedure to visualise the soft tissues of the body. It makes better images of organs and soft tissue than other scanning techniques and is particularly useful for imaging the brain, the bones, etc. An external magnetic field is used to send radio waves through the body which produces images of the body on a computer screen as well as on film.
Malignancy: it is a term used when cancer cells divide without control and invade nearby tissues or spread to other parts of the body through the blood and lymphatic systems. Some of the different types of malignancy are: Carcinoma – a malignancy that begins in the skin or in tissues that form the lining of internal organs, Sarcoma – a malignancy that begins in connective tissues of bone, cartilage, muscle, blood vessels, etc., Leukaemia – a malignancy that begins in blood-forming tissues and Lymphoma – malignancy that begins in the immune system cells .
Mammogram: It is an x-ray of the breast taken to diagnose breast cancer. It is also used to screen for breast cancer early in women even before there are any signs and symptoms. A special type of x-ray machine is used for this purpose.
Mastectomy: It is a surgery to remove a part or the entire breast with the purpose of treating or preventing breast cancer. There are various types of mastectomy depending on the amount of breast tissue and lymph nodes removed. Prophylactic mastectomy is done for the purpose of preventing cancer. Only the cancer affected part of the breast with a margin of healthy breast tissue surrounding it is removed in partial mastectomy. In total mastectomy the breast and areola are removed. In modified radical mastectomy the breast, areola, nipple, skin, and most of the axillary lymph nodes are removed on the same side but the chest muscles are left intact.
Metastasis: The spread of cancer from one part of the body to another through blood or lymphatic system is called metastasis. If the cancer spreads to the lymph nodes or tissues close to its origin (primary site), it’s a regional or local metastasis. If the cancer spreads to tissues or organs farther away it’s called a distant metastasis.
Monoclonal antibodies: Antibodies produced in laboratory and used in diagnosis and treatment of cancer. They may be used alone or attached to chemotherapy drugs/radioactive substances. They hunt for antigens distinctive to cancer cells and deliver the drugs directly to the cancer cells thereby killing them without harming healthy cells.
Mutation: It is a change in the DNA of a cell caused by faults during cell division, or by exposure to certain agents in the environment. They are thought to be responsible for cancers or other diseases and can be inherited.
Myeloma:  Also known as multiple myeloma.  It is a malignant tumour of the plasma cells (antibodies producing WBCs) where there is an abnormal accumulation of plasma cells in the bone marrow.
Myelosuppression: Myelosuppression or bone marrow suppression is the decreased number of red blood cells, white blood cells and platelets due to decreased bone marrow activity as a result of cancer treatments like chemotherapy or radiotherapy. Severe or complete myelosuppression is called myeloablation.
Needle biopsy: A type of biopsy procedure in which a needle is used to remove a sample of tissue or fluid for diagnosing tumours. In core needle biopsy a needle with a special tip is used. When a thin needle is used, the procedure is called a fine-needle aspiration biopsy.
Neoadjuvant: A type of induction therapy in which a treatment like chemotherapy, radiation therapy or hormone therapy is given to shrink a tumour before surgically removing it. It is a preoperative treatment aimed at making the main treatment more effective or less destructive.
Neoplasm: Normal cells grow, divide and die. Cells in a neoplasm are abnormal, they do not do so and form an abnormal mass of tissue called a neoplasm or tumour. It may be benign or malignant.
Oncogene: Oncogenes are mutated genes that cause growth of cancer cells. They may be produced due to exposure to certain substances in the environment or can be inherited. They may result due to activation of proto-oncogenes which control normal cell growth thereby resulting in uncontrolled cell growth.
Oncologist: An oncologist is a doctor specially trained to diagnose and treat cancer.
Oncology: Branch of medicine that deals with diagnosis and treatment of cancer. Oncology includes medical oncology, radiation oncology and surgical oncology.