Dictionary of selected medical words

Adjuvant treatment – A treatment given in addition to the main treatment to try to prevent a cancer from returning e.g. as a follow-up to surgery to remove any cancer which may be left behind.

Alopecia – The loss of hair as a (usually temporary) side-effect of some forms of chemotherapy or radiotherapy.

Anaemia– A reduction in the number of red blood cells (that carry oxygen). Symptoms of anaemia include feeling tired, weak or short of breath.

Angiogenesis – The growth of new blood vessels. Cancers trick the body into being given the blood vessels they need to grow.

Anti- angiogenesis treatment –  Anti- angiogenic drugs are designed to starve the blood supply to cancers (and they are also likely to give fewer side effects than chemo).

Anti-emetic – A medicine that controls or prevents nausea and vomiting.

Apoptosis – The normal death of cells. Cancer cells escape normal cell death. Cancer scientists also try to treat cancer by blocking the growth of a wide range of common cancer cells, by targeting particular molecules, causing them to self destruct.

Benign tumour – A non-cancerous growth that does not spread to other parts of the body.

Biopsy – The removal and examination of a sample of tissue to see whether cancer cells are present.

Blood Count – The number of red blood cells, white blood cells, and platelets in a sample of blood. This is sometimes called a complete blood count (CBC).

Brachytherapy (Greek for short range) – Involves placing small radioactive sources within the body to apply high doses of radioactivity precisely.

Carcinomatosis – A condition in which multiple (epithelial) carcinomas develop simultaneously after spreading from a primary source. It goes further than cancer spread to regional nodes and is usually taken to mean that there are multiple secondaries in multiple sites.

Cachexia – The loss of weight, muscle loss, loss of appetite, fatigue, weakness in someone who is not actively trying to lose weight.

Cancer classification – Cancers are classified by the type of cell that resembles the tumor and, therefore, the tissue presumed to be the origin of the tumour. Examples of general categories include: Carcinoma (epithelial tissue), Sarcoma (connective tissue), Lymphoma (blood-forming cells), Germ cell tumours (e.g. testical, ovary).

Carboplatin – A platinum based anti-cancer drug similar to Cisplatin with somewhat lower toxicity.

Carcinoma – An invasive malignant tumour derived from epithelial tissue that tends to metastasise to other areas of the body. The most common cancers e.g in breast, prostate, colon, lung.

Carcinoma in situ (CIS) – A malignant tumour which has not yet become invasive but is confined to the layer of cells from which it arose.

Catheter – A thin flexible tube through which fluids can enter or leave the body.

Cell death – see Apoptosis

Chemotherapy – Treatment with anti-cancer drugs. These may be used singly or in combination to kill or prevent the growth and division of cells. Although aimed at the cancer cells, chemotherapy will also unavoidably (but usually temporarily) affect rapidly dividing normal cells such as those in the hair (hair loss), gut (nausea), blood & bone marrow (anaemia), and sperm (infertility) .

Chest X-ray – A chest x-ray is an x-ray picture of the upper chest. It is a quick and inexpensive diagnostic tool to detect lung metastases.

Cisplatin – A platinum based chemotherapy drug.

CNS – Cancer or Clinical Nurse Specialist. A CNS may be allocated to a cancer patient to help navigation through the treatment pathway. See also Key Worker.

Combination chemotherapy – Treatment with more than one anti-cancer drug at a time.

Computed tomography (CT Scan) – An X-ray procedure that uses a computer to produce a detailed picture of a cross-section of the body; also called CT scan or CAT scan.

CUP tumours – The National Cancer Institute in America report 15% of all CUP tumours to be breast, prostate, ovarian and thyroid cancers and these are “all treatable even when metastatic.”

Cycle – A cycle is the time period over which the chemotherapy is given, including rest periods.

Cytotoxic – ‘Toxic to cells’ – anti-cancer treatment.

Differentiation – The degree to which a tumour resembles normal tissue. In general, the closer the resemblance, the better the prognosis. Well differentiated tumours closely resemble normal tissue.

Disseminated disease – Disease in which the cancerous cells have spread (metastasised) from the tissue of origin to other organs.

DNA – Deoxyribonucleic acid. Genes are made from a long molecule called DNA which is copied and inherited across generations.  DNA is a molecule that encodes the genetic instructions used in the development and functioning of all known living organisms and many viruses. It is made of simple units that line up in a particular order within this long molecule. The order of these units carries genetic information, similar to how the order of letters on a page carries information. The language used by DNA is called the genetic code.

Empiric chemotherapy – A chemo regimen based on the experience of the oncologist.

Epithelial tissue – This covers body surfaces, forms glands and lines body cavities. It is one of the four primary tissues of the body. The major characteristic of epithelium is that the cells are close together.

Etiology – The cause or possible cause of a disease. For example, smoking is a cause of lung cancer.

Extravasation – Leaking of a chemotherapy drug out of the vein and into the skin.

False Negative – A test that shows no evidence of disease when disease is actually present.

False Positive – A test that shows evidence of disease when disease is not actually present.

Fraction – A term used in radiation oncology where the radiotherapy dose is divided into a number of smaller doses to reduce side effects.

Gemcitabine – A chemotherapy drug.

Germ Cell Tumour – A tumour arising from germ cells.

Grade – the grade of a tumour is defined by the pathologist and is based on a measurement of the activity of the tumour.

Gray (Gy) – The modern unit of radiation dosage.

Half Life – The time required for half the amount of a substance (such as a tumour marker) in or introduced into the body to be eliminated or disintegrated by natural processes.

Histology – The study of the appearance and behaviour of tissue, usually carried out under a microscope by a pathologist (a doctor) or a histologist (not necessarily a doctor).

Hormones – Chemicals produced by certain glands in the body.

Infusion – Slow and/or prolonged intravenous delivery of a drug or fluids.

Key Worker (see also CNS) – A medical professional who, with the patient’s agreement, takes a key role in co-ordinating the patient’s care; ensuring actions are taken and advising the patient and family on information sources and advice.

Local treatment – Treatment that affects the tumour and the area close to it. (e.g. Radiation therapy).

Lymphoma – A cancer of the lymphatic system. There are many types of lymphoma. One type is called Hodgkin’s; the rest are called non-Hodgkin’s lymphoma. Non-Hodgkin’s lymphomas begin when a type of white blood cell, called a T cell or B cell, becomes abnormal.

Lymph – A nearly colourless fluid that bathes body tissues and contains cells that help the body fight infection.

Lymph nodes – Also called lymph glands.  Small bean-shaped structures located throughout the body along the channels of the lymphatic system. Nodes filter circulating lymph and trap bacteria or cancer cells that may travel through the lymphatic system.

Lymphatic system – The tissues and organs–including the bone marrow, spleen, thymus, and lymph nodes–that  produce and store cells that fight infection and the network of channels that carry lymph.

Malignant – Cancerous.

Margin – The surgical edge of a pathology specimen. Positive margins means that cancer cells were found at the surgical edge of the specimen, and this implies that cancer was left behind in the body.

Melanoma – A cancer of the pigment depression cells of the skin. The word ‘melanoma’ comes from the Greek word ‘melas’, meaning black.

Metastasis (plural=metastases) – cancer that has spread to a site distant from the first (or primary) tumour site. In cancer slang, to have “mets” means that the disease has spread. An untreated primary tumour will try and find fresh nutrients and space to grow by spreading within the body. Spread occurs through the blood stream, the lymphatic system or between organs in the same body cavity. The secondary tumours are likely to have different characteristics from the primary tumour making it difficult to identify the primary and treat.

Metastasise – To spread from one part of the body to another. When cancer cells metastasise and cause secondary tumours, the cells in the metastatic tumour are like those in the original cancer.

Monoclonal antibody therapy – This is the use of monoclonal antibodies (mAb) to specifically bind to target cells. This may then stimulate the patient’s immune system to attack those cells. There is a large amount of research and development currently being undergone to create monoclonals for different types of cancers.

Multi-Disciplinary Team – MDT – the medical team responsible for cancer treatment. An MDT will include all the major specialities, including pathology and nursing staff.

Necrosis – Dead cells. A biopsy may contain necrotic cells. Residual masses after chemotherapy often are composed completely of necrotic tissue.

Neo-adjuvant – treatment prior to surgery designed to improve the prospects of a successful operation. Often chemotherapy, but sometimes radiotherapy.

Neoplasm – Another name for a cancer tumour.

NICE – NICE stands for The National Institute for Health and Care Excellence. NICE aims to give independent advice about which treatments should be available on the NHS in England and Wales and to make sure that people have the same access to treatment and care wherever they live. There are different bodies in Scotland and N. Ireland.

Occult metastasis – A metastasis that is hidden i.e. CUP.

Oncologist – doctor specialising in cancer. Oncologists may be surgical (surgeons), clinical (experts in radiotherapy) or medical (experts in drug treatments).

Palliative – Anything that serves to alleviate symptoms caused by the underlying cancer but not expected to cure it. Palliative care is the active process of caring for the patient with cancer that may not be curable to achieve the best possible quality of life. Many aspects of palliative care are applicable in the earlier stages of the cancer pathway in association with, and to help maximise, other treatments.

Pathologist – A doctor who specialises in the diagnosis of disease by studying cells and tissues removed from the body.

Patient pathway – the medical journey of the patient from the time he or she suspects something may be wrong to beyond the end of treatment.

Performance status – The commonly used ( ECOG/WHO/Zubrod) scores run from 0 to 5, with 0 denoting perfect health:

0 – Fully active, able to carry on all pre-disease activities without restriction

1 – Restricted in physically strenuous activity but ambulatory and able to carry out , for e.g., light housework, office work

2 – Ambulatory and capable of all self care but unable to carry out any work activities. Up and about more than 50% of waking hours

3 – 50% in bed, but not bedbound (Capable of only limited self-care)

4 – Completely disabled. Totally confined to bed or chair

5 – Death

Peripheral neuropathy – A condition of the nervous system that usually begins in the hands and/or feet with symptoms of numbness, tingling, burning and/or weakness. Can be caused by certain anti-cancer drugs like Cisplatin.

PET Scan (Positron Emission Tomography) – An imaging technique using low-dose radioactive sugar to measure metabolic activity. This technique is very sensitive in picking up active tumour tissue but does not measure the size of it.

Photo Dynamic Therapy (PDT) – PDT uses laser, or other light sources, combined with a light-sensitive drug to destroy cancer cells and is a treatment for some types of cancer. The theory is that when the light is directed at the area of the cancer, the drug is activated and the cancer cells are destroyed. PDT may be used to try and cure certain cancers or to reduce symptoms by shrinking the tumour. PDT may be used in conjunction with chemo, radiotherapy or surgery.

Primary – The initial site of the cancer tumour.

Prognosis – The probable outcome of a disease; the prospect of recovery.

Prognostic factors – Factors which are associated with a better or worse outcome of the disease.

Protocol – A detailed treatment plan using certain drugs on certain days.

Rad – An old unit of radiation dose now superseded by the Gray. 1 Gray = 100 rads.

Radiotherapy/ radiation therapy – Treatment with high-energy radiation from X-rays or other sources of radiation. See Teletherapy and Brachytherapy.

Radiologist – a clinical expert in use of imaging and the diagnostic interpretation of images.

RCT – Randomised Controlled Trial – usually a Phase 3 clinical study comparing a standard and a new therapy.

Recurrence – Return of symptoms / cancer cells after a period of quiescence/cure.

Sarcoma – A cancer of connective tissues such as bone, cartilage, fat, muscle, nerve sheath, or blood vessels.

Squamous cell carcinoma (SCC) is a form of carcinoma that may occur in many different organs, including the skin, lips, mouth, esophagus, urinary bladder, prostate, lungs, vagina, and cervix. It is a malignant tumour of squamous epithelium (epithelium that shows squamous cell differentiation). Most cases of head and neck cancer (cancer of the mouth, nasal cavity, throat and associated structures) are due to squamous cell carcinoma. Symptoms may include a poorly healing mouth ulcer, a hoarse voice or other persistent problems in the head and neck area. Treatment is usually with surgery and radiotherapy.

Staging – Classifying a cancer by looking at the size of the tumour and whether it has spread and to decide the best course of treatment. Clinical staging is based upon clinical or radiological evidence, while Pathological staging is based upon histological evidence. In general, the higher the stage, the more extensive the disease / the more the spread.

Stem Cells – Serving as a sort of repair system for the body, these immature cells have the remarkable potential to develop into many different tissue types in the body. When a stem cell divides, each new cell has the potential to either remain a stem cell or become another type of cell with a more specialized function, such as a muscle cell, a red blood cell, or a brain cell.

Steroids – Steroids occur naturally in the body but they may be supplemented during cancer treatment with drugs (such as dexamethasone, prednisolone, methylprednisolone and hydrocortisone) to help combat nausea, reduce inflammation or stimulate the appetite.

Surveillance – The practice of closely watching for (more) evidence of problems before deciding a course of action.

Systemic treatment – Treatment, such as chemotherapy, that reaches and affects cells all over the body.

Teletherapy – Radiation therapy directed from a source outside, or at a distance from, the patient.

Treatment Planning – Individualizing the patient’s treatment plan by the doctors  in consultation with published literature, specialist colleagues, calculation of dosages and schedules.

Tumour – An abnormal mass of tissue.

Tumour Marker – A substance detectable in the blood or urine that suggests the presence of cancer. Markers (e.g PSA for men) may also be used in treatment to measure treatment effects. Because CUP is so non specific, and the markers the same, the value of markers in diagnosis lies in identifying a cancer that is highly treatable. Particular markers may be used if there are specific presentations which suggest likely primaries to help confirm or not confirm the primary.

Ultrasound – A diagnostic technique in which high-frequency sound waves are bounced off tissues inside the body and the echoes are converted into pictures. Tissues of different densities reflect sound waves differently. While an ultrasound may find tumours it may not help in distinguishing them from benign conditions.