| Term | Definition |
| Adjuvant therapy or treatment | A treatment given after the main treatment for cancer to reduce the risk of recurrence. |
| Adverse event | Detrimental change in health occurring in a person receiving the treatment whether or not it has been caused by the treatment. |
| Axillary | In the armpit. |
| Biopsy | Removal of a sample of tissue from the body to assist in diagnosis or inform the choice of treatment of a disease. |
| BRAF V600 mutation | BRAF is a human gene that makes a protein called B‐Raf which is involved in the control of cell growth. BRAF mutations (damaged DNA) occur in around 40% of melanomas, which can then be treated with particular drugs. |
| BRAF inhibitors | Therapeutic agents which inhibit the serine‐threonine protein kinase BRAF mutated metastatic melanoma. |
| Breslow thickness | A scale for measuring the thickness of melanomas by the pathologist using a microscope, measured in mm from the top layer of skin to the bottom of the tumour. |
| Cervical (lymph nodes) | Lymph nodes found in the neck area of the body. |
| Computed tomography (CT) | Imaging technique in which the person lies on a table within an x‐ray gantry. The images are acquired using a spiral (helical) path and banks of detectors, allowing presentation of the internal organs and blood vessels in different projections including 3‐D views. |
| Coronal | Frontal plane dividing the body into front and back. |
| False negative | An individual who is truly positive for a disease, but whom a diagnostic test classifies them as disease‐free. |
| False positive | An individual who is truly disease‐free, but whom a diagnostic test classifies them as having the disease. |
| Histopathology | The study of tissue, usually obtained by biopsy or excision, for example under a microscope. |
| Incidence | The number of new cases of a disease in a given time period. |
| Inguinal | Lymph nodes in or just above or just below the groin. |
| Isolated limb perfusion | A medical procedure that directly delivers a drug through the bloodstream in a limb to the site affected by melanoma. |
| Local recurrence | Regrowth of a tumour in the area from which it was originally removed. |
| Locoregional recurrence | Regrowth of a tumour in the area from which it was originally removed or in the regional lymph nodes (usually nearest to the original tumour site). |
| Lymph node | Lymph nodes filter the lymphatic fluid (clear fluid containing white blood cells) that travels around the body to help fight disease; they are located throughout the body often in clusters (nodal basins). |
| Lymph node dissection | Surgical removal or one or more lymph nodes in the absence of proven involvement with melanoma. |
| Lymphadenectomy | Lymphadenectomy or lymph node dissection is a surgical operation to remove one or more groups of lymph nodes. |
| Lymphoscintigraphy | An imaging technique used to identify the lymph drainage basin, determine the number of sentinel nodes, differentiate sentinel nodes from subsequent nodes, locate the sentinel node in an unexpected location, and mark the sentinel node over the skin for biopsy. It requires the injection of a radioisotope into the skin around the biopsy scar and a scan some hours later to determine to which lymph nodes the tracer has travelled. |
| Lymphovascular invasion | Tumour cells which have spread to involve the blood vessels and lymphatic vessels within the skin. |
| Magnetic resonance imaging (MRI) | A type of scan which uses a magnetic field and radio waves to produce images of sections of the body. |
| Mediastinal and hilar adenopathy | Enlargement of the pulmonary lymph nodes. |
| MEK inhibitors | Drugs that inhibit the mitogen‐activated protein kinase enzymes which are often upregulated in melanoma. |
| Meta‐analysis | A form of statistical analysis used to synthesise results from a collection of individual studies. |
| Metastases/metastatic disease | Spread of cancer away from the primary site to somewhere else through the bloodstream or the lymphatic system. |
| Micrometastases | Micrometastases are metastases so small that they can only be seen under a microscope. |
| Mitotic rate | Microscopic evaluation of number of cells actively dividing in a tumour. |
| Morbidity | Detrimental effects on health. |
| Mortality | Either (1) the condition of being subject to death; or (2) the death rate, which reflects the number of deaths per unit of population in relation to any specific region, age group, disease, treatment or other classification, usually expressed as deaths per 100, 1000, 10,000 or 100,000 people. |
| Multidisciplinary team | A team with members from different healthcare professions and specialties (e.g. urology, oncology, pathology, radiology, and nursing). Cancer care in the National Health Service (NHS) uses this system to ensure that all relevant health professionals are engaged to discuss the best possible care for that patient. |
| Nodal basin | Cluster of lymph nodes which filter lymphatic fluid as it travels around the body; clusters are located under the arm (axilla), in the groin, neck, chest and abdomen. |
| Oncology | The study of cancers. This term also refers to the medical specialty of cancer care, with particular reference to the use of radiotherapy or drugs to treat cancer. The medical specialty is often split into clinical oncology (doctors who use radiotherapy and drug treatment) and medical oncology (doctors who use drug treatment). |
| Palpation | Feeling with the fingers or hands as part of a clinical examination of the body. |
| Positron emission tomography (PET) | A nuclear medicine imaging technique whereby a radioactive glucose (usually 18FDG) is administered intravenously before a scan is conducted to create an image using colours to show where the FDG (or other radioactive tracer) has been taken up in the body. |
| Prevalence | The proportion of a population found to have a condition. |
| Prognostic factors/indicators | Specific characteristics of a cancer or the person who has it which might affect the patient’s prognosis. |
| Radiotherapy | The use of radiation, usually high energy x‐rays to control the growth of cancer cells. |
| RAS‐RAF‐MEK‐ERK signalling pathway | A chain of proteins which allow signals from a receptor on the surface of a cell to be sent to the DNA in the cell nucleus; a mutation in one of the proteins in the pathway is associated with the development of many cancers. |
| Recurrence | Recurrence is when new cancer cells are detected following treatment. This can occur either at the site of the original tumour or at other sites in the body. |
| Relapse | Where cancer starts to grow again after treatment. |
| Sagittal | Median plane dividing the body into left and right. |
| Sensitivity | In this context the term is used to mean the proportion of individuals with a disease who have that disease correctly identified by the study test. |
| Sentinel lymph node biopsy (SLNB) | A radioactive tracer and blue dye are injected into the skin surrounding the primary lesion and the 'sentinel' lymph nodes to which the tracer drains are located by imaging (usually lymphoscintigraphy) and then removed and examined for nodal metastatic spread that cannot be detected clinically or on imaging. |
| Signal transduction | Occurs when extracellular signalling molecules activate a specific receptor which then triggers cellular pathways. |
| Staging | Clinical description of the size and spread of a patient’s tumour, fitting into internationally agreed categories. |
| Stereotactic radiotherapy | A technique for delivering high dose radiotherapy very accurately to small areas inside the body which reduces the damage done by the radiotherapy to adjacent healthy tissues. |
| Subclinical (disease) | Disease that is usually asymptomatic and not easily observable, e.g. by clinical or physical examination. |
| Systemic treatment | Treatment, usually given by mouth or by injection, that reaches and affects cancer cells throughout the body rather than targeting one specific area. |
| Ultrasound | A type of scan in which high‐frequency sound waves are used to outline a part of the body. |
