Glossary
Short definitions first, then a little more detail. Across the site, dotted underlined words like show a definition when you hover or tap.
33 terms
Also called: non-cancerous
Not cancer. A benign growth does not invade nearby tissue or spread, though it can still need treatment if it causes problems.
Benign lumps such as cysts, fibroadenomas and lipomas are very common. Some benign conditions are monitored; others are removed because of their size or position.
Also called: breast imaging reporting and data system
A scoring system (0 to 6) radiologists use to describe how suspicious a breast imaging finding looks and what should happen next.
BI-RADS 0 means more images are needed; 1 and 2 are normal or benign; 3 is probably benign with a short-interval check; 4 and 5 usually lead to a biopsy; 6 means cancer has already been confirmed. It describes a finding, not a diagnosis.
Also called: tissue sample
Taking a small sample of tissue so a pathologist can examine the cells. It is usually needed to confirm cancer.
Biopsies can be done with a needle, during an endoscopy or colonoscopy, or in a small operation. The sample goes to a laboratory, where a pathologist examines it and writes a report.
Also called: CTC, CTCs, circulating tumor cells
Whole cancer cells that have broken away from a tumour and travel in the bloodstream. Some liquid biopsies count or study them.
CTCs are very rare, often a few cells among billions of blood cells. In some advanced breast, prostate and bowel cancers, the number of CTCs can help estimate outlook. Their role in early detection and routine treatment decisions is still being studied.
Also called: ctDNA, cell-free tumour DNA
Small fragments of DNA that tumours shed into the bloodstream. Liquid biopsies look for them.
ctDNA is often a tiny fraction of all the cell-free DNA in blood, especially in early cancer. It is used to guide treatment in some advanced cancers and is being studied for monitoring and early detection.
Also called: bowel scope
A test that uses a thin flexible camera to look inside the large bowel, and can remove polyps at the same time.
Colonoscopy is used to investigate symptoms, follow up a positive stool test and, in some countries, for screening. It needs bowel preparation the day before.
A test result that says nothing was found when the condition is actually present.
No test is perfect. A false negative can give false reassurance, which is why new or lasting symptoms should be checked even after a normal screening result.
A test result that suggests a problem when there is none. It usually leads to more tests that turn out normal.
False positives are an expected part of screening. They can cause worry and further tests. Programmes try to balance finding cancers against creating too many false alarms.
Also called: tumour sequencing, biomarker testing, NGS
Testing a tumour's DNA for changes that may guide treatment, such as targeted drugs or clinical trials.
Genomic profiling of a tumour looks at changes inside cancer cells (somatic changes). It is different from inherited (germline) testing, which looks for gene changes present from birth that may affect relatives.
Also called: hereditary testing, BRCA test
A blood or saliva test for inherited gene changes, such as BRCA1 or BRCA2, that raise cancer risk in a family.
Genetic counselling before and after testing helps people understand results, including what they may mean for relatives. Most cancers are not caused by inherited changes.
Also called: tumour grade
How different cancer cells look from normal cells under the microscope, which hints at how fast they may grow.
Low-grade cancers tend to grow more slowly; high-grade cancers tend to grow faster. Grade is different from stage, which describes size and spread.
Also called: papillomavirus
A very common virus passed on by skin-to-skin contact. Long-lasting infection with high-risk types causes almost all cervical cancers and some others.
Most HPV infections clear on their own. HPV vaccination prevents infection with the main high-risk types, and HPV testing is now the main cervical screening test in many countries.
A blood test that looks for tumour signals such as circulating tumour DNA (ctDNA) or circulating tumour cells (CTCs). It does not replace a tissue biopsy for diagnosis.
Established uses include finding treatment-guiding gene changes in some advanced cancers. Uses for monitoring and multi-cancer early detection are emerging or investigational.
Also called: lymph gland, gland
Small bean-shaped glands that are part of the immune system. They often swell with infections.
Cancer can spread to nearby lymph nodes, so they are checked during staging. Swollen glands are far more often caused by infections than by cancer.
Also called: cancerous
Cancerous: cells that can grow into nearby tissue and may spread to other parts of the body.
A pathologist decides whether a growth is malignant by examining tissue. Scans can suggest it, but a biopsy usually confirms it.
Also called: mammography
A low-dose X-ray of the breast used for screening and to check breast symptoms.
Screening mammograms look for cancer in people without symptoms. Diagnostic mammograms are used to check a lump or other change.
Also called: metastatic, secondary cancer, spread
When cancer spreads from where it started to another part of the body. The new tumour is still named after the original cancer.
For example, breast cancer that has spread to bone is called metastatic breast cancer, not bone cancer. Metastatic cancer can often be treated and controlled, sometimes for many years.
Also called: MCED
Blood tests that look for signals of many cancers at once in people without symptoms. They are investigational and do not replace recommended screening.
A positive MCED result needs scans and usually a biopsy to confirm or rule out cancer. A negative result does not rule cancer out. Large trials are testing whether these tests reduce cancer deaths.
Also called: tumour board
A group of specialists, such as surgeons, oncologists, radiologists, pathologists and nurses, who plan care together.
Many hospitals discuss each new cancer diagnosis at an MDT meeting. You can ask what the team recommended and why.
A doctor who specialises in treating cancer. Medical oncologists use medicines; radiation oncologists use radiotherapy; surgical oncologists operate.
Haematologists treat blood cancers. Your care may involve several specialists working as a team.
Finding a cancer through screening that would never have caused symptoms or harm in a person's lifetime.
Overdiagnosis is not a mistake by a doctor: at the time of diagnosis it is usually impossible to know which slow-growing cancers would stay harmless. It can lead to treatment that was not needed, which is why screening involves trade-offs.
Also called: supportive care
Specialist care for symptoms, stress and difficult decisions at any stage of a serious illness, alongside other treatment.
Palliative care is not the same as end-of-life care or giving up. It can start at diagnosis. Hospice care is one part of it, near the end of life.
Also called: histology, histopathology
The medical specialty that examines tissue and cells to diagnose disease. The pathologist writes the report that confirms cancer.
Pathology reports describe the cancer type, grade and features such as receptors or margins. Ask your team to go through the report with you.
A small growth on the lining of an organ such as the bowel. Most are harmless, but some can slowly become cancer if left.
Removing bowel polyps during colonoscopy is one way screening prevents cancer.
Also called: PPV
The chance that a positive test result really means the condition is present.
PPV depends on how accurate the test is and how common the condition is in the people tested. The same test has a lower PPV in a group where the condition is rare.
Also called: PSA test
A protein made by the prostate. A raised PSA level can have many causes and does not by itself mean cancer.
Enlarged prostate, infection, recent ejaculation and vigorous exercise can raise PSA. Decisions about PSA testing are best made after discussing benefits and harms.
Also called: complete remission, partial remission
When signs and symptoms of cancer have reduced (partial) or can no longer be found (complete) after treatment.
Remission is not always the same as cure, which is why follow-up continues. Your team can explain what remission means for your situation.
Also called: cancer screening
Testing people who have no symptoms to find cancer or pre-cancer early. It is different from checking a symptom.
If you have symptoms, do not wait for a screening invitation: see a clinician. Screening programmes set ages and intervals based on evidence of benefit and harm.
How good a test is at finding people who do have the condition. Lower sensitivity means more missed cases.
A test with 90% sensitivity finds about 90 out of 100 people who have the condition and misses about 10.
How good a test is at correctly clearing people who do not have the condition. Lower specificity means more false alarms.
Even a small drop in specificity can create many false positives when a large, mostly healthy population is tested.
Also called: staging, TNM
How large a cancer is and whether it has spread. Staging uses scans, examination and pathology.
Many cancers use the TNM system: Tumour size, lymph Nodes involved, and Metastasis (spread). Stages are often summarised from 1 to 4. Stage guides treatment choices.
Also called: living with and beyond cancer
Life during and after cancer treatment, including follow-up care, late effects, emotional health, work and relationships.
A survivorship care plan summarises the treatment you had, what to watch for and who follows you up.
Also called: tumor marker, CA-125, CEA
A substance in blood or urine that can be higher with some cancers, and also with many non-cancer conditions. It cannot diagnose cancer alone.
Tumour markers are mainly used to monitor a known cancer over time. Raised levels always need interpretation alongside symptoms, examination and imaging.
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