It is important to learn more about cancer, but it should not require a medical degree. Here you can find explanations for common terms used by doctors, medical sites and news reports.

If you can’t find the word you are looking for, email us at
We will send you an explanation and update this page, too.

3D conformal radiation therapy
Three dimensional conformal radiation therapy is the current standard technique for delivery of radiation therapy. 3D planning is based on information given from CT scans, in contrast to older techniques that use 2D planning based on X-Ray films.
3D treatment planning uses single beams with unique intensity and aims to deliver radiation dose that conforms to the target volume and minimizes exposure to other healthy structures.

Alpha-fetoprotein Tumor Marker
A marker which may indicate germ cell tumors (teratocarcinoma & embryonal cell carcinoma). However, its value is also increased in cases of viral hepatitis, cirrhosis of the liver, and liver cancer.

The death of cells. In normal cells, apoptosis is a natural part of a cell's lifecycle, in which the cell dies normally. In cancer cells, this death may come as a result of the body's own immunity mechanisms, chemotherapy, radiotherapy, or damage in their DNA structure.

Biological therapy
A type of treatment focusing on the immune system. It is used against cancer, or against side-effects from other cancer treatments.

Cancer Antigen (CA) 15-3 Tumor Marker
A tumor marker with normal values <30 U/ml. Increased values may indicate signs of breast cancer, pancreatic cancer, ovarian cancer, colon cancer, lung cancer, stomach (gastric) cancer, cervical cancer, and liver cancer. However, it may be related to benign tumors in the breast and liver as well.

Carcinoembryonic Antigen (CEA) Tumor Marker
A tumor marker based on a substance normally produced during the development of the person as a fetus. Normal values are <5 ng/ml. Increased values may indicate signs of colon cancer, stomach (gastric) cancer, pancreatic cancer, cholangiocarcinoma, breast cancer, lung cancer, as well as gynecological cancers. However, it is also found increased in cases of ulceritive colitis, ulcer, pancreatitis, cirrhosis, hepatitis, renal failure, chronic bronchitis. Finally, smoking may increase the value of this marker as well.

Cryoablation is a procedure for destroying tumor tissue using extreme cold temperatures.

Cyber Knife
Cyber Knife is a type of radiation therapy equipment, which uses a small “linear accelerator” device with a single source of radiation. It is specifically used for tumors in the head’s protective bone (cranium) or outside it. It uses a radiotherapy technique based on 3D models to focus on the specific location on the patient's body.
It has high accuracy minimizing side effects to normal tissue. It can deliver treatment either through a single large dose, or in fractions.

De novo mutation
A "De novo mutation" in a person's genes is a genetic mutation that has not been inherited by any of the person's parents.

Familial condition
A familial condition is one that occurs with a higher frequency among members of the same family, compared to the frequency of the condition in individuals.

Gamma Knife
Gamma Knife is a type of radiation therapy equipment, which uses "radioactive isotope cobalt-60 source". It is specifically used for tumors in the brain. Gamma Knife equipment uses 3D models to focus on the specific location on the patient's brain only.
It has a high accuracy, and therefore minimizes side effects to normal brain tissue.

Hormone therapy
A treatment approach which aims to control cancer cells sensitive to hormones. It is applicable mostly to breast cancer and prostate cancer.

Image-Guided Radiation Therapy (IGRT)
Image-Guided Radiation Therapy (IGRT) is the process used in Radiation Therapy to guide the radiation using images, prior to each radiation treatment. In particular, 2D or 3D images of the treatment plan are compared with images taken on the linear accelerator in order to make any needed positioning corrections.
The goal is to more accurately target the entire tumor, as well as to increase normal organ protection.

Intensity Modulated Radiation Therapy (IMRT)
Intensity Modulated Radiation Therapy (IMRT) is an advanced form of 3D conformal radiation therapy. IMRT uses non-uniform radiation beam intensities to maximize the dose to the target and minimize the dose to the normal tissue.
The goal is to increase accuracy and reduce the effect on healthy tissue.

Laparoscopic surgery
Laparoscopic surgery is performed in a "minimally invasive" way: small incisions (1 or 2 cm) are made, through which surgical elements are operated with the help of a camera. Laparoscopic surgery is considered to be associated with shorter recovery times, less pain, and reduced blood loss.

Linear accelerator
The linear accelerator is the main equipment used in most types of radiation therapy. It generates energy beams which are directed from a rotating arm (called the "gantry") to the tumor's location.

Monotherapy is a therapy with a single drug.

PARP inhibitors
PARP inhibitors are substances used in targeted cancer therapy, as they react with enzymes which help repair DNA damage.

Partial Nephrectomy
Partial removal of the kidney using surgery, without affecting healthy tissue.

Proton therapy
Proton therapy is a kind of Radiation treatment based on a machine that delivers proton beams. With this technology, the high-dose radiation is focused on the tumor area, minimizing irradiation of surrounding normal tissues. Furthermore, protons enter the body and reach the target where they release most of their energy; after that, their energy decreases fast, and therefore the impact on the rest of the body is reduced.
Compared to “traditional” radiation therapy (which uses photons), proton therapy is considered less likely to result in secondary cancers.

Radiation dermatitis
A common side-effect of radiation therapy which causes the skin to turn red temporarily.

Radical Nephrectomy
Removal of the entire kidney using surgery.

Radiofrequency ablation
Radiofrequency ablation is a procedure for destroying tumor tissue using extreme hot temperatures.

Radiosensitizing chemotherapy
Radiosensitizing chemotherapy is a type of chemotherapy which increases the sensitivity of the tissue to radiation therapy.

Robotic surgery
Robotic surgery is a type of surgery in which the surgeon operates the equipment using robotic tools. This is done with small incisions (1 or 2 cm), which, combined with the precision provided by the robotic technology, usually leads to shorter recovery times, less pain, and reduced blood loss.

Stereotactic body radiation therapy (SBRT)
Stereotactic body radiation therapy (SBRT) is a radiation therapy technique which delivers one (or very few) high-dose fractions to a specific area of the patient's body. This technique is using multiple convergent beams.
Practically, SBRT can deliver a high dose to the tumor, and only allow a clinically insignificant dose to adjacent normal tissue.

Targeted therapy
Treatment using an agent that specifically affects a particular molecular target in the tumor cells, which is responsible for cancer progression. These are usually small "molecule inhibitors" and "monoclonal antibodies".

Tomotherapy is a type of radiation therapy in which the tumor is radiated in slices, and not all at once.

A medical term for patients who have not undergone any treatment for the particular condition.

Tumor markers
Substances which can be tracked for diagnosis, prognosis, evaluating treatment effectiveness, as well as ongoing monitoring. These substances are usually sampled from the patient's blood.

Tumor suppressor gene
A tumor suppressor gene is a gene which can prevent cells from becoming cancerous. When a fault appears in such genes (e.g. a mutation), they may lose this property. The loss of this property, combined with other factors, may lead to the creation of a tumor. An example tumor suppressor gene is the TP53 (which encodes the p53 protein).

Tyrosine Kinase Inhibitor
Tyrosine Kinase Inhibitors, also called TKIs, block (inhibit) signals sent to human cells to grow. They are used in cancer treatments for slowing down, or stopping, the growth of cancer cells.

Wild type
A wild type gene is the normal, non-mutated version of the gene.

X-Knife is a radiotherapy technique based on a “high energy linear accelerator”. It is specifically used for stereotactic radiosurgery of brain tumors (benign and malignant). It delivers a high dose radiation in a single fraction and it uses 3D models to focus on the specific location on the patient's brain.