R
- Radiation:
- A term used to describe energy in the form of waves or particles. Radiation can be used in the diagnosis and treatment of cancer.
- Radiation fibrosis:
- The formation of scar tissue as a result of radiation therapy.
- Radiation oncologist:
- A doctor who specializes in the treatment of cancer using high dose X-rays.
- Radiation therapy:
- Treatment of cancer with high energy X-rays which kills cancerous cells.
- Radical maxillectomy:
- Surgical removal of the upper jaw, nasal bone, and part of the sinuses. This surgery may be recommended for advanced cases of cancer in the sinus or upper jaw.
- Radical neck dissection:
- A surgical procedure removing tissue from the collarbone to the jaw, and from the front of the neck to the back. The muscle on the side of the neck is removed, along with the major vein, the spinal accessory nerve, and all of the cervical lymph nodes.
- Radical prostatectomy:
- Surgery to remove the prostate gland and the two seminal vesicle glands attached to the prostate.
- Radioactive implant:
- A material that gives off high-dose radiation and is placed directly into the body to destroy cancerous cells.
- Radioactive iodine:
- A radioactive form of iodine that is used for imaging studies or as a treatment for cancer.
- Radioisotopes:
- An unstable element that releases radiation as it breaks down. Radioisotopes can be used in imaging studies or in cancer treatments.
- Radiologist:
- A doctor who specializes in the diagnosis and treatment of diseases using X-ray examinations.
- Radiosensitizers:
- Drugs that make cancer cells more sensitive to radiation therapy.
- Radiotherapy:
- Another term used to describe radiation therapy or the use of radiation to treat cancer.
- Randomized:
- In a clinical trial, the human subjects are assigned by chance to separate groups that compare different treatments. A computer generates the treatment assignments in order to avoid bias.
- Receptors:
- A molecule inside or on a cell surface that binds to a substance and causes a specific action in the cell. For example, in breast cancer, doctors test for estrogen and progesterone receptors.
- Rectum:
- A short muscular tube that forms the last five to six inches of the colon or large intestine.
- Recurrence:
- The return of a cancer at its original site after a period of remission.
- Red blood cells (erythrocyte):
- The blood cells that carry oxygen and are responsible for the red color of blood.
- Red blood count:
- A blood test to count the number of red blood cells.
- Reed-sternberg cells:
- A particular type of cell that appears in people with Hodgkinís Disease.
- Refractory:
- Resistant to therapy.
- Regimen:
- A treatment plan that specifies the drug and dosage, the schedule of treatments, and how long the treatments will last.
- Regional involvement:
- The spread of cancer from its original site to nearby surrounding areas. Regional cancers are confined to one location in the body.
- Regression:
- Reduction in the size of a tumor.
- Rehabilitation:
- A program that assists a sick/disabled person to regain as many normal life activities as possible.
- Relapse:
- A reappearance of cancer after it had disappeared for a period of time. The disease is active again and causing symptoms.
- Remission:
- A state or period of time during which the symptoms of a disease have disappeared.
- Reproductive:
- The organs in the woman and man that enable them to produce a child. In women, the organs include the ovaries, fallopian tubes, uterus, cervix, and vagina. In men, the organs include the prostate, testes, and penis.
- Resection:
- The surgical removal of part of an organ or structure.
- Respiratory tract:
- The organs that carry oxygen from the air to the bloodstream and then expel carbon dioxide. It includes the nose, nasal passages, nasopharynx, larynx, trachea, bronchi, and lungs. The upper respiratory tract includes the nose, nasal passages, and nasopharynx. The lower respiratory tract includes the larynx, trachea, bronchi and lungs.
- Retropubic prostatectomy:
- A surgery to remove the prostate through an incision in the abdominal wall.
- Rickham reservoir:
- A port placed into the brain through a neurosurgical procedure. It can be used for repeated taps into the Cerebrospinal Fluid (CSF) for drainage or medication administration.
- Risk factor:
- Something, such as a lifestyle habit, that increases the risk or chance that cancer will develop. Examples are eating a diet high in fats or cigarette smoking.
- RNA: Ribonucleic acid.
- One of the two types of nucleic acids found in cells. The other is DNA. RNA helps send information from the DNA to the proteins produced by each cell. This is how the DNA controls the function of the cell.
S
- Salpingectomy:
- Surgery to remove a fallopian tube. It is done because of tubal pregnancy, infection, or cancer.
- Salpingo-oophorectomy, right and/or left (RSO or LSO):
- Surgery to remove a fallopian tube and ovary. It is done to remove pelvic abscesses, cancer, pelvic inflammatory disease, or endometriosis.
- Sample size:
- In a clinical trial, the sample size is the total number of people participating in the trial.
- Sarcoma:
- A form of cancer that originates in the supportive or connective tissues, such as bone, cartilage, fat or muscle.
- Screening:
- Testing for the presence of disease in persons who are having no symptoms.
- Scrotum:
- In males, the sac of skin below the penis which contains the testicles.
- Secondary malignancy:
- A tumor that develops as a result of treatment for a cancer, such as leukemia after treatment for Hodgkinís Disease.
- Second-look surgery:
- A surgery performed after the primary treatment to see if tumor cells are still present.
- Segmented neutrophils:
- A type of white blood cell that fights bacterial infections. Also called segs or neutrophils. If the seg count is less than 1,000, the patient is at great risk for infection.
- Segs:
- Another word that is sometimes used for neutrophils or segmented neutrophils. If the seg count is less than 1,000, the patient is at great risk for infection.
- Semen:
- The fluid that is released through the penis during sexual orgasm. It is made up of sperm from the testicles, and fluid from the prostate and other male reproductive organs.
- Seminal vesicle glands:
- Pouch-like glands in the male reproductive system, which form a secretion that is released into the semen during ejaculation.
- Sentinel lymph node:
- The lymph node a cancer is most likely to spread to first from the primary tumor.
- Sentinel lymph node biopsy:
- A procedure where a dye or radioactive substance is injected near the primary tumor and then flows to the lymph nodes. The first node the dye or substance flows to is the sentinel lymph node. A surgeon looks for the dye or uses a scanner to identify the sentinel node, and removes it to check for the presence of cancer cells.
- Shingles:
- A condition caused by a virus that settles around certain nerves causing blisters, swelling and pain.
- Side effects:
- A secondary effect of medications or cancer treatments.
- Sigmoidoscope:
- A thin, lighted tube used to examine the lower portion of the inside of the colon.
- Sigmoidoscopy:
- Examination of the lower colon using a lighted, hollow tube called a sigmoidoscope.
- Simple mastoidectomy:
- A surgical procedure performed to enlarge and clean the mastoid cavity, a cavity in the bone behind the ear.
- Single-blinded:
- In a clinical trial, this method is used to prevent bias. The patient is not told if he/she is receiving the standard treatment or the new treatment being studied.
- Skin graft:
- A surgical procedure where the doctor removes a piece of healthy skin from one part of the body to replace skin that was removed because of a cancer or burn area. New cells grow from the transplanted skin to cover the exposed area.
- Small intestine:
- Part of the gastrointestinal system that is a long tube in the abdomen connecting the stomach to the large intestine or the colon.
- Soft palate:
- The soft tissue at the back of the roof of the mouth.
- Sperm:
- The male sex cell produced in the testes that is responsible for fertilizing the female egg.
- Sperm banking:
- Freezing of sperm for future use. This procedure can allow men to father children who may lose their fertility due to cancer treatments.
- Sputum:
- Material made up of secretions from the lungs and coughed up from the breathing passages.
- Squamous cell:
- Squamous cells are found on the surface of the skin, in the lining of the hollow organs, and in all the passages of the respiratory, digestive, and genitourinary tracts. Squamous cells have a flat, scale-like appearance.
- Squamous intraepithelial lesion (SIL):
- A term used to describe the abnormal growth of squamous cells on the cervix.
- Staging:
- The determination of the extent of a cancer. The staging helps determine appropriate treatment and prognosis.
- Standard treatment:
- A currently accepted or widely used treatment for a certain type of cancer.
- Statistically significant:
- Describes a mathematical measure between groups. The figure is significant if it is larger than what might happen by chance alone.
- Stem cell:
- The cells from which all blood cells develop. These cells may divide to form more stem cells or mature into a variety of different blood cells. The stem cells may be collected from the blood system through a procedure called apheresis. After they are collected, they may be given to a patient as a rescue after high dose chemotherapy or in place of autologous bone marrow for transplantation.
- Stereotactic:
- A type of biopsy that uses a computer and a three dimensional scanning device to find a tumor site and guide the removal of suspicious tissue for examination by a pathologist.
- Stereotaxis:
- Use of a computer and scanning devise to create 3-dimensional pictures. It can be used during biopsies, external beam radiation therapy, or during the insertion of radioactive implants.
- Steroids:
- A type of hormone used to reduce swelling and inflammation.
- Stoma:
- A surgically created opening in the body.
- Stomach:
- The organ that breaks down food mechanically and chemically so that it can be digested and absorbed into the body.
- Stomatitis:
- Inflammation and soreness of the mucus membranes in the mouth.
- Stool blood test:
- The use of a chemical to determine if occult (hidden) blood is present in a bowel movement. It is used to detect early signs of digestive tract conditions, such as polyps and cancers of the colon and rectum.
- Stratification:
- In a clinical trial, stratification allows the principal investigator to separate patients into different groups with similar characteristics. An example would be separating those whose cancer has spread, from those whose cancer has not spread. At the end of the clinical trial, researchers can study the differences between the subgroups.
- Subglottis:
- The lowest part of the larynx.
- Sun protection factor (SPF):
- A scale for rating how effective sunscreen is in preventing sunburn. The higher the SPF, the more protection it provides.
- Sunscreen:
- A substance that protects the skin from the sunís ultraviolet rays and overexposure to the sun, the leading cause of skin cancer.
- Supportive care:
- Treatment given to prevent, control or relieve side effects and improve the comfort and quality of life of people who have cancer.
- Supraglottic laryngectomy:
- Surgical removal of the glottis, or the tissue of the larynx in the area above the vocal cords.
- Supraglottis:
- The upper part of the larynx.
- Surgery:
- An operation.
- Symptoms:
- A sign that a person may have a condition or disease.
- Systemic:
- Affecting the entire body.
- Systemic disease:
- Disease that affects the whole body instead of just one organ.
- Systemic treatment:
- Treatment affecting the cells throughout the whole body.