O
- OCN (Oncology Certified Nurse):
- A registered nurse who has met the requirements and successfully completed a certification exam.
- Omentectomy:
- A surgery to remove all or part of the omentum, a fold in the peritoneum that surrounds the stomach and other organs of the abdomen.
- Ommya reservoir:
- A port placed in the brain in a neurosurgical procedure. It can be used for repeated taps into the Cerebrospinal Fluid (CSF) for drainage or to give medications.
- Oncogene:
- A gene that has the potential to cause a normal cell to become cancerous. Genes that when inappropriately activated, can promote or allow the growth of cancer.
- Oncologist:
- A doctor who specializes in the study and treatment of cancer.
- Oncology:
- The study of tumors (cancer).
- Oophorectomy:
- A surgical procedure to remove an ovary. It is done to remove infection, tumor or in association with hysterectomy.
- Optic nerve:
- The nerve that carries visual impulses from the retina to the brain.
- Orbital decompression:
- A surgical procedure to relieve pressure on the optic nerve to preserve or restore vision.
- Orchiectomy:
- Surgical removal of a testicle, the male organ that is the source of testosterone, the male sex hormone. Removal of both testicles is called a bilateral or radical orchiectomy. Removal of both testicles causes infertility or the inability to father children. Orchiectomy may be done to treat testicular cancer or to remove a source of hormones stimulating prostate cancer cells to grow.
- Oropharynx:
- A part of the throat that includes the soft palate, the base of the tongue, and the tonsils.
- OTO:
- Otolaryngology, the medical specialty concerned with the ear, nose, and throat.
- Otolaryngologist:
- A doctor who specializes in treating diseases of the ear, nose and throat.
- Ovarian cystectomy:
- A surgical procedure using a small incision and a lighted, tubular instrument called a laparoscope to remove a small cyst of the ovary. It can also refer to a surgery where an abdominal incision is made to remove a cyst on the ovary and determine the extent of disease. It is done to rule out or diagnose a possible cancer or neoplasm.
- Ovarian epithelial cancer:
- A cancer that starts in the cells that line the ovaries.
- Ovary or ovaries:
- Glands located on either side of the uterus. This is where eggs are developed and some female hormones are produced.
P
- P53 gene:
- A tumor suppressor gene that normally stops the growth of tumors. This gene is altered or deficient in many cancers.
- Palliative treatment:
- Treatment that relieves symptoms, such as pain or bleeding, but does not change the course of the disease or cure it. Its primary purpose is to improve the quality of life.
- Palpation:
- Physical examination by touching or feeling. A palpable mass is one that can be felt.
- Pancreatectomy:
- A surgery to remove the pancreas.
- Pancytopenia:
- A condition where there is a reduction in the red and white blood cells and platelets.
- Panendo:
- Another term forpanendoscopy.
- Panendoscopy:
- Direct examination of the larynx, esophagus, and air passages of the lungs usually done in the operating room.
- Panorex:
- A panoramic X-ray view of the upper (maxilla) and lower (mandible) jaw.
- Pap test:
- A microscopic examination of cells of the cervix. This test can detect cancer of the cervix in the early stages.
- Paracentesis:
- A procedure that removes fluid from the abdomen, using a needle under local anesthesia.
- Parotidectomy:
- A surgical procedure for the removal of benign and malignant tumors of the parotid gland, a gland near the ear.
- Pathologist:
- A doctor who specializes in the examination of normal and diseased tissue.
- Pathology:
- The study of tissue under a microscope to arrive at a diagnosis. Any tissue diagnosed as cancer has had a pathologic examination under a microscope.
- Peer review:
- A scientific review by a group of experts.
- Pelvic:
- Having to do with the pelvis area.
- Pelvic examination:
- An internal examination of the female reproductive organs.
- Pelvis:
- Also called pelvic area. The part of the body located below the waist and surrounded by the hip and pubic bones.
- Perfusion:
- Administration of chemotherapy drugs directly into the blood that is going to an affected limb or body part. This allows a higher dose of drugs to reach the tumor.
- Perineal:
- See perineum.
- Perineum:
- Also called perineal. In females, the area of the body between the vagina and the rectum, and in males, the area located between the scrotum and the rectum.
- Peripheral blood stem cells:
- 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.
- Peritoneal fluid:
- The fluid that bathes the organs of the peritoneum or abdominal cavity, including the intestines, stomach, and liver.
- Peritoneum or peritoneal cavity:
- The lower part of the abdomen. The space in which abdominal organs are located such as the liver, spleen, kidneys, bladder, intestines, uterus, ovaries, and fallopian tubes. All organs are bathed in peritoneal fluid.
- Petechiae:
- Small areas of bleeding that appear on the skin. This can be due to low platelet counts.
- Pharynx:
- A tube about five inches long that connects the back of the mouth and nose to the esophagus. Air and food pass through the pharynx on the way to the trachea (windpipe) or esophagus (food tube). The upper part of the pharynx, called the nasopharnyx, connects the nasal cavity to the area behind the soft palate of the mouth. The oropharynx, the middle part, runs from the nasopharnyx to below the tongue. The lowest part, the hypopharynx, joins with the esophagus, and/or trachea.
- Phase 1-4 trials:
- Clinical trials are organized into phases, with each phase answering different questions about a new treatment.
- Phase I:
- Phase I is the first step in evaluating a new treatment in humans. The questions being answered include: what is the best way to give the treatment? (mouth, intravenously, injection), how many times per day?, what is the maximum tolerated dose?, and what are the side effects?
- Phase II:
- Phase II trials focus on learning whether or not the new treatment is effective in treating tumors. For example, does the new treatment shrink the tumor in size, or improve blood test results? Which cancers is it effective against?
- Phase III:
- These trials compare the results of people taking the new treatment with the results of people taking standard treatment. For example, which group has better survival rates or fewer side effects?
- Phase IV:
- After a new treatment has been approved and marketed, a phase 4 study looks at side effects that were not apparent in earlier trials.
- Phlebitis:
- Inflammation of a vein, which can be quite painful.
- Photodynamic therapy:
- Therapy using a certain type of light and a special chemical to kill cancer cells.
- Photophobia:
- An abnormal sensitivity to and discomfort from light.
- Photosensitivity:
- A condition where the skin becomes extremely sensitive to the effects of the sun.
- Physician data query (PDQ):
- A computer database designed and maintained by the National Cancer Institute. The database contains summaries for patients and health professionals on cancer treatment, prevention, screening, genetics, and supportive care. It also includes a listing of clinical trials from around the world and a directory of physicians and organizations that provide cancer care.
- Placebo:
- An inactive substance ("sugar pill") used in research to compare the effects of a given treatment against no treatment.
- Plasma:
- The colorless fluid part of blood that is mostly water. Plasma contains antibodies, hormones, salts, electrolytes, nutrients, wastes and blood clotting factors.
- Plasma cells:
- A type of white blood cell produced by the B-lymphocytes that produces antibodies.
- Plasmapheresis:
- Blood is taken from a vein and circulates through a machine, which separates the cells, platelets, and plasma. The plasma is removed and replaced with a substitute, which is returned to the body along with the blood cells.
- Platelet:
- A blood cell that assists in blood clotting. Patients are at risk to bleed if the platelet count is less than 50,000.
- Platelet count:
- The number of platelets in a blood sample.
- Ploidy analysis:
- A test to measure the amount of DNA contained in a cell. Most cancer cells are aneuploid, which means they contain an abnormal amount of DNA.
- Pneumonectomy:
- A surgical procedure to remove a lung.
- Polycythemia vera:
- A type of myeloproliferative disorder where the number of
red blood cells in the blood is higher than normal. Some patients may also have an increased number of white blood cells and platelets. - Polyp:
- A projecting mass or growth of tissue in a body cavity such as the nose, colon or larynx. Polyps can be benign or malignant.
- Polypectomy:
- The removal of a polyp.
- Port:
- A device that is surgically placed in the body. It is used to administer intravenous fluids and chemotherapy. Blood tests can be withdrawn through the device also.
- Positron emission tomography (PET) scan:
- A computerized scan that studies the metabolic activity of body tissue to see if there is disease present.
- Pre-cancerous:
- Abnormal cellular changes that have the potential to become malignant (cancerous).
- Preleukemia:
- Another word for Myelodysplastic Syndromes.
- Prevalence:
- The percentage of the population that is affected by a certain disease (such as cancer) at a specific time.
- Prevention:
- Reducing the number of cases of cancer by avoiding the substances or habits that are known to cause cancer.
- Primary tumor:
- The place where a cancer started. A patient may have cancer that started in the breast and spread to the bone, but the primary tumor is still the breast.
- Principal investigator (PI):
- In a clinical trial, the PI is the person, usually a doctor, who is in charge of the trial.
- Procto:
- An abbreviation for sigmoidoscopy. A procto is an examination of the rectum and lower colon with a hollow lighted tube called a sigmoidoscope.
- Progesterone:
- A female hormone produced by the ovaries.
- Progesterone-receptor assay:
- A test done on a breast cancer tissue specimen to determine if it is dependent on female hormones for growth.
- Prognosis:
- The prediction of survival from a disease.
- Progressive disease:
- Cancer that continues to increase in size or severity.
- Prophylatic:
- The use of medicine or medical or surgical procedures to prevent the onset of disease.
- Prostate:
- One of the male sex glands that is located at the base of the bladder. It produces fluid that becomes part of the semen, or the fluid that contains sperm.
- Prostatectomy:
- A surgical procedure to remove the prostate gland.
- Prostatic acid phosphatase:
- Also called PAP. An enzyme produced by the prostate. The level in the blood increases in some men who have prostate cancer.
- Prosthesis:
- An artificial device used to replace a missing part of the body.
- Protocol:
- The outline or plan which specifies times and dosages for treatment methods such as surgery, chemotherapy or radiation therapy. Various tests at specific times may also be part of the protocol.
- P.S.A. (Prostatic Specific Antigen):
- A tumor marker blood test that measures the level of the prostatic specific antigen, a protein, made by prostate cells. This test is used to monitor or diagnose either benign or malignant prostate disease.
- Pubic bone:
- Also called pubis. The smallest of the three bones that make up the hipbone. It is located in the lower abdomen.