Glossary P-Q

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p27: a protein that helps to regulate cell growth and a loss of p27 expression is associated with poor prognosis in prostate cancer

p53: a protein that detects and repairs gene damage, coordinating events that cause the cell to stop its growth and repair the damage. If the damage is too great, p53 becomes the catalyst directing the damaged cell to commit suicide.

PAACT: Patient Advocates for Advanced Cancer Treatment –

paclitaxel (Taxol®): one of the chemotherapy agents called taxanes that block cell division

Palladium-103: radioactive source used for brachytherapy. Pd-103 gives off energy more quickly than iodine. The radioactive half-life of palladium is 17 days.

palliative: designed to relieve a particular problem without necessarily solving it; for example, palliative therapy is given in order to relieve symptoms and improve quality of life, but does not cure the patient

palpable: capable of being felt during a physical examination by an experienced physician; in the case of prostate cancer, this normally refers to some form of abnormality of the prostate which can be felt during a digital rectal examination

palpation: physical examination in medical diagnosis by pressure of the hand or fingers to the surface of the body especially to determine the condition (as of size or consistency) of an underlying part or organ

pamidronate: a disodium bisphosphonate bone-resorption inhibitor C3H9NNa2O7P2 administered as an intravenous infusion in the treatment of hypercalcemia associated with malignancy called also pamidronate disodium

pancreas, pancreatic: A gland situated near the stomach that secretes a digestive fluid into the intestine through one or more ducts and also secretes the hormone insulin

PAP (prostatic acid phosphatase): an enzyme or biomarker secreted by prostate cells associated with a higher probability of disease outside the prostate when levels are 3.0 or higher; PAP elevations suggest that the disease is not OCD (organ confined disease)

papaverine: a drug which causes blood vessels to expand, thereby increasing blood flow; when papaverine is injected into the penis, it produces an erection by increasing blood flow to the penis; see also phentolamine, “bimix”, “trimix

para-aortic: close to the aorta

paracrine: a form of signaling in which the target cell is close to the signal-releasing cell; compare to endocrine.

paramagnetic: a substance in which an induced magnetic field is parallel and proportional to the intensity of the magnetizing field but is much weaker than in ferromagnetic materials

parathormone: a hormone that regulates ion levels in neurons and controls excitability of the nervous system

parathyroid hormone (PTH): one of the principal calcium-regulating hormones in the body

partial response (PR): a 50% or greater decline in parameters that are being used to measure anti-cancer activity; parameters include abnormalities involving physical exam findings, lab and radiologic studies; also see complete response (CR)

partial voluming: the presence of different tissue types (e.g. healthy and malignant) within a spectroscopic volume leading to an averaging of the resulting spectra – a loss of resolution due to excessively large voxels, typically caused by scan slices that are too thick

Partin tables: tables constructed based on results of the PSA, clinical stage and Gleason score involving thousands of men with PC; used to predict the probability that the prostate cancer has spread to the lymph nodes, seminal vesicles, penetrated the capsule or that it remains confined to the prostate; developed by a group of scientists at the Brady Institute for Urology at Johns Hopkins University. Related Paper    

pathogen, adj. pathogenic: an organism that causes disease in another organism

pathologist: a physician who specializes in the examination of tissues and blood samples to help decide what diseases are present and therefore how they should be treated

pathology, pathological: a science which specializes in the examination of tissues and blood samples to help decide what diseases are present and therefore how they should be treated

PC, PCa: abbreviations for prostate cancer

PC-3: human PC cell line that is androgen independent

PCA3: a specific gene that is profusely expressed in prostate cancer tissue, and not expressed in any other kind of human tissue

PCA3 score: ratio of PCA3 to PSA mRNA. See PCRI Paper PCA3: A Genetic Marker of Prostate Cancer

PCNA (proliferating cell nuclear antigen): an index of cell division or proliferation

PCRI: The Prostate Cancer Research Institute; a non-profit organization located in Los Angeles whose goal is to educate patients and physicians about PC; telephone number is 310-743-2116; Web site:

PC SPES: a herbal therapy for PC comprised of 8 herbs that is no longer available

Pd: pyridinoline; a bone resorption marker; a bone collagen breakdown product

PDGF: platelet-derived growth factor; an important factor involved in tumor growth involving angiogenesis

PDQ: physicians data query; a NCI supported database available to physicians, containing current information on standard treatments and ongoing clinical trials

pelvic lymph node dissection: removal of lymph nodes in the area of the pelvis to check for presence of cancer

pelvis, pelvic: that part of the skeleton that joins the lower limbs of the body together

penile: of the penis

penile bulb: the base of the penis that attaches to the perineal membrane

penis: the male organ used in urination and intercourse

peptide: a compound of two or more amino acids where the alpha carboxyl group of one is bound to the alpha amino group of another

percutaneous: through the skin

perfluorocarbon liquid: a colorless and odorless liquid in which all hydrogen atoms have been replaced by fluorine atoms. This liquid is injected within the MEDRAD endorectal coil instead of air to increase image and spectral quality.

perfusion: fluid passing through an organ or tissue

perineal: of the perineum; an area of the body between the scrotum and the anus

perineum: the area of the body between the scrotum and the anus;  a perineal procedure uses this area as the point of entry into the body

perineural invasion (PNI): PC invading the nerve sheath surrounding the nerves that enter the prostate

peripheral: outside the central region

peripheral neuropathy (PN): any disorder of the nervous system outside the brain and spinal column, such as tingling or numbness in the hands or feet

peripheral zone: the largest portion of the prostate located in the back closest to the rectum

periprostatic: pertaining to the soft tissues immediately adjacent to the prostate

perirectal: the tissues surrounding the rectum

peritoneum, adj. peritoneal: the serous membrane that lines the walls of the abdominal cavity and folds inward to enclose the viscera

PET (positron emission tomography) scan: using a radioactive isotope that is taken up by tumor tissue showing that the tumor is functional

PGE-2 (prostaglandin E2): an unfavorable metabolite of arachidonic acid

phagocytosis: the engulfing and ingesting of a substance within a cell;  e.g. a macrophage may phagocytize bacteria or other cells

pharmacologic: the characteristics or properties of a drug, especially those that make it medically effective

phase I, II or III clinical trial: see Clinical Trial

phentolamine: given by injection causes blood vessels to expand, thereby increasing blood flow; when injected into the penis, it increases blood flow to the penis, which results in an erection. see also papaverine, “bimix”, “trimix

phenotype, adj. phenotypic: the observable physical or biochemical characteristics of an organism or group, as determined by both genetic makeup and environmental influences

phosphodiesterase (PPD) inhibitors: drugs which may help a man achieve an erection

phosphorylation: the addition of phosphate to an organic compound through the action of a phosphorylase or kinase

photon: A unit of energy of a light ray or other form of radiant energy. Most conventional radiation uses photons to deliver ionizing radiation.

physiologic: of or consistent with a living organism's normal functioning

PI3 kinase: an enzyme which influences a wide variety of cellular functions, including cell growth, differentiation and survival, glucose metabolism and cytoskeletal organization

PICP: carboxy-terminal propeptide of type 1 procollagen; a bone formation marker

PIN: prostatic intraepithelial (or intraductal) neoplasia; a pathologically identifiable condition characterized by microscopic changes in the epithelial cells; also known more simply as dysplasia by many physicians; broken down into high-grade PIN or PIN 2 and PIN 3 or low-grade PIN or PIN 1. High grade PIN is what is believed to be a precursor to PC

pituitary: a small gland at the base of the brain that supplies hormones that control many body processes including the production of testosterone by the testis

placebo: a form of safe but non-active treatment frequently used as a basis for comparison with pharmaceuticals in research studies

planimetry: the measurement of plane surfaces

planning target volume (PTV): Equivalent to the clinical target volume plus a margin to account for uncertainty in immobilization and localization of the patient anatomy during treatment

plasma: The clear, yellowish fluid portion of blood, lymph, or intramuscular fluid in which cells are suspended. It differs from serum in that it contains fibrin and other soluble clotting elements.

platelet: a particle found in the bloodstream that binds at the site of a wound to begin the blood clotting process; platelets are formed in bone marrow.

plexus: a structure in the form of a network, especially of nerves, blood vessels, or lymphatics

ploidy: a term used to describe the number of sets of chromosomes in a cell; see also diploid and aneuploid

PNI: perineural invasion

polyamine: Any of a group of organic compounds, such as spermine and spermidine, composed of only carbon, nitrogen, and hydrogen and containing two or more amino groups

polymerase chain reaction (PCR): system for in vitro amplification of DNA that involves separating the DNA into its two complementary strands and using DNA enzymes to synthesize two-stranded DNA from each single strand, and repeating the process

polyp: a small tumor-like growth projecting from a mucous membrane (as in the intestine)

polyphenol: Any of a class of aromatic organic compounds comprised of more than one hydroxyl group (-OH) attached directly to a benzene ring

positive: the term used to describe a test result which shows the presence of the substance or material for which the test was carried out; for example, a positive bone scan would show signs of bone metastases

positive margin: the pathologic finding of cancer cells on the outer edge of the tissue removed

positive predictive value: refers to the chance that a positive test result will be correct.

posterior: the rear; for example, the posterior of the prostate is the part of the prostate that faces a man's back

posterolateral: behind and to one side

PPO: preferred provider organization – an insurance plan which allows choice of any provider in the network

PR (progesterone receptor): the docking site on a cell that interacts with progestins

preclinical: before a disease becomes recognizable based on direct observation

precursor: a biochemical substance, such as an intermediate compound, from which a more stable or definitive product is formed

prednisone (Orasone® or Deltasone® or Liquid Pred® or Meticorten®): a glucocorticoid steroid used to treat anorexia and cachexia and some cancers. It is similar to a steroid hormone made by the adrenal glands in the body.

priapism: an abnormal, painful erection where the penis remains erect for an extended period of time that is usually not accompanied with sexual desire

procollagen: the soluble precursor of collagen

Procrit®: a recombinant human erythropoietin used to treat anemia

proctitis: inflammation of the rectum; in PC therapy may be associated with radiation therapy

progesterone: a specific steroid hormone used in the treatment of hot flashes in men having suppressions in LH and testosterone; an example of a progestin is Megace® or Depo-Provera®

prognosis: the patient's potential clinical outlook based on the status and probable course of his disease; chance of recovery

progression: continuing growth or regrowth of the cancer

prolactin (PRL): a trophic hormone produced by the pituitary that increases androgen receptors, increases sensitivity to androgens & regulates production & secretion of citrate

proliferation: production of new tumor cells by a rapid succession of cell divisions

proliferative inflammatory atrophy (PIA): chronic inflammatory prostate lesions that may result in prostate cancer

prone: referring to the position of the body when lying face downward

prophylactic, prophylaxis: a drug, procedure or piece of equipment used to prevent disease

Proscar®: brand name of finasteride; a 5 AR inhibitor

prospective: relating to or being a study (as of the incidence of disease) that starts with the present condition of a population of individuals and follows them into the future — compare retrospective

prostaglandin: hormone like substances that stimulate target cells into action; they differ from hormones in that they act locally, near their site of synthesis, and they are metabolized very rapidly; any of various oxygenated unsaturated cyclic fatty acids of animals that have a variety of hormone like actions (as in controlling blood pressure or smooth muscle contraction)

ProstaScint®: a monoclonal antibody test directed against the prostate specific membrane antigen (PSMA); seems to focus on androgen independent tumor tissue which may contain a greater amount of PSMA

prostate: the gland surrounding the urethra and immediately below the bladder in males which provides fluid to nourish and transport sperm during intercourse

prostatectomy: surgical removal of part or all of the prostate gland

prostate specific antigen (PSA): a protein secreted by the epithelial cells of the prostate gland including cancer cells; an elevated level in the blood indicates an abnormal condition of the prostate gland, either benign or malignant; it is used to detect potential problems in the prostate gland and to follow the progress of PC therapy (see screening)

prostate-specific membrane antigen (PSMA): a biomarker of prostate epithelial cell activity that is expressed in the membrane of prostate epithelial cells. PSMA is composed of a short 19 amino acid intra-cellular domain, a 24 amino acid transmembrane domain and a 707 amino acid extra-cellular domain. PSMA antigen is radiologically identified (imaged) using a monoclonal antibody attached to a radioactive Indium 111 isotope (ProstaScint scan) to allow visualization of PSMA antigen-containing tissue found within lymph nodes and/or prostate gland. 

prostatic acid phosphatase (PAP): an enzyme or biomarker secreted by prostate cells associated with a higher probability of disease outside the prostate when levels are 3.0 or higher; PAP elevations suggest that the disease is not OCD (organ confined disease)

prostatic pedicle: a stalk at the base of the prostate through which the prostate receives its nourishment.

prostatism: a symptom resulting from compression or obstruction of the urethra, due most commonly to hyperplasia of the prostate; results in urinary difficulties and, occasionally, urinary retention

prostatitis: infection or inflammation of the prostate gland treatable by medication and/or manipulation; (BPH is a more permanent laying down of fibrous and connective tissue caused when the prostate tries to contain a relatively silent chronic lower-grade infection, often requiring a TURP to relieve the symptoms)

prostatovesical junction: the area in which the prostate connects to the bladder.

prosthesis: a manufactured device used to replace a normal body part or function

protease: any enzyme that catalyzes the splitting of proteins into smaller peptide fractions and amino acids by a process known as proteolysis

protease inhibitor: a substance that inhibits the action of a protease

protein: any of a group of complex organic macromolecules that contain carbon, hydrogen, oxygen, nitrogen, and usually sulfur and are composed of one or more chains of amino acids. Proteins are fundamental components of all living cells and include many substances, such as enzymes, hormones, and antibodies, that are necessary for the proper functioning of an organism. They are essential in the diet of animals for the growth and repair of tissue and can be obtained from foods such as meat, fish, eggs, milk, and legumes

protocol: a precise set of methods by which a treatment or research study is to be carried out

proton beam radiation therapy: a form of RT that uses the proton, a positively charged nuclear particle, to deliver ionizing radiation. The proton can be programmed to stop at a particular depth within tissue for the delivery of its radiation payload

proton pump inhibitors (PPI): drugs that reduce gastric acidity by inhibiting the proton pump within the gastric lining cells; examples of PPI include Prilosec® and Nexium®

proximal: a part of the body that is nearer to the point of reference, compare to distal

PSA: see prostate-specific antigen.

PSA density (PSAD): The amount of PSA per unit volume of the prostate gland; the quotient of PSA divided by gland volume; a reflection of tumor density within the prostate

PSA doubling time (PSADT): the calculation of the time it takes for the PSA value to double based on at least three values separated by at least three months each; before diagnosis, a PSADT of less than 10 years may be an indication of the presence of PC

PSA failure: the ASTRO definition of PSA failure as being three consecutive increases in PSA level following treatment

PSA II: see free PSA.

PSA mRNA: messenger RNA which replicates the DNA code of the PSA protein

PSA nadir (PSAN): the lowest value the PSA reaches during or after a particular treatment; a progressive rise after a PSA nadir has been reached usually indicates biologic activity of PC

PSA relapse-free survival: survival of the PC patient that relates to no evidence of biochemical relapse based on a rising PSA as seen in 3 consecutive determinations; also called biochemical relapse-free survival ( bRFS)

PSA response: normally referred to as a decline in PSA of > 50%

PSA slope: the rate of rise in the PSA level normally expressed as ng/mL per month

PSA velocity (PSAV): the calculation of the rate of increase in PSA levels in succeeding PSA tests; before diagnosis, a PSAV of 0.75 ng/ml/year (or higher) may be an indication of the presence of PC

PSM: prostate specific membrane; a membrane that surrounds the protoplasm (cytoplasm) of prostate cells

PSMA: prostate specific membrane antigen

psychogenic: produced or caused by psychological or mental factors rather than organic factors; compare to neurogenic

PTEN: a gene acts as a tumor suppressor gene by deactivating Akt and rendering prostate cancer cells more susceptible to suicide

PTHrP: Parathyroid hormone-related protein; a protein involved in osteoblast stimulation; a product also of the PC cell elaborated by neuroendocrine cells that make CGA (chromogranin A)

Pub Med: a Web site which allows access to thousands of published medical studies. It is a service of the National Institute of Health and can be found at

pubic arch: the arch formed by the inferior rami of the pubic bones

pubo-prostatic: relating to the structures/supports which connects the capsule of the prostate gland to symphysis pubis

pulmonary embolism: a blood clot in a lungs, causing a severe impairment of respiratory function

Pyrilinks-D (Dpd): a urine test that quantitates bone resorption; the second voided urine specimen is ideal to use; other markers of bone resorption are ICTP and N-telopeptide

pyrophosphate: a salt or ester of pyrophosphoric acid

qCT: quantitative CT bone densitometry; an alternate way to evaluate bone density besides the DEXA scan; qCT is not falsely elevated due to calcium deposits in blood vessels or due to degenerative joint disease

quality of life (QOL): an evaluation of health status relative to the patient's age, expectations and physical and mental capabilities