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Paget’s disease

This is a rare form of breast cancer that begins in the breast ducts and spreads to the skin of the nipple and areola. The affected skin may appear to be crusted, scaly, red, or oozing.


A condition that occurs when all layers of the uvea are inflamed.

Parallel assignment

A clinical trial in which two or more groups of participants receive different interventions, e.g., a two-arm parallel design involves two groups of participants, one receiving drug A and the other receiving drug B, therefore “in parallel” to each other.

PEG-J Percutaneous endoscopic gastrostomy

Percutaneous endoscopic gastrostomy (PEG) is a procedure in which a tube (PEG tube) is passed into a patient's stomach in order to provide food or medication. The PEG procedure is an alternative to the open surgical gastrostomy insertion, and does not require a general anesthetic; mild sedation is typically used. PEG tubes may also be extended into the small intestine by passing a jejunal (the second part of the small intestine) extension tube (PEG-J tube).

Peutz-Jeghers syndrome

People with this condition have a mutation in the STK11 (also called LKB1) tumour suppressor gene.


The processes (in a living organism) of absorption, distribution (in the body), metabolism (process by which the body breaks down and converts medication into active chemical substances to treat a disease), and excretion of a drug or vaccine (usually via feces, urine and even respiration).

Philadelphia chromosome

An abnormality of chromosome 22. Bone marrow cells that contain the Philadelphia chromosome are often found in ALL.

Physician global assessment (PGA)

A tool that is used to grade psoriasis plaques on the skin: a score of 0 or 1 indicates that the skin is either clear of psoriasis plaques or they are reduced to a minimum.

Physiotherapist (provides physiotherapy)

Professional who treats people with physical disorders through manipulation, mobilization techniques and prescribing strengthening exercises and advice.


An inactive pill, liquid, or powder that has no treatment value. In clinical trials, experimental treatments are often compared with placebos to assess the treatment's effectiveness.


Placebo-controlled study

The study method whereby an inactive substance (the placebo) is given to one group of patients while another group receives the drug being tested. The results are then compared to see if the test treatment is more effective than the placebo in treating the condition.

Placebo effect

A physical or emotional change after a substance is taken, that is not the result of any property or ingredient of the substance. The change may be beneficial, reflecting the expectations of the patient and often, the expectations of the person giving the substance.


Platelets are found in the blood and spleen. They help form blood clots to slow or stop bleeding, and to help wounds heal. Also called thrombocyte.

Post-marketing trial (PMOS)

Phase IV studies that collect results after the medication has been introduced into the general population. This data complements the results from the three previous trial phases. Most often, these are observational studies that collect data from “real life” patients taking the medication as prescribed by their doctors.


Inflammation of the ileal pouch (an artificial rectum surgically created out of ileal gastrointestinal tissue in patients who have undergone a colectomy).


Prednisolone is a steroid that prevents the release of substances in the body that cause inflammation. The steroid can be used to treat many different conditions such as allergic disorders, skin conditions, ulcerative colitis, arthritis, lupus, psoriasis, or breathing disorders.

Preliminary analysis


Principal investigator

The trial doctor - a highly qualified physician who carries out the research and interacts with the patients. All trial doctors also have additional training in trials and research.

Product monograph

The factual scientific document describing the drug. Devoid of promotional material, it describes the drug’s properties, claims, indications and conditions of use, as well as any information required for the optimal, safe and effective use of the drug.


Progesterone is a hormone made by the body that plays a role in the menstrual cycle and pregnancy. The hormone progesterone can also be made in the laboratory. It is used for birth control and as a treatment for menstrual disorders, infertility, symptoms of menopause, and other conditions.

Progesterone receptor

A progesterone receptor is a protein found inside the cells of the female reproductive tissue, some other types of tissue, as well as some cancer cells. The hormone progesterone will bind (attaches) to the receptors inside the cells and may cause the cells to grow.


The probable outcome or course of a disease; can also refer to the chance of recovery or recurrence.


The relationship of the observation period to the time of patient enrollment. Prospective: looking forward using periodic observations usually collected following patient enrollment.



The study plan on which the clinical trial is based. All plans are carefully designed to safeguard the patients, as well as answer specific research questions. A protocol describes who may participate in the trial, and the schedule of tests, procedures, medications, and regular follow-ups by research staff to monitor the health, safety and effectiveness of the treatment.


Psoriasis is a disease of the skin that causes itchy or sore patches of thick and red skin with silvery scales.

Psoriasis Area and Severity Index (PASI)

A tool physicians use to define the severity of psoriasis. It combines assessment of erythema, induration (plaque thickness) and desquamation (scaling) of the skin and the percentage of affected areas on a scale between 0 and 4.


Thick, yellowish-white fluid formed at the site of inflammation during infection.