NCI Dictionary of Cancer Terms
The NCI Dictionary of Cancer Terms features 7,790 terms related to cancer and medicine.
Browse the dictionary by selecting a letter of the alphabet or by entering a cancer-related word or phrase in the search box.
- observational study
- listen (OB-ser-VAY-shuh-nul STUH-dee)
- A type of study in which individuals are observed or certain outcomes are measured. No attempt is made to affect the outcome (for example, no treatment is given).