Definitions for "First-degree relative"
parent, sibling or child.
A mother, sister or daughter; this term is used when assessing risk of developing ovarian cancer. If a first-degree relative develops ovarian cancer, you should be tested for the disease also.
A mother, father, sister, brother, daughter or son. When used in assessing risk of developing cancer, the health care professional is interested in case history of first-degree relatives. For example, if a first-degree relative develops ovarian cancer, you should be tested for the disease also.