Olaparib Medicine use to maintain the response of various types of ovarian (female reproductive organs where eggs are formed), fallopian tube (tube that transports eggs release with the ovaries to the uterus), and peritoneal (layer of tissue that lines the abdomen) cancer in people who complete response or partially responses to their first or later chemotherapy treatments. Olanib tablets also use to treat various types of breast cancer that has spread to other parts of the body and has not improved or has worsened after treatment with other therapies.