If a blood relative, such as a parent, sibling or child, has been diagnosed with prostate cancer, your risk may be increased. Also, if you have a family history of genes that increase the risk of breast cancer (BRCA1 or BRCA2) or a very strong family history of breast cancer, your risk of prostate cancer may be higher. Obesity. Ovarian cancer can occur at any age but is most common in women ages 50 to 60 years. Inherited gene mutations. A small percentage of ovarian cancers are caused by gene mutations you inherit from your parents. The genes known to increase the risk of ovarian cancer are called breast cancer gene 1 (BRCA1) and breast cancer gene 2 (BRCA2).