Removing the ovaries (prophylactic oophorectomy) does not completely eliminate the risk of ovarian cancer because women can still develop primary peritoneal cancer that behaves like ovarian cancer.

Analysis

People often assume that taking out the ovaries guarantees complete protection because the organ where most ovarian cancers arise is gone. The nuance that cancer can arise from the peritoneal lining is less well known, leading to the misconception that surgery offers 100% safety. This matters because patients considering risk‑reducing surgery need realistic expectations about residual risk and the importance of continued surveillance. Understanding the small remaining risk also helps clinicians counsel patients on the benefits of hormone replacement therapy and lifestyle monitoring after surgery, without causing undue fear or false reassurance.