StopGCT, Inc. is a nonprofit organization dedicated to supporting women affected by granulosa cell tumor (GCT), a rare form of ovarian cancer. Its mission is to advance information, advocacy, community, and research, with the vision that every woman with GCT can live a long and productive life. Recognizing that rare cancers may receive limited medical attention and that care can be overly generalized, StopGCT helps patients engage more effectively with their physicians and pursue informed, individualized care.

The organization offers free, case-specific support, including reviews of medical histories and diagnostic or treatment options, help finding second opinions, and guidance in locating relevant scientific literature, protocols, and clinical trials. Its advocates may prepare technical communications for physicians and, when needed, accompany clients to appointments. StopGCT also fosters community through social media, online groups, webinars, and conferences, sharing updates and experience with people affected by GCT. In addition, it funds research and related activities internationally and works with physicians and medical institutions to promote better understanding, diagnosis, and treatment of this rare cancer. Its services are supported by donations.