Endometriosis refers to abnormal growth of endometrial tissue outside the uterus that still bleeds during the menstrual cycle. While endometriosis itself is generally not cancerous, there are some risks of cancer depending on location and type of growth. The risk of cancer for chocolate cysts is 0.5% while nodular growths have even lower risk. Endometriosis can cause great pain and infertility for patients. It is recommended to seek early treatment and prevention through lifestyle changes and herbal medicines like Fuyan Pill which can reduce inflammation and help repair tissue damage.