If a tumor in a premenopausal woman is determined to be a low malignant potential tumor during surgery, and it is clearly stage I cancer, only the affected ovary is removed. For postmenopausal women with low malignant potential tumors, hysterectomy with bilateral salpingo-oophorectomy is still the preferred option. During staging, the appendix can be examined or removed. This is particularly important with mucinous tumors. In children or adolescents with ovarian cancer, surgeons typically attempt to preserve one ovary to allow for the completion of puberty, but if the cancer has spread, this is not always possible. Dysgerminomas, in particular, tend to affect both ovaries: 8–15% of dysgerminomas are present in both ovaries. People with low-grade (well-differentiated) tumors are typically treated only with surgery, which is often curative. In general, germ cell tumors can be treated with unilateral surgery unless the cancer is widespread or fertility is not a factor. In women with surgically staged advanced epithelial ovarian cancer (stages III and IV), studies suggest all attempts should be made to reach complete cytoreduction (surgical efforts to remove the bulk of the tumor).