For functioning tumors, the somatostatin analog class of medications, such as octreotide, can reduce the excessive production of hormones. Lanreotide can slow tumor growth. If the tumor is not amenable to surgical removal and is causing symptoms, targeted therapy with everolimus or sunitinib can reduce symptoms and slow progression of the disease. Standard cytotoxic chemotherapy is generally not very effective for PanNETs, but may be used when other drug treatments fail to prevent the disease from progressing, or in poorly differentiated PanNET cancers.