MSI-H Solid Malignant Tumor

The four tumour streams that will be studied in this protocol are based on immunotherapy sensitive rare cancers from CA209-538 which will be further investigated under this protocol and divided into four groups: 1. Neuroendocrine cancers: Atypical bronchial carcinoid, neuroendocrine carcinoma and Grade 3 NETs independent of primary site (SCLC excluded) 2. Biliary tract cancers: Intrahepatic cholangiocarcinoma and gallbladder carcinoma 3. Gynaecological malignancies: Ovarian clear cell carcinoma, uterine clear cell carcinoma, uterine/ovarian carcinosarcoma, uterine leiomyosarcoma and vaginal/vulva squamous cell carcinoma 4. Mismatch repair protein deficient (MSI-H) cancers (excluding colorectal carcinoma). The role of immunotherapy is being defined in more common cancer types, however because of their rarity, the efficacy of immunotherapy for these cancers is poorly defined. This protocol provides an important opportunity to establish whether the combination of nivolumab \& ipilimumab has efficacy in these cancers.