Patients can not have any neuroendocrine histology in pathology Have a histologically proven locally advanced or metastatic high grade neuroendocrine carcinoma (NEC)\r\n* Includes small cell and large cell neuroendocrine carcinoma of unknown primary or any extrapulmonary site\r\n* Includes neuroendocrine prostate cancer (de novo or treatment-emergent) of prostate if small cell or large cell histology\r\n* Mixed tumors, e.g. mixed adenoneuroendocrine carcinoma (MANEC) or mixed squamous or acinar cell NEC are allowed if the high grade (small or large cell) NEC component comprises > 50% of the original sample or subsequent biopsy Has Merkel cell carcinoma, small cell lung carcinoma, or large cell NEC of lung \r\n* Intermediate grade neuroendocrine tumors are excluded\r\n* Well differentiated grade 3 neuroendocrine tumors are excluded\r\n* Metastatic high-grade prostate carcinoma with evidence of focal neuroendocrine differentiation on prostate biopsy (e.g., positive chromogranin staining by immunohistochemistry) without small cell or large cell NEC morphology are excluded, as are neuroendocrine prostate cancers with phenotype intermediate between adenocarcinoma and small cell\r\n* Atypical bronchial carcinoid and well differentiated G2 gastro-entero-pancreatic neuroendocrine tumors (GEP-NET) are excluded Histologically confirmed prostate cancer; small cell/neuroendocrine differentiated allowed but not required for study participation Pancreatic neuroendocrine tumors (islet cell carcinoma) will be excluded from this study; all non functional and functional islet cell carcinomas such as insulinoma, glucagonoma, gastrinoma, vasoactive intestinal peptide (VIP)oma will be excluded pure small cell, neuroendocrine or other variant (non-adenocarcinoma) prostate cancer histology Gastroenteropancreatic neuroendocrine tumors (GEPNET). Subject’s biopsy specimen reveals neuroendocrine or small cell features High-Grade Neuroendocrine Carcinoma (HGNEC), any organ of origin, including a pathology of neuroendocrine features, in patients previously been treated with chemotherapy Although neuroendocrine tumors may be classified differently based on organ of origin, in the context of this protocol they are defined as high grade on the basis of either Histologic features: (a) Neuroendocrine tumors of lung origin are considered high grade if in any part of the tumors, there are >10 mitoses/2mm2 or 10 high power field (HPF). Large zones of necrosis are usually present. This includes small cell lung carcinoma and large cell neuroendocrine lung carcinoma. [SCLC will not enroll in the HGNEC cohort.] (b)Neuroendocrine tumors of gastroenteropancreatic origin are considered high grade if in any part of the tumors there are either >20 mitoses/2mm2 or 10 high power field (HPF) OR Ki67. Histological variants in the primary tumor, other than adenocarcinoma; for example: neuroendocrine tumor, small cell or sarcomatoid Neuroendocrine carcinoma or sarcoma histology Participation in Iowa Neuroendocrine Tumor Registry Confirmed or suspected diagnosis of stage IV or recurrent non-small cell lung cancer (NSCLC); for suspected NSCLC, diagnosis must be histologically or cytologically confirmed prior to start of nivolumab treatment; neuroendocrine cancers, or mixed neuroendocrine features in > 10% of tumor cells, are excluded Neuroendocrine-like prostate cancer, based on histology OR based on clinical presentation as defined by meeting one of the two below criteria; all subjects must submit their primary tumor or metastatic biopsy pathology specimens to the Duke Cancer Institute where they will be centrally reviewed by Duke Pathology (Dr. Jiaoti Huang); central Duke pathologic review is not required for screening but rather for confirmation of histologic subtype; local pathologic review is sufficient for eligibility determination\r\n* Criterion 1: presence of 1 of 3 histologically proven diagnoses:\r\n** Primary small cell carcinoma of the prostate, defined by classic histologic features such as small tumor cells with scanty cytoplasm, darkly stained nuclei with homogeneous chromatin pattern; the tumor cells do not form glandular structure but grow as solid sheets with frequent mitotic figures and necrosis\r\n** Intermediate atypical carcinoma of the prostate, which has histologic features distinct from small cell carcinoma or adenocarcinoma; the tumor grows as solid sheets or vague glandular structures; the tumor cells have moderate amounts of cytoplasm and centrally located, round and regular nuclei with fine, granular and homogeneous chromatin; mitosis and necrosis are absent\r\n** Mixed histology tumors of the prostate, containing both adenocarcinoma and neuroendocrine or small cell components\r\n* Criterion 2: presence of histologically proven adenocarcinoma of the prostate without any sign of neuroendocrine or small cell histology that is radiographically progressing despite castrate levels of testosterone (< 50 ng/mL) with the following poor risk features:\r\n** Prior progression despite therapy with either abiraterone acetate and/or enzalutamide\r\n** At least one of the following:\r\n*** Liver metastases\r\n*** Bulky radiographic progression (>= 2 cm short axis lymph nodes or >= 1 cm long axis visceral metastases) combined with low serum PSA (< 10 ng/mL)\r\n*** High serum LDH (> 1 X upper limit of normal) Histologically or cytologically confirmed previously untreated non-small cell lung cancer. If a diagnostic biopsy is available, a pre-treatment biopsy is not required. Patients with a suspected lung cancer are eligible, but pathology must be confirmed prior to initiating treatment on study. Neuroendocrine carcinomas are not eligible. Carcinomas with neuroendocrine differentiation are eligible Subject has predominant histologically or cytologically confirmed neuroendocrine prostate cancer (mixed histology is permissible, as is positivity of serum CgA and CEA) Patients with neuroendocrine or small cell features are not eligible Other histologic types of prostate cancers such as ductal, sarcomatous, lymphoma, small cell, and neuroendocrine tumors Histologic evidence of small cell/neuroendocrine prostate cancer Small-cell lung cancer/mixed NSCLC with small cell component or other neuroendocrine lung cancers (typical and atypical carcinoids, large-cell neuroendocrine carcinomas). Large-cell carcinoma. Histology other than adenocarcinoma (neuroendocrine or acinar cell) Prostate cancer with significant sarcomatoid or spindle cell or neuroendocrine small cell components Patients must have cytologic or histologic confirmation of carcinoma arising in the pancreas; patients with neuroendocrine tumors are excluded Subjects with histology other than adenocarcinoma; examples include: neuroendocrine tumors, acinar cell cancer, sarcoma or lymphoma of the pancreas Subjects with neuroendocrine and/or small cell CRPC Patients must have histologically or cytologically confirmed neuroendocrine carcinoma of the gastrointestinal (GI) tract; patients with unknown origin for the neuroendocrine carcinoma in which a gastroenteropancreatic origin is suspected (per pathologist or investigator discretion) will be eligible for the study Neuroendocrine tumors Patients with neuroendocrine or small cell features are not eligible Unequivocally confirmed diagnosis of SCLC by histology or cytology, preferably including the presence of neuroendocrine features by immunohistochemistry Poorly differentiated neuroendocrine carcinoma, high-grade neuroendocrine carcinoma, adenocarcinoid, goblet cell carcinoma, or small cell carcinoma Patients with neuroendocrine neoplasms will be excluded. Neuroendocrine tumors, pancreatic basket:\r\n* Grade 3, poorly differentiated neuroendocrine carcinoma\r\n* Large cell or small cell histology Neuroendocrine tumors, extrapancreatic basket:\r\n* Grade 3, poorly differentiated neuroendocrine carcinoma\r\n* Large cell or small cell histology Any neuroendocrine differentiation including small cell carcinoma on histology or cytology. Participation in Iowa Neuroendocrine Tumor Registry Neuroendocrine (carcinoid, islet cell) or acinar pancreatic carcinoma Histologically or cytologically confirmed non-small cell lung cancer; patients with a suspected lung cancer are eligible, but pathology must be confirmed prior to initiating treatment on study; neuroendocrine carcinomas are not eligible; carcinomas with neuroendocrine differentiation are eligible Patients with small cell or neuroendocrine tumours. Patients must not have any of the following: acinar cell carcinoma, neuroendocrine carcinoma, cystadenocarcinoma, carcinosarcoma Unequivocally confirmed diagnosis of SCLC by histology or cytology, preferably including the presence of neuroendocrine features by immunohistochemistry Other pancreatic cancer histology (islet cell, acinar, neuroendocrine tumors) Presence of islet-cell or pancreatic neuroendocrine tumor or mixed adenocarcinoma-neuroendocrine carcinoma Tumors must be histologically or cytologically proven and considered low or intermediate grade; patients with high grade neuroendocrine carcinomas or small cell carcinomas are excluded from the study High grade NET or small cell neuroendocrine carcinoma Unequivocally confirmed diagnosis of SCLC by histology or cytology, preferably including the presence of neuroendocrine features by immunohistochemistry Prostate cancer with significant sarcomatoid or spindle cell or neuroendocrine small cell components Neuroendocrine cancer of the thyroid or thymus. Rare pancreatic neuroendocrine cancers such as, insulinomas, glucagonomas, gastrinomas. Presence of documented neuroendocrine differentiation on the original pathology report Clear cell, neuroendocrine, adenosquamous, serous carcinoma or other high-risk histologies Patient must have histologically or pathologically confirmed locally unresectable or metastatic low or intermediate grade pancreatic neuroendocrine tumor, excluding small cell carcinoma Diagnosis of prostate cancer with neuroendocrine differentiation Women with neuroendocrine histologies, or histologies other than squamous, adenosquamous or adenocarcinoma Known or suspected neuroendocrine/small cell feature. Squamous, small cell, carcinoid, adenosquamous, large-cell neuroendocrine, or mixed histology containing small-cell or squamous-cell NSCLC Histological features of neuroendocrine or bronchioalveolar differentiation. Histologic diagnosis of small cell or neuroendocrine prostate cancer Diagnosis of high-grade (WHO Grade 3) or poorly differentiated NET; high-grade neuroendocrine carcinoma; large cell neuroendocrine carcinoma, small cell carcinoma, or mixed small and large cell carcinoma. Neuroendocrine prostate cancer. Patients with clear cell or neuroendocrine cell types Neuroendocrine cancer Men with small cell neuroendocrine tumors or features of small cell disease Patients with islet cell/neuroendocrine or papillary cystic neoplasm Neuroendocrine or acinar pancreatic carcinoma Have small cell carcinoma or neuroendocrine component > 50% Patients with small cell/neuroendocrine cervical carcinoma Participation in the Iowa Neuroendocrine Tumor Registry Malignancy consistent with a neuroendocrine histology Known or suspected somatostatin receptor positive neuroendocrine tumors (NETs) (e.g. carcinoid, pancreatic neuroendocrine tumors, and pheochromocytoma); supporting evidence may include magnetic resonance imaging (MRI), CT, biochemical markers, and or pathology report Histologic evidence of small cell prostate cancer or neuroendocrine differentiation in > 50% of biopsy tissue Known diagnosis of neuroendocrine tumor (NET) or suspected somatostatin receptor (SSTR) positive tumors Patients with histology other than adenocarcinoma, e.g., neuroendocrine cancer or acinar cancers, are ineligible* Patients must not have poorly differentiated neuroendocrine carcinoma, high-grade neuroendocrine carcinoma, adenocarcinoid, goblet cell carcinoid and small cell carcinoma Participants must have histologically or cytologically confirmed low- to intermediate-grade neuroendocrine tumor (carcinoid tumor) Participants must have histologically confirmed well differentiated or moderately differentiated neuroendocrine tumor from either a primary or metastatic site; carcinoid tumors of any primary site are eligible Poorly differentiated carcinoma, high grade neuroendocrine tumor or small cell carcinomas are excluded from this study Neuroendocrine Tumors (well- and moderately-differentiated) of the lung, appendix, small intestine, colon, rectum, or pancreas Histological or cytological proof of chemotherapy-naive, extensive, small cell lung cancer or neuroendocrine cancers that are either high grade or poorly differentiated Have a histologically proven well-differentiated neuroendocrine tumor (World Health Organization [WHO] grade 1, grade 2, or morphologically and/or clinically well-differentiated grade 3) Histopathologically confirmed, well-­differentiated metastatic NETs Documentation of Disease:\r\n* Histologic Documentation: Well- or moderately-differentiated neuroendocrine tumors of pancreatic and non-pancreatic (i.e. carcinoid) origin by local pathology\r\n** The pathology report must state ONE of the following: 1) well- or moderately-differentiated neuroendocrine tumor, 2) low- or intermediate-grade neuroendocrine tumor, or 3) carcinoid tumor or atypical carcinoid tumor; documentation of histology from a primary or metastatic site is allowed\r\n** Patients with poorly differentiated neuroendocrine carcinoma, high-grade neuroendocrine carcinoma, adenocarcinoid tumor, or goblet cell carcinoid tumor are not eligible\r\n* Stage: Locally advanced/unresectable or metastatic disease\r\n* Tumor Site: Histological documentation of neuroendocrine tumor of pancreatic, gastrointestinal (GI), lung, or unknown primary site; GI, lung, and unknown primary NETs will enroll in the carcinoid tumor cohort of the study\r\n** Functional (associated with a clinical hormone syndrome) or nonfunctional tumors are allowed\r\n* Radiologic Evaluation: Target lesions must have shown evidence of disease progression by Response Evaluation Criteria in Solid Tumors (RECIST) version (v)1.1 criteria in the 12 months prior to registration; the radiologic images, imaging reports, and clinic notes indicating growth of existing lesions, development of new lesions, or treatment changes must be submitted Metastatic poorly differentiated and/or high-grade neuroendocrine tumor/carcinoma originating outside of the lung (including unknown primary) A pathologically confirmed (histology or cytology) malignant neoplasm that is determined to be well-differentiated neuroendocrine tumor (i.e. grade 1 or grade 2); the primary tumor location should be known or believed to be midgut Patients with documentation of well differentiated liposarcoma only (of the well differentiated/dedifferentiated liposarcoma family) are specifically excluded, owing to its characteristically slow growth. If high grade areas are suspected (dedifferentiation), but not proved by pathology analysis (e.g. after primary resection of a well-differentiated liposarcoma), a biopsy must be performed to demonstrate the high-grade dedifferentiated disease Patients must have histological evidence of a metastatic well differentiated or moderately differentiated mucinous appendiceal epithelial neoplasm (AEN) Have metastatic and/or unresectable pathologically confirmed well-differentiated, typical or atypical neuroendocrine tumor of the lung Histologic evidence of Well differentiated Neuroendocrine tumors (NETs) of the lung (typical and atypical according to the World Health Organisation (WHO criteria), evaluated locally) Poorly differentiated or high grade carcinoma, or patients with neuroendocrine tumors not of lung origin are excluded Well-differentiated (G1 or G2) based on local pathology report, non-functional neuroendocrine tumor of GI, pancreatic or thoracic (including lung and thymus) origin. Poorly-differentiated GEP-NEC based on local pathology report Poorly-differentiated GEP-NEC group: Disease progression while on or after prior treatment. Well-differentiated grade 3 neuroendocrine tumors; poorly-differentiated neuroendocrine carcinoma of any origin (other than GEP-NEC); including NEC of unknown origin, adenocarcinoid, and goblet cell carcinoid Chordoma (poorly differentiated or de-differentiated) Subjects with a history of endometrial cancer are eligible only if they presented with a stage lower than 1A and if the histology was a subtype other than poorly differentiated Patient must have histologically or cytologically confirmed well differentiated or moderately differentiated (low grade or intermediate grade) neuroendocrine tumor that is locally advanced or metastatic and not of pancreatic origin Neuroendocrine tumors, pancreatic basket\r\n* Grade 1 or grade 2 (or described as low grade, intermediate grade, well differentiated, or moderately differentiated) according to reviewing pathologist\r\n* Progressive disease over the preceding 12 months\r\n* Any number of prior therapies, including 0\r\n* Patients using a somatostatin analogue for symptom control must be on stable doses for 56 days prior to enrollment Neuroendocrine tumors, extrapancreatic basket\r\n* Grade 1 or grade 2 (or described as low grade, intermediate grade, well differentiated, or moderately differentiated; typical or atypical carcinoid if originating in lung) according to reviewing pathologist\r\n* Progressive disease over the preceding 12 months\r\n* Any number of prior therapies, including 0\r\n* Patients using a somatostatin analogue for symptom control must be on stable doses for 56 days prior to enrollment Patients with well-differentiated neuroendocrine carcinoma (carcinoid tumor) Histologically or cytologically confirmed metastatic and/or unresectable progressive, well differentiated carcinoid or pancreatic neuroendocrine tumor (NET) carcinoids Histologically or cytologically confirmed low or intermediate grade, unresectable well differentiated foregut neuroendocrine tumors (thymic, bronchopulmonary, gastric, duodenal and pancreatic); patients with multiple neuroendocrine tumors associated with MEN1 syndrome will be eligible Low- or intermediate-grade neuroendocrine carcinoma, including the following subtypes: carcinoid tumor, low- to intermediate-grade or well- to moderately-differentiated neuroendocrine carcinoma or tumor, atypical carcinoid tumor; documentation from a primary tumor or metastatic site is sufficient; patients with poorly differentiated neuroendocrine carcinoma, high-grade neuroendocrine carcinoma, adenocarcinoid tumor, or goblet cell carcinoid tumor are not eligible Histologic documentation of well differentiated or moderately differentiated locally unresectable or metastatic pancreatic neuroendocrine tumor from either a primary or metastatic site with documented disease progression =< 12 months prior to enrollment with whose disease is not currently amenable to surgery, radiation or modality therapy with curative intent; if different histologic classification schemes are used, equivalent histologic classifications (for example “grade 1,” “low grade,” or “intermediate grade”) are allowed; there must be histologic documentation of a pancreatic primary site or clinical evidence of a pancreatic neuroendocrine primary tumor as determined by the treating physician; documentation from a metastatic site is sufficient if there is clinical evidence of a pancreatic primary site; in the case of discordant pathology, patient eligibility will be determined by the principal investigator (PI) after review of available records; patients with neuroendocrine tumors (e.g., gastrinoma, vasoactive intestinal peptidase [VIPoma]) in whom a pancreatic or peripancreatic primary site is strongly suspected are also eligible Poorly differentiated neuroendocrine carcinoma or small cell carcinoma Patient must have a histologically or cytologically confirmed diagnosis of pancreatic cancer or poorly differentiated neuroendocrine tumor and must have been treated with a regimen with known benefit for pancreatic cancer/poorly differentiated neuroendocrine tumor (MTD expansion cohort only) Poorly differentiated or high grade pancreatic neuroendocrine tumors Locally unresectable or metastatic, histologically-confirmed, carcinoid or pancreatic neuroendocrine tumor; tumors must be considered well- or moderately-differentiated; patients with poorly differentiated neuroendocrine carcinoma are excluded from the study For patients with carcinoid tumors, patients must have progressed on, be currently receiving, or be intolerant to octreotide therapy; for patients with pancreatic neuroendocrine tumors, the prior or current use of octreotide or somatostatin analogues is permitted, but not required; if the patient is on octreotide, regardless of whether the patient has a carcinoid or pancreatic neuroendocrine tumor, the patient must be on a stable dose of somatostatin analogue for at least two months High grade or poorly differentiated neuroendocrine tumors Well-differentiated liposarcoma or atypical lipomatous tumor High grade or poorly differentiated NET Patients must have histologically or cytologically confirmed low or intermediate grade pancreatic NET; patients with neuroendocrine tumors associated with multiple endocrine neoplasia type 1 (MEN1) syndrome will be eligible Histologically or cytologically confirmed well differentiated low or intermediate grade (World Health Organization [WHO] Grade 1 or 2) NET of pancreatic, gastrointestinal, lung, or undetermined origin that is locally advanced or metastatic and has progressed within the past 12 months The participant has well-differentiated or moderately-differentiated, histologically confirmed neuroendocrine carcinoma, including carcinoid of any location and islet cell tumors Pathologically confirmed metastatic unresectable well differentiated (low grade and intermediate grade) neuroendocrine tumors (Ki-67 < 20% and mitotic rate < 2 per 10 high power field) that demonstrate progressive disease (by serial computed tomography [CT] or magnetic resonance imaging [MRI] scans) in past 12 months including\r\n* Carcinoid tumors originating anywhere in the body including the gastrointestinal (GI) tract or bronchial tree or thymus\r\n* Pancreatic neuroendocrine tumors (including functional and non-functional islet cell, insulinomas and glucagonomas)\r\n* Pheochromocytomas\r\n* Gastrinomas (Zollinger-Ellison syndrome)\r\n* Multiple endocrine neoplasia (MEN type I/II),\r\n* Adrenal carcinomas with NET markers by immunohistochemistry (IHC) or serum\r\n* Somatostatinoma\r\n* VIPoma (vasoactive intestinal peptide)\r\n* Merkel cell tumors\r\n* Medullary thyroid carcinoma\r\n* Neuroendocrine tumors of unknown primary site Histologic diagnosis of a well- to moderately differentiated PNET (low-intermediate grade); NOTE: pathology report should state one of the following: low-grade, intermediate grade, moderately- or well-differentiated NET, pancreatic NET (or neuroendocrine carcinoma of the pancreas); patients who have tumors with a Ki67 of 20 % - 30 % are eligible if the pathologist determines the tumor has the appearance of a well- to moderately differentiated neuroendocrine tumor Patient's malignancy is consistent with well differentiated neuroendocrine (carcinoid) histology PHASE I: Eligible patients include patients with histologically proven neuroendocrine tumors (paraganglioma, PHEO [pheochromocytoma], or well differentiated neuroendocrine tumor [NET] of the lung or gastrointestinal [GI] system) or neuroblastoma (NB); patients, who have NB, the diagnosis must be in accordance with the International Criteria, i.e., either histopathology or bone marrow involvement; patients must be able to undergo PET scan without sedation Patients malignancy consistent with well differentiated (carcinoid) neuroendocrine histology Has a metastatic neuroendocrine histology with MSKCC pathology confirmation as moderately or poorly differentiated or intermediate or high grade Patients with poorly differentiated pancreatic neuroendocrine tumors (according to WHO 2000 classification). Diagnosis of anal or small bowel carcinoma. Previously identified small cell neuroendocrine tumours or pure small cell carcinoma of the prostate, based on a prior biopsy of the prostate. Pathology consistent with majority of specimen having small cell carcinoma of the prostate (prostate cancer with neuroendocrine features is acceptable) Pathologic findings consistent with small-cell or neuroendocrine carcinoma of the prostate Histologic diagnosis of prostate adenocarcinoma\r\n* Pure small cell carcinoma will be excluded; however, component of neuroendocrine /small cell differentiation will be allowed provided that adenocarcinoma constitutes majority of the tissue specimen Patients must have histologically or cytologically confirmed adenocarcinoma of the prostate with no histological variants (such as small cell, sarcomatoid, pure ductal cancer, transitional cell carcinoma). Pathologically–confirmed small cell carcinoma of any primary site Diagnosis of germ cell tumor, small cell carcinoma or hematologic malignancy Histologic evidence of neuroendocrine or small cell carcinoma of the prostate Patients with histologic evidence of small cell carcinoma of the prostate will not be eligible Have a pathological diagnosis of prostate carcinoma Patients with histologic evidence of small cell carcinoma of the prostate will not be eligible Pathological finding consistent with small cell carcinoma of the prostate Pathological finding consistent with small cell, neuroendocrine carcinoma of the prostate or any other histology different than adenocarcinoma Diagnosis of anal or small bowel carcinoma. Patients with neuroendocrine or small cell carcinoma of the prostate Pathology consistent with majority of specimen having small cell carcinoma of the prostate (prostate cancer with other neuroendocrine features is acceptable) History of small-cell or neuroendocrine prostate carcinoma Pathological finding consistent with small cell, ductal or neuroendocrine carcinoma of the prostate Transitional cell, small cell, or squamous cell carcinoma of the prostate Small cell or neuroendocrine carcinoma of the prostate Pathology consistent with small cell carcinoma of the prostate Pathological finding consistent with small cell carcinoma of the prostate Pathological finding consistent with small cell carcinoma of the prostate Pathologic finding consistent with small cell carcinoma of the prostate Diagnosis of anal or small bowel carcinoma. Pathological finding consistent with small cell carcinoma of the prostate Small cell carcinoma of the prostate Have histologically confirmed carcinoma of the prostate that is metastatic or otherwise incurable, and a BMI defined as obese (i.e. > 30 kg/m^2); any histologic variant is acceptable other than small cell carcinoma Small cell prostate cancer Patients with tumors that have a component of small cell carcinoma Pathological finding consistent with small cell carcinoma of the prostate. Patients with variant histologies (e.g., ductal or small cell carcinoma) Pure small cell carcinoma of the prostate or any mixed histology cancer of the prostate (eg: neuroendocrine) that contains < 50% adenocarcinoma, as observed on biopsy obtained at the time of diagnosis or on any subsequent biopsies Prior pathology consistent with small cell carcinoma or prostate cancer with predominantly neuroendocrine differentiation Patients with histologic evidence of small cell carcinoma of the prostate will not be eligible Patients with histologic evidence of small cell carcinoma of the prostate will not be eligible Small cell carcinoma of the prostate Have a pathological diagnosis of prostate carcinoma Pure small cell carcinoma of the prostate History of neuroendocrine variants of prostate cancer, including small cell carcinoma of the prostate Histologically or cytologically confirmed adenocarcinoma of the prostate. No evidence of neuroendocrine differentiation or small cell features. Histologically confirmed diagnosis of prostate adenocarcinoma; variants of prostate cancer, including neuroendocrine features and small cell carcinoma of the prostate, are not permitted Histologic or cytologic diagnosis of adenocarcinoma of the prostate without neuroendocrine differentiation or small cell features Histologically confirmed prostate adenocarcinoma without neuroendocrine differentiation or small-cell features Histologically confirmed metastatic adenocarcinoma of the prostate without histological neuroendocrine differentiation or small cell features Histologically or cytologically confirmed adenocarcinoma of the prostate without neuroendocrine differentiation or small cell features Histologically confirmed adenocarcinoma of the prostate without signet cell or small cell features Histologically-confirmed diagnosis of prostate adenocarcinoma; variants of prostate cancer, including neuroendocrine features and small cell carcinoma of the prostate, are not permitted Histologically or cytologically confirmed adenocarcinoma of the prostate without signet cell, or small cell features. Progressive castration-resistant metastatic prostate cancer with histologically or cytologically confirmed adenocarcinoma of the prostate without neuroendocrine differentiation or small cell features Histologically or cytologically confirmed carcinoma of the prostate (excluding neuroendocrine differentiation or squamous cell histology) Histologically or cytologically confirmed carcinoma of the prostate (excluding neuroendocrine differentiation or squamous cell histology) Histologically confirmed diagnosis of adenocarcinoma of the prostate; histologic variants of prostate cancer comprising of > 50% of the tumor including neuroendocrine features and small cell carcinoma of the prostate are excluded Histologically confirmed adenocarcinoma of the prostate without morphologic neuroendocrine differentiation or small cell features. Histologically or cytologically confirmed adenocarcinoma of the prostate at initial biopsy, without neuroendocrine differentiation, signet cell, or small cell features; Histologically or cytologically confirmed prostate cancer (individuals with primary neuroendocrine carcinoma of prostate are excluded) Subject is diagnosed with histologically or cytologically confirmed adenocarcinoma of the prostate without neuroendocrine differentiation, signet cell or small cell histology. Histologically or cytologically confirmed adenocarcinoma of prostate without neuroendocrine differentiation or small cell features. Histologically or cytologically confirmed adenocarcinoma of the prostate without neuroendocrine differentiation, signet cell, or small cell features; Histologically or cytologically confirmed adenocarcinoma of the prostate without neuroendocrine differentiation, or signet cell or small cell features; Histologically confirmed adenocarcinoma of the prostate without histological variants (including overt neuroendocrine differentiation, small cell neuroendocrine carcinoma features, sarcomatoid features, pure ductal adenocarcinoma, squamous or transitional cell carcinoma) Participants must have histologically or cytologically confirmed adenocarcinoma of the prostate without > 50% neuroendocrine differentiation or small cell histology Progressive castration-resistant metastatic prostate cancer with histologically or cytologically confirmed adenocarcinoma of the prostate without neuroendocrine differentiation or small cell features Histologically or cytologically confirmed adenocarcinoma of the prostate without neuroendocrine differentiation or small cell features with high risk for development of metastases, defined as prostate-specific antigen doubling time (PSADT) less than or equal to (<=) 10 months. PSADT is calculated using at least 3 prostate-specific antigen (PSA) values obtained during continuous ADT (androgen deprivation therapy) Participants must have histologically or cytologically confirmed adenocarcinoma of the prostate without >= 50% neuroendocrine differentiation or small cell histology Histologically confirmed diagnosis of adenocarcinoma of the prostate; histologic variants of prostate cancer, including neuroendocrine features and small cell carcinoma of the prostate are excluded Histologically confirmed adenocarcinoma of the prostate without neuroendocrine differentiation or small cell features Expansion Cohort 6: Subjects with metastatic CRPC (adenocarcinoma of the prostate without neuroendocrine differentiation or small cell features) who have radiographically progressed in soft tissue on or after enzalutamide and/or abiraterone acetate for metastatic disease. Histologically or cytologically confirmed adenocarcinoma of the prostate without neuroendocrine differentiation or small cell features Histologically or cytologically confirmed adenocarcinoma of the prostate without signet ring cell features. Histologically or cytologically confirmed carcinoma of the bladder of all histologies except neuroendocrine differentiation or squamous cell histology Histologically or cytologically confirmed adenocarcinoma of the prostate without neuroendocrine differentiation or small cell features Histologically confirmed adenocarcinoma of the prostate without histological variants comprising > 50% of the sample as determined by academic center central review (including neuroendocrine differentiation, small cell, sarcomatoid, ductal adenocarcinoma, squamous or transitional cell carcinoma) Histologically confirmed diagnosis of adenocarcinoma of the prostate; small cell or neuroendocrine tumors of the prostate are also permitted Histologically confirmed adenocarcinoma of the prostate; patients with small cell, neuroendocrine, and transitional cell carcinomas are not eligible Histologically or cytologically confirmed adenocarcinoma of the prostate without neuroendocrine differentiation or small cell histology