EA2176: Phase 3 Clinical Trial of Carboplatin and Paclitaxel +/- Nivolumab in Metastatic Anal Cancer Patients

Inclusion Criteria: * Patient must have inoperable, recurrent, or metastatic disease not amenable to curative therapy * Patient must have histological or cytological confirmation of anal squamous cell carcinoma (includes basaloid and cloacogenic lesions) from the primary tumor or a newly diagnosed recurrent/metastatic lesion * Patient must be \>= 18 years of age * Patient must have Eastern Cooperative Oncology Group (ECOG) performance status =\< 0-1 * Patients must have measurable disease according to Response Evaluation Criteria in Solid Tumors (RECIST) criteria version 1.1 and based on radiologic assessment performed \< 4 weeks prior to randomization * Patient receiving palliative (limited-field) radiation therapy is allowed, as long as the lesion treated for palliation is not a target lesion and is \> 7 days from completion from palliative radiation * Patients with brain metastasis are eligible if patient is asymptomatic and if treatment ended \> 3 months prior to randomization. Patients with treated brain metastases are eligible if follow-up brain imaging after central nervous system (CNS)-directed therapy shows no evidence of progression within 4 weeks prior to randomization * Patient must not be pregnant or breast-feeding due to the potential harm to an unborn fetus and possible risk for adverse events in nursing infants with the treatment regimens being used. All patients of childbearing potential must have a blood test or urine study with a minimum sensitivity of 25 …