We are conducting a comprehensive investigation of body composition and the immune/inflammatory state at the time of cancer diagnosis and outcomes at eight years post-diagnosis in the Be-Well Study of 1,472 non-muscle invasive bladder cancer survivors. Our aims are to: determine the association of body composition (sarcopenia, adiposity, myosteatosis) with NMIBC recurrence (first and multiple) and progression, by age and sex; determine the association of body composition with BCG immunotherapy outcomes including adverse events and treatment failure; and examine the role of circulating inflammatory/immune biomarkers in the relationship of body composition with BCG outcomes and non-muscle invasive bladder cancer prognosis.