Observational Study of Nivolumab Monotherapy or in Combination With Ipilimumab in Participants With Advanced Melanoma and in Participants With Adjuvant Nivolumab Therapy

Inclusion Criteria:

For Cohort 1 and 2: (Recruitment ended by 02/20/2020)

* Advanced melanoma (Stage III/Stage IV)
* Histologically confirmed diagnosis
* Treatment decision for nivolumab monotherapy or nivolumab/ipilimumab combination therapy has already been taken

For Cohort 3: (Recruitment ended by 08/31/2020)

* Primary diagnosis of advanced melanoma after complete surgical tumor resection and no evidence of disease
* Treatment decision for adjuvant nivolumab therapy has already been taken

Exclusion Criteria:

For Cohort 1 and 2: (Recruitment ended by 02/20/2020)

* Current primary diagnosis of a cancer other than advanced melanoma, that requires systemic or other treatment or has not been treated curatively (as per discretion of the investigator)
* Previous treatment with nivolumab, for nivolumab monotherapy cohort only
* Current active participation in an interventional clinical trial

For Cohort 3: (Recruitment ended by 08/31/2020)

* Current diagnosis of persisting advanced melanoma or a cancer other than advanced melanoma that requires systemic or other treatment or has not been treated curatively (as per discretion of the investigator)
* Current active participation in an interventional clinical trial

Other protocol-defined inclusion/exclusion criteria apply