The Commodores announced Cockrell's health issues Friday on the athletic department's website.
Cockrell, a sophomore from Acworth, Georgia, noticed two lumps on the right side of his neck last fall. He was diagnosed with melanoma in November, underwent surgery in December to remove cancerous lymph nodes from his neck and later had radiation therapy.
After a full-body scan showed unusual growths in Cockrell's lungs, doctors said in July that his cancer had spread. He is now undergoing treatment at the MD Anderson Cancer Center in Houston.
Cockrell watched Vanderbilt's season-opening 35-7 victory over Middle Tennessee last week from the coach's suite in the press box. He received the game ball afterward.