A year later, Gumbel, 62, tells PEOPLE his prognosis is excellent.
"I'm still doing well," he said at the UNICEF Snowflake Ball Tuesday in New York City. "Doctors tell me I'm free and clear, so I hope for better times."
Gumbel revealed his health crisis last year while filling in for Regis Philbin on Live with Regis and Kelly. "They opened up my chest, they took out a malignant tumor, they took out part of my lung and they took out some other goodies," he said at the time.
The surgery took place two months before he revealed it on Live, and Gumbel said he kept it quiet at the time, not even revealing it to the staff of his HBO show Real Sports.
On Tuesday, Gumbel looked thin but wore a big smile as he walked the red carpet with his wife, Hilary Gumbel, who served on the event's gala committee.
"I've got very little to complain about," he told PEOPLE about life now. "I'm doing well."