The New York Mets say general manager Sandy Alderson has cancer and will begin chemotherapy this week.

Chief operating officer Jeff Wilpon said in a statement Friday the cancer is "very treatable" and doctors are "optimistic about his full recovery." The team did not say what kind of cancer he has.

The 68-year-old Alderson collapsed at a news conference Nov. 4 to announce a contract extension for manager Terry Collins. The Mets say Alderson had a medical procedure three weeks ago and surgery was performed at Memorial Sloan Kettering in New York.

He'll have 8 to 12 weeks of chemotherapy and continue his work as general manager throughout the treatments. Alderson, whose team reached the World Series this year, will miss next week's annual GM winter meetings in Nashville, Tennessee.