Hall of Fame second baseman Ryne Sandberg has been diagnosed with metastatic prostate cancer.

The 64-year-old Sandberg said Monday in a release put out by the Baseball Hall of Fame that he has started treatment.

Sandberg hit .285 with 282 homers, 1,061 RBIs and 344 steals in 16 seasons in the majors. He made his big league debut with Philadelphia in 1981 and appeared in 13 games with the Phillies before he was traded to the Chicago Cubs in January 1982.

Sandberg turned into one of the majors’ best all-around performers with the Cubs. He made 10 All-Star teams and won nine Gold Gloves. He also was the NL MVP in 1984.

He was inducted into Cooperstown in 2005.