Hall of Fame second baseman Ryne Sandberg says the prostate cancer he thought had been eliminated by radiation has returned and spread.

The Chicago Cubs great made the announcement Tuesday on Instagram.

Sandberg announced in January he had metastatic prostate cancer and in August said he was cancer-free after chemotherapy and radiation treatments.

"Unfortunately, we recently learned the cancer has relapsed and it has spread to other organs," he wrote Tuesday. "This means that I'm back to more intensive treatment. We will continue to be positive, strong, and fight to beat this. Thank you for your thoughts and prayers for me and my family."

Sandberg was the National League MVP in 1984 and a 10-time all-star during 15 seasons for the Cubs from 1982 to 1997, with 282 home runs and 344 stolen bases. After his playing career, he served as manager of the Philadelphia Phillies from 2013 to 2015, going 119-159.

The Cubs honoured him this summer with a statue outside Wrigley Field.

"Ryne is an inspiration to cancer survivors everywhere," Cubs owner Tom Ricketts said in a statement Tuesday. "I know all Cubs fans join my family and me in sending positive thoughts to Ryne and keeping him and his family in our prayers as he faces this next round of treatments to defeat cancer.

"Ryne has the heart and soul of a champion and that will serve him well in this challenge."