Snooker's Ali Carter fighting lung cancer
Snooker's Ali Carter (L) punches the air after beating Xiao Guodong of China in the World Snooker Championship first round match at The Crucible in Sheffield, on April 20, 2014 - by Andrew Yates
The 34-year-old from Chelmsford, who suffers from Crohn's disease, last year recovered from testicular cancer to resume his career.
Carter, a winner of three ranking titles and twice runner-up at the World Championship, was due to play in the Wuxi Classic qualifiers in Gloucester this weekend, but has withdrawn from the event.
World Professional Billiards and Snooker Association chairman Jason Ferguson said: "Ali is the toughest competitor I know and having spoken to him over the last few days I can assure everyone he has the fight to get through the battle ahead."