The band have been forced to cancel their upcoming 14-date tour of Australia and New Zealand so the 67-year-old can undergo urgent treatment.
The news comes after they completed the European leg of their first world tour in four years, which saw former member and McVie’s ex-wife Christine rejoin them on stage as a guest.
The band say in a statement: “We are sorry not to be able to play these Australian and New Zealand dates.
“John McVie, one of the co-founding and original members of Fleetwood Mac [actually an early member, having taken over from Bob Brunning], is scheduled to be in treatment for cancer during that period of time.
“We hope our Australia and New Zealand fans, as well as fans everywhere, will join is in wishing John and his family all the best.”
The tour leg was to begin in Sydney on November 10 and end in Auckland on December 7. No word has been given on the status of a show planned for Las Vegas on December 30.
During the summer Mac released their first new material in a decade, in the form of an EP titled Extended Play. Guitarist Lindsey Buckingham recently said a full-length album could only be made if vocalist Stevie Nicks wanted to do it – and he could understand why she might not.