Stan Lee cancels forthcoming appearances

Comic book legend Stan Lee has cancelled his forthcoming appearances, raising concerns over his health.

The 89-year-old former president and chairman of Marvel Comics was set to appear at an event in Toledo, but was forced to pull out, according to his agent, due to 'a very serious circumstance'.

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Forthcoming events Lee was set to appear at have also been shelved 'for the near future'.

Lee was forced to pull out of the Hero Complex Film Festival in May citing fatigue, but appearances at Wizard World in New Orleans and other events have now been cancelled.

Fans have since taken to the web and social networking sites to wish Lee well.

The comic book writer and publisher is credited with co-creating, along with fellow legends Jack Kirby and Steve Ditko, characters including Spider-Man, the Hulk, X-Men, the Fantastic Four, Iron Man and Thor.

He also makes frequent cameos in films from the Marvel stable, recently showing up in 'Avengers Assemble' and 'The Amazing Spider-Man'.