Australian actor Andy Whitfield, who has played the lead title character on the Starz TV drama Spartacus: Blood and Sand, will not return for the series’ second season after suffering a setback in his battle against cancer.

The actor has been forced to leave the series he’s fronted since its premiere in Jan. 2010 after experiencing a recurrence of non-Hodgkin lymphoma, for which he must undergo “aggressive treatment.” Production of the show’s second season was postponed this spring when Whitfield was diagnosed with the life-threatening illness. He had been responding well to treatment, but was crushed last week when he learned that his cancer has returned.

“It’s with a deep sense of disappointment that I must step aside from such an exceptional project as Spartacus and all the wonderful people involved/ It seems that it is time for myself and my family to embark on another extraordinary journey,” Whitfield remarked in a heartfelt statement issued over the weekend.

Upon hearing news of Whitfield’s cancer diagnosis, Starz CEO Chris Albrecht praised the actor’s courageous fight against a debilitating disease:

“Our hearts and prayers are with Andy and his family during this difficult time. Andy is not only an incredible actor whose portrayal of Spartacus made an indelible impression on Starz audiences, he is also an amazing human being whose courage, strength and grace in the face of adversity have inspired all of us.”

The future of the show remains uncertain. On Saturday, the network announced that series stars Lucy Lawless and John Hannah will take center stage for a six-episode prequel leading up to Spartacus’ arrival. The show is tenatively scheduled to debut in Jan. 2011.

Best wishes to Andy. May he continue to kick cancer’s ass.