07/13/2009 AT 02:35 PM EDT
Maura Tierney revealed Monday that she will be having surgery to remove a breast tumor.
"In an effort to guard my privacy, it seems that the wording of NBC's press release has unfortunately caused some confusion and undue alarm about my health," Tierney, 44, said in a statement regarding her "illness," which NBC Universal announced Friday
was delaying production of her new series, Parenthood
"I have discovered a tumor in my breast which requires surgery. I will not know either my exact diagnosis or course of treatment until that surgery is performed. My doctors have all assured me this is a very treatable condition," the statement read. "I'm very optimistic as to the outcome and want to thank everyone who has sent positive thoughts and support. I look forward to going back to work soon."
The show, which plays off the 1989 film of the same name, centers around four siblings (Peter Krause, Tierney, Erika Christensen and Dax Shepard) and their parents (Bonnie Bedelia and Craig T. Nelson). It had been scheduled to premiere on Sept. 23.