AceShowbiz - Former "ER" star Maura Tierney has revealed she pulled out of TV drama "Parenthood" because she didn't want her cancer battle to be documented on television. The actress dropped out of the new show after she was diagnosed with breast cancer last year - but she insists it wasn't because she was too ill to act.

In her first interview since undergoing treatment for cancer, Tierney tells the New York Times, "I felt terrible leaving the 'Parenthood' team in the lurch, but doing the show would have been very stressful because I didn't want that phase of my life documented on film."

Tierney is slowly returning to TV - she'll revive her character in firefighting drama "Rescue Me" in 2011. She has also signed on to join Frances McDormand onstage in Los Angeles and New York in the play North Atlantic.