 In 1982 she was a candidate for the Democratic Party nomination for governor, but lost in the primary to Knoxville mayor Randy Tyree, who lost in the general election to Republican governor Lamar Alexander.In the 1980s, O'Brien was diagnosed with breast cancer, underwent a mastectomy, and received a silicone implant.Subsequently, she worked to enact legislation to require health insurers to provide coverage for mammograms and later cosponsored a bill to expand women's rights to sue over defective breast implants by extending the statute of limitations for product liability lawsuits for implants.