Julia Louis-Dreyfus has breast cancer, she announced on Thursday, less than two weeks after her record-setting Emmy win for “Veep.”

The news was met with words of support from fellow performers, cancer survivors and a former vice president.

“1 in 8 women get breast cancer,” Ms. Louis-Dreyfus, 56, wrote on Twitter and Instagram. “Today, I’m the one.”

She then immediately shifted the conversation to health care and cancer research. “The good news is that I have the most glorious group of supportive and caring friends, and fantastic insurance through my union,” she wrote. “The bad news is that not all women are so lucky, so let’s fight all cancers and make universal health care a reality.”