Julia Louis-Dreyfus has completed her second round of chemotherapy as she battles breast cancer.

56-year-old Veep star Louis-Dreyfus revealed her breast cancer diagnosis in September and has gone through two rounds of chemotherapy treatment.

"Chemo #2 finito," she posted to her Instagram account. "We are NOT f***ing around here."

Louis-Dreyfus then quoted a lyric from Katy Perry's song Roar, saying, "I've got the eye of the tiger. The Fighter dancing through the fire cuz I am a champion and you're going to hear me ROAR."

At the time of her announcement on September 28, Louis-Dreyfus posted on Twitter, "1 in 8 women get breast cancer. Today, I'm the one."

"The good news is that I have the most glorious group of supportive and caring family and friends, and fantastic insurance through my union," continued the former Seinfeld star. "The bad news is that not all women are so lucky, so let's fight all cancers and make universal health care a reality."

In a statement, Veep's makers, HBO, said: "Our love and support go out to Julia and her family at this time.

"We have every confidence she will get through this with her usual tenacity and undaunted spirit, and look forward to her return to health and to HBO for the final season of Veep."

Earlier that month, Louis-Dreyfus made history at the Emmy Awards by winning her sixth consecutive Best Comedy Actress Emmy for her role as Veep's Selina Meyer.