International Tennis Hall of Famer Martina Navratilova says she has beaten cancer for a second time. 

The 18-time Grand Slam singles champion shared the news of her "all clear" in a Twitter post on Monday after receiving a battery of tests at Memorial Sloan Kettering Cancer Center in New York City.

"After a day full of tests at Sloan Kettering, I got the all clear!" she wrote. "Thank you to all the doctors, nurses, proton and radiation magicians ... What a relief."

Navratilova, 66, shared in January that she had been diagnosed with Stage 1 breast and throat cancers. In March, she returned to work as a commentator for Tennis Channel, declaring she was in remission.

Navratilova's news was met with well-wishes from the tennis family, including her fellow Tennis Channel commentators, and former players including fellow cancer survivor Carla Suárez Navarro.

Navratilova had previously been treated for a noninvasive form of breast cancer in 2010 and had a lumpectomy.