Tennis great Martina Navratilova has breast cancer

Navratilova will reportedly start radiation therapy next month

Former tennis champion Martina Navratilova has revealed she has been diagnosed with breast cancer.

Speaking to US magazine People, she said she had cried after finding out.

"I feel so in control of my life and my body, and then this comes, and it's completely out of my hands," she is quoted as saying by the magazine.

According to the report, her prognosis is excellent. During her career, she won 18 Grand Slam singles titles, nine of them at Wimbledon.

Navratilova, 53, said the disease had been detected early thanks to a routine mammogram.

Martina Navratilova talks abut her breast cancer - Courtesy ABC's Good Morning America

But, she said, she was lucky that was the case because she had left it four years since her last check-up.

"I let it slide. Everyone gets busy, but don't make excuses," she told the magazine. "I stay in shape and eat right, and it happened to me.

"Another year and I could have been in big trouble."

Navratilova has had a lumpectomy and will begin six weeks of radiation therapy in May, the report says.

The Prague-born former champion, who became a US citizen in 1981 and now has dual US-Czech citizenship, still plays tennis and competes in triathlons.

She played her last Wimbledon tournament in July 2006.