Martina Navratilova has been diagnosed with both throat and breast cancer. Navratilova, 66, said both cancers had been caught at an early stage.

The 18-time Grand Slam singles champion, who previously had breast cancer in 2010, will start treatment in New York later this month.

"The double whammy is serious, but fixable, and I'm hoping for a favourable outcome," she said. "It's going to stink for a while, but I'll fight with all I have got."

Navratilova noticed an enlarged lymph node in her neck during November's WTA Finals in Fort Worth, Texas. A subsequent biopsy revealed stage one throat cancer.

Navratilova was due to cover this month's Australian Open from the Tennis Channel studio, but will instead make some occasional remote appearances.

The nine-time Wimbledon singles champion said she felt "helpless" after she was diagnosed with cancer in 2010,

but decided to go public with the news to help other women suffering similar health problems. A subsequent biopsy revealed stage one throat cancer.