It was started in connection with the discovery of a swollen lymph node in the neck in November.
The two forms of cancer must be completely independent of each other and be of a mild nature.
- This double blow is serious but can still be fixed, says the Czech-born American.
Had television jobs in Australia planned
- I hope for a positive result.
It will be difficult for a while but I will fight with everything I have, she says on her social media.
Twelve years ago, Navratilova was cured of breast cancer after radiotherapy.
The diagonism and the upcoming treatment means that Navratilova, who has a total of 59 Grand Slam titles including doubles and mixed, will not go to Australia to commentate this year's first Grand Slam for a television company.