Eighteen-time Grand Slam champion Martina Navratilova has announced that she has been diagnosed with throat and breast cancer.

The 66-year-old had previously undergone radiation therapy for breast cancer in 2010 and will begin a course of treatment later in January.

"This double whammy is serious but still fixable, and I'm hoping for a favourable outcome," Navratilova said in a statement. "It's going to stink for a while but I will fight with all I have got."

A statement from Navratilova's agent confirmed that the former world number one would not be able to carry out her punditry duties at the Australian Open later this month, but her prognosis is a "good one".

"Martina Navratilova has been diagnosed with stage one throat cancer. The prognosis is good and Martina will start her treatment this month," Navratilova's representative said.

"Martina noticed an enlarged lymph node in her neck during the WTA finals in Fort Worth. When it didn't go down, a biopsy was performed, the results came back as stage one throat cancer."

Navratilova's breast cancer was discovered after doctors noticed a "suspicious form" while examining her throat, and the two cancers are "completely unrelated" to one another.

"Both these cancers are in their early stages with great outcomes. Martina won't be covering the Australian Open for Tennis Channel from their studio but hopes to be able to join in from time to time by Zoom."

During her illustrious playing career, Navratilova won a staggering 167 singles titles - which remains a women's record in the Open Era - including nine Wimbledon victories. body check tags ::