New York, Jan 15 (IANS): Tennis great Chris Evert, the winner of 18 Grand Slam singles and three doubles titles, has said she has Stage 1C ovarian cancer and is undergoing treatment.

The Hall of Fame member, whose rivalry with Martina Navratilova became legendary in the 70s and 80s, posted on Twitter a link to an ESPN story she co-wrote with Chris McKendry, in which she said, "I feel very lucky that they caught it early and expect positive results from chemo plan… thanks to all of you for respecting my need to focus on my mental health and treatment plan. You will see me appear from home at times during ESPN's coverage of the Aussie Open."

The Australian Open commences in Melbourne on January 17.

Evert, 67, also posted a message on social media, saying, "I wanted to share my stage 1 ovarian cancer diagnosis and the story behind it as a way to help others. I feel very lucky that they caught it early and expect positive results from my chemo plan. Thanks to Chris McKendry for her friendship and for co-writing this very personal story with me."

According to sportsnaut.com, Evert's sister Jeanne Evert Dubin died at age 62 of ovarian cancer. The report also said that, cancer has not been detected in any other part of Evert's body, and she began the first of six rounds of chemotherapy this week.

"When I go into chemo, she is my inspiration," Chris Evert said of her sister. "I'll be thinking of her. And she'll get me through it."

Navratilova tweeted her support to Evert.

"We are all with you and behind you Chrissie, you are a true champion and I have no doubt you will conquer this nasty opponent with nary a sweat! Xoxox," Navratilova's tweet read.

Several players took to social media to wish Evert speedy recovery.

"All the best @ChrissieEvert. Wishing you a quick recovery," tweeted Spanish tennis ace Garbine Muguruza, while another top Spanish player Paula Badosa wrote, "Wishing you a speedy recovery Chris."