Navratilova's inspiring fight with cancer

Watch "Martina: My Toughest Opponent" on CNN International at 1830 CET August 7, 1300 and 2030 CET August 8 and 0400 CET August 9

Paris, France (CNN) -- She's arguably the greatest women's tennis player of all time, an icon in women's sports. So when Martina Navratilova agreed to have CNN follow her throughout her breast cancer treatment, I wondered what it would be like covering such a strong, accomplished individual.

I quickly found Martina Navratilova wasn't going to let a cancer diagnosis get in the way of anything she planned to do.

"My gut was telling me I just need to go on, and don't like put everything on hold. I still played hockey and I still went skiing and I played tennis of course," she said.

Navratilova won 59 Grand Slam titles in singles, doubles and mixed doubles during a glittering career which only ended four years ago, when she retired just months shy of her 50th birthday.

Navratilova was diagnosed with breast cancer February 24, a day that left her in tears, but only for a short time.

She said: "I thought for sure I would keep it private, keep it quiet, nobody needs to know. It's a very personal issue of course, and I wanted to save my energy for fighting it.

"But then the more I found out about what I had and why I was so lucky -- that it was diagnosed so early on because I had the mammogram that I had been putting off for a couple of years because I just couldn't be bothered -- I thought for sure I was fine."

After the initial shock Navratilova told us how thankful she was that her cancer was discovered early, because the longer it went undetected the more trouble it would have been.

When news of her diagnosis was picked up by the world's media weeks later, the 53-year-old could have been forgiven for locking herself away.

But in the same way she faced countless challenges on the court, she instead made herself available to journalists, giving multiple interviews in an attempt to make more women aware of this preventable killer.

Her treatment would have two steps -- a lumpectomy in March and then radiation treatment in May-June.

My cameraman and I met Navratilova outside the L'Institut Curie in Paris, France, where she would undergo six weeks of radiation treatment.

Read more about how Navratilova handled her cancer treatment

At least four times a week, Navratilova would walk up the hospital steps alongside patients of all ages who were undergoing various cancer treatments.

Before leaving Paris for London, Navratilova mentioned that she had a Ralph Lauren shopping trip planned. She needed to expand her wardrobe ahead of her work for The Tennis Channel at the French Open. She asked me: "Do you have 56 outfits?"

She was relaxed as she went shopping. A salesperson held up a blouse with multiple ruffles and she said, distinctly, "That's not me!"

We returned to Paris for week four of Navratilova's treatment. She still looked strong and was optimistic, but the treatments were starting to wear on the athlete.

Navratilova was trying to balance treatments in the morning with her work at the Tennis Channel at the French Open.

And after spending the day broadcasting, Martina would play tennis in the evenings. She was practicing for the Legends Tour. Her tennis partner would be 1998 Wimbledon champion Jana Novotna.

Even with Navratilova struggling, the pair still won the championship on a hot day in Paris.

Thousands had turned out to watch the sports icon in action. Navratilova thanked the crowd in French and then English. Her words were telling: "You never know what life is going to throw at you. You better be prepared."

We returned to Paris for one final visit on June 16 and arrived at the hospital 20 minutes before Navratilova got there. This time Novotna was there for support. Two Czech-born athletes, side by side.

Navratilova was so happy, so pleased to be nearly done with radiation. "I really was counting down in a big way but it was because it just takes over your life, you can't do anything, you can't go anywhere."

We watched her walk through the double glass doors, and we waited outside the hospital. It was a much longer wait than normal -- but the outcome was worth it.

Navratilova was so happy to be done with radiation: She threw her hands above her head, did a little dance, and then tried to slide down the banister. She walked straight towards the camera -- so happy, so relieved that it was over.

"Everybody's so excited. I've been getting so many texts and emails saying "Last day! Last day! Hallelujah" We're going to have a little party tonight to celebrate."

Navratilova knows that there's a chance the cancer could return some day. She said: "I learned a lot and I hope I won't have to go through something like that for a long time. But if it happens again, I'll be ready."

Navratilova and a close circle of her support team attended a dinner party that night.

They sat in a circle on the patio, enjoying the Paris evening until the early morning hours. Navratilova was thankful for her friends, thankful for their support, but most of all ready to get on with her life.

CNN camerman Harvey Hogan contributed to this report