Cheryl Ladd battled cancer in secret.

The Charlie's Angels star, 74, underwent treatment after being diagnosed with an "aggressive form" of the disease and she branded her cancer journey a "humbling experience" but insisted she was supported by a "wonderful" team of doctors as well as her husband Brian Russell.

During a PaleyFest panel in Los Angeles, Cheryl explained: "Mine was an aggressive form ... [but] I had wonderful doctors ...

"I was bald. It was a humbling experience and yet I have a wonderful husband ... he was there for me at every turn.

"Eventually I started to get little sprouts of hair. It was a long, long, hard road, but you just get on with it."

Cheryl appeared on the panel alongside fellow Charlie's Angels stars Jaclyn Smith and Kate Jackson, who have also both battled cancer.

Kate was diagnosed with breast cancer in 1987 and underwent treatment but the disease returned two years later and she underwent a partial mastectomy.

Jaclyn was diagnosed with breast cancer in 2002 and has been cancer-free since undergoing a lumpectomy and radiation therapy.

Fellow Charlie's Angels star Farrah Fawcett was also diagnosed with cancer in 2006, but she died three years three years later at the age of 62.

During the panel discussion, Jaclyn opened up about her late co-star's health battle and revealed she gave her the wigs she wore during her own cancer treatment.

She said: "The first thing I did was send her my wigs. She was so brave."

Cheryl went on to urge others not to ignore symptoms, adding: "If you find a little something in your breasts ... do not ignore it."

The trio's PaleyFest reunion marked the 50th anniversary of the hit TV show, which launched back in 1976 with Kate, Jaclyn and Farrah in the lead roles while Cheryl was drafted in for season two to replace Farrah after she quit the series to pursue her movie career.

In a statement announcing the reunion, the surviving trio said: "Charlie's Angels surprised everyone when Farrah, Jackie and I hit the ground running (thanks, in part, to Farrah's iconic poster) and the pilot went through the glass ceiling.

"Overnight, we were hailed with something akin to 'rock star fame.' When Cheryl joined us in the second season, she added a special element uniquely hers and the crazy went on ...

"We are proud that we were able to entertain the television viewing audience for an hour each week, let them put their feet up, forget their troubles and, at the same time, inspire and empower young women all over the world.

"We look forward to reuniting on the PaleyFest stage to celebrate Charlie's Angels milestone anniversary and to reflect on our work in television across the decades."