Suzanne Somers, best known for starring on the TV sitcoms Three's Company and Step by Step, has died at age 76.

The actor died early Sunday, on the eve of her 77th birthday, after living with breast cancer for more than two decades, according to Somers' publicist R. Couri Hay.

"Suzanne was surrounded by her loving husband Alan, her son Bruce, and her immediate family," Hay said in a statement. "Her family was gathered to celebrate her 77th birthday on October 16th. Instead, they will celebrate her extraordinary life, and want to thank her millions of fans and followers who loved her dearly."

Somers leveraged her celebrity to launch a successful business career centered around wellness. She became the spokeswoman for the leg-toning ThighMaster. She's authored 27 books, largely on the topic of natural health, according to her publicist's website.

She was first diagnosed with breast cancer in 2000. Her approach to health drew controversy at the time, when she decided to forgo chemotherapy treatment and embraced alternative remedies.

In July, she announced she'd been privately facing cancer since her initial diagnosis.

"As you know, I had breast cancer two decades ago, and every now and then it pops up again, and I continue to bat it down," Somers said in an Instagram post. "I have used the best alternative and conventional treatments to combat it. This is not new territory for me. I know how to put on my battle gear and I'm a fighter."

Somers first gained attention for her role driving a white Thunderbird in George Lucas' American Graffiti in 1973. Her only words were mouthing the words "I love you" to Richard Dreyfuss' character, The Associated Press reported. She later said that role "changed her life forever," the AP reported.

She gained lots of TV and film credits during the 1970s but became best known as one of the stars of Three's Company from 1977 to 1981, about two women and a man living as roommates. She played the stereotypical "dumb blonde," Chrissy Snow.

"Creating her was actually intellectual. How do I make her likable and loveable ... dumb blondes are annoying. I gave her a moral code. I imagined it was the childhood I would've liked to have had," she told CBS in 2020.

She told the network she was fired from the show "for having the audacity to ask to be paid commensurate with men. They were making 10 to 15 times more and [co-star] John [Ritter] was making much more than me."

Her longest-running role was as a mother in a blended family on Step by Step. The series lasted from 1991 to 1998.

A private family burial will be held this week, with a memorial to follow next month, her publicist Hay said.

James Doubek contributed reporting.