Actress Jane Fonda says she has cancer

US actress and activist Jane Fonda announced Friday that she has cancer, and has begun chemotherapy in her battle against the disease.

The 84-year-old Oscar winner, a prominent supporter of the Democratic Party, vowed to fight the "very treatable" illness.

"I´ve been diagnosed with non-Hodgkin´s Lymphoma and have started chemo treatments," she wrote on her verified Instagram account.

"This is a very treatable cancer. 80 percent of people survive, so I feel very lucky.

"I´m also lucky because I have health insurance and access to the best doctors and treatments."

Fonda, an avowed environmentalist and social campaigner, said her position was more fortunate than that of many others in her situation.

"Almost every family in America has had to deal with cancer at one time or another and far too many don´t have access to the quality health care I am receiving and this is not right," she wrote.

Non-Hodgkin´s lymphoma is a kind of cancer that starts in the lymphatic system, a part of the body´s immune defenses, and can develop into widespread tumors.