Dr. Ernest Rosenbaum arrives early, shmoozing with his fellow cancer patients while they wait for the third-floor dance studio to open up. The crowded, noontime-yoga class at the Jewish Community Center of San Francisco is still in session, but soon the lithe leotard set departs.

Rosenbaum and four others cheerily file in.

This group is not so lithe. Most are elderly and all are living with cancer. The exercise session, led by physical therapist Francine Manuel, is a key component of their survival strategy.

Part of the Laurence Myers Cancer Supportive Care Program, the class has called the JCC home for more than two years. Rosenbaum, who founded the program, has dedicated his career to providing holistic support for cancer patients.

But he is here today not as an observer but as a participant. An oncologist by training, Rosenbaum has had several serious bouts with cancer himself — along with pneumonia, glaucoma, a bypass and three heart attacks.

Today, he has come in search of a little healing for mind, body and spirit.

Manuel puts on a CD of Mascagni’s “Cavelleria Rusticana,” then leads the class in a series of stretching exercises. As the arias bounce off the mirrored walls, participants do leg lifts and shoulder rolls. “Anyone see the 49ers game?” asks Manuel. “What a horrible game.”

That’s the only touch of negativity that creeps into the session. This hour is all about positive thinking, something Rosenbaum, 77, knows a lot about. He and his wife, Isadora, literally wrote the book on it: “Everyone’s Guide to Cancer Supportive Care: A Comprehensive Handbook for Patients and Their Families” (Andrews McMeel Publishing, 1995). First published in 1980, it is now in its fourth edition.

“It makes a difference to be physically fit when facing cancer and cancer therapy,” Rosenbaum says. “Making patients more physically fit is the goal, and it can only be done with a good diet, and psychological and exercise programs.”

For much of the last 40 years, he has done just that, designing the Stanford Integrative Medicine Clinic Cancer Care Program and similar setups at UCSF and Mt. Zion medical centers.

The good doctor says much of his interest in helping others can be traced to his Orthodox upbringing in Albuquerque, N.M., where he grew up “a Jewish cowboy.” Though he initially wanted to be a pilot, Rosenbaum went into medicine, interning at Stanford and doing his residency at Mt. Zion. After a medical research stint at Boston’s MIT, he returned permanently to the Bay Area in 1963, where, among other positions, he became associated with UCSF and Mt. Zion, and served as medical director of the Better Health Foundation of Northern California.

Back at the JCC, Manuel puts the class through its paces. She has everyone reach down to touch his or her toes. This isn’t a problem for Rosenbaum. “I’m on steroids,” he says. “I can reach down lower.”

“Don’t forget to breathe,” Manuel adds.

They won’t. The breath of life is precious to these folks. Madalin Levie of San Francisco has endured two bouts of breast cancer, and says the program has helped her. “It’s made me more physically agile,” she says. “If I could do it more than once a week, I would.”

Much of the program emphasizes positive attitude, which is something Rosenbaum can relate to, for sure. His long list of illnesses would tax anyone’s emotional fortitude. “It’s bad luck,” he says. “You do get a little angry that you’ve had more than you deserve. But in life there are earthquakes, hurricanes and tsunamis. Illness is a natural phenomenon.”

He adds that his wife of 57 years has been an important part of his wellness strategy. “I always had good support,” he says, looking back on his periods of illness. “I would get well in a couple of weeks and get back to work. People who sit around and do nothing get more depressed. Those active and working keep their minds off their illness and are more productive.”

Manuel ends the session with quiet meditation. Lights out, the participants lying on floor mats, she guides the class toward a deep calm. “The idea,” she says, “is to consciously relax. To get a sense that everything is all right.”

After walking around the room to get the blood circulating, participants are ready to leave. They then depart, off to face recovery with ongoing courage and determination. They’ll be back.

Rosenbaum, too, will be back. What started as his gift to others ultimately became a gift to himself. “People need empowerment,” he says of his program. “We know it makes a difference.”

For more information on the Laurence Myers Cancer Supportive Care Program, call Jackie Lewis at the SFJCC: (415) 292-1241