New York ? The off-color jokes flew around the room. As the anecdotes got bawdier, the laughter intensified. Some recited from memory, others read from notebooks they brought along.

The setting for the hilarity was the Montefiore Einstein Cancer Center at Montefiore Hospital. The participants were cancer patients, some with advanced stages of the illness.

They were taking part in the hospital’s monthly “Strength Through Laughter” therapy. It is one of several types of laughter or humor therapy being offered by medical facilities around the country for patients diagnosed with cancer or other chronic diseases.

The programs feature joke sessions, clown appearances and funny movies.

While the verdict is out on whether laughter plays a role in healing, the American Cancer Society and other medical experts say it reduces stress and promotes relaxation by lowering blood pressure, improves breathing and increases muscle function.

On a recent day before Halloween, many of the two dozen patients at Montefiore arrived in costume to “spook cancer.”

“The session makes you feel better,” said Luz Rodriguez, 57, a breast cancer patient now in remission, who came disguised as a security officer. “I feel healthy when I laugh.”

Their facilitator, senior oncology social worker Gloria Nelson, started the session five years ago to help cancer patients focus on living, instead of dying.

“They have such amazing strength, but it’s a constant challenge, the fear of it coming back, how to go on living knowing you have cancer,” Nelson said.

The most famous case of laughter’s therapeutic effects on the body was described by Norman Cousins, editor of the Saturday Review, in his 1979 book, “Anatomy of an Illness.” He claimed that a combination of laughter and vitamins cured him of a potentially fatal illness.

“I made the joyous discovery that 10 minutes of genuine belly laughter had an anesthetic effect,” he wrote.

Still, laughter therapy is not for everyone. Some cancer patients are so overwhelmed with their diagnosis that they are unable to participate.

Medical experts stress that laughter and other complementary therapies are not substitutes for traditional medical treatment but can be used to help relieve the anxiety brought on by the disease.