CBS News New hope for Prostate Cancer

(CBS)  It's very early to tell, but there may be new hope for men being treated for inoperable prostate cancer.

CBS News medical correspondent Dr. Jon LaPook discussed on The Early Show Tuesday a study by the Mayo Clinic, which uses a new kind of immune therapy drug that enables the immune system to fight the cancer.

"Now those immune cells are hopefully able to attack the cancer and shrink it," LaPook said. 

The first thing that happens, LaPook explained, is hormone therapy is given, which sends immune cells to the prostate cancer and removes testosterone. Testosterone, LaPook said, is known to fuel prostate cancer. 

Early Show co-anchor Harry Smith said the findings are "big-time" stuff, but are very preliminary. 

LaPook said the study has only been done on 54 patients, but it's good news because three of the patients had prostate cancer that extended outside the prostate to the bladder. 

"They got the therapy," LaPook said. "It came right back in, so it was confined to the prostate, and the surgeon was able to remove the prostate and no evidence of any spread."

The news, Smith remarked, is especially applicable, to people who have inoperable prostate cancer.

LaPook agreed, but advised this is an early study that can have side effects from the immune system. Two of the patients, LaPook said, developed autoimmune colitis -- or an inflamed colon -- that was treated with steroids.

The study has been broken, LaPook reported, but the Mayo Clinic is starting over in the fall with a new study. And if that's successful, LaPook said, the study will go to its next phase. 

Except for skin cancer, cancer of the prostate is the most common cancer in American men, according to the National Cancer Institute. More than 186,000 men in the United States are diagnosed with prostate cancer each year, according to NCI. 

Last year, according to the Institute, nearly 29,000 men died of prostate cancer