James Tyree, the Mesirow Financial chief executive who last week disclosed that he has stomach cancer, will begin chemotherapy next week.

“I feel pretty good,” he told the Tribune Wednesday night. “I’m sitting here stronger and greater than ever, and it’s stunning that these things are inside me”

In a note to Mesirow workers on Thursday, Tyree said that, over the past week, he has completed additional tests and consulted with several more doctors.

“I’m glad to say that the cancer has not spread to other organs, but it is in my stomach and in some fluid around my abdomen,” he said in the note. “Unfortunately, there is no easy way to deal with the cancer in the fluid, so the consensus of all the doctors is to begin chemotherapy.”

That starts next week, and the treatments will continue every other week.

“My plan will also include alternative medicine, including teas, herbs and vitamins that several friends have recommended for helping combat the side-effects associated with these treatments,” Tyree told employees. “After three-to-six months of this treatment, scans will be taken.”

He said he plans to continue working at his privately owned, Chicago-based diversified financial services firm.

On Wednesday night, Tyree told the Tribune he still doesn’t know what stage the cancer is at.

“I don’t think they’ll ever give me a stage,” he said. “What they tell me it’s outside of just the stomach and it’s in the fluid in the abdomen but no other organs.”

Asked about his prognosis, he said “They can’t tell me until they see how I’m affected by the chemo.”

Tyree, 52,  suffered from Type 1 diabetes for 25 years, and in late 2006 had a kidney and pancreas transplant that he said essentially cured the diabetes.. He has also had four eye surgeries and a defibrillator implanted in his chest, he told the Tribune in 2007.

Tyree has 8-year-old twin boys and an 11-year-old daughter.

Tyree also is chairman and owner of Sun-Times Media.