James Tyree, the Mesirow Financial chief executive who was diagnosed with stomach cancer in October four years after undergoing kidney and pancreas transplants, told employees of his Chicago-based financial services firm on Wednesday that thanks to chemotherapy “the cancer has not spread, and it is shrinking.”

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

“When people ask me how I’m feeling, I can’t help but say, ‘awful, it’s like trucks and trains running over me,’ ” Tyree wrote in an e-mail to Mesirow workers on Wednesday.

But the chemo is doing its job, he said.

“I just got the results of a scan that shows the cancer has not spread, and it is shrinking,” Tyree told workers. “The doctor said ‘this is a good news set of scans.’ ”

Tyree has completed three months of chemo and will continue it for three more.

“If the chemo continues to be effective, that will open up the option for surgery, maybe late-summer,” Tyree said. “My goal is to be cancer-free by 2012.

“I am confident I can achieve it, thanks to each and every person here at Mesirow Financial; your kind words, prayers and inspiration keep me focused,” he said.

He said he’d provide another update in about three months.

byerak@tribune.com