A team of Canadian researchers has discovered why some patients with a form of leukemia are resistant to standard therapy.

Chronic lymphocytic leukemia (CLL) is the most common form of leukemia in North America, with 12,000 new cases diagnosed each year in the U.S.

In CLL, too many stem cells develop into a type of white blood cell called lymphocytes that aren't able to fight infection very well. Healthy blood cells get crowded out.

Chronic lymphocytic leukemia is a malignant disorder of blood cells

Four years ago, Alden Hankewich of Saskatoon was diagnosed with CLL. "I was lacking in energy, I was not up to par of my normal self," recalled Hankewich.

The doctors were puzzled because Hankewich's cancer cells were resistant to standard chemotherapy and radiation therapy. About 30 per cent of CLL patients have these "death defiant" cancer cells.

A team led by Dr. Anurag Saxena of the department of pathology at the University of Saskatchewan discovered the MCL-1 gene that programs death defiant cells is unique.

"If this particular change is present in this gene, these patients are unlikely to respond to the conventional treatment," said Saxena. "The disease is going to progress at a rapid rate in these patients."

Saxena's research was published in the May 5 issue of the Journal of the National Cancer Institute.

Knowing the role of the gene "forecasts a day" when understanding how the cells cheat death may guide individual therapies for CLL patients, wrote Dr. Shinichi Kitada and Dr. John Reed of the Burnham Institute in La Jolla, Calif., in the journal's editorial.

Saxena's team is studying whether similar changes are important in breast, prostate, lung and colon cancer.

In the meantime, when standard treatments didn't work for Hankewich, he had a stem cell transplant and his cancer is now in remission.

"I think with this new technology a lot of us have a legitimate hope to look forward to rather than the standard of treatment," said Hankewich.