Imagine you had a life-threatening cancer that a wonder drug had kept in remission for years. Would you risk quitting?

Thousands of people with a blood cancer called chronic myelogenous leukemia, or CML, now have that choice.

New treatment guidelines in the U.S. say certain patients can consider stopping Gleevec or similar drugs which were long thought to be needed for the rest of their lives. It’s just a pill or two a day but the drugs are expensive and have side effects.

A European study recently found it’s safe for carefully selected patients to try, and a U.S. study hoping to confirm that just finished enrollment.

“Our goal is to truly cure CML, which is essentially to have patients off drug,” said Dr. Ehab Atallah, a leukemia expert at the Medical College of Wisconsin who helps lead the U.S. study. “We’re hoping to figure out better who can and cannot stop.”

Some patients want to try, but others won’t dare.

“Like playing Russian roulette,” said Jee-Won Schally, 54, a former history teacher from Milwaukee who has taken Gleevec for 10 years and doesn’t want to stop.

Nor does Doug Jensen, 83, a retired engineer near Portland, Oregon, who still gets the drug for free because he was in the original study that proved it worked.

But for Nina Schlidt, quitting a similar drug nearly two years ago was wonderful and “financially, a godsend.” The 67-year-old suburban Milwaukee woman’s husband delayed retiring until 70 to keep insurance to cover her drug, which would have cost her thousands.

Meghann Bell, 38, a marketing director in Seattle, went off Gleevec in 2010 to start a family because the drug isn’t safe during pregnancy. She resumed after the birth, then decided to go off again two and a half years ago.

“I kept thinking how I had been in remission” during pregnancy, she said. “I felt like I was cured and really didn’t want to be on this drug for all my life.”