Breast cancer researchers say they could cut years off the time required to test new drugs for treating certain kinds of tumors under a study about to begin at the University of Minnesota and the Mayo Clinic.

The study, being launched at 17 centers nationwide, is among the first of its kind, researchers from a national consortium said Wednesday.

Known as I-SPY2, the study is designed to compare several experimental drugs at once and tailor them to the breast cancer patients who are most likely to benefit.

Thanks to technological advances, researchers say, they will quickly identify which drugs are effective for different groups of patients, based on the genetic or molecular makeup of their tumors. At the same time, drugs that show no benefit can be quickly dropped, without wasting years and millions of dollars on further study.

"This is really a very novel step forward," said Dr. Judy Boughey, a breast cancer surgeon at the Mayo Clinic and one of the study leaders.

The research could cut 10 years off the time it takes to get a new drug approved, said Dr. Tufia Haddad, a breast cancer specialist who is heading the research at the university.

"That is a massive difference," she said, noting that it can take more than 15 years now. "And the cost savings, I can't even put a number on it."

The study will also give scientists a chance to genetically match the right drug to the right patient, said Dr. Douglas Yee, head of the university's Masonic Cancer Center, and a breast cancer specialist. "I'm much more interested in finding the precise drug for that woman's tumor," said Yee, who helped select the experimental drugs for the study.

Haddad said the university hopes to enroll several dozen patients over the course of the five-year study. Mayo expects nearly 100 volunteers, out of a nationwide total of 800.

The study is open to women with recently diagnosed "locally advanced" tumors, measuring more than 2.5 centimeters (about an inch). They make up about 10 or 15 percent of breast cancer patients, doctors say, and have a higher mortality rate than women whose tumors are typically discovered by mammograms.

"These are absolutely the women who could benefit most," Haddad said, "because the standard of care just isn't good enough right now."

As part of the study, most volunteers will get one experimental drug, plus standard chemotherapy, for 12 weeks before surgery to remove their tumors. They'll be monitored closely the entire time, with biopsies and MRI scans.

By the time the tumor is removed, they'll know if the drug has made a difference, said Boughey. "We'll get the results immediately," she said.

Other drug studies typically take years because they have to follow large groups of patients to see if a new drug improves survival rates.

In this case, researchers will be able to literally observe the drug's effect on the tumor itself.

"We'll be able to see how the tumor responds to treatment in real time," said Haddad, and "know right upfront, in real time, whether or not this new drug shows promise."

Scientists realize that some drugs work on a small percentage of breast cancers, Yee said, but until now it's been difficult to pinpoint who's most likely to benefit.

"Twenty years ago, we all understood that was the goal," he said. "But we really didn't have the technology to do that."

Maura Lerner • 612-673-7384