Mayo Clinic likes to say that its team-based, patient-centric approach to medical care increases value. On Tuesday it released the latest evidence — research showing that a novel technique improves outcomes for women with breast cancer, the nation's No. 2 cause of cancer deaths for women, after lung cancer.

Mayo's unique method of pathologic evaluation when removing cancerous tumors from breast tissue — a lumpectomy — is so effective that just 3 percent of patients require a second surgery to track down missed cancer cells, according to a study released by the journal Surgery.

That compares with a national rate that ranges between 15 percent and 40 percent — raising the prospect that surgeons could reduce the stress and infection rates associated with additional surgery and improve the breast cancer resection process.

Mayo's method of performing a lumpectomy involves a team of specialists, including pathologists who perform tests on the excised lumpectomy specimens while the patient is still on the operating table.

By freezing an entire tumor and taking slices from around its periphery, they can determine within 20 to 30 minutes whether the surgeons need to cut away more tissue to be certain that they've removed all of the cancerous cells.

"In breast cancer, what I think is critical is that multidisciplinary team," said Dr. Judy Boughey, a professor of surgery at Mayo who was the article's lead author.

"The pathologists here are making me look good … because I'm doing the same [excision] procedure I would do anywhere else."

Value over volume

Mayo developed the method for freezing tissue samples more than 100 years ago. Asked why it published a paper about it now, Boughey said: "We're really looking to show people the value of what Mayo provides. It's cost. It's patient care. It's minimizing reoperations, improving patient experience."

The need to reward value rather than volume in U.S. health care has been a frequent theme of Dr. John Noseworthy, Mayo's CEO, who contends that Mayo's method of using interdisciplinary teams provides high-quality care at relatively lower costs by reducing duplication of procedures, readmissions and errors.

The lumpectomy study compared Mayo's own surgical results with 24,217 lumpectomies tracked by the American College of Surgeons and found that patients nationally were more than four times as likely to need a second operation.

The new study follows a 2011 article by Mayo authors in the Annals of Surgical Oncology that found that Mayo's frozen-tissue analysis takes a bit longer but can save costs overall.

The study concluded that analyzing frozen tissue from breast lumpectomies is labor-intensive and can't be done at every hospital. But for cancer centers where it's feasible, it can save money for providers and payers, "and importantly it can also dramatically improve patient experience."

Comparing costs

The average nationwide cost for a medical institution to remove an entire breast tumor ranged from $4,835 to $6,306. Mayo's average was $5,708, which was less expensive, on balance, when the reoperation rate exceeded 36 percent. The cost to payers, such as Medicare, ranged from $3,577 to $4,665 nationwide and averaged $3,913 at Mayo. Its method was less expensive for payers when the reoperation rate exceeded 26 percent.

Boughey said different sites use a variety of methods for ensuring that they excise all of the cancerous cells during a lumpectomy. But she said as far as she knows, only the University of Michigan and Mayo routinely conduct an analysis of the entire tumor during the operation.

A University of Michigan study published in 2012 found that analyzing frozen sections of tumor margins is not a common practice for patients undergoing lumpectomies, but like Mayo, it found that doing so offers a significant reduction in reoperations.

"Surgeons tread a fine line between achieving negative [cancer-free] margins and removing more tissue than necessary; therefore, re-excision rates will remain high without intraoperative evaluation," the Michigan study concluded.

Boughey said the method is not perfect, however. So the tumors are reanalyzed the day after the surgery.

Mayo's method requires additional resources, prolongs operations and increases upfront costs, the study said. "However, reducing the total number of operations to achieve negative margins after lumpectomy will reduce health care costs, especially when multiplied across the national scale."

Dan Browning • 612-673-4493