(Reuters Health) - When surgeons remove a breast tumor, shaving an extra millimeter or two of surrounding tissue cuts the need for follow-up surgery by half, a team of Yale researchers has concluded.
In addition, being more aggressive about tissue removal did not affect the way patients regarded the cosmetic outcome, they found.
The so-called cavity shave margin technique is not expected to increase survival because decades of research has already shown that going to the extreme of removing the whole breast doesn’t help cancer patients live longer compared to removing part of it with a lumpectomy and using follow-up treatment with radiation and chemotherapy.
But cutting the odds that a patient will need more surgery because the surgeon didn’t catch all of the cancer cells the first time “does make a difference in terms of patient angst and the emotional impact of returning to the operating room,” Dr. Anees Chagpar of the Yale University School of Medicine in New Haven, chief author of the study, told Reuters Health by phone.
The study, reported at the American Society of Clinical Oncology’s annual meeting in Chicago and published online by The New England Journal of Medicine, was an attempt to resolve the controversy over whether surgeons should take just a bit more tissue when they’re removing a breast tumor.
Chagpar, one of those doctors who didn’t think it was necessary, said she has become a convert.
“Now that we have data from a Level 1 randomized controlled trial, many surgeons are changing their practice,” she said. “It’s really hard to ignore Level 1 evidence that shows you can cut the reoperation rate in half without changing the cosmetic outcome or increasing complications. That’s kind of a no-brainer.”
Typically, 20 percent to 40 percent of patients need to have that second operation because a microscopic examination of the removed tissue reveals cancer cells where the surgeon cut, a problem doctors refer to as “positive margins.”
Four Yale surgeons did the tumor removals for the study, using their best judgment to decide how much tissue to take around the tumor.
“We told the surgeons, do your best operation and once you’re happy and ready to close, you’re going to open an envelope and be instructed to close, or take a little bit more tissue all the way around,” said Chagpar.
Among the 119 treated with shaved margins, the rate of positive margins - defined as tumor touching the edge of the extracted tissue or within 1 mm of the edge in cases of ductal carcinoma in situ - was 19 percent, versus 34 percent among the 116 patients in the no-shave group, where no extra tissue was taken (P=0.001).
In addition, the likelihood of needing a second surgery to clear out those missed cancer cells was also lower - 10 percent in the shaved margins group vs. 21 percent in the control group. The decision whether to recommend a follow-up operation was left to the discretion of the surgeon.
In both groups of women, 37 percent rated the cosmetic outcome of their surgery as excellent, with 50 percent in the shave group and 54 percent in the no-shave group saying their outcome was good. The patients were queried before being told what group they were in.
“We found that the perception of cosmetic outcome was equivalent in the two groups . . . despite the fact that the shave group had more tissue excised,” the researchers said.
Overall, among the women who had a little extra breast tissue removed, 12 percent had evidence of cancer cells in that extra tissue.
Chagpar said that aside from reducing the need for follow-up surgery, “the importance of these findings is still uncertain” because most of the women who didn’t have the extra tissue removed would probably have done fine with established therapy.
“It may be that there’s no impact and that in the modern era, with the existing treatments after breast-conserving surgery, it may be that the disease found in the shaved margins may make no difference whatsoever,” she said. “This is a question we may be able to answer as we follow these patients long-term.”
SOURCE: bit.ly/1SC8ZTn New England Journal of Medicine, online May 30, 2015.
Story refiled to clarify in para 15 that 12 percent in the shaving group had cancer cells in the extra tissue that was removed.