Blog | Monday, March 5, 2012

Why the wide variation in reoperations after lumpectomy?

The Feb. 1 issue of the Journal of the American Medical Association includes a major report on the practice of lumpectomy in the U.S. The study examined what happened to 2,206 women at four medical centers who opted for breast-conserving surgery at the time of breast cancer diagnosis.

The main finding was that after lumpectomy, nearly one in four women had another operation to remove cancerous cells in the breast. Among all the breast cancer patients who began with a lumpectomy, 8.5% wound up with a mastectomy.

Many of the women who had additional procedures did so for concern over having "clean margins," that upon removal of a tumor, the edges of the specimen don't reveal malignant cells. Re-excision for patients with negative margins varied by hospital; at one medical center the re-excision rate was 1.7%, at another it was 20.9%.

Analysis by surgeon revealed huge variation, with re-excision rates ranging between 0 and 70%. The incidence of positive margins was 14%. For those women who did have positive margins--meaning that cancerous cells were evident along the edge of the lump removed--nearly 15% didn't have a second procedure.

The big picture is that there was little pattern, or reason evident at least at the collective level, for the surgeries and decisions to reoperate after lumpectomy for breast cancer.

The NIH-funded study was large enough to merit concern. It involved careful chart and pathology review of the specimens through a consortium of four medical centers around the country: the University of Vermont, Kaiser Permanente Colorado, Group Health in Washington State and the Marshfield Clinic in Wisconsin. And it reflects current practice; the surgeries took place between 2003 and 2008.

This is a very common procedure, and a significant issue, in terms of costs, and risks, and decisions women make every day upon receiving a new breast cancer diagnosis. An estimated 60 to 70% of newly diagnosed breast cancer patients choose breast-conserving surgery. So we're talking about 160,000 or so lumpectomies per year in the U.S. (This is a very approximate calculation I made, based on two-thirds of 240,000 new breast cancer cases). The variable results affect cosmetic outcome--the very reason many women choose lumpectomy to begin with--and potentially the rate of breast cancer recurrence.

In the discussion, the authors write: "Our finding ... suggests that patients under similar clinical conditions are likely to undergo re-excision based on the treating surgeon and not just the clinical characteristics." They offer possible explanations, including differences in surgical training, surgeons' confidence in their operative techniques, how tumors are assessed in the operating room, and variation in how pathologists review specimens and "call" the margins positive or negative.

All of this meshes with my experience knowing women who've had breast-conserving surgery and then got mixed information about the results and what to do next. You'd think lumpectomy would be a standard procedure by now, and that decisions about what to do after the procedure, surgically speaking (let alone decisions about chemo, hormonal treatments and radiation) would be straightforward in most cases.

This post originally appeared at Medical Lessons, written by Elaine Schattner, ACP Member, a nonpracticing hematologist and oncologist who teaches at Weill Cornell Medical College, where she is a Clinical Associate Professor of Medicine. She shares her ideas on education, ethics in medicine, health care news and culture. Her views on medicine are informed by her past experiences in caring for patients, as a researcher in cancer immunology and as a patient who's had breast cancer.