British reoperation rates high after breast-conserving surgery
One in five women in England who had breast-conserving surgery for breast cancer had a reoperation within 3 months, prompting researchers to urge that women be informed of the risk for reoperation when deciding on the type of surgical treatment to undergo for breast cancer.
Lead study author Dr. David A. Cromwell, a senior lecturer in health services research at the London School of Hygiene & Tropical Medicine in the United Kingdom, and colleagues evaluated reoperation rates within 3 months after primary breast-conserving surgery. They analyzed National Health Service (NHS) data from women older than age 16 years who had a diagnosis of invasive carcinoma or carcinoma in situ and who underwent breast-conserving surgery from April 2005 through March 2008.
Of the 55,297 women who had primary breast-conserving surgery over the 3-year period, 11,032 (20%) had at least one reoperation. Of the 10,212 women (18.5%) who had only one reoperation, 5,943 (10.7%) had another breast-conserving procedure, and 4,269 (7.7%) had a mastectomy.
The 9,504 women with carcinoma in situ were more likely to have had at least one reoperation (2,803; 29.5%) than were the 45,793 women with isolated invasive disease (8,229; 18%).
Primary breast-conserving surgery may result in incomplete excision of cancer or inadequate clearance margins, both of which require reoperation, pointed out Cromwell's team in their report for BMJ (2012;345:e4505). Reoperation after breast-conserving surgery can delay adjuvant treatments and may be associated with increased rates of local and distal recurrence. Reoperation is also likely to cause a significantly poorer cosmetic outcome, regardless of whether it is a second breast-conserving procedure or a mastectomy, and create emotional distress for the woman.
The investigators noted great variations in reoperation rates among various NHS sites, probably at least partially due to a lack of consensus as to what constitutes an adequate incision margin, particularly when adjuvant radiotherapy is planned:
- The US National Cancer Institute has questioned the need for completely clear microscopic margins in breast-conserving surgery.
- England's National Institute for Health and Clinical Excellence has recommended a minimum 2 mm radial excision margin for ductal carcinoma in situ, but has not recommended margins for invasive disease.
- Canada's national guidelines apply only to invasive disease and recommend that margins are microscopically clear and that any involved margins be re-excised.