NEW YORK (Reuters Health), Feb 12 - Including MRI in the preoperative workup of breast cancer does not reduce reoperation rates, according to the results of the Comparative Effectiveness of MR Imaging in Breast Cancer (COMICE) trial.
The U.K. National Health Service Breast Screening Program has set a goal of less than 10% for reoperation rates for incomplete tumor excision. When the COMICE protocol was written in 2001, the rate was 14.2%, and no drop has occurred since then.
MRI reportedly detects breast lesions that may be missed with x-ray mammography or ultrasound, the study investigators note in The Lancet for February 13. Theoretically, then, using MRI to detect these missed lesions would allow the operative plan to be altered, to improve the odds of complete tumor excision.
The COMICE trial involved 1,623 women with breast cancer who were scheduled for wide local excision after "standard triple assessment": i.e., clinical, radiological (x-ray mammography and ultrasound), and pathological (fine-needle aspiration cytology or core biopsy) evaluation. Each agreed to be randomized either to undergo MRI or to proceed to surgery with no further imaging.
As lead author Dr. Lindsay Turnbull, from Hull Royal Infirmary, U.K., and colleagues report, MRI had no effect on reoperation rates. In fact, 19% of patients in each group required repeat operation or further mastectomy within six months of randomization.
Because MRI could potentially overestimate the size and extent of disease, leading to "pathologically avoidable mastectomy at initial operation," the authors analyzed this end point as well. However, the rates were similar in the MRI and no-MRI groups: 2% versus < 1%.
So should preoperative MRI be abandoned? Not yet, according to an editorial.
"COMICE does not fully answer whether preoperative breast MRI adds benefit because recurrence and overall survival were not examined," Dr. Elizabeth A. Morris, from Sloan-Kettering Cancer Center, New York, writes.
"It is too early to completely dispense with preoperative breast MRI," she says, noting that more research is needed.
Dr. Morris adds, however, that "COMICE has shown that preoperative breast MRI might not be for all women."
Last Updated: 2010-02-11 18:30:16 -0400 (Reuters Health)
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