Caution with breast-conserving surgery

We read with interest the 2002 update of the clinical practice guidelines for the care and treatment of breast cancer.1 Although we generally agree with most of the article, we are concerned about the following comment in Table 1: “In some cases, preoperative chemotherapy can shrink a large primary tumour and allow for [breast-conserving surgery].” The European Organization for Research and Treatment of Cancer trial 10902, quoted by the authors of the update, included a caveat about downstaging. While conceding that the trial was not a randomized comparison, its authors reported that “Patients who were planned for mastectomy but underwent breast- conserving surgery because of downstaging of the tumor did worse in terms of overall survival (HR, 2.53; 95%CI, 1.02-6.25)” (where HR = hazard ratio) than did patients for whom breast- conserving surgery was planned and who underwent treatment accordingly.2 The authors also commented that using more breast-conserving modalities to treat tumours that had been downstaged by chemotherapy may result in a higher false-negative rate for the surgical margins. Given evidence from recent meta-analyses of the value of aggressive local therapy in terms of survival of women with breast cancer,3^,4 would it not be preferable to err on the side of caution when it comes to altering guidelines for breast-conserving surgery?

Theodore A. Vandenberg Associate Professor Vivien H. Bramwell Professor Department of Oncology University of Western Ontario London, Ont.