Kathleen I. Pritchard

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PURPOSE To compare the clinical features, natural history, and outcomes for women with "triple-negative" breast cancer with women with other types of breast cancer. EXPERIMENTAL DESIGN We studied a cohort of 1,601 patients with breast cancer, diagnosed between January 1987 and December 1997 at Women's College Hospital in Toronto. Triple-negative breast(More)
BACKGROUND In hormone-dependent breast cancer, five years of postoperative tamoxifen therapy--but not tamoxifen therapy of longer duration--prolongs disease-free and overall survival. The aromatase inhibitor letrozole, by suppressing estrogen production, might improve the outcome after the discontinuation of tamoxifen therapy. METHODS We conducted a(More)
BACKGROUND Most recurrences in women with breast cancer receiving 5 years of adjuvant tamoxifen occur after 5 years. The MA.17 trial, which was designed to determine whether extended adjuvant therapy with the aromatase inhibitor letrozole after tamoxifen reduces the risk of such late recurrences, was stopped early after an interim analysis showed that(More)
PURPOSE This randomized, controlled, multicenter, open-label, phase III study compared docetaxel versus paclitaxel in patients with advanced breast cancer that had progressed after an anthracycline-containing chemotherapy regimen. PATIENTS AND METHODS Patients (n = 449) were randomly assigned to receive either docetaxel 100 mg/m2 (n = 225) or paclitaxel(More)
PURPOSE To determine the relative efficacy of an intensive cyclophosphamide, epirubicin, and fluorouracil (CEF) adjuvant chemotherapy regimen compared with cyclophosphamide, methotrexate, and fluorouracil (CMF) in node-positive breast cancer. PATIENTS AND METHODS Premenopausal women with node-positive breast cancer were randomly allocated to receive(More)
BACKGROUND The 21-gene recurrence score assay is prognostic for women with node-negative, oestrogen-receptor-positive breast cancer treated with tamoxifen. A low recurrence score predicts little benefit of chemotherapy. For node-positive breast cancer, we investigated whether the recurrence score was prognostic in women treated with tamoxifen alone and(More)
PURPOSE Vitamin D has been linked to breast cancer risk, but prognostic effects are unknown. Such effects are biologically plausible given the presence of vitamin D receptors in breast cancer cells, which act as nuclear transcription factors to regulate gene activity. PATIENTS AND METHODS The study was conducted in a prospective inception cohort of 512(More)
BACKGROUND Prior studies with the use of a prospective-retrospective design including archival tumor samples have shown that gene-expression assays provide clinically useful prognostic information. However, a prospectively conducted study in a uniformly treated population provides the highest level of evidence supporting the clinical validity and usefulness(More)
Breast cancer is the second leading cause of cancer death in North American women. There is considerable need for reliable prognostic markers to assist clinicians in making management decisions. Although a variety of factors have been tested, only tumor stage, grade, size, hormone receptor status, and S-phase fraction are used on a routine basis. The cell(More)
BACKGROUND Treatment with adjuvant trastuzumab for 1 year improves disease-free survival and overall survival in patients with human epidermal growth factor receptor 2 (HER2)-positive early breast cancer. We aimed to assess disease-free survival and overall survival after a median follow-up of 4 years for patients enrolled on the Herceptin Adjuvant (HERA)(More)