Study protocol
The combination of Ki67, histological grade and estrogen receptor status identifies a low-risk group among 1,854 chemo-naïve women with N0/N1 primary breast cancer
1 Lund University, Division of Oncology, Department of Clinical Sciences Lund, Skåne University Hospital, Barngatan 2B, SE-221 85, Lund, Sweden
2 Department of Pathology, Odense University Hospital, Odense, DK-5000, Denmark
3 Unilabs, Mammography, Bergaliden, SE-252 23, Helsingborg, Sweden
4 Department of Surgery, Helsingborg Hospital, SE-281 85, Helsingborg, Sweden
5 Uppsala University, Department of Oncology, Radiology and Clinical Immunology, SE-751 85, Uppsala, Sweden
6 Lund University, Department of Pathology, Skåne University Hospital, SE-221 85, Lund, Sweden
7 Division of Pathology, Department of Clinical Sciences Lund, Lund University, SE-221 85, Lund, Sweden
8 Skåne Department of Oncology, Skåne University Hospital, SE-221 85, Lund, Sweden
9 Department of Clinical and Experimental Medicine, Faculty of Health Sciences, Department of Clinical Pathology and Clinical Genetic, County Council of Östergötland, Linköping University, Molecular and Immunological Pathology, SE-581 91, Linköping, Sweden
10 Lund University, Division of Surgery, Department of Clinical Sciences Lund, Skåne University Hospital, SE-221 85, Lund, Sweden
11 Linköping University, Division of Oncology, Department of Clinical and Experimental Medicine, Faculty of Health Sciences, County Council of Östergötland, SE-581 85, Linköping, Sweden
SpringerPlus 2013, 2:111 doi:10.1186/2193-1801-2-111
Published: 14 March 2013Abstract
Background
The aim was to confirm a previously defined prognostic index, combining a proliferation marker, histological grade, and estrogen receptor (ER) in different subsets of primary N0/N1 chemo-naïve breast cancer patients.
Methods/design
In the present study, including 1,854 patients, Ki67 was used in the index (KiGE), since it is the generally accepted proliferation marker in clinical routine. The low KiGE-group was defined as histological grade 1 patients and grade 2 patients which were ER-positive and had low Ki67 expression. All other patients made up the high KiGE-group. The KiGE-index separated patients into two groups with different prognosis. In multivariate analysis, KiGE was significantly associated with disease-free survival, when adjusted for age at diagnosis, tumor size and adjuvant endocrine treatment (hazard ratio: 3.5, 95% confidence interval: 2.6–4.7, P<0.0001).
Discussion
We have confirmed a prognostic index based on a proliferation marker (Ki67), histological grade, and ER for identification of a low-risk group of patients with N0/N1 primary breast cancer. For this low-risk group constituting 57% of the patients, with a five-year distant disease-free survival of 92%, adjuvant chemotherapy will have limited effect and may be avoided.
