Outcome Differences Between Patients With Node-Negative Breast Cancer Classified According to the St. Gallen Risk Categories

PurposeThe purpose of this study was to compare the 2007 St. Gallen risk categories with the outcomes of patients with node-negative breast cancer (NNBC).Patients and MethodsWe retrospectively reviewed the medical records of 1500 women with pathologically T1-T3 NNBC treated at the Clinic Hospital, Valencia University (Spain) from 1982 to 2000. Systemic adjuvant treatment was administered to 89.9% of the patients in the whole sample (37% received only hormonal therapy and 52.9% chemotherapy). The 2007 St. Gallen criteria were used to divide the whole sample into 1201 patients with intermediate risk (with ≥ 1 of the following: pathologic tumor size > 2 cm, grade 2-3, estrogen receptor and progesterone receptor absent, HER2/neu gene overexpressed or amplified, or age < 35 years) and 299 patients with low risk. Of the 1201 patients with intermediate risk, 56% received adjuvant chemotherapy. The intermediate- and low-risk groups were compared for relapse-free survival (RFS) and breast cancer–specific survival (BCSS).ResultsMedian follow-up of the entire sample was 61 months (range, 2-251 months). At 5 years, the overall RFS rate was 86%, and the BCSS rate was 95%. For low-risk patients, the RFS rate was 92%, and the BCSS rate was 98%. For intermediate-risk patients, the RFS rate was 84%, and the BCSS rate was 94%. There was a statistically significant difference between the 2 groups in terms of RFS (P = .006) and BCSS (P = .041) independent of received treatment.ConclusionUsing the St. Gallen risk categories resulted in significantly different outcomes for patients with NNBC. The St. Gallen classification might be a valuable clinical tool when assessing patients with NNBC.