Abstract
Aims and background
Based on estrogen receptor (ER), progesterone receptor (PgR) and Her2/neu (HER2) expression, four breast cancer subtypes have been distinguished: luminal A (ER and/or PgR/HER2–, Ki67 <14%), luminal B (ER and/or PgR/HER2–, Ki67 ≥14% or ER and/or PgR/HER2), triple-negative (ER-/PgR-/HER2–), and HER2 (ER-/PgR-/HER2). Our aim was to evaluate the prognosis of these phenotypes in the pre-trastuzumab era in a large cohort of Italian women.
Methods and study design
We studied 2347 breast cancer patients, in stage I-II, registered by the Modena Cancer Registry from 1999 to 2006 in the Modena province, Italy. Overall survival, disease-free survival and second non-mammary tumors were evaluated.
Results
A total of 1868 luminal A (79.6%), 195 luminal B (8.3%), 205 triple-negative (8.7%) and 79 HER2 (3.4%) patients were identified. A better prognosis was observed for luminal A than for luminal B, HER2 and triple-negative subtypes (5-year overall survival, 91% vs 89% vs 87% vs 86%, respectively, P <0.001). Disease-free survival for pT1a and pT1b tumors was worse in HER2 (82%) than in triple-negative (90%), luminal B (95%) and luminal A (97%) (P = 0.013). Finally, luminal B patients had a significantly higher rate of second non-mammary tumors than the other groups.
Conclusions
In the pre-trastuzumab era, luminal A patients showed a better 5-year overall survival than luminal B, HER2 and triple-negative patients, but in terms of disease-free survival, HER2 subtype represented an unfavorable group over time, whereas the triple-negative group had an increased risk of relapse in the first 42 months and then decreased. Among each prognostic factor, ER <10%, Ki67 >14% and HER2 overexpression are considered as risk factors, but only HER2 positivity seems to preserve the role over time.
Get full access to this article
View all access options for this article.
