The Relevance of Breast Cancer Subtypes in the Outcome of Neoadjuvant Chemotherapy

Abstract

BackgroundBreast cancer is increasingly considered a heterogeneous disease. The aim of this study was to assess the differences between histological and receptor-based subtypes in breast-conserving surgery and pathological complete response (pCR) after neoadjuvant chemotherapy.MethodA consecutive series of 254 patients with operable breast cancer treated with neoadjuvant chemotherapy was analyzed. Tumors were classified according to their receptor status in estrogen receptor (ER)-positive tumors (HER2-negative), triple-negative tumors, and HER2-positive tumors. The type of surgery feasible prior to neoadjuvant chemotherapy was compared with the actual surgery performed.ResultsThe overall increase in breast-conserving surgery was 37% (73 of 198). In patients with ductal and lobular carcinomas this increase was 41% (63 of 152, 95% confidence interval [95% CI] 0.34–0.49) and 20% (7 of 35, 95% CI 0.10–0.36), respectively (P = 0.02). Half of the patients with lobular carcinoma had to undergo a secondary mastectomy because of incomplete resection margins. In ER-positive, triple-negative and HER2-positive tumors, the increase in breast-conserving surgery was 39% (42 of 109, 95% CI 0.30–0.48), 24% (11 of 45, 95% CI 0.14–0.38), and 45% (20 of 44, 95% CI 0.32–0.60) (P = 0.11). The pCR rate in ductal and lobular carcinomas was 12% (23 of 195) and 2% (1 of 42), respectively (P = 0.09). In ER-positive, triple-negative and HER2-positive tumors the pCR rates were 2% (3 of 138), 28% (16 of 57), and 18% (10 of 56), respectively. Multivariate analysis showed that the receptor-based subtype was the only significant predictor of pCR (P = 0.004).ConclusionIn lobular tumors the benefit with regard to breast-conserving surgery of neoadjuvant chemotherapy is questionable. Although in ER-positive tumors the pCR rate is low, the increase in breast-conserving surgery was remarkable in ductal ER-positive tumors.

Early monitoring of response to neoadjuvant chemotherapy in breast cancer with 18F-FDG PET/CT: defining a clinical aim

“…However, it is important to note that, for most clinicians, a pCR should not only concern the primary tumour but also the axillary lymph nodes [5,20]. Berriolo-Riedinger et al considered as responders the patients who presented a total or near total therapeutic effect in the primary tumour (Sataloff T-A) and no residual nodal disease (Sataloff N-A/B).…”

“…ILC is a well-established source of weak FDG uptake [26] and PET might not be suitable for early evaluation in this subtype. The chemosensitivity of lobular carcinoma is low [5,20]. In the GeparTrio trial, pCR was obtained in 24% for patients with an invasive ductal carcinoma and only in 10.2% in patients with an ILC [20].…”

“…In the GeparTrio trial, pCR was obtained in 24% for patients with an invasive ductal carcinoma and only in 10.2% in patients with an ILC [20]. Moreover, patients thought to be candidates for BCS after NAC often require repeat surgery because of involved margins [5]. Some authors question the use of NAC in lobular carcinoma [5].…”

“…Moreover, patients thought to be candidates for BCS after NAC often require repeat surgery because of involved margins [5]. Some authors question the use of NAC in lobular carcinoma [5].…”

Estrogen receptor‐positive/human epidermal growth factor receptor 2‐negative breast tumors

“…1 To some degree, these molecular subtypes can be distinguished using immunohistochemistry. 2 Estrogen receptor (ER)-positive/HER2-negative (ERþ/HER2À) breast cancer regroups the majority of luminal A and B tumors. This important group is characterized by potential hormone sensitivity and a relatively good prognosis, mainly for luminal A subtype.…”