Biological Subtypes and Distant Relapse Pattern in Breast Cancer Patients After Curative Surgery (Study of Anatolian Society of Medical Oncology)

Abstract

Purpose: The aim of the study was to investigate the association between the molecular subtypes and patterns of relapse in breast cancer patients who had undergone curative surgery. Methods: We retrospectively evaluated 1,350 breast cancer patients with relapses after curative surgery between 1998 and 2012 from referral centers in Turkey. Patients were divided into 4 biological subtypes according to immunohistochemistry and grade: triple negative, HER2 overexpressing, luminal A and luminal B. Results: The percentages of patients with luminal A, luminal B, HER2-overexpressing, and triple-negative breast cancer were 32.9% (n = 444), 34.9% (n = 471), 12.0% (n = 162), and 20.2% (n = 273), respectively. The distribution of metastases differed among the subgroups: bone (66.2% and 53.9% in luminal A and B vs. 38.9% in HER2-overexpressing and 45.1% in triple negative, p < 0.001), liver (40.1% in HER2-overexpressing vs. 24.5% in luminal A, 33.5% in luminal B, and 27.5% in triple negative, p < 0.001), lung (41.4% in triple negative and 35.2% in HER2-overexpressing vs. 30.2% and 30.6% in luminal A and B, p = 0.008) and brain (25.3% in HER2-overexpressing and 23.1% in triple negative vs. 10.1% and 15.1% in luminal A and B, p < 0.001). Conclusions: Organ-specific metastasis may depend on the molecular subtype of breast cancer. Tailored strategies against distant metastasis concerning the molecular subtypes in breast cancer should be considered.

A Population-Based Study on Liver Metastases in Women with Newly Diagnosed Breast Cancer

“…Nevertheless, results from a single institution study (104 patients) showed that breast cancer subtypes were not associated with survival after liver metastases (18), which are less likely to be generalizable. Our data are consistent with some of the general trends reported in academic center-based retrospective studies (24,33,42). Importantly, given the potential referral bias and other biases that can be presented in academic center-based series, we confirmed in a population-based sample of patients with newly diagnosed breast cancer and liver metastases that a median survival of nearly 3 years after diagnosis is now achieved in patients with HR-positive HER2-positive tumors.…”

“…In a retrospective case-control study of 103 patients with metastatic breast cancer, Buonomo and colleagues (33) showed that HER2-positive subtypes had a stronger association with systemic spread (OR, 2.127; 95% CI, 1.2-3.8) than other subgroups. In a retrospective study of 1,350 patients from referral centers in Turkey, Kaplan and colleagues (24) indicated that liver was the most frequent site of first metastases among HER2-overexpressing patients. Besides, results from other two studies suggested that HER2-rich subtypes have a liver-homing (OR ¼ 2.99) characteristic (5,26).…”

“…Thus, the association of breast cancer subtypes and survival after liver metastases was unclear and remained controversial. Nevertheless, several studies suggested that the risk of liver metastases was subtype-dependent, and patients with HER2-positive experienced significantly higher rates of liver metastasis than patients (with HER2-negative) tumors (5,(24)(25)(26). Besides, other sociodemographic and clinical predictors of outcome have not been well characterized on a population-based level, which makes the prognostic assessment and management very challenging.…”

Failure patterns according to molecular subtype in patients with invasive breast cancer following postoperative adjuvant radiotherapy: long-term outcomes in contemporary clinical practice

“…Importantly, this study revealed the subtype-based differential susceptibility to distant metastasis in the contemporary era of breast cancer treatment. Several previous reports have explored the subtype-related preferential sites of distant metastasis [16,[21][22][23][24][25][26]. However, their results were inconsistent.…”

“…However, their results were inconsistent. Although a potential bone-seeking phenotype of luminal tumors has been suggested [21][22][23][24], some reports could not verify this tendency [16,25]. In the study by Sihto et al of 234 patients diagnosed with distant metastasis as the first site of failure, the authors found higher frequencies of liver (27.1%) and lung (22.9%) metastases in patients with HER2 tumors and higher frequencies of lung (20.8%) and brain (9.5%) metastases in patients with basal-like tumors [21].…”