Metastatic behavior and overall survival according to breast cancer subtypes in stage IV inflammatory breast cancer.

BACKGROUND: Distant metastatic disease is frequently observed in inflammatory breast cancer (IBC), with a poor prognosis as a consequence. The aim of this study was to analyze the association of hormone receptor (HR) and human epidermal growth factor receptor-2 (HER2) based breast cancer subtypes in stage IV inflammatory breast cancer (IBC) with preferential site of distant metastases and overall survival (OS). METHODS: For patients with stage IV IBC, diagnosed in the Netherlands between 2005 and 2016, tumors were classified into four breast cancer subtypes: HR+/HER2-, HR+/HER2+, HR-/HER2+, and HR-/HER2-. Patient, tumor, and treatment characteristics and sites of metastases were compared. OS of the subtypes was compared using Kaplan-Meier curves and the log-rank test. Association between subtype and OS was assessed in multivariable models using logistic regression. RESULTS: In total, 744 eligible patients were included: 340 (45.7%) tumors were HR+/HER2-, 148 (19.9%) HR-/HER2+, 131 (17.6%) HR+/HER2+, and 125 (16.8%) HR-/HER2-. Bone was the most common metastatic site in all subtypes. A significant predominance of bone metastases was found in HR+/HER2- IBC (71.5%), and liver and lung metastases in the HR-/HER2+ (41.2%) and HR-/HER2- (40.8%) subtypes, respectively. In multivariable analysis, the HR-/HER2- subtype was associated with significantly worse OS as compared to the other subtypes. CONCLUSION: Breast cancer subtypes in stage IV IBC are associated with distinct patterns of metastatic spread and display notable differences in OS. The use of breast cancer subtypes can guide a more patient-tailored staging directed to metastatic site and extend of disease.

Inflammatory breast cancer in the Netherlands; improved survival over the last decades.

PURPOSE: Locally advanced breast cancer (LABC) includes inflammatory breast cancer (IBC) as well as non-inflammatory LABC (NI-LABC). The aim of this population-based study was to compare the tumour characteristics, treatment and relative survival of IBC and NI-LABC patients. METHODS: Patients with either IBC (cT4d) or NI-LABC (cT4a-c) were identified from the nationwide Netherlands Cancer Registry from the period 1989-2015. In each group, patients are divided into three time periods in order to perform a trend analysis: 1989-1997, 1998-2006, and 2007-2015. RESULTS: IBC comprised 1.1% and NI-LABC 4.6% of all diagnosed breast cancer patients. IBC patients showed more nodal metastases (77.8 vs. 69.7%, P < 0.001) and distant metastases (39.7 vs. 34.1%, P < 0.001). IBC tumours were more often triple negative (23.2 vs. 12.8%, P < 0.001) and poorly differentiated (69.8 vs. 53.8%, P < 0.001). Trimodality therapy (neoadjuvant chemotherapy, surgery and adjuvant radiotherapy) was more often applied over time in both groups (IBC: 23.7%-56.0%-68.6%; NI-LABC: 3.7%-25.9%-43.6%; P trend < 0.001). In IBC patients, relative 5-year survival was significantly shorter than in patients with NI-LABC (30.2 vs. 45.1%, P < 0.001). The relative survival significantly improved for IBC from 17.2% (1989-1997) to 30.0 and 38.9% for the last two time periods (1998-2006: P < 0.001; 2007-2015: P < 0.001). In contrast, survival did not significantly improve in NI-LABC breast cancer: from 44.7% (1989-1997) to 44.0 and 48.4% (1998-2006: P = 0.483; 2007-2015: P = 0.091). CONCLUSIONS: IBC has tumour characteristics that determine its aggressive biology compared to NI-LABC. Trimodality therapy was increasingly applied in both groups, but did not improve survival in NI-LABC. Although relative survival in IBC patients has improved during the last decades, it remains a disease with a dismal prognosis.

[18F]FDG PET/CT in the staging of inflammatory breast cancer: A systematic review.

Up to 78 % of patients with inflammatory breast cancer (IBC) present with axillary lymph node involvement and up to 40 % with distant metastases. Previous studies indicate that 2-deoxy-2-(18F)fluoro-d-glucose ([18F]FDG) positron emission tomography/computed tomography (PET/CT) might be used for initial staging in patients with inflammatory breast cancer (IBC). In other cancer types, [18F]FDG PET/CT has been demonstrated to be a sensitive technique, providing complementary information on locoregional and distant disease to conventional imaging modalities. This systematic review showed that 18F]FDG PET/CT detects additional locoregional lymph node metastases and distant metastases in 10.3 % of patients, that were not detected with standard staging imaging. Compared with conventional imaging procedures, [18F]FDG PET/CT had better diagnostic performance for detection of locoregional and distant metastases and should standardly be used in the diagnostic work-up of IBC patients.

Better survival after surgery of the primary tumor in stage IV inflammatory breast cancer.

INTRODUCTION: Information regarding the effects of resection of the primary tumor in stage IV inflammatory breast cancer (IBC) is scarce. We analyzed the impact of resection of the primary tumor on overall survival (OS) in a large stage IV IBC population. MATERIALS AND METHODS: Patients diagnosed with stage IV IBC between 2005 and 2016 were selected from the Netherlands Cancer Registry, excluding patients without any treatment. To correct for immortal time bias, we performed a landmark analysis including patients alive at least six months after diagnosis. With propensity score matching, patients undergoing surgery of the primary tumor were matched to patients not receiving surgery. Multivariable Cox proportional hazard analyses were performed to determine the association between treatment strategy and OS in the non-matched and matched cohort. RESULTS: Of the 580 included patients after landmark analysis, 441 patients (76%) received only non-surgical treatments and 139 (24%) underwent surgery (96% mastectomy). Median follow-up was 28.8 and 20.0 months in the surgery and no surgery group, respectively. Surgery in the non-matched cohort was independently associated with better survival (HR0.56[95%CI:0.42-0.75]). In the matched cohort (n = 202), surgically treated patients had improved survival over nonsurgically treated patients (p < 0.005). Multivariable analysis of the matched cohort revealed that surgery was still associated with better survival (HR0.62[95%CI:0.44-0.87]). CONCLUSION: Although residual confounding and confounding by severity cannot be ruled out, this study suggests that surgery of the primary tumor is associated with improved OS and should be considered as part of the treatment strategy in stage IV IBC.

Inflammatory breast cancer: an overview.

Inflammatory breast cancer (IBC) is the most aggressive entity of breast cancer. Management involves coordination of multidisciplinary management and usually includes neoadjuvant chemotherapy, ablative surgery if a tumor-free resection margin is expected and locoregional radiotherapy. This multimodal therapeutic approach has significantly improved patient survival. However, the median overall survival among women with IBC is still poor. By elucidating the biologic characteristics of IBC, new treatment options may become available. We performed a comprehensive review of the English-language literature on IBC through computerized literature searches. The objective of the current review is to present an overview of the literature related to the biology, imaging and multidisciplinary treatment of inflammatory breast cancer.