Breast cancer survival by molecular subtype: a population-based analysis of cancer registry data

Abstract

Breast cancer is the most commonly diagnosed cancer and the second most common cause of cancer-related death among women in Ontario.1 More than 10 000 cases are diagnosed each year in the province.1 Several molecular subtypes of breast cancer have been identified b ased o n h ormone receptor and human epidermal growth factor receptor 2 (HER2) status.2 These molecular subtypes have been shown to affect survival: patients with hormone-receptor-negative tumours tend have greater mortality and lower survival than those with hormone-receptor-positive tumours. [3][4][5] Although the relation between breast cancer molecular subtype and survival has been studied in other jurisdictions, including British Columbia, 6,7 limited information is available for Ontario. The goal of this study was to determine how breast cancer molecular subtype affects survival among Ontario women and how survival for each subtype varies by selected demographic and tumour-based characteristics. Methods Setting and study populationThe study population included all cases of malignant breast cancer diagnosed in girls and women aged 15 years or more in Ontario between Jan. 1, 2010, and Dec. 31, 2012. We chose this period because data on molecular subtype were unavailable for cases diagnosed before 2010, and mortality data were unavailable for cases diagnosed after 2012. The relation between breast cancer molecular subtype and survival has been studied in several jurisdictions, but limited information is available for Ontario. The aim of this study was to determine breast cancer survival by molecular subtype and to assess the effect on survival of selected demographic and tumour-based characteristics.

Impact of biomarkers and genetic profiling on breast cancer prognostication: A comparative analysis of the 8th edition of breast cancer staging system

“…Even though HER2+ BCs are a biologically aggressive subgroup, and carry a poor prognosis, 17 HER2-targeted therapy has dramatically improved the outcome of HER2+ BCs ( 8,(18)(19)(20) [21][22][23][24] Because of their intrinsic aggressive behavior, and the lack of targeted therapy, TN status has a global upstaging effect in the TNM + Biomarkers system across all stage groups as seen in our study and several other published studies. 1,6,7,9,18 The TNM More studies are needed to refine the TNM + Biomarkers (PS) system for a more accurate prognostic stratification of this heterogeneous group of tumors.…”

“…Triple negative (TN) BCs constitute 10%‐17% of BCs and, in general, carry a poor prognosis . Because of their intrinsic aggressive behavior, and the lack of targeted therapy, TN status has a global upstaging effect in the TNM + Biomarkers system across all stage groups as seen in our study and several other published studies .…”

“…In contrast, ER+/PR− or ER−/PR+ BCs were infrequently downstaged (3 ER+/PR− and 2 ER−/PR+). Single hormone‐positive BCs have less favorable prognosis compared to ER+/PR+ BCs . Thus, the TNM + Biomarkers system downstages ER+/PR+ BCs and conveys the survival advantage associated with ER+/PR+ status vs positivity for only one of the two hormone receptors …”

Do all patients with recurrent ovarian cancer need systemic therapy?

“…The Charlson Comorbidity Index (CCI) is a weighted index with which to predict death within 1 year of hospitalization, with specific comorbid conditions that are summed to produce a score. 25,26 Platinum-resistant ROC Inevitably, the majority of patients with ROC will develop resistance to chemotherapy and will die as a result of PR-ROC. The overall survival of patients with stage IV ovarian cancer has been shown to correlate with the comorbidity score, with a significantly worse outcome noted among patients with high scores compared with those with a score of 0.…”

“…24 However, the CCI has been reported to be an independent predictor of the overall survival (OS) of patients with recurrent bladder cancer as well as recurrent breast cancer. 25,26 Platinum-resistant ROC Inevitably, the majority of patients with ROC will develop resistance to chemotherapy and will die as a result of PR-ROC. However, there are many patientrelated and tumor-related factors that need to be taken into consideration when making treatment recommendations to an individual patient with PR-ROC (Table 1).…”