RESUMO
BACKGROUND: Invasive lobular carcinomas (ILC) form 5%-10% of breast cancer and rarely show overexpression of human epidermal growth factor receptor 2 (HER2). AIM: To describe the prevalence and prognostic factors of HER2 positive (HER2+) ILC in an Asian population. METHODS: A retrospective review of patients with ILC seen between January 1985 and March 2018 at various SingHealth medical institutions was conducted. Demographic and clinical data were collected from medical records. We examined clinicopathological characteristics and survival in relation to HER2 status. RESULTS: A total of 864 patients were included. Prevalence of HER2 positivity was 10.1% (87 patients). Compared with HER2 negative (HER2-) ILC, HER2+ ILC was associated with a higher proportion of estrogen receptor negative (24.4% vs 5.9%, P < 0.001), progesterone receptor negative (PR-) (40.2% vs 24%, P = 0.002) and grade 3 tumours (Grade 3, 29.0% vs 10.2%, P < 0.001). Overall survival rate was poorer in patients with HER2+ compared to HER2- ILC (56.7% vs 72.9% alive at 10 years; hazard ratio 1.87, 95% confidence interval: 1.21-2.90, P = 0.004). Based on multivariate analysis, negative prognostic factors for overall survival included HER2 positivity, PR negativity, older age, Indian ethnicity and higher tumour stage. CONCLUSION: Prevalence of HER2+ ILC was 10.1%. HER2+ ILC was more likely to have poorer prognostic features such as estrogen receptor negative, PR- and higher tumour grade, and have a poorer survival.
RESUMO
BACKGROUND: Breast cancer (BC) patients with brain metastases (BM) are heterogeneous with markedly variable survival. The Breast Graded Prognostic Assessment (B-GPA) and Modified B-GPA (mB-GPA) have been proposed as useful tools for stratifying survival in this population. However, extra-cranial disease progression, a clinically important variable, is not incorporated into the final model. We undertook the validation of B-GPA and mB-GPA in an Asian cohort and further explore extra-cranial disease progression as a prognostic factor. METHODS: Data of BC patients with newly diagnosed BM between 2006 and 2017 was extracted retrospectively from a prospectively maintained institutional database. Patients were classified based on their B-GPA and mB-GPA scores. Univariate (UVA) and multivariate analysis (MVA) using the Cox proportional hazard model were performed to investigate the factors prognostic of overall survival (OS). The Kaplan-Meier method was used to estimate OS and log-rank test to compare survival between scores. The performances of B-GPA and mB-GPA were compared using Harrell's concordance index (C-index) and Akaike information criterion (AIC). RESULTS: In our cohort of 282 patients, the B-GPA and mB-GPA were validated as prognostic tools for OS, demonstrating excellent separation between survival curves (P <0.001). In MVA, we found all components of mB-GPA (age, performance status, number of BM, tumour subtype) to be independent predictors of survival. C-index was 0.64 and AIC was 2,483.39 for B-GPA. mB-GPA demonstrated marginally better discrimination with a C-index of 0.65 and AIC of 2,445.78. Extra-cranial progression was an independent predictor for survival in our population (P <0.001). CONCLUSIONS: The mB-GPA incorporates four simple clinical variables each of independent prognostic significance. Both B-GPA and mB-GPA demonstrate moderate discriminative capabilities for OS with mB-GPA performing marginally better. Inclusion of extra-cranial disease progression as a factor in future model development may further improve its prognostic value.
