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Background: A 23-gene classifier has been developed based on gene expression profiles of Taiwanese luminal-like breast cancer. We aim to stratify risk of relapse and identify patients who may benefit from adjuvant chemotherapy based on genetic model among distinct clinical risk groups. Methods: There were 248 luminal (hormone receptor-positive and human epidermal growth factor receptor II-negative) breast cancer patients with 23-gene classifier results. Using the modified Adjuvant! Online definition, clinical high/low-risk groups were tabulated with the genetic model. The primary endpoint was a recurrence-free interval (RFI) at 5 years. Results: There was a significant difference between the high/low-risk groups defined by the 23-gene classifier for the 5-year prognosis of recurrence (16 recurrences in high-risk and 3 recurrences in low-risk; log-rank test: p < 0.0001). Among the clinically high-risk group, the 5-year RFI of high risk defined by the 23-gene classifier was significantly higher than that of the low-risk group (15 recurrences in high-risk and 2 recurrences in low-risk; log-rank test: p < 0.0001). Conclusion: This study showed that 23-gene classifier can be used to stratify clinically high-risk patients into distinct survival patterns based on genomic risks and displays the potentiality to guide adjuvant chemotherapy. The 23-gene classifier can provide a better estimation of breast cancer prognosis which can help physicians make a better treatment decision.

Breast cancer is the most common cancer and the leading cause of cancer-related deaths in women. The estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2) are the important biomarkers in the prognosis of breast cancer, and their expression is used to categorize breast cancer into subtypes. We aimed to analyze the concordance among ER, PR, and HER2 expression levels and breast cancer subtyping results obtained by immunohistochemistry (IHC, for protein) and reverse transcriptase-polymerase chain reaction (RT-PCR, for mRNA) and to assess the recurrence-free survival (RFS) of the different subtypes as determined by the two methods. We compared biomarker expression by IHC and RT-PCR in 397 operable breast cancer patients and categorized all patients into luminal, HER2, and triple-negative (TN) subtypes. The concordance of biomarker expression between the two methods was 81.6% (κ = 0.4075) for ER, 87.2% (κ = 0.5647) for PR, and 79.1% (κ = 0.2767) for HER2. The κ-statistic was 0.3624 for the resulting luminal, HER2, and TN subtypes. The probability of 5-year RFS was 0.78 for the luminal subtype versus 0.77 for HER2 and 0.51 for TN, when determined by IHC (P=0.007); and 0.80, 0.71, and 0.61, respectively, when determined by the RT-PCR method (P=0.008). Based on the current evidence, subtyping by RT-PCR performs similar to conventional IHC with regard to the 5-year prognosis. The PCR method may thus provide a complementary means of subtyping when IHC results are ambiguous.

Background The information of Oncotype DX applied in Asian breast cancer patients is limited. A recurrence index for distant recurrence (RI-DR) has been developed for early-stage breast cancer (EBC) from tumor samples in Chinese patients. In this study, we compared the prognostic performance of the Oncotype DX (ODx) recurrence score (RS) with the RI-DR for any recurrence risk type. Materials and methods One hundred thirty-eight (138) patients with hormone receptor-positive and human epidermal growth factor receptor 2-negative EBC who were previously tested with ODx were included for testing with the RI-DR. The cutoff score to partition the low- and high-risk patients was 26 for RS and 36 for RI-DR. The primary endpoint was recurrence-free survival (RFS). Results The concordance between the RI-DR and RS was 83% in N0 patients and 81% in node-positive patients when the RS score cutoff was set at 26. With a median follow-up interval of 36.8 months, the 4-year RFS for the high- and low-risk groups categorized by the RS were 61.9% and 95.0%, respectively (hazard ratio: 10.6, 95.0% confidence interval [CI]: 1.8–62.9). The 4-year RFS in the high- and low-risk groups categorized by the RI-DR were 72.6% and 98.5%, respectively (hazard ratio: 18.9, 95% CI: 1.8–138.8). Conclusion This paper illustrated the performance of RI-DR and ODx RS in breast cancer women in Taiwan. There was high concordance between the RI-DR and RS. The RI-DR is not inferior to the RS in predicting RFS in EBC patients. This study will fill the gap between the current and best practice in Chinese patients., Utilization of Oncotype DX is uncommon in Asia due to lack of clinical data. We compare a clinical-genomic model, developed from Taiwan, to Oncotype 21-gene panel in Chinese patients.

BackgroundNumerous prospective studies, predominantly in the Caucasian population, have proven the clinical utility of using multigene expression tests to prevent overtreatment in early-stage breast cancer patients with early-stage disease. In this study, we used an Asian population to validate a clinical-genomic assay (RecurIndex®) for estimating the risk of distant recurrence and relapse in early-stage breast cancer patients. MethodsA total of 298 patients with early-stage breast cancer, luminal-like subtype (85.6%) and HER2-enriched/ triple-negative subtype (14.4%), was enrolled in a retrospective study across five participating medical centers in Taiwan. The inclusion criteria were as follows: women (1) who underwent primary surgery without prior induction treatments, (2) with an early pathologic N stage and (3) who received either mastectomy or breast-conserving surgery. Kaplan Meier method and Cox proportional hazards model were used to, respectively, identify independent prognostic factors and calculate the 5- and 10-year survival rates of patients in the low- and high-risk groups assigned by the diagnostic test. A forest plot was produced to assess hazard ratios and 95% confidence intervals. The primary endpoint was distant recurrence-free survival (DRFS) and the secondary endpoint was relapse-free survival (RFS).ResultsThe 10-year DRFS rate was significantly higher in the good prognosis group than in the poor prognosis group (91.9% [95% CI, 86.1-98.1%] versus 62.9% [95% CI, 49.8-79.4%]). The overall hazard ratio for distant recurrence was 1.031 [95% CI, 1.017 - 1.046] per unit Recurrence index-distant recurrence (RI-DR) score increment. ConclusionsThe present study provides robust evidence of the clinical utility of using the RI-DR score to accurately predict clinical outcomes. RecurIndex® could be used to determine the utility of adjuvant chemotherapy in Asian patients, especially those having hormone-receptor positive tumors, leading to a meaningful reduction in adjuvant chemotherapy recommendations.

We report a 23- gene-classifier profiled from Asian women, with the primary purpose of assessing its clinical utility towards improved risk stratification for relapse for breast cancer patients from Asian cohorts within 10 years’ following mastectomy. Four hundred and twenty-two breast cancer patients underwent mastectomy and were used to train the classifier on a logistic regression model. A subset of 197 patients were chosen to be entered into the follow-up studies post mastectomy who were examined to determine the patterns of recurrence and survival analysis based on gene expression of the gene classifier, age at diagnosis, tumor stage and lymph node status, over a 5 and 10 years follow-up period. Metastasis to lymph node (N2-N3) with N0 as the reference (N2 vs. N0 hazard ratio: 2.02 (1.05–8.70), N3 vs. N0 hazard ratio: 4.32 (1.41–13.22) for 5 years) and gene expression of the 23-gene panel (P=0.06, 5 years and 0.02, 10 years, log-rank test) were found to have significant discriminatory effects on the risk of relapse (HR (95%CI):2.50 (0.95–6.50)). Furthermore, survival curves for subgroup analysis with N0-N1 and T1-T2 predicted patients with higher risk scores. The study provides robust evidence of the effectiveness of the 23-gene-classifier and could be used to determine the risk of relapse event (locoregional and distant recurrence) in Asian patients, leading to a meaningful reduction in chemotherapy recommendations.

3560 Background: Numerous prospective studies, predominantly in Caucasian population, have proven the clinical utility of using multigene expression tests to prevent overtreatment in early breast cancer (EBC) patients. Since racial and ethnic disparities exist in genetic and biological factors that could influence the disease, the primary purpose of this study is to access the clinical utility of RecurIndex, a recurrence risk test, that is based on a genomic profiling derived from Asian women. Methods: A total of 298 patients with EBC, luminal subtype (85.6%), HER2 subtype (7.7%) and triple-negative subtype (6.7%), were enrolled in a retrospective study across Taiwan medical centers. Kaplan Meier and Cox Proportional Hazards model were used to, respectively, identify independent prognostic factors and calculate the survival rates. The prediction model was then tested using the area under the receiver operating characteristic curve (AUC). The primary endpoint was distant recurrence-free survival (DRFS). Results: The 10-year DRFS was significantly higher in the good-prognosis group than the poor-prognosis group (92.0% [95% CI, 86.1-98.2] versus 63.0% [95% CI, 49.9-79.5]) (Table). The overall hazard ratio for distant recurrence was 1.031 (95% CI, 1.017±1.046) per RI score increment. In addition, in a subset of 179 cases (60.1%), the model yielded an 82.3% correct classification rate for predicting DR with a sensitivity of 87.0%, a specificity of 68.6% and negative predictive values of 97.3%. Conclusions: The present study provides robust evidence of the clinical utility of RI-DR to predict clinical outcomes. RecurIndex could be used to determine the utility of chemotherapy in Asian patients, especially in hormone-receptor positive and HER2 negative disease, leading to a meaningful reduction in adjuvant chemotherapy recommendations. [Table: see text]

Background Schizophrenia is a complex disease with multiple factors contributing to its pathogenesis. In addition to environmental factors, genetic factors may also increase susceptibility. In other words, schizophrenia is a highly heritable disease. Some candidate genes have been deduced on the basis of their known function with others found on the basis of chromosomal location. Individuals with multiple candidate genes may have increased risk. However it is not clear what kind of gene combinations may produce the disease phenotype. Their collective effect remains to be studied. Results Most pathways except metabolic pathways are rich in protein-protein interactions (PPIs). Thus, the PPI network contains pathway information, even though the upstream-downstream relation of PPI is yet to be explored. Here we have constructed a PPI sub-network by extracting the nearest neighbour of the 36 reported candidate genes described in the literature. Although these candidate genes were discovered by different approaches, most of the proteins formed a cluster. Two major protein interaction modules were identified on the basis of the pairwise distance among the proteins in this sub-network. The large and small clusters might play roles in synaptic transmission and signal transduction, respectively, based on gene ontology annotation. The protein interactions in the synaptic transmission cluster were used to explain the interaction between the NRG1 and CACNG2 genes, which was found by both linkage and association studies. This working hypothesis is supported by the co-expression analysis based on public microarray gene expression. Conclusion On the basis of the protein interaction network, it appears that the NRG1-triggered NMDAR protein internalization and the CACNG2 mediated AMPA receptor recruiting may act together in the glutamatergic signalling process. Since both the NMDA and AMPA receptors are calcium channels, this process may regulate the influx of Ca2+. Reducing the cation influx might be one of the disease mechanisms for schizophrenia. This PPI network analysis approach combined with the support from co-expression analysis may provide an efficient way to propose pathogenetic mechanisms for various highly heritable diseases.