Clinical Value of RNA Sequencing-Based Classifiers for Prediction of the Five Conventional Breast Cancer Biomarkers: A Report From the Population-Based Multicenter Sweden Cancerome Analysis Network-Breast Initiative.

PURPOSE: In early breast cancer (BC), five conventional biomarkers-estrogen receptor (ER), progesterone receptor (PgR), human epidermal growth factor receptor 2 (HER2), Ki67, and Nottingham histologic grade (NHG)-are used to determine prognosis and treatment. We aimed to develop classifiers for these biomarkers that were based on tumor mRNA sequencing (RNA-seq), compare classification performance, and test whether such predictors could add value for risk stratification. METHODS: In total, 3,678 patients with BC were studied. For 405 tumors, a comprehensive multi-rater histopathologic evaluation was performed. Using RNA-seq data, single-gene classifiers and multigene classifiers (MGCs) were trained on consensus histopathology labels. Trained classifiers were tested on a prospective population-based series of 3,273 BCs that included a median follow-up of 52 months (Sweden Cancerome Analysis Network-Breast [SCAN-B], ClinicalTrials.gov identifier: NCT02306096), and results were evaluated by agreement statistics and Kaplan-Meier and Cox survival analyses. RESULTS: Pathologist concordance was high for ER, PgR, and HER2 (average κ, 0.920, 0.891, and 0.899, respectively) but moderate for Ki67 and NHG (average κ, 0.734 and 0.581). Concordance between RNA-seq classifiers and histopathology for the independent cohort of 3,273 was similar to interpathologist concordance. Patients with discordant classifications, predicted as hormone responsive by histopathology but non-hormone responsive by MGC, had significantly inferior overall survival compared with patients who had concordant results. This extended to patients who received no adjuvant therapy (hazard ratio [HR], 3.19; 95% CI, 1.19 to 8.57), or endocrine therapy alone (HR, 2.64; 95% CI, 1.55 to 4.51). For cases identified as hormone responsive by histopathology and who received endocrine therapy alone, the MGC hormone-responsive classifier remained significant after multivariable adjustment (HR, 2.45; 95% CI, 1.39 to 4.34). CONCLUSION: Classification error rates for RNA-seq-based classifiers for the five key BC biomarkers generally were equivalent to conventional histopathology. However, RNA-seq classifiers provided added clinical value in particular for tumors determined by histopathology to be hormone responsive but by RNA-seq to be hormone insensitive.

The Sweden Cancerome Analysis Network - Breast (SCAN-B) Initiative: a large-scale multicenter infrastructure towards implementation of breast cancer genomic analyses in the clinical routine.

BACKGROUND: Breast cancer exhibits significant molecular, pathological, and clinical heterogeneity. Current clinicopathological evaluation is imperfect for predicting outcome, which results in overtreatment for many patients, and for others, leads to death from recurrent disease. Therefore, additional criteria are needed to better personalize care and maximize treatment effectiveness and survival. METHODS: To address these challenges, the Sweden Cancerome Analysis Network - Breast (SCAN-B) consortium was initiated in 2010 as a multicenter prospective study with longsighted aims to analyze breast cancers with next-generation genomic technologies for translational research in a population-based manner and integrated with healthcare; decipher fundamental tumor biology from these analyses; utilize genomic data to develop and validate new clinically-actionable biomarker assays; and establish real-time clinical implementation of molecular diagnostic, prognostic, and predictive tests. In the first phase, we focus on molecular profiling by next-generation RNA-sequencing on the Illumina platform. RESULTS: In the first 3 years from 30 August 2010 through 31 August 2013, we have consented and enrolled 3,979 patients with primary breast cancer at the seven hospital sites in South Sweden, representing approximately 85% of eligible patients in the catchment area. Preoperative blood samples have been collected for 3,942 (99%) patients and primary tumor specimens collected for 2,929 (74%) patients. Herein we describe the study infrastructure and protocols and present initial proof of concept results from prospective RNA sequencing including tumor molecular subtyping and detection of driver gene mutations. Prospective patient enrollment is ongoing. CONCLUSIONS: We demonstrate that large-scale population-based collection and RNA-sequencing analysis of breast cancer is feasible. The SCAN-B Initiative should significantly reduce the time to discovery, validation, and clinical implementation of novel molecular diagnostic and predictive tests. We welcome the participation of additional comprehensive cancer treatment centers. TRIAL REGISTRATION: ClinicalTrials.gov identifier NCT02306096.

Serum calcium and tumour aggressiveness in breast cancer: a prospective study of 7847 women.

Experimental, epidemiological and clinical studies suggest that calcium and/or its regulating hormones affect breast cancer risk. There has been no prospective cohort study investigating serum calcium levels and breast cancer aggressiveness, as determined by tumour histology and stage. Dichotomized prediagnostic serum calcium levels were investigated in relation to breast cancer aggressiveness as determined by grade (mitotic frequency, tubule formation, nuclear atypia) and stage (tumour size and axillary lymph node status). Cox's proportional hazards analysis and heterogeneity analysis were used to investigate the associations between low/high calcium and grade/stage in a prospective cohort study of 7847 women, out of whom 462 women were diagnosed with incident breast cancer during a mean follow-up of 17.2 years. All analyses were stratified for body mass index and menopausal status. Prediagnostic serum calcium levels in premenopausal women were positively associated with increased tumour aggressiveness as determined by a higher risk of nodal metastasis; relative risk (RR) for calcium above median as compared with calcium below median was 1.88 with a 95% confidence interval (CI) of 1.04-3.38. In overweight women, prediagnostic serum calcium levels were also associated with tumour aggressiveness, as determined by both a higher risk of nodal metastasis [RR (95% CI) 1.69 (0.95-3.02)] and severe nuclear atypia [RR (95% CI) 2.06 (1.10-3.86)]. Results also indicate that, in overweight women, calcium is positively associated with worse grade as determined by tubule formation and mitotic frequency. In conclusion, prediagnostic serum calcium levels are positively associated with increased tumour aggressiveness in premenopausal and/or overweight women.

L-lactate after embolization of the superior mesenteric artery.

BACKGROUND: Plasma markers for intestinal ischemia have not proven to be accurate. The value of L-lactate is unclear. Experimental models based on open surgery confound the effects of surgical trauma with that of ischemia. The aim was to create an endovascular model for acute superior mesenteric artery thromboembolism, and then to study L-lactate and lactate dehydrogenase (LD) activity in plasma and peritoneal fluid in pigs with extensive, high-grade intestinal ischemia. MATERIALS AND METHODS: Nine pigs underwent full superior mesenteric artery embolization with 4 h of intended intestinal ischemia, whereas six were control animals. Sampling of central venous and arterial blood was performed throughout the experiment, ending with laparotomy to collect peritoneal fluid and segmental intestinal biopsies. A pathologist, blinded to the performed interventions, graded the ischemic lesions. RESULTS: There were no differences in plasma L-lactate (P = 0.61) or LD activity levels (P = 0.69), measured at different time points from baseline to end of study, between animals with extensive, high-grade intestinal ischemia and sham. Intraperitoneal L-Lactate (P = 0.005) and LD activity (P = 0.018) levels were elevated compared with sham. There were differences in grades of ischemia in the duodenum (P = 0.003), small intestine (P < 0.001), proximal (P < 0.001), and sigmoid (P = 0.032) colon between experimental animals and sham. The grade of small bowel ischemia (n = 15) correlated to intraperitoneal fluid L-lactate (r = 0.80; P < 0.001) and LD activity levels (r = 0.72; P = 0.003). CONCLUSIONS: This endovascular study in a porcine model showed that L-lactate and LD activity levels in peritoneal fluid, not in plasma, reflect intestinal ischemia. The study suggests that plasma L-lactate not is a useful early marker in patients with suspicion of intestinal ischemia.