Abstract 4361: The plasma proteome as a cardiovascular disease risk assessment tool in cancer survivors

Cardiovascular disease (CVD) is the most common non-cancer cause of death in cancer survivors and there is an unmet clinical need for easy, accurate, and safe CVD prognostic risk-stratification in adult cancer survivors. This study investigated whether a previously validated 27-plasma protein prognostic model for four-year cardiovascular (CV) events could have such a utility. We used the 27-plasma protein model to predict the four-year risk of a CV event (myocardial infarction, stroke, transient ischemic attack, heart failure hospitalization, death) in 906 participants with a prior history or active malignancy of any type of cancer and compared predictive results to follow-up CV outcome data. The participants were from the BASEL VIII or ARIC (visit 3) studies with a medically adjudicated prior diagnosis of cancer. BASEL VIII is an observational cohort study in patients with suspected coronary artery disease. ARIC is a multi-site cohort study funded by the NHLBI, NCI, and NPCR investigating risk factors for CV health. A subset analysis was conducted to assess model performance in participants with no prior history of CVD and those with stable CVD. The 27-plasma protein model accurately stratified participants into 4 distinct and non-overlapping (95% CI) risk bins. The median time to event for all cancer survivors who had an event in this study was 1.3 years. Observed 4-year event rates across the 4 risk bins (low, medium-low, medium-high, and high) were 11.0%, 17.3%, 31.2% and 60.2%, respectively, which were higher than stratified event rates from our previously published metacohort analyses (5.6%, 11.2%, 20.0% and 43.4%, respectively) in participants with elevated CVD risk factors (e.g., prior events, diabetes, kidney disease and suspected coronary artery disease). The plasma protein model accurately predicted 4-year CVD risk with a C-index of 0.71 (0.68, 0.74) and 4-year AUC of 0.74 (0.69, 0.79). Performance of the protein model was comparable between participants with no prior history of CVD (C-Index: 0.69; AUC: 0.71) and stable CVD (C-Index: 0.69; AUC: 0.72), demonstrating the model accurately predicts CV event risk in cancer survivors regardless of cardiovascular history. Cancer survivors in this cohort can be distinguished with 4-year CV event rates as high as 60.2%, underscoring the urgent need for an easy and accurate risk stratification tool for this population. Prognostic protein testing may provide a novel tool for CVD risk assessment in adult cancer survivors.

Citation Format: Emma V. Troth, Matthew Ayala, Jessica Chadwick, Erin Hales, Michael Hinterberg, Jessica N. Kuzma, Clare Paterson, Rachel Ostroff, Joan E. Walter, Christian Mueller, Josef Coresh. The plasma proteome as a cardiovascular disease risk assessment tool in cancer survivors. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 4361.

Simultaneous quantification of vitamin E and vitamin E metabolites in equine plasma and serum using LC-MS/MS

Vitamin E deficiencies can impact normal growth and development in humans and animals, and assessment of circulating levels of vitamin E and its metabolites may be an important endpoint for evaluation. Development of a sensitive method to detect and quantify low concentrations of vitamin E and metabolites in biological specimens allows for a proper diagnosis for patients and animals that are deficient. We developed a method to simultaneously extract, detect, and quantify the vitamin E compounds alpha-tocopherol (α-TP), gamma-tocopherol (γ-TP), alpha-tocotrienol (α-TT), and gamma-tocotrienol (γ-TT), and the corresponding metabolites formed after β-oxidation of α-TP and γ-TP, alpha-carboxymethylbutyl hydroxychroman (α-CMBHC) and alpha- or gamma-carboxyethyl hydroxychroman (α- or γ-CEHC), respectively, from equine plasma and serum. Quantification was achieved through liquid chromatography-tandem mass spectrometry. We applied a 96-well high-throughput format using a Phenomenex Phree plate to analyze plasma and serum. Compounds were separated by using a Waters ACQUITY UPLC BEH C18 column with a reverse-phase gradient. The limits of detection for the metabolites and vitamin E compounds were 8-330 pg/mL. To validate the method, intra-day and inter-day accuracy and precision were evaluated along with limits of detection and quantification. The method was then applied to determine concentrations of these analytes in plasma and serum of horses. Alpha-TP levels were 3-6 µg/mL of matrix; the metabolites were found at much lower levels, 0.2-1.0 ng/mL of matrix.

3,3',4,4'-tetrachlorobiphenyl (TCB) can enhance DMBA-induced mammary carcinogenesis in the rat

Polychlorinated biphenyls (PCBs) are fat-soluble environmental pollutants which can be stored in the fatty tissue of breast and secreted in milk. Previous studies have shown that PCBs can influence liver carcinogenesis in animal models but no such studies have been reported in breast. These experiments aimed to determine whether a PCB congener could influence mammary carcinogenesis using the rat DMBA-induced mammary tumour model system. 3,3',4,4'-Tetrachlorobiphenyl (TCB) enhanced the development of DMBA-induced mammary tumours in young female rats and did so in animals fed either a low-fat (5% w/w corn oil) or a high-fat (20% w/w corn oil) diet. The combination of TCB and high-fat diet resulted in tumours growing so fast that the experiment had to be terminated at 10.5 weeks for humane reasons. At termination the total numbers of tumours in each group of 20 rats were: 4 in the low-fat group, 22 in the low-fat plus TCB group, 25 in the high-fat group and 50 in the high-fat plus TCB group. Histopathological analysis confirmed that 98% of the tumours were mammary carcinomas, predominantly in situ ductal carcinomas, but, in addition, revealed that 13 of the tumours had an invasive phenotype of which 12/13 had all arisen in TCB-treated animals. This demonstrates, for the first time, that a PCB congener can influence mammary carcinogenesis.

Duodenal atresia in utero in association with Down's syndrome and annular pancreas

A 28-weeks' gestational trisomic-21 male, with duodenal atresia due to annular pancreas, is presented. The atresia was diagnosed in utero by sonographic techniques. A review of the pertinent literature and discussion of management are presented.