Aldo-keto reductases are biomarkers of NRF2 activity and are co-ordinately overexpressed in non-small cell lung cancer

BACKGROUND: Although the nuclear factor-erythroid 2-related factor 2 (NRF2) pathway is one of the most frequently dysregulated in cancer, it is not clear whether mutational status is a good predictor of NRF2 activity. Here we utilise four members of the aldo-keto reductase (AKR) superfamily as biomarkers to address this question. METHODS: Twenty-three cell lines of diverse origin and NRF2-pathway mutational status were used to determine the relationship between AKR expression and NRF2 activity. AKR expression was evaluated in lung cancer biopsies and Cancer Genome Atlas (TCGA) and Oncomine data sets. RESULTS: AKRs were expressed at a high basal level in cell lines carrying mutations in the NRF2 pathway. In non-mutant cell lines, co-ordinate induction of AKRs was consistently observed following activation of NRF2. Immunohistochemical analysis of lung tumour biopsies and interrogation of TCGA data revealed that AKRs are enriched in both squamous cell carcinomas (SCCs) and adenocarcinomas that contain somatic alterations in the NRF2 pathway but, in the case of SCC, AKRs were also enriched in most other tumours. CONCLUSIONS: An AKR biomarker panel can be used to determine NRF2 status in tumours. Hyperactivation of the NRF2 pathway is far more prevalent in lung SCC than previously predicted by genomic analyses

Functional Polymorphisms Associated with Disease-Free Survival in Resected Carcinoma of the Esophagus

Purpose: The aim of this study was to determine whether clinical outcome after surgical resection of esophageal adenocarcinoma (EAC) or esophageal squamous cell carcinoma (ESCC) could be predicted by functional polymorphisms in different proto-oncogenes and tumor suppressor genes. Experimental De

Vitamin D and breast cancer: interpreting current evidence

Preclinical investigations and selected clinical observational studies support an association between higher vitamin D intake and 25-hydroxyvitamin D levels with lower breast cancer risk. However, the recently updated report from the Institute of Medicine concluded that, for cancer and vitamin D, the evidence was 'inconsistent and insufficient to inform nutritional requirements'. Against this background, reports examining vitamin D intake, 25-hydroxyvitamin D levels and breast cancer incidence and outcome were reviewed. Current evidence supports the pursuit of several research questions but not routine 25-hydroxyvitamin D monitoring and vitamin D supplementation to reduce breast cancer incidence or improve breast cancer outcome

Abstract ES13-3: Novel epigenomic targets in TNBC

Abstract Triple negative breast cancer is a heterogenous disease, characterized by a dearth of recurrent actionable genetic alterations. Epigenetic alterations have been implicated in the pathogenesis of triple negative breast cancer, as well as in the acquisition of drug resistance, which is a commonly observed phenomenon and persisting clinical challenge. An expanding array of tools for epigenomic characterization, together with novel selective inhibitors of epigenetic regulators are enabling new opportunities to identify and target these processes in triple negative breast cancer. Examples of recent and emerging therapeutic strategies using conventional therapies and epigenetic-targeted agents to exploit these vulnerabilities in triple negative breast cancer will be discussed. Citation Format: DW Cescon. Novel epigenomic targets in TNBC [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr ES13-3.</jats:p

Abstract P5-13-09: Feasibility of a Randomized Controlled Trial of Vitamin D vs. Placebo in Recently Diagnosed Breast Cancer Patients

Abstract Background: Vitamin D (Vit D) supplementation is an area of interest in the primary and secondary prevention of many cancers. We previously reported a high prevalence of Vit D insufficiency and deficiency in newly diagnosed breast cancer (BC) patients. Low Vit D levels were associated with poor BC outcomes. Here we evaluate the state of Vit D adequacy and supplementation in a more recently diagnosed cohort of BC patients from 2 large urban centres, and we examine the feasibility of a placebo-controlled randomized trial (RCT) of supplementation in this population. Patients and Methods: Women diagnosed with T1-3, N0-3, M0 invasive BC within the previous 2 years were prospectively identified from institutional registries and recruited from Mount Sinai Hospital, Toronto and UCLA, Los Angeles (LA), between March 2009 and January 2010. Anthropometric measurements were performed, and dietary, lifestyle and medication histories were obtained using structured questionnaires and interviews. Tumor and treatment characteristics were obtained from clinical records; blood samples were collected for analysis of Vit D levels. The pre-specified feasibility criteria for a Vit D (vs placebo) RCT were: ≥30% of patients with (i) deficient or insufficient Vit D levels, (ii) taking ≥1000 IU Vit D/day and (iii) willing to participate in such a trial. Results: 173 eligible patients were enrolled (80 Toronto, 93 LA). Median age at enrollment was 57 years; 73.4% were post-menopausal. Median tumor size (1.8 cm), lymph node involvement (39%), ER (80%), PR (65%) and Her2 (15%) positivity were similar between centres. Treatment characteristics including rates of mastectomy (44%), adjuvant chemotherapy (56%), radiation (68%), hormonal therapy (69%) and trastuzumab (14%) did not differ between centres. 84.4% of women reported use of Vit D containing supplements, with median daily doses of 1200 IU (Toronto) and 1400 IU (LA) (p=0.3) among users. Respective median 25-OH Vit D levels were 85.5 nmol/L (34.3 ng/mL) and 98.5 nmol/L (39.5 ng/mL) (p=0.04), and rates of deficiency, insufficiency and adequacy were 3.8%, 23.8%, 72.5% (Toronto) and 4.3%, 20.7%, 75.0% (LA) (p=0.88). No Vit D levels were in the toxic range. 25-OH Vit D levels correlated with Vit D supplement use (r=0.41, P&amp;lt;0.0001). 68% of women expressed willingness to participate in a Vit D RCT; however, only 12.7% of the study population met the pre-specified feasibility criteria. Conclusions: Vit D levels and supplementation rates are substantially higher in these BC patients than in previous cohorts, though more than 25% of women do not have adequate levels. Rates of adequacy did not differ between patients recruited in Toronto and LA. While the maj ority of women would be willing to participate in an RCT of Vit D supplementation, low levels of deficiency/insufficiency and high rates of supplement use may limit the feasibility of such a study. Funded by the Breast Cancer Research Foundation. Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P5-13-09.</jats:p

Abstract P5-12-02: Effect of 5 vs 2.5 mg/day letrozole on residual estrogen levels in post-menopausal women with high BMI - A prospective crossover study

Abstract Background: Some studies have suggested that women with high BMI have less benefit from aromatase inhibitors (AI) vs. tamoxifen as adjuvant treatment for early breast cancer. One possible mechanism for this observation is that complete suppression of estrogen is not achieved in these women with the standard flat dose of AI. We evaluated whether a doubling of letrozole to 5 mg/day for 4 weeks affected residual estrogen levels in this population. Methods: Post-menopausal women with early breast cancer and BMI&amp;gt;25 already taking adjuvant letrozole for at least 3 months were recruited from medical oncology clinics at 4 sites in Toronto, Canada. Fasting blood samples were collected 24 hours following the last dose at baseline (routine use of own letrozole), after 28 days of monitored adherence to a provided supply of letrozole (Femara) 2.5 mg/day (Part A), and after an additional 28 days of letrozole (Femara) 5 mg/day (Part B). Symptom/quality of life questionnaires were completed at the same timepoints. Estradiol and estrone were measured using a high sensitivity liquid chromatography-tandem mass spectrometry assay. One interim analysis for futility and efficacy was planned after 31 eligible patients had completed the study, using estradiol and O'Brien-Fleming boundaries with an inner wedge. Results: 36 patients were enrolled and started on study, and 31 eligible patients completed Parts A and B. The 5 non-completers withdrew because of adverse events (n=4, unlikely related to drug) or withdrawal of consent (n=1). Median age was 62 (range 48 to 77) and BMI 28.3 kg/m2 (Range 25.2 to 42.2 kg/m2). One patient had non-postmenopausal estrogen levels at Day 29 and Day 57 and one patient's blood assay was unsuccessful; both were excluded from further analyses. The predetermined stopping rule for futility was met. Estradiol levels (mean±standard deviation) changed from 2.68±0.40 pg/mL at baseline to 2.67±0.59 pg/mL at Day 29 to 2.70±0.53 pg/mL at Day 57. Mean change from Day 29 to Day 57 was 0.03±0.48 pg/mL (95% confidence interval -0.15 to 0.21 pg/mL). Four patients reported new or increased arthralgias (to NCI CTCAE Grade 2 or 3) while taking letrozole 5 mg/day in Part B. There was no association between changes in estradiol levels and either study non-completion or the development of arthralgias. Estrone results were similar. Conclusion: Increasing letrozole from 2.5 to 5 mg/day did not further suppress estrogen levels in women with BMI&amp;gt;25. It is unlikely that letrozole dosing tailored to body size would improve clinical outcomes. The letrozole 5 mg/day intervention was terminated based on the results of the interim analysis for futility. Citation Format: Cescon DW, Ennis M, Pritchard KI, Townsley C, Warr D, Elser C, Rao L, Stambolic V, Sridhar S, Goodwin PJ. Effect of 5 vs 2.5 mg/day letrozole on residual estrogen levels in post-menopausal women with high BMI - A prospective crossover study. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P5-12-02.</jats:p