Citations

Abstract Background: Microsatellite instability (MSI) and BRAF mutation status are associated with colorectal cancer survival, whereas the role of body mass index (BMI) is less clear. We evaluated the association between BMI and colorectal cancer survival, overall and by strata of MSI, BRAF mutation, sex, and other factors. Methods: This study included 5,615 men and women diagnosed with invasive colorectal cancer who were followed for mortality (maximum: 14.7 years; mean: 5.9 years). Prediagnosis BMI was derived from self-reported weight approximately one year before diagnosis and height. Tumor MSI and BRAF mutation status were available for 4,131 and 4,414 persons, respectively. Multivariable hazard ratios (HR) and 95% confidence intervals (CI) were estimated from delayed-entry Cox proportional hazards models. Results: In multivariable models, high prediagnosis BMI was associated with higher risk of all-cause mortality in both sexes (per 5-kg/m2; HR, 1.10; 95% CI, 1.06–1.15), with similar associations stratified by sex (Pinteraction: 0.41), colon versus rectum (Pinteraction: 0.86), MSI status (Pinteraction: 0.84), and BRAF mutation status (Pinteraction: 0.28). In joint models, with MS-stable/MSI-low and normal BMI as the reference group, risk of death was higher for MS-stable/MSI-low and obese BMI (HR, 1.32; P value: 0.0002), not statistically significantly lower for MSI-high and normal BMI (HR, 0.86; P value: 0.29), and approximately the same for MSI-high and obese BMI (HR, 1.00; P value: 0.98). Conclusions: High prediagnosis BMI was associated with increased mortality; this association was consistent across participant subgroups, including strata of tumor molecular phenotype. Impact: High BMI may attenuate the survival benefit otherwise observed with MSI-high tumors. Cancer Epidemiol Biomarkers Prev; 24(8); 1229–38. ©2015 AACR.

Objectives To determine event‐free survival after transcatheter closure of ventricular septal defect (VSD), and to identify predictors of adverse events (AE) in post myocardial infarction VSD (post‐MI VSD) subgroup. Background There are limited data on mid‐term follow‐up after transcatheter VSD closure. Methods Retrospective review of 27 cases of transcatheter VSD closure (post‐MI = 18 and non‐ischemic = 9) performed from 1999 to 2013. We defined AE as death, device embolization, hemolysis requiring blood transfusion, heart block and reintervention. Results In the post‐MI VSD subgroup, mean age and follow‐up was 69 ± 11 and 7.3 ± 7 years, respectively. AE occurred in 8 (44%) patients (death‐3, device embolization‐1, hemolysis‐1, surgical VSD closure‐2, reintervention‐1). Event‐free survival was 56% at 1 month and 5 years, and all AE occurred in the periprocedural period. Cardiogenic shock (HR: 3.21, CI: 1.82–5.41, P = 0.002), and VSD closure in acute phase (HR: 2.14, CI: 1.12–4.31, P = 0.004) were independent predictors of AE. In the non‐ischemic VSD subgroup, mean age and follow‐up was 49 ± 15 and 8.7 ± 8 years, respectively. AE occurred in 3 (33%) patients (late death‐1, surgical VSD closure‐2). For the entire cohort, freedom from death was 89% and 85% at 1 month and 5 years, and event‐free survival was 70% and 61% at 1 month and 5 years. Conclusions Transcatheter closure of post‐MI VSD carries a moderate risk of periprocedural complications but low event rates afterwards. By comparison, device closure of non‐ischemic VSD has lower periprocedural morbidity but some patients continued to experience AE during follow‐up. © 2015 Wiley Periodicals, Inc.

Abstract The clinical efficacies of molecularly targeted glioblastomas therapies have been vastly disappointing. The multitudes of resistance mechanisms suggest that glioblastomas possess highly dynamic molecular circuits grounded in functional redundancy. Emerging data suggests that the expression of functionally redundant oncogenes induced similar forms of cellular stress, requiring hyper-activation of common compensatory pathways to ensure cell viability. Targeting these pathways, therefore, afford potential opportunities for tumor ablation while by-passing the redundancy of oncogenic circuitry. To explore this paradigm, we carried out a siRNA screen to identify synthetic lethal partners of the oncogenic Epidermal Growth Factor Receptor variant III (EGFRvIII) in glioblastoma cells and identified Polo-Like Kinase 1 (PLK1). Treatment using a PLK1 inhibitor, BI2536, or siRNAs induced preferential toxicity to the EGFRvIII expressing glioblastoma cells in multiple in vitro (serum and neurosphere lines) and in vivo models (heterotopic and orthotopic xenograft models). Consistent with the heightened PLK1 requirement, EGFRvIII expressing glioblastomas harbored increased levels of the p-Thr210 PLK1 (an activated form of PLK1). Inhibition of PLK1 by BI2536 treatment induced an increase in the proportion of cells that co-stained for p-Histone H3 and γH2AX foci, suggesting accumulation of mitotic DNA damage. This effect was exacerbated by EGFRvIII expression, implicating induction of mitotic DNA damage as a major contributor to the observed synthetic lethality. Consistent with this observation, EGFRvIII expression induced the formation of aberrant mitosis as well as prolonged mitotic progression. Further supporting an essential role for PLK1 in suppressing DNA damage accumulation, BI2536 treatment significantly enhanced the tumoricidal effect of the DNA damaging chemotherapy, temozolomide. Mechanistically, inhibition of PLK1 suppressed the expression of Rad51, the accumulation of pS14 Rad51 (an active form of Rad51), as well as overall homologous recombination efficiency in vitro. We validated the clinical pertinence of these results using three clinically annotated glioblastoma databases (TCGA, REMEBMRANDT, CGGA). In all three datasets, increased expression of a PLK1 signature consistently associated with increased expression of HR genes and lowered gene expression signature associated with DNA damage accumulation. Supporting our proposed paradigm, the tumoricidal effect of BI2536 was universally observed in a panel of eight murine ink4a/arf (-/-) EGFRvIII expressing glioblastoma clones that developed resistance to EGFR inhibitors by distinct and independent mechanisms. In aggregate, our results support the essential role of PLK1 in suppressing mitotic DNA damage and provide a novel framework for glioblastoma therapy. Citation Format: Ying Shen, Masayuki Nitta, Jie Li, Diahnn Futalan, Tyler Steed, Zack Taich, Jeffrey M. Treiber, Deanna Stevens, Mark A. Schroeder, Jann N. Sarkaria, Hong-Zhuan Chen, Tao Jiang, Bob S. Carter, Fumiko Esashi, Jill Wakosky, Frank Furnari, Webster K. Cavenee, Arshad Desai, Clark C. Chen. Modulation of mitotic DNA damage as a paradigm for glioblastoma therapy. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 2737. doi:10.1158/1538-7445.AM2014-2737

Abstract Background: Mammographic breast density (MBD) reflects the proportion of fibroglandular tissue in the breast, and is an established risk factor for breast cancer. Benign breast disease (BBD) is also a known risk factor for breast cancer. We previously showed an association between lobular involution (physiologic atrophy) and MBD in a large cohort study of women with BBD. We performed a comprehensive evaluation of the association of histologic features of BBD with MBD. Methods: The Mayo BBD cohort includes women, 18 to 85 years, who were diagnosed with BBD at Mayo Clinic in Rochester, MN between 01/01/1967 and 12/31/1991. For this study, we included women who had a mammogram within 6 months of BBD diagnosis, and diagnosed with BBD between 1985 and 1991 when parenchymal pattern of breast density was clinically recorded. Risk factor information such as age, and body mass index (BMI) was collected from medical records. Parenchymal pattern, assessed clinically and previously used in multiple studies of MBD and risk, classified breast density based on extent and type of density, into four categories: N1 (non-dense, no ducts visible); P1 (ductal prominence occupying <25% breast); P2 (prominent ductal pattern occupying >25% of the breast; DY (homogenous plaque-like areas of density). All assessments of benign breast tissue were performed by expert breast pathologists blinded to both MBD and BBD reports. Histologic characteristics included overall impression (non-proliferative disease (NPD), proliferative disease without atypia (PDWA), and atypical hyperplasia (AH)), proportion of normal lobules that were involuted (no (0%), partial (1 to 74%), or complete (≥75%)), type of AH (ADH or ALH), ductal and lobular hyperplasia, calcifications, sclerosing adenosis, columnar alteration, cyst, fibroadenoma, marked fibrosis, intra-ductal papilloma, radial scar (number and size), duct ectasia, and mucocele like tumors. Associations of parenchymal pattern with BBD characteristics were examined using multicategorical nominal logistic regression models. We first examined associations after adjustment for age and BMI. All variables statistically significant (p<0.05) in these models were then simultaneously included in a fully-adjusted model. Results: Of 2,257 women in the study, 14% were <40 years old, 52.7% between 40- 59 years, and 32.9% were ≥60 years. In this sample, 55.2% of women had NPD, 36% had PDWA, and AH in 8.8%. MBD was classified as N1 in 21.8%, P1 in 12.6%, P2 in 23.7% and DY in 41.9%. Age- and BMI-adjusted analyses showed that there was an association of parenchymal pattern with overall impression, lobular involution, ductal hyperplasia, sclerosing adenosis, columnar alteration, cyst, duct ectasia and fibrosis. Multivariate analyses found that women of younger age (p<0.001) and with lower BMI (p<0.001), presence of fibrosis (p<0.001) and no involution (p=0.016) were more likely to have P2 or DY parenchymal pattern than women without those characteristics. Conclusion: Among women with benign breast disease, higher MBD is associated with younger age, lower BMI, fibrosis, and lack of lobular involution. These findings, concordant with other studies of MBD, provide insight into underlying mechanisms by which MBD and BBD contribute to breast cancer risk. Citation Format: Karthik Ghosh, Robert A Vierkant, Ryan D Frank, Daniel W Visscher, Vernon S Pankratz, Christopher G Scott, Derek C Radisky, Marlene H Frost, Lynn C Hartmann, Amy C Degnim, Celine M Vachon. Association between mammographic breast density and histologic features of benign breast disease [abstract]. In: Proceedings of the Thirty-Seventh Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2014 Dec 9-13; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2015;75(9 Suppl):Abstract nr P6-10-14.

Abstract Introduction: Current models to predict breast cancer risk do not differentiate risk for estrogen receptor (ER) positive and negative breast cancer (BC), despite growing evidence that these tumors are biologically very different. We hypothesized that women with ER+ BC cancers have different clinical risk factors and histologic findings on prior benign breast biopsies than those with ER- BC. Methods: After IRB approval, we examined associations of age at benign biopsy and histologic features of the benign biopsy with ER status of incident BCs within the Mayo Benign Breast Disease Cohort. Benign biopsy slides were reviewed for extent of lobular involution and degree of epithelial proliferation by a single breast pathologist blinded to BC events. Invasive BCs occurring within 15 years after benign biopsy were classified as ER+ if ER staining was >1%. BC case-only associations with ER status were evaluated using multivariate logistic regression. Full-cohort hazard ratios (HR) and 95% confidence intervals (CI) for risk of ER-specific subtypes were estimated using Cox proportion hazards regression. Results: Among 13,410 women undergoing a benign breast biopsy from 1967-2001, 656 invasive BCs (459 ER+, 106 ER, 106 unknown) occurred within 15 years. Women who developed ER+ and ER- BCs were similar in age at the time of their prior benign breast biopsy (p=0.34). Although benign biopsies in women who later developed ER+ BC were more likely to show complete involution (23% vs 15% for ER- BC), this was not statistically significant (p=0.06). However, the degree of epithelial proliferation was significantly associated with ER status of later BCs (p=0.001), with ER+ BCs more likely than ER- BCs to have had a prior biopsy with atypical hyperplasia (16% vs 8%), and ER+ BCs less likely than ER- BCs to have had a prior biopsy with proliferative disease without atypia (33% vs 52%); this association remained after multivariate adjustment (p=0.003). We further pursued the association of epithelial proliferation with differential risk of ER+ and ER- BC in our overall cohort of 13,410 women (Table 1). Compared to women with non-proliferative disease, women with proliferative disease +/- atypia had ∼2-fold hazard ratios for ER- BC, whereas hazard ratios for ER+ BC were higher in women with atypical hyperplasia (∼4-fold) compared to proliferative disease. Hazard Ratio of ER+ and ER- BC within 15 years of BBD based upon degree of epithelial proliferation at benign biopsyCancer TypeGroupNN EventsHazard Ratio (95% CI)p-valueInvasive ER- ≤15 yearsNP8478421.00 (ref)<0.0001 PD4229542.63 (1.76, 3.93) AH70382.60 (1.22, 5.54) Invasive ER+ ≤15 yearsNP84782321.00 (ref)<0.0001 PD42291511.33 (1.09, 1.64) AH703744.41 (3.39, 5.73) NP=nonproliferative disease, PD=proliferative disease without atypia; AH=atypical hyperplasia Conclusion: ER+ and ER- breast cancers appear to have different features on prior benign breast biopsy, with atypical hyperplasia showing increased risk for both types of breast cancer, but a greater risk for ER+ tumors. Citation Format: Amy C Degnim, Derek C Radisky, Robert A Vierkant, Ryan D Frank, Marlene H Frost, Vernon S Pankratz, Celine M Vachon, Tanya L Hoskin, Julie M Cunningham, Chen Wang, Jean-Pierre Kocher, Teresa M Allers, Joanne L Johnson, Tina J Hieken, Karthik Ghosh, Lynn C Hartmann, Daniel W Visscher. Histologic features of benign breast biopsy tissue and association with ER positive and ER negative breast cancer in the Mayo BBD cohort study [abstract]. In: Proceedings of the Thirty-Seventh Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2014 Dec 9-13; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2015;75(9 Suppl):Abstract nr P6-10-06.

Abstract Background: Although breast cancer (BC) may occur at any age, its prevalence is greater postmenopause. Greater than 75 % of postmenopausal BCs are hormone dependent. Aromatase inhibitors suppress postmenopausal estrogen biosynthesis. Letrozole has demonstrated efficacy against BC in the adjuvant and metastatic setting at the treatment dose of 2.5 mg daily. Its potential role in BC prevention has been inferred from reductions in contralateral BCs. Its side effect profile, similar to other AIs, includes exacerbation of menopausal symptoms that negatively impact quality of life (QOL) and may result in discontinuation of the drug. Both anastrazole and exemestane have been demonstrated to reduce BC in high-risk women. Hypothesis: Lower and intermittent doses of letrozole effectively suppress estrogen in the high-risk postmenopausal woman and provide a better side effect profile. Methods: A randomized, double-blind study comparing the impact of varying letrozole doses (2.5 mg daily, 2.5 mg MWF, 1.0 mg MWF, or 0.25 mg MWF) on estrogen suppression and side effects--lipids, bone resorption, menopause, and QOL-- was conducted. Participants randomized to intermittent dosing received placebo on nontreatment days. Results: 112 participants were enrolled at 2 clinical sites. Mean patient age was 62.8 years, and average BMI was 29.8. Analysis of available data after 24 weeks of therapy revealed statistically significant increase in triglycerides (N=94): 114.67±48.39 to 125.79±54.31 (p<0.01); vasomotor symptoms (N=95): 2.25±1.26 to 2.74±1.67 (p<0.01); and C-telopeptide (N=75): 0.39±0.23 to 0.55±0.28 (p<0.0001). Statistically significant decrease in estradiol (N=68): 5.57±5.19 to 1.26±1.41 (p<0.0001) and estrone (N=68): 22.39±13.02 to 1.64±2.66 (p<0.0001) were observed. No differences in QOL (SF 36) were noted after letrozole treatment. P-values were derived from paired t-test (signed rank test) for the difference between baseline and after 24 weeks of study drug. Conclusions: De-escalating doses of letrozole suppress postmenopausal estrogen effectively and result in statistically significant increases in triglycerides, C-telopeptide and vasomotor symptoms without impact on QOL. Presentation will include unblinded intervention arm outcomes. Citation Format: Ana Maria Lopez, Hsiao Hui Sherry Chow, Denise Frank, Sandhya Puthi, Judy Boughey, Paul Hsu, Jose Guillen, Marjorie Perloff, Michelle Ley, Julie E Lang. De-escalating doses of letrozole in post menopausal women at high risk for breast cancer [abstract]. In: Proceedings of the Thirty-Seventh Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2014 Dec 9-13; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2015;75(9 Suppl):Abstract nr P5-12-04.