Citations

Abstract Background: Obesity has been associated with risk of non-Hodgkin lymphoma (NHL) in several recent studies. However, the effect of weight gain during adulthood, a potentially modifiable risk factor, on the incidence of NHL is not clear. We therefore examined the association of weight gain since age 18 years with the risk of NHL among older women. Methods: We examined this association in the Iowa Women’s Health Study, a prospective study of 37,762 Iowa women aged 55 to 69 years at enrollment in 1986. Lifestyle and other risk factors, including weight at age 18 and at enrollment, were self-reported on a mailed questionnaire. We defined stable weight as no increase in weight or up to a 10% weight loss from age 18 to enrollment, while percent weight gain was divided into tertiles based on the distribution observed in the cohort. NHL incidence through 18 years of follow-up was ascertained by linkage with the Iowa SEER Cancer Registry. Cox proportional hazards models were used to estimate relative risks (RRs) and 95% confidence intervals (CIs) of percent weight gain with NHL incidence, adjusting for age (Age-adjusted model) and age, marital status, farm residence, transfusion history, diabetes, use of hormone replacement therapy, alcohol use, smoking, and intake of red meat and fruits (Multivariate model). Results: The mean age of the women in the cohort in 1986 was 62.1 years. During 593,474 person-years of follow-up, 379 incident cases of NHL were observed. The mean age at diagnosis was 72.6 years (range 58–87 years). The main results are reported in the table. Similar results were found for absolute weight gain. Stratification of these results on body mass index at age 18 (using a cutpoint of 21 kg/m2) showed similar results, with the exception of >10% weight loss for women with a BMI of <21 at age 18 where we could not estimate a RR (no cases observed). Conclusions: Weight gain or large weight loss (>10% of body weight) during adulthood were both associated with increased risk of NHL, although the RRs for percent weight gain were not statistically significant and there was no dose-response. This study suggests another potential benefit of avoiding adult weight gain, although further studies are needed to confirm these novel findings. Association of percent weight change during adulthood (age 18 to age 55–69 years) and risk of NHL % Weight Change NHL Cases Person-years Age-Adjusted RR(95% CI) Multivariate RR (95% CI) >10% weight loss 15 17053 2.06 (1.05–4.02) 2.02 (1.03–3.95) Stable 20 45973 1 (reference) 1 (reference) 0–18.2% gain 115 175883 1.50 (0.94–2.42) 1.50 (0.93–2.41) 18.3–34.8% gain 119 176258 1.54 (0.96–2.47) 1.53 (0.95–2.47) >34.8% gain 110 178308 1.40 (0.87–2.25) 1.32 (0.82–2.14).

Abstract Abstract 684 Background. Obesity has been associated with an increased risk of developing of lymphoma, particularly DLBCL. Genetic variation in several energy balance genes, including leptin (LEP), its receptor LEPR, ghrelin (GHRL) and neuropeptide Y (NPY) have been shown to modulate risk of lymphoma, although their impact on survival is not known. In contrast, recent studies suggest that patients either overweight (Body Mass Index (BMI), 25 to<30 kg/m2) or obese (≥30 kg/m2) may have a superior prognosis in DLBCL, although its impact in FL and in the current treatment era is not known. We evaluated the association of BMI at the time of diagnosis, 2 years prior to diagnosis and at ages 18, 35 and 50 years, along with germline genetic variation in selected energy balance genes with event-free (EFS) and overall (OS) survival in DLBCL and FL. Methods. We evaluated these associations in a prospective cohort of newly diagnosed DLBCL (N=764) and FL (N=649) patients enrolled at the Mayo Clinic and University of Iowa from 2002–2009 as part of the Molecular Epidemiology Resource. Peripheral blood DNA, clinical data and self-reported historical weights were collected at enrollment. Patients received standard disease treatment strategies, and were systematically followed for disease progression, re-treatment, and death. Single nucleotide polymorphisms (SNPs) were genotyped as part of a custom Illumina iSelect panel. The most prevalent homozygous genotype was used as the reference group, and each SNP was modeled as having a log-additive effect in the regression model. Cox proportional hazards regression was used to estimate hazard ratios (HRs) and 95% confidence intervals (CI) for the association of the obesity measures and SNPs with outcome, adjusted for treatment class and subtype specific prognostic factors (IPI, FLIPI). Results. For DLBCL patients (median age 63 years, range 18–92) the median follow-up was 47 months (range 0–101); 58% had an IPI 0–1 risk disease; and 87% received immunochemotherapy. For FL patients (median age 60 years, range 25–94), the median follow-up was 60 months (range 11–110); 24% had FLIPI score 3–5; and main initial treatments were observation (32%), rituximab (R)-monotherapy (12%), CVP +/−R (19%), and anthracycline +/−R (22%). The main results for BMI and prognosis are reported in the Table. For DLBCL, obese patients at diagnosis had better EFS and OS; this association was weaker for BMI at age 50 and 35 years. In contrast, for FL, overweight and obese patients at diagnosis had a poorer EFS and OS, and this was also observed for BMIs two years before diagnosis and at ages 50 and 35 years. In FL, the LEP SNP rs2167270 was associated with inferior EFS (HR=1.25; 95%CI 1.05–1.49) and OS (HR=1.28; 95%CI 0.90–1.83). The NPYSNP rs16147 was associated with inferior FL OS (HR=1.50; 95%CI 1.03–2.17) but was not associated with EFS. None of the energy balance and metabolism SNPs were associated with DLBCL EFS or OS. Conclusions. Higher BMI prior to and at diagnosis, as well as SNPs in LEP and NPY,were significantly associated with FL prognosis, with inferior outcomes in overweight and obese patients. These novel findings in the modern treatment era suggest an important role of obesity pathways in FL prognosis. In DLBCL, we confirm the recent findings of improved survival in DLBCL in obese patients, and extend this to the modern treatment era and BMI earlier in life. Disclosures: No relevant conflicts of interest to declare.

Abstract Background: Different molecules within coffee may be pro-carcinogenic, while others may have anti-oxidant and anti-neoplastic effects. Hence, it can be hypothesized that coffee may have differing risk associations with specific colorectal cancer (CRC) subtypes. The aim of this study was to evaluate associations between coffee consumption and incident CRC overall, by anatomic subsite, and by molecularly defined tumor subtypes, in the population-based Iowa Women's Health Study (IWHS). Methods: IWHS participants, ages 55-69 years, provided dietary intake estimates using self-reported food frequency questionnaires at baseline (1986). From 35,216 women included the final analysis, 1298 developed CRC (673 with proximal CRC, 597 with distal CRC) through December 31, 2002 (end of the IWHS molecular epidemiology project study period). Archived, paraffin-embedded tissue specimens for 732 representative CRC cases were collected and analyzed to determine if coffee consumption (none or &lt;1 cup/month, &lt;1 cup/week, 1 cup/day, 2-3 cups/day and ≥4 cups/day) was associated with microsatellite instability (MSI-L/MSS or MSI-H), CpG island methylator phenotype (CIMP-negative or CIMP-positive), BRAF mutation status (BRAF-wildtype or BRAF-mutated), KRAS mutation status (KRAS-wildtype and KRAS-mutated), p53 protein expression level (p53 absent, low or high) and estrogen receptor β protein expression level (ERβ absent, low or high). Multivariable Cox regression models were fit to estimate relative risks (RR) and 95% confidence intervals (CI) with adjustment for age, smoking, alcohol use, diabetes, body mass index and waist-hip ratio, physical activity, estrogen use, dietary intake of fat, calcium, vitamin E, sucrose, red meat and methionine. P-values were not adjusted for multiple testing. Results: There was no significant difference in the risk of overall (RR, 1.05; 95% CI, 0.85-1.29; Ptrend=0.50), proximal (RR, 0.91; 95% CI, 0.68-1.21; Ptrend=0.57) or distal CRC (RR, 1.18; 95% CI, 0.86-1.64; Ptrend=0.19) in women who consumed ≥4 cups of coffee/day (caffeinated or decaffeinated), as compared to non-consumers. By CRC molecular subtypes for these same two exposure groups, women with ≥4 cups of coffee/day were more likely to develop ERβ-low CRC (RR, 2.98; 95% CI, 1.04-8.51; Ptrend=0.06), though no significant associations were observed for caffeinated or decaffeinated coffee specifically. In contrast, women who consumed ≥4 cups of decaffeinated coffee/day were less likely to develop MSI-L/MSS (RR, 0.57; 95% CI, 0.36-0.92; Ptrend=0.04) and BRAF-WT (RR, 0.69; 95% CI, 0.44-1.06; Ptrend=0.06) CRCs than non-consumers. Women who consumed ≥4 cups of caffeinated coffee/day were also less likely to develop p53-low CRCs (RR, 0.53; 95% CI, 0.24-1.15; Ptrend=0.02). Null associations were observed between decaffeinated coffee consumption and risk of CIMP-, KRAS- and p53- defined CRC subtypes, as well as between caffeinated coffee consumption and risk of MSI-, BRAF-, CIMP- or KRAS-defined CRC subtypes. Conclusion: In this prospective cohort study of older women, though coffee consumption was not associated with risk of overall or site-specific CRC, unique associations were observed with molecularly defined CRC subtypes, supporting a need for further investigation of the potential pro- and anti-carcinogenic effects of coffee constituents on biologic targets involved in colorectal carcinogenesis. Citation Format: Siddharth Singh, Robert Vierkant, Lori Tillmans, Alice Wang, Daniel Weisenberger, Peter Laird, Maki Inoue-Choi, Andrea Mariani, Charles Lynch, Kristin Anderson, Amy French, Robert Haile, Lisa Harnack, John Potter, Susan Slager, Thomas Smyrk, Stephen Thibodeau, James Cerhan, Paul Limburg. Coffee consumption and colorectal cancer risk by molecularly defined subtypes in a prospective cohort study of older women. [abstract]. In: Proceedings of the Twelfth Annual AACR International Conference on Frontiers in Cancer Prevention Research; 2013 Oct 27-30; National Harbor, MD. Philadelphia (PA): AACR; Can Prev Res 2013;6(11 Suppl): Abstract nr A44.

Objective To assess stroke/systemic embolism, major bleeding and other outcomes, and treatment effect of apixaban versus warfarin, in patients with atrial fibrillation (AF) and different types of valvular heart disease (VHD), using data from the Apixaban for Reduction in Stroke and Other Thromboembolic Events in Atrial Fibrillation trial. Methods There were 14 793 patients with known VHD status, categorised as having moderate or severe mitral regurgitation (MR) (n=3382), aortic regurgitation (AR) (n=842) or aortic stenosis (AS) (n=324); patients with moderate or severe mitral stenosis were excluded from the trial. Baseline characteristics, efficacy and safety outcomes were compared between each type and no significant VHD. Treatment effect was assessed using an adjusted model. Results Patients with MR or AR had similar rates of stroke/systemic embolism and bleeding compared with patients without MR or AR, respectively. Patients with AS had significantly higher event rates (presented as rate per 100 patient-years of follow-up) of stroke/systemic embolism (3.47 vs 1.36; adjusted HR (adjHR) 2.21, 95% CI 1.35 to 3.63), death (8.30 vs 3.53; adjHR 1.92, 95% CI 1.41 to 2.61), major bleeding (5.31 vs 2.53; adjHR 1.80, 95% CI 1.19 to 2.75) and intracranial bleeding (1.29 vs 0.51; adjHR 2.54, 95% CI 1.08 to 5.96) than patients without AS. The superiority of apixaban over warfarin on stroke/systemic embolism was similar in patients with versus without MR (HR 0.69, 95% CI 0.46 to 1.04 vs HR 0.79, 95% CI 0.63 to 1.00; interaction P value 0.52), with versus without AR (HR 0.57, 95% CI 0.27 to 1.20 vs HR 0.78, 95% CI 0.63 to 0.96; interaction P value 0.52), and with versus without AS (HR 0.44, 95% CI 0.17 to 1.13 vs HR 0.79, 95% CI 0.64 to 0.97; interaction P value 0.19). For each of the primary and secondary efficacy and safety outcomes, there was no evidence of a different effect of apixaban over warfarin in patients with any VHD subcategory. Conclusions In anticoagulated patients with AF, AS is associated with a higher risk of stroke/systemic embolism, bleeding and death. The efficacy and safety benefits of apixaban compared with warfarin were consistent, regardless of presence of MR, AR or AS. Clinical trial registration ARISTOTLE clinical trial number NCT00412984.

Background— Diabetes mellitus (DM) adversely affects morbidity and mortality for cardiovascular diseases and procedures. Data evaluating the outcomes of transcatheter aortic valve replacement (TAVR) in diabetic patients are limited by small sample size and contradictory results. We aimed to establish the magnitude of risk and the incremental influence of insulin dependency by examining short- and long-term adverse outcomes according to DM status and therapy in the world’s largest TAVR registry. Methods and Results— We analyzed data from the Society of Thoracic Surgeons/American College of Cardiology Transcatheter Valve Therapy Registry. In-hospital mortality, 30-day mortality, and 1-year mortality after TAVR in patients with and without DM were evaluated using multivariate modeling. Among 47 643 patients treated with TAVR from November 2011 through September 2015 at 394 US hospitals, there were 17 849 (37.5%) patients with DM. Overall, 6600 of the diabetic patients were insulin treated (IT). Thirty-day mortality was 5.0% in patients with DM (6.1% in IT DM and 4.4% in non-IT DM; P <0.001) versus 5.9% in patients without DM ( P <0.001). Overall, 1-year mortality was 21.8% in patients with DM (24.8% in IT DM and 20.1% in non-IT DM; P <0.001) versus 21.2% in patients without DM ( P =0.274). In a multivariable model, DM was associated with increased 1-year mortality (hazard ratio, 1.30; 95% confidence interval, 1.13–1.49; P <0.001). Subgroup multivariable analysis showed stronger mortality association in IT diabetics (hazard ratio, 1.57; 95% confidence interval, 1.28–1.91; P <0.001) than in non-IT diabetics (hazard ratio, 1.17; 95% confidence interval, 1.00–1.38; P =0.052). Conclusions— Our data establish the magnitude of short- and long-term risk conferred by DM and the incremental risk conferred by insulin dependency in the performance of TAVR. Clinical Trial Registration— URL: https://www.clinicaltrials.gov . Unique identifier: NCT01737528.

AbstractBackground: Hormonal and reproductive history has been associated with risk of some hematologic malignancies, but their role in myeloproliferative neoplasms (MPN) is largely unknown.Methods: Using a population-based cohort study, we evaluated the association of these factors with risk of MPN overall, and for essential thrombocythemia (ET) and polycythemia vera (PV) specifically. Incident MPN cases from 1993 to 2004 were identified via linkage to Medicare. RR and 95% confidence intervals (CI) were estimated utilizing Cox proportional hazard regression.Results: After &gt;250,000 person-years of follow-up, 257 cases of MPN were identified (172 ET, 64 PV). Ever use of hormone therapy (HT) was associated with an increased risk of ET (RR = 1.63; 95% CI, 1.19–2.23) but a decreased risk of PV (RR = 0.58; 95% CI, 0.34–0.98). There were no statistically significant associations of oral contraceptives or reproductive factors with MPN risk overall, or by MPN subtype. Bilateral oophorectomy was associated with increased risk of ET (RR = 1.58; 95% CI, 1.11–2.25) and decreased risk of PV (RR = 0.32; 95% CI, 0.12–0.88). There was no association of ovulatory years with ET risk; however, there was increased risk of PV (RR = 1.68 for &gt;36.8 compared with ≤27.6 years; P trend = 0.045). Adjustment for potential confounding factors did not alter these associations.Conclusions: HT use and bilateral oophorectomy had opposite associations for ET and PV. Except for ovulatory years and PV risk, reproductive history did not appear to play a role in the etiology of MPN.Impact: This study suggests different mechanistic impacts of estrogen, and perhaps distinct etiologies, for the two major MPN subtypes. Cancer Epidemiol Biomarkers Prev; 25(1); 151–7. ©2015 AACR.

Abstract Background: The standard treatment for epithelial ovarian cancer (EOC) patients with advanced disease is initial debulking surgery followed by carboplatin-paclitaxel combination therapy. Unfortunately, even with modern chemotherapy, most patients with advanced disease relapse and die of EOC. One of the biggest challenges in the treatment of EOC is the large inter-patient variation in clinical response and toxicity observed for taxane and platinum therapies. Purpose: To determine pharmacogenomic markers related to carboplatin-paclitaxel therapy with 33 Epstein-Barr virus (EBV) transformed lymphoblastoid cell lines (LCLs) derived from EOC patients for which genome-wide genetic information exists. Methods: The 33 LCLs were treated with increasing concentrations of carboplatin and/or paclitaxel, followed by MTT cytotoxicity and Caspase3/7 assays. Using the measurements of MTT absorbance or Caspase3/7 fluorescence, dose response curves were fit to estimate the in vitro drug response (MTT or caspase3/7) for each LCL and treatment (paclitaxel, carboplatin, and combination) using the inflection point of the fitted curve (i.e.., the MTT IC50 or effective dose that kills 50% of the cells). The six in vitro phenotypes where then associated with genome-wide SNP data, imputed up to the markers in the 1000 Genomes Project. Results: Genetic association analysis of carboplatin, paclitaxel and combination therapy cell viability, as measured by MTT, found one SNP, rs202167095 within HS3ST4, in common with all three phenotypes (p &lt; 0.0001). HS3ST4 is regulated by TRF2 and activates natural killer cells. Furthermore, TRF2 maintains telomere integrity and is involved in activating DNA damage response (DDR) pathway.. Similarly, three SNPs were found to be associated with the three Caspase3/7 activities: SNPs on chromosome 3 (rs13098237 and rs13098239), and a SNP on chromosome 10 (rs138004421 within LINC00858). Lastly, SNPs in the following genes were associated with carboplatin IC50 with p &lt; 1x10-6 (i.e., the top associated SNPs with any drug response phenotype): JAKMIP3 (p=2.3x10-7), TSHZ3 (p = 4.9x10-7) and TGFA (p=3.6x10-7). JAKMIP3 has been implicated in some cancers and interacts with other janus kinases and JAK-STAT pathways, while TSHZ3 inhibits the expression of CASP4, thus limiting cell apoptosis. Lastly, TGFA codes for a growth factor that is a ligand for epidermal growth factor receptor, which activates a signaling pathway for cell proliferation, differentiation and development. Conclusions: Identifying genetic loci associated with response to platinum-taxane therapies will ultimately improve clinicians' ability to tailor therapy decisions for EOC patients. This research discovered novel candidate genes for which further research is needed to understand the mechanism by which they impact clinical response. Citation Format: Brooke L. Fridley, Taraswi M. Ghosh, Alice Wang, Ellen L. Goode, Jatinder Lamba. In vitro pharmacogenomic study of ovarian cancer finds novel genetic variants associated with response to platinum and taxane therapies. [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 5565. doi:10.1158/1538-7445.AM2014-5565

Abstract Background: Cigarette smoking (smoking), hormone therapy (MHT), and folate intake (folate) are each thought to influence colorectal cancer risk, but the underlying molecular mechanisms remain incompletely defined. Expression of estrogen receptor β (ESR2) has been associated with colorectal cancer stage and survival. Methods: In this prospective cohort study, we examined smoking, MHT, and folate-associated colorectal cancer risks by ESR2 protein expression level among participants in the Iowa Women's Health Study (IWHS). Self-reported exposure variables were assessed at baseline. Archived, paraffin-embedded colorectal cancer tissue specimens were collected and evaluated for ESR2 protein expression by IHC. Multivariate Cox regression models were fit to estimate relative risks (RR) and 95% confidence intervals (CI) for associations between smoking, MHT, or folate and ESR2-defined colorectal cancer subtypes. Results: Informative environmental exposure and protein expression data were available for 491 incident colorectal cancer cases. Positive associations between ESR2-low and -high tumors and several smoking-related variables were noted, most prominently with average number of cigarettes per day (RR, 4.24; 95% CI, 1.81–9.91 for ESR2-low and RR, 2.15; 95% CI, 1.05–4.41 for ESR2-high for ≥40 cigarettes compared with nonsmokers). For MHT, a statistically significant association with ESR2-low tumors was observed with longer duration of exposure (RR, 0.54; 95% CI, 0.26–1.13 for &gt;5 years compared with never use). No associations were found for folate. Conclusions: In this study, smoking and MHT were associated with ESR2 expression patterns. Impact: These data support possible heterogeneous effects from smoking and MHT on ERβ-related pathways of colorectal carcinogenesis in older women. Cancer Epidemiol Biomarkers Prev; 24(4); 713–9. ©2015 AACR.

Abstract Background: Hormone therapy (HT) may prevent colorectal cancer (CRC), but the molecular mechanisms have not been fully defined. Expression of estrogen receptor beta (ERβ) has been associated with CRC stage and survival and may influence HT-related prevention pathways. In this prospective cohort study, we examined HT-associated CRC risk by ERβ protein expression levels in the population-based Iowa Women's Health Study (IWHS). Methods: The IWHS recruited 41,836 randomly selected Iowa women, ages 55-69 years, with a valid driver's license at study entry (1986). Exposure variables were assessed at baseline, by self-report. Incident CRC cases were ascertained by annual linkage with the Iowa Cancer Registry. Archived, paraffin-embedded tissue specimens were collected from 732 CRC cases, diagnosed through 12/31/2002, for molecular epidemiology studies. HT was categorized as never, former, and current and with durations of &lt;=5 years or &gt;5 years. ERβ protein expression was determined by immunohistochemistry on tissue microarrays. For each tumor core, both staining intensity (0-3) and proportion of cells stained (0-5) were scored. These two scores were added to determine negative (0), low (1-5) or high (6-8) ERβ protein expression levels. Multivariate Cox regression models were fit to estimate relative risks (RRs) and 95% confidence intervals (CIs). Results: Complete HT and ERβ data were available from 484 CRC cases. Associations between HT and CRC subtypes defined by ERβ expression level are shown in the Table. Conclusions: Data from the IWHS cohort suggest that current and longer-duration HT exposure favorably influence the risk for ERβ-neg or ERβ-low CRC cases to a greater degree than ERβ-high CRC cases. Further investigation is required to confirm these observations, and to clarify the underlying mechanisms. ERβ Neg or Low ERβ High Hormone Therapy Person years Events, N RR* (95% CI) Events, N RR* (95% CI) Never 341377 128 1.00 (Ref.) 196 1.00 (Ref.) Ever 212696 62 0.74 (0.54,1.03) 98 0.82 (0.63,1.07) Former 151535 48 0.79 (0.56,1.12) 67 0.73 (0.54,0.99) Current 61161 14 0.60 (0.33,1.09) 31 1.11 (0.74,1.64) P-trend 0.05 0.52 Duration &lt; = 5yrs 148704 47 0.84 (0.59,1.19) 68 0.80 (0.60,1.08) &gt;5yrs 60064 14 0.5 (0.26,0.93) 28 0.89 (0.59,1.34) P-trend 0.03 0.25 Citation Format: Lori S. Tillmans, Robert A. Vierkant, Alice H. Wang, Charles F. Lynch, Kristin E. Anderson, Amy J. French, Robert W. Haile, John D. Potter, Susan L. Slager, Thomas C. Smyrk, Stephen N. Thibodeau, James R. Cerhan, Paul J. Limburg. Hormone therapy and incident colorectal cancer risk by ER beta protein expression level in a population-based cohort of older women. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 3652. doi:10.1158/1538-7445.AM2013-3652

Abstract Background: Essential thrombocythemia (ET), polycythemia vera (PV) and myelofibrosis (MF) are collectively classified as myeloproliferative neoplasms (MPN). Given that little is known about their etiology, we investigated the role of anthropometric, medical and lifestyle factors in the development of MPNs and the common subtypes (ET & PV) in a population-based cohort of women. Methods: The IWHS is a prospective cohort of Iowa women aged 55-69 years at enrollment in 1986. Participants completed 6 self-administered questionnaires between 1986-2004. This analysis includes 27370 women who completed the 1993 questionnaire, had no history of cancer, and were enrolled in Medicare at least 1 year. MPN cases through 2004 were identified by linkage to Medicare. Relative risks (RR) and 95% confidence intervals (CI) were estimated using Cox proportional hazard regression, with age as the underlying time variable. Results: After &gt;250,000 person-years of follow-up, 257 cases of MPNs were identified (172 ET, 64 PV and 21 MF). Height, body mass index (BMI) and waist-to-hip ratio were not associated with risk of MPN. In subtype analysis, BMI was positively associated with risk of ET (RR=1.52 for &gt;29.3 vs &lt;23.5 kg/m2; p-trend=0.042) but not PV. Physical activity (PA) showed a suggestive association with MPN (RR=0.74 for high vs low activity; p-trend=0.063), specific only to ET (RR=0.66; p-trend=0.04). Diabetes (DM) was positively associated with risk of MPN (RR=1.51; 95% CI 1.02-2.24), also specific only to ET (RR=1.82; 95% CI 1.16-2.84). Regular use of aspirin, but not other non-steroidal anti-inflammatory agents, was associated with a lower risk of MPN (RR=0.71; 95% CI 0.55-0.92); slightly stronger for ET (RR=0.68; 95% CI 0.50-0.93) than for PV (RR=0.84; 95% CI 0.50-1.43). There was no dose-response with frequency of use. Cigarette smoking was associated with risk of MPN, which was stronger for PV (RR=0.94 for former and RR=2.83 for current; p-trend=0.016) than for ET (RR=1.28 for former and RR=1.32 for current; p-trend=0.15). There were no associations with alcohol use. In a multivariate model for ET, the associations for BMI (RR=1.28; p-trend=0.21) and DM (RR=1.51; 95% CI 0.92-2.46) attenuated, while there was little change for PA (RR=0.66; p-trend=0.062) or aspirin use (RR=0.70; 95% CI 0.51-0.96). In PV, there was little impact on the association with smoking (RR=0.92 for former and RR=2.67 for current; p-trend=0.028) after adjustment for BMI, PA, DM and aspirin use. Conclusions: Risk factors were unique to the 2 most common types of MPN. ET was associated with obesity-related factors (PV was not), and PV was associated with current smoking (ET was not). Aspirin use had a stronger inverse association for ET. Our results suggest distinct etiologies of these PMN subtypes, and raises mechanistic hypotheses related to inflammation for ET and smoking-related carcinogenic pathways for PV. Citation Format: Alexis D. Leal, Carrie A. Thompson, Alice Wang, Robert A. Vierkant, Thomas M. Habermann, Julie A. Ross, Beth A. Virnig, James R. Cerhan. Anthropometric, medical history and lifestyle risk factors for myeloproliferative neoplasms in the Iowa Women's Health Study (IWHS) cohort. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 2536. doi:10.1158/1538-7445.AM2013-2536