Harnack, Lisa

Objective: We aimed to investigate prospective associations between milk bioactives related to metabolic health (glucose, insulin, leptin, C reactive protein [CRP], and interleukin 6 [IL-6]) and incident formula initiation at 3 and 6 months postpartum. Design: This study included 363 mother–infant dyads who were fully breastfed at 1 month and participated in the prospective Mothers and Infants Linked for Healthy Growth study from pregnancy to 6 months postpartum. Associations between milk glucose, leptin, insulin, CRP, and IL-6 at 1 and 3 months and incident formula feeding (FF) at 3 and 6 months, respectively, were tested using multiple logistic regression, adjusting for numerous potential confounders such as maternal age and prepregnancy body mass index. Results: At 3 months postpartum, 1-month glucose (odds ratio [OR] 0.45 [95% confidence interval (CI): 0.27–0.75], p ≤ 0.01) and smaller decreases in glucose from 1 to 3 months (OR 0.51 [95% CI: 0.28–0.92], p = 0.03) were associated with lower odds of FF, whereas 1-month leptin (OR 2.30 [95% CI: 1.30–4.07], p < 0.01) and larger increase in insulin (OR 1.86 [95% CI: 1.23–2.81], p < 0.01) and leptin (OR 2.17 [95% CI: 1.29–3.68], p < 0.01) from 1 to 3 months were associated with increased odds of FF. At 6 months, insulin increases (OR 2.08 [95% CI: 1.03–4.17], p = 0.04) were associated with higher odds of FF. Conclusions: In a cohort of women with established lactation, 1-month milk glucose, insulin, and leptin predicted initiation of FF at 3 months. Early milk composition may provide a window into mammary gland function, allowing identification of women at risk of not meeting their breastfeeding goals.

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.

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 Cigarette smoking (CS), hormone therapy (HT), and folate intake (FI) are each thought to influence colorectal cancer risk, but the underlying molecular mechanisms remain incompletely defined. The TP53 (p53) protein, encoded by the TP53 tumor-suppressor gene that is commonly mutated in colorectal cancer, can be readily assessed to differentiate biologically distinct colorectal cancer subtypes. In this prospective cohort study, we examined CS-, HT-, and FI-associated colorectal cancer risks by TP53 protein expression level among Iowa Women's Health Study (IWHS) participants. The IWHS recruited 41,836 randomly selected Iowa women, ages 55 to 69 years, with a valid driver's license at study entry in 1986. Self-reported exposure variables were assessed at baseline. Incident colorectal cancer cases were ascertained by annual linkage with the Iowa Cancer Registry. Archived, paraffin-embedded tissue specimens were collected and evaluated for TP53 protein expression by immunohistochemistry. Multivariate Cox regression models were fit to estimate relative risks (RR) and 95% confidence intervals (CI) for associations between CS, HT, or FI and TP53-defined colorectal cancer subtypes. Informative environmental exposure and protein expression data were available for 492 incident colorectal cancer cases: 222 (45.1%) TP53 negative, 72 (14.6%) TP53 low, and 198 (40.2%) TP53 high. Longer duration (&gt;5 years) of HT was inversely associated with TP53 high colorectal cancers (RR, 0.50; 95% CI, 0.27–0.94). No other statistically significant associations were observed. These data support possible heterogeneous effects from HT on TP53-related pathways of colorectal carcinogenesis in older women. Cancer Epidemiol Biomarkers Prev; 23(2); 350–5. ©2013 AACR.

Abstract Background: Cigarette smoking (CS) is an established colorectal cancer (CRC) risk factor. The p53 protein, encoded by the TP53 tumor suppressor gene that is commonly mutated in CRC, is important in cell cycle arrest needed to repair DNA damage or induce apoptosis to prevent tumor propagation. In this prospective cohort study, we examined CS-associated CRC risks by p53 protein expression level 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). CS and other 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. CS was categorized by smoking status (never, current, former), average number of cigarettes per day (1-19, 20-39, &gt; 40) and cumulative pack-years (1-19, 20-39, &gt; 40). P53 protein expression was determined by immunohistochemistry on tissue microarrays. Tumor cores were scored by combining both staining intensity and percent of cells stained to determine negative, low or high p53 protein expression levels. Multivariate Cox regression models were fit to estimate relative risks (RRs) and 95% confidence intervals (CIs). Results: Of the 732 available CRC cases, 486 (66%) had complete CS and p53 data. Associations between CS and CRC subtypes defined by p53 expression level are shown in the Table. Conclusions: These data demonstrate no clear heterogeneity of CS with CRC subtypes defined by p53 expression levels among older women. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 1677. doi:1538-7445.AM2012-1677

Abstract Background: Cigarette smoking (CS) is an established colorectal cancer (CRC) risk factor. The p53 protein, encoded by the TP53 tumor suppressor gene that is commonly mutated in CRC, is important in cell cycle arrest needed to repair DNA damage or induce apoptosis to prevent tumor propagation. In this prospective cohort study, we examined CS-associated CRC risks by p53 protein expression level 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). CS and other 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. CS was categorized by smoking status (never, current, former), average number of cigarettes per day (1-19, 20-39, &gt; 40) and cumulative pack-years (1-19, 20-39, &gt; 40). P53 protein expression was determined by immunohistochemistry on tissue microarrays. Tumor cores were scored by combining both staining intensity and percent of cells stained to determine negative, low or high p53 protein expression levels. Multivariate Cox regression models were fit to estimate relative risks (RRs) and 95% confidence intervals (CIs). Results: Of the 732 available CRC cases, 486 (66%) had complete CS and p53 data. Associations between CS and CRC subtypes defined by p53 expression level are shown in the Table. Conclusions: These data demonstrate no clear heterogeneity of CS with CRC subtypes defined by p53 expression levels among older women. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 1676. doi:1538-7445.AM2012-1676

Abstract Background: Colorectal cancer (CRC) is a molecularly heterogeneous disease. Three molecular pathways (traditional, serrated and alternate) have been recently proposed based on integrated combinations of microsatellite instability (MSI), CpG island methylation phenotype (CIMP), BRAF mutation, and KRAS mutation status (Gastroenterol 2010;138:2088-2100). To our knowledge, clinicopathologic associations with these CRC pathways have not been previously described. Methods: Data and tissue resources were obtained from the population-based Iowa Women's Health Study, which recruited 41,836 randomly selected women, ages 55-69 years, at study entry (1986). 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. Established laboratory methods were used to characterize CRC cases by MSI (MSS/MSI-L or MSI-H), CIMP (neg, low, or high), BRAF mutation (wt or mut), and KRAS mutation (wt or mut) status. Molecular pathways were defined as: traditional (MSS/MSI-L, CIMP-neg, BRAF wt, and KRAS wt); serrated (any MSI, CIMP-high, BRAF mut, and KRAS wt), alternate (MSS/MSI-L, CIMP-low, BRAF wt, and KRAS mut), or other pathway. Chi-square tests and analyses of variance were used to compare clinicopathologic features at CRC presentation (age, anatomic subsite, tumor grade, and SEER stage) across the molecular pathways. Results: Comlete and informative MSI, CIMP, BRAF and KRAS data were obtained for 491/732 (67%) CRC cases. Clinicopathologic associations are shown in the Table. Conclusions: These data suggest that distributions of age at diagnosis, subsite, and tumor grade, but not SEER stage, differ across the traditional, serrated, and alternate carcinogenic pathways, which may have implications for molecularly-targeted CRC prevention and/or therapy strategies. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 5518. doi:1538-7445.AM2012-5518

Abstract Background: Despite recent advances in prevention and therapy, colorectal cancer (CRC) continues to account for nearly 50,000 deaths per year in the US. TNM stage is the current CRC prognostic standard, yet within-stage prognostic heterogeneity is well documented. Microsatellite instability (MSI), CpG island methylation phenotype (CIMP), and BRAF- and KRAS-mutation status represent candidate prognostic markers. However, associations between these markers and CRC survival have not been described in a population-based setting. Methods: Data and tissue resources were obtained from the Iowa Women's Health Study (IWHS), which recruited 41,836 women, ages 55-69 years, at study entry (1986). Incident CRC cases were ascertained by annual linkage with the Iowa Cancer Registry. Archived, paraffin-embedded tissue specimens were collected from 732 representative CRC cases diagnosed through 12/31/2002. Established laboratory methods were used to characterize CRC cases: MSI-H or MSS/MSI-L (by instability in β3 vs. &lt;3 out of 10 markers, respectively); CIMP+ or CIMP− (by promoter hypermethylation in β3 vs. 0-2 out of 5 genes, respectively); BRAFwt or BRAFmut (by fluorescent allele specific PCR to detect the V600E point mutation in exon 15); and KRASwt or KRASmut (by direct sequence analysis of codons 12 and 13 in exon 2). Cox regression models were fit to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for time to death of any cause adjusted for age, stage, grade, and treatment status. Results: CRC cases with informative molecular marker data ranged from 515/732 (70%) for KRAS to 548/732 (75%) for MSI status. Mean follow-up was 4.4 years for deceased individuals and 11.2 years for women alive at last contact. After multivariable adjustment, both MSS/MSI-L (p=0.004) and KRASmut (p=0.048) tumors were associated with poorer survival. Survival did not significantly differ across levels of CIMP and BRAF status. Conclusions: MSI and KRAS status may influence CRC survival among older women. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 4492. doi:1538-7445.AM2012-4492

Abstract Background: Folate intake (FI) appears to affect colorectal cancer (CRC) risk, but the molecular mechanism(s) involved are incompletely defined. In this study, we analyzed associations between FI and incident CRC, overall and by KRAS mutation status, 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). FI and other 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 recently collected from 732 representative CRC cases diagnosed through 12/31/2002. FI (including supplements) was categorized by quartiles. KRAS mutation status (wildtype [wt] vs. mutated [mut]) was determined by direct sequence analysis of codons 12 and 13 (exon 2). Multivariate Cox regression models were fit to estimate relative risks (RRs) and 95% confidence intervals (CIs). Results: Of the 732 available CRC cases, 470 (64%) had complete FI and KRAS data. FI was not associated with incident CRC overall (for quartile 4 vs. quartile 1, RR = 1.03; 95% CI = 0.82-1.28; p trend = 0.90), or with the KRAS-wt or KRAS-mut subtypes (see Table). Conclusions: These data do not support an association between FI and incident CRC, overall or by KRAS-defined subtypes, among older, predominately white, non-Hispanic women. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1892. doi:10.1158/1538-7445.AM2011-1892

Abstract Background: Cigarette smoking (CS) is an established, although relatively modest, colorectal cancer (CRC) risk factor. Emerging data suggest that CS might affect distinct pathways of colorectal carcinogenesis. In this study, we examined CS-associated CRC risks by KRAS mutation status in the population-based Iowa Women's Health Study (IWHS). Methods: The IIWHS recruited 41,836 randomly selected Iowa women, ages 55-69 years, with a valid driver's license at study entry (1986). CS and other 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 representative CRC cases diagnosed through 12/31/2002. CS was categorized by smoking status (current, former), average number of cigarettes per day (1-19, 20-39, &gt; 40) and pack-years (1-19, 20-39, &gt; 40); never smokers were defined as the reference group. KRAS mutation status (wildtype [wt] vs. mutated [mut]) was determined by direct sequence analysis of codons 12 and 13 (exon 2). Multivariate Cox regression models were fit to estimate relative risks (RRs) and 95% confidence intervals (CIs). Results: Of the 732 available CRC cases, 507 (69%) had complete CS and KRAS data. Each of the CS-related variables was more strongly associated with KRAS-wt vs. KRAS-mut tumors (see Table). However, event rates were relatively small in some cells, and tests for heterogeneity between KRAS-defined subtypes were not statistically significant (p &gt; 0.05 for each comparison). Conclusions: These findings suggest that CS may affect colorectal carcinogenesis through KRAS-independent pathways, but additional data are needed from larger, more diverse study populations. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1891. doi:10.1158/1538-7445.AM2011-1891