Sarah J. O. Nomura

WCRF/AICR recommendation adherence and breast cancer incidence among postmenopausal women with and without non-modifiable risk factors

Taller height, family history of breast cancer, greater number of years of potential fertility and nulliparity are established non‐modifiable risk factors for postmenopausal breast cancer. Greater adherence to the World Cancer Research Fund/American Institute for Cancer Research (WCRF/AICR) diet, physical activity and body weight recommendations has previously been shown to be associated with lower breast cancer risk. However, no prior studies have evaluated whether women with non‐modifiable risk factors receive similar benefits from recommendation adherence compared to women without these risk factors. In the Iowa Womens Health Study prospective cohort, we investigated whether associations of WCRF/AICR recommendation adherence differed by the presence/absence of non‐modifiable breast cancer risk factors. Baseline (1986) questionnaire data from 36,626 postmenopausal women were used to create adherence scores for the WCRF/AICR recommendations (maximum score = 8.0). Overall and single recommendation adherence in relation to breast cancer risk (n = 3,189 cases) across levels of non‐modifiable risk factors were evaluated using proportional hazards regression. Mean adherence score was 5.0 points (range: 0.5–8.0). Higher adherence scores (score ≥6.0 vs. ≤3.5, HR = 0.76, 95% CI = 0.67–0.87), and adherence to the individual recommendations for body weight and alcohol intake were associated with a lower breast cancer incidence. While not statistically significant among women with more non‐modifiable risk factors (score ≥6.0 vs. ≤3.5, HR = 0.76, 95% CI = 0.36–1.63), hazard ratios were comparable to women with the no non‐modifiable risk factors (score ≥6.0 vs. ≤3.5, HR = 0.74, 95% CI = 0.49–0.93) (p‐interaction = 0.57). WCRF/AICR recommendation adherence is associated with lower breast cancer risk, regardless of non‐modifiable risk factor status.

Adherence to diet, physical activity and body weight recommendations and breast cancer incidence in the Black Women's Health Study.

Adherence to cancer prevention recommendations has been associated with lower incidence of breast cancer in previous studies, but evidence in African American women is limited. This project evaluated the association between adherence to the World Cancer Research Fund/American Institute for Cancer Research (WCRF/AICR) cancer prevention recommendations and breast cancer incidence among African American women. The Black Womens Health Study (analytic cohort = 49,103) is an ongoing prospective cohort study of African American women, ages 21–69 years at baseline (1995). Adherence scores for seven WCRF/AICR recommendations (adherent = 1, partial adherence = 0.5, non‐adherence = 0) were calculated using questionnaire data and summed for overall (maximum = 7) and diet only (maximum = 5) scores. Associations between baseline and time‐varying adherence scores and breast cancer incidence (N = 1,827 incident cases through 2011) were evaluated using proportional hazards regression. In this cohort, 8.5% adhered >4 recommendations. Adherence at baseline was not associated with breast cancer incidence. Higher overall time‐varying adherence (per 0.5 point increase) was associated with lower breast cancer incidence (HR: 0.90, 95% CI: 0.84–0.96). Adherence to physical activity, sugar beverage and red and processed meat recommendations were also associated with reduced risk. Adherence to the WCRF/AICR recommendations was low and may be associated with lower breast cancer incidence in African American women.

Fruit and VegeTable Intake and Lung Cancer Incidence Among Black Women According to Cigarette Smoking Status

Abstract This project evaluated associations between fruit and vegetable intake, cigarette smoking and lung cancer incidence among U.S. Black women. The Black Women’s Health Study is a prospective cohort study (analytic cohort = 46,889) among Black women between the ages 21 and 69 at baseline (1995). Fruit and vegetable intake and smoking history were ascertained via questionnaires at baseline and during follow-up. Associations between fruit and vegetable intake, smoking and lung cancer incidence (N = 306 incident cases through 2013) were evaluated using Cox proportional hazards regression. Among women in this cohort, 6.1% and 5.6% reported consuming at least three servings/d of fruit or vegetables, respectively. Smoking history was associated with increased lung cancer incidence. Being a current smoker of ≥15 cigarettes/d was associated with higher lung cancer incidence compared to never smokers (HR = 17.4, 95% CI: 11.5, 26.4). Fruit and vegetable was not associated with lung cancer incidence intake (≥5 vs. <3 servings/d, adjusted HR: 0.86, 95% CI: 0.54, 1.36). Associations between fruit and vegetable intake and lung cancer incidence did not differ by smoking history. Fruit and vegetable intake was low in this study population, but results do not support an association between fruit and vegetable intake and lung cancer incidence, regardless of smoking history.

Abstract A18: Association of anthropometric factors with risk of colorectal neoplasia in the Black Women's Health Study

Evidence for the association of anthropometric factors with colorectal neoplasms is limited for African Americans. Association of 6 anthropometric measures with the risk of both colorectal adenomas and colorectal cancer (CRC) in the ongoing Black Women9s Health Study cohort was examined. Using a nested case-control design for the adenoma analyses, 954 cases of colorectal adenoma were compared with 3,816 controls without a colorectal polyp, matched on age and follow-up time. For the CRC analyses, 413 incident CRC cases were identified over a 16-year follow up (802,783 person-years). Cases of adenoma and CRC were verified by medical record review. We used multivariable logistic regression analyses (for adenoma) and Cox proportional hazards analyses (for CRC) that included anthropometric exposures and selected confounders. Among postmenopausal women, risk of adenoma increased by 10% (95% CI: 1.00, 1.22), 11% (95% CI: 1.01, 1.29), and 9% (1.00, 1.19) with 1 standard deviation increase in body mass index, waist circumference, and weight change since age 18 , respectively. Anthropometric factors were not associated with adenoma risk among premenopausal women. None of the anthropometric factors were associated with CRC risk among either pre- or postmenopausal women. Future research should attempt to replicate the modest association of obesity with colon adenoma risk but not CRC risk among postmenopausal African American women. Citation Format: Chiranjeev Dash, Lynn Rosenberg, Jeffrey Yu, Sarah Nomura, Julie Palmer, Lucile L. Adams-Campbell. Association of anthropometric factors with risk of colorectal neoplasia in the Black Women9s Health Study [abstract]. In: Proceedings of the AACR International Conference: New Frontiers in Cancer Research; 2017 Jan 18-22; Cape Town, South Africa. Philadelphia (PA): AACR; Cancer Res 2017;77(22 Suppl):Abstract nr A18.

Abstract 1743: Sedentary behavior and breast cancer in the Black Women's Health Study

Background: Rates of breast cancer incidence among African American women are increasingly similar to rates among Caucasian American women. Lifestyle behaviors, such as sedentary time, may contribute to differences in breast cancer incidence, but have not been well studied among African American women. Sedentary activities (physically inactive tasks that require little to no additional energy expenditure beyond basal metabolic rate) account for a large proportion of time per day in the United States and are more prevalent among African American women. Sedentary behavior may contribute to cancer risk independently of physical activity, but has not been well studied among African American women. Objective: The objective of this study was to evaluate the association between sedentary behaviors over time on breast cancer incidence in the Black Women9s Heath Study. Methods: In this ongoing prospective cohort of African American women (analytic cohort N = 55,629), 2,482 incident breast cancer cases were diagnoses between baseline (1995) and 2013. Questionnaire data (collected every two years since 1995) was used to calculate time spent sitting. Time spent sitting at work and sitting doing recreational activities (watching TV, using internet) was summed to total sedentary time. A time-varying analytic approach was utilized (Anderson-Gill method) to reduce within-person variation and better represent long-term habits. Results: Among women in this cohort, 23.8% reported spending Conclusions: Our findings suggest that high sedentary time may increase risk for breast cancer among African American women. Additionally, leisure time physical activity levels and body size did not change associations, suggesting sedentary time may confer additional risk. Previously reported frequent sedentary behavior among African Americans could contribute to breast cancer disparities and should be explored further in future studies. Citation Format: Sarah Nomura, Chiranjeev Dash, Jeffrey Yu, Julie Palmer, Lynn Rosenberg, Lucile L. Adams-Campbell. Sedentary behavior and breast cancer in the Black Women9s Health Study. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 1743.

Abstract 1744: Is adherence to the WCRF/AICR cancer prevention recommendations associated with colorectal cancer in African American women in the Black Women's Health Study

Background: African American women are more likely to be diagnosed with colorectal cancer than women from other racial/ethnic groups. Differences in adherence to cancer prevention recommendations may contribute to disparities. Adherence to cancer prevention guidelines has previously been shown to be associated with lower breast cancer incidence, but previous study populations have included few African Americans. Objective: The purpose of this study was to evaluate adherence to the World Cancer Research Fund/American Institute for Cancer Research (WCRF/AICR) cancer prevention recommendations and colorectal cancer incidence in the Black Women9s Health Study (BWHS). Methods: In this ongoing prospective cohort of African American women (analytic cohort N = 49,103), 354 incident colorectal cancers were diagnosed between baseline (1995) and 2011. Adherence scores for seven WCRF/AICR recommendations (adherent = 1 point, non-adherence level 1 = 0.5 points, non-adherence level 2 = 0 points) were created using questionnaire data and summed to an overall adherence score (maximum = 7). Diet-specific recommendations were additionally summed for a diet only score (maximum = 5). Recommendation adherence and incidence of colorectal cancer combined and colon cancer only were evaluated using baseline and time-varying data in Cox regression models. Results: Guideline adherence was low with 8.5% of women (5.6% among women who later developed colorectal cancer) adhering to more than four recommendations at baseline. Adherence to a greater number of WCRF/AICR recommendations was not statistically significantly associated with colorectal cancer risk in time-varying or baseline models. In time-varying analyses, the HR (per 0.5 point increase) was 0.98 (95% CI: 0.84-1.15) and 0.51 (95% CI: 0.23-1.10) among women who adhered to >4 compared to 4 vs. 4 vs. Conclusions: Further research in diverse populations is essential to evaluate the validity of existing recommendations, and to assess whether there are alternative recommendations that are more beneficial for colorectal cancer prevention in specific populations. Citation Format: Sarah J. O. Nomura, Chiranjeev Dash, Lynn Rosenberg, Jeffrey Yu, Julie R. Palmer, Lucile L. Adams-Campbell. Is adherence to the WCRF/AICR cancer prevention recommendations associated with colorectal cancer in African American women in the Black Women9s Health Study. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 1744.