The association of the healthy eating index with risk of colorectal cancers (overall and by subsite) among Canadians

BACKGROUND

Healthy dietary patterns characterized by high intake of fruits and vegetables, grains/cereals, and lean meat/fish, and low intake of red/processed meats and refined carbohydrates, have been shown to be associated with reduced risk of colorectal cancer, but evidence regarding their association with colorectal cancer subsites is limited. Hence, this study was conducted to assess the association of a healthy dietary pattern, as reflected in the Healthy Eating Index (HEI) (a composite score based on consumption of various food groups), with risk of colorectal cancer, overall and by subsite.

METHODS

We conducted a case-cohort study in the Canadian Study of Diet, Lifestyle and Health (CSDLH). The study included all cases of incident colorectal cancer in the entire cohort, and an age-stratified subcohort of 3185 women and 2622 men. Cox regression models were used to estimate hazard ratios (HR) for the association between the HEI and the risk of colorectal cancer, overall and by subsite. We also assessed the association by sex and by selected metabolic factors.

RESULTS

For both sexes combined, the highest quintile of the HEI score was inversely associated with risk of colorectal cancer, colon cancer and proximal colon cancer (HR: 0.65; 95% CI: 0. 49-0.85, HR: 0.60, 95% CI: 0.44-0.83 and HR: 0.54, 95% CI: 0.35-0.85, respectively). However, these associations were mostly observed among men (HR: 0.56; 95% CI: 0.38-0.81, HR: 0.44, 95% CI: 0.28-0.69 and HR: 0.26; 95% CI: 0.12-0.56, for colorectal cancer, colon cancer and proximal colon cancer, respectively; p-interactions=0.029, 0.032 and 0.063, respectively). An inverse association was also observed between the HEI and risk of colorectal cancer among normal weight participants, overweight/obese participants, non-smokers, non-alcohol drinkers and participants who were physically inactive.

CONCLUSION

A healthy dietary pattern may reduce risk of colorectal cancer, particularly among men.

New-Onset Diabetes after an Obesity-Related Cancer Diagnosis and Survival Outcomes in the Women's Health Initiative

BACKGROUND

Individuals diagnosed with an obesity-related cancer (ORC survivors) are at an elevated risk of incident diabetes compared with cancer-free individuals, but whether this confers survival disadvantage is unknown.

METHODS

We assessed the rate of incident diabetes in ORC survivors and evaluated the association of incident diabetes with all-cause and cancer-specific mortality among females with ORC in the Women's Health Initiative cohort (N = 14,651). Cox proportional hazards regression models stratified by exposure-risk periods (0-1, >1-3, >3-5, >5-7, and >7-10 years) from ORC diagnosis and time-varying exposure (diabetes) analyses were performed.

RESULTS

Among the ORC survivors, a total of 1.3% developed diabetes within ≤1 year of follow-up and 2.5%, 2.3%, 2.3%, and 3.6% at 1-3, 3-5, 5-7, and 7-10 years of follow-up, respectively, after an ORC diagnosis. The median survival for those diagnosed with diabetes within 1-year of cancer diagnosis and those with no diabetes diagnosis in that time frame was 8.8 [95% confidence interval (CI), 7.0-14.5) years and 16.6 (95% CI, 16.1-17.0) years, respectively. New-onset compared with no diabetes as a time-varying exposure was associated with higher risk of all-cause (HR, 1.27; 95% CI, 1.16-1.40) and cancer-specific (HR, 1.17; 95% CI, 0.99-1.38) mortality. When stratified by exposure-risk periods, incident diabetes in ≤1 year of follow-up was associated with higher all-cause (HR, 1.76; 95% CI, 1.40-2.20) and cancer-specific (HR0-1, 1.82; 95% CI, 1.28-2.57) mortality, compared with no diabetes diagnosis.

CONCLUSIONS

Incident diabetes was associated with worse cancer-specific and all-cause survival, particularly in the year after cancer diagnosis.

IMPACT

These findings draw attention to the importance of diabetes prevention efforts among cancer survivors to improve survival outcomes.

Supplemental B-Vitamins and Risk of Upper Gastrointestinal Cancers in the Women's Health Initiative

B-vitamins contribute to DNA synthesis, maintenance, and regulation. Few studies have examined associations of supplemental sources of B-vitamins with the incidence of upper gastrointestinal (GI) cancers [including gastric (GCA) and esophageal (ECA) cancers]; the only prior study to comprehensively examine such intakes reported potential elevated risks of ECA. We examined 159,401 postmenopausal women, ages 50-79 years at baseline, including 302 incident GCA and 183 incident ECA cases, over 19 years of follow-up within the Women's Health Initiative observational study and clinic trials. Adjusted Cox regression models estimated hazard ratios (HR) and 95% confidence intervals (CI) for associations of supplemental B-vitamins [riboflavin (B2), pyridoxine (B6), folic acid (B9), or cobalamin (B12)] with GCA and ECA risk, respectively. Although HRs were generally below 1.0, we observed no statistically significant associations between supplemental intakes of any of the evaluated B-vitamins with the risk of GCA or ECA. As the first prospective study to comprehensively assess these associations, our findings do not corroborate prior research indicating potential harm from supplemental B-vitamin intake for upper GI cancer risk. This study adds evidence that supplemental intakes of B-vitamins may be used by postmenopausal women without regard to their relationship with upper GI cancer risk.

The association of predicted resting energy expenditure with risk of breast cancer among postmenopausal women in the Women's Health Initiative cohort

Obesity and obesity-related metabolic disorders, such as obesity and chronic inflammation, have been positively associated both with postmenopausal breast cancer and with resting energy expenditure (REE). However, there is limited epidemiological evidence on the associations between REE and risk of postmenopausal breast cancer. We used multivariable Cox proportional hazards models to examine the association between predicted REE (calculated using the Ikeda, Livingston and Mifflin equations) and risk of postmenopausal breast cancer overall and by subtypes, and by level of body fat) among 137,305 postmenopausal women in the Women's Health Initiative (WHI). All predicted REEs were positively associated with risk of invasive breast cancer (HRq5 vs q1: 1.69; 95% CI: 1.57-1.81, HR: 1.69; 95% CI: 1.57-1.82 and HR: 1.68; 95% CI: 1.56-1.80 for Ikeda, Livingston and Mifflin, respectively). These positive associations were observed irrespective of the hormone receptor subtype, grade and stage of the tumors, but were most pronounced for estrogen receptor positive/progesterone receptor positive tumors. After additional adjustment for BMI, the associations were mostly attenuated and remained statistically significant for most of the outcomes. We also observed an interaction between the predicted REEs and BMI, with the associations being somewhat stronger among normal weight and overweight women than among obese women (pinteractions <0.05). Our findings indicate that relatively high REE is associated with increased risk of invasive breast cancer among postmenopausal women (particularly for the obesity-related tumor subtypes), irrespective of the equation used. Further studies using more objective measures of REE are, however, needed to confirm our findings.

Association of a healthy lifestyle index with risk of breast cancer among women with normal body mass index in the UK Biobank

BACKGROUND

A high healthy lifestyle index (HLI), a composite score based on good diet quality, low alcohol consumption, no smoking, moderate to high physical activity, and waist circumference <80cm, has been consistently associated with a reduced risk of breast cancer (BC). Recently, high levels of body fat were found to be associated with an elevated risk of BC in postmenopausal women with a normal body mass index (BMI) (18.5-<25 kg/m2). Whether the HLI is associated with BC risk in women with normal BMI is unknown.

METHODS

We studied 102,572 women aged 40-69 years with a normal BMI at enrollment into the UK Biobank cohort study. The HLI was created by assigning to each component higher scores for healthier behaviors and then summing the scores. The HLI was categorized by tertiles and age- and multivariable-adjusted hazard ratios (HRs) for the association of the HLI with BC risk by menopausal status were estimated using Cox proportional hazards models.

RESULTS

In postmenopausal women, compared to a low HLI, higher scores were associated with a reduced risk of BC (HRHLI-3rd tertile 0.76; 95% CI, 0.64-0.91). Findings were similar for premenopausal women, although they did not reach statistical significance, except when smoking status was excluded from the HLI score (HLIwithout smoking: HR3rd tertile, 0.71; 95% CI, 0.56-0.90).

CONCLUSIONS

In normal BMI postmenopausal women, a high HLI score was associated with a reduced risk of BC.

IMPACT

Following a healthy lifestyle may reduce the risk of BC among normal weight postmenopausal women.

Cancer Risk in Normal Weight Individuals with Metabolic Obesity: A Narrative Review

Obesity represents one of the most significant public health challenges worldwide. Current clinical practice relies on body mass index (BMI) to define the obesity status of an individual, even though the index has long been recognized for its limitations as a measure of body fat. In normal BMI individuals, increased central adiposity has been associated with worse health outcomes, including increased risks of cardiovascular disease and metabolic disorders. The condition leading to these outcomes has been described as metabolic obesity in the normal weight (MONW). More recent evidence suggests that MONW is associated with increased risk of several obesity-related malignancies, including postmenopausal breast, endometrial, colorectal, and liver cancers. In MONW patients, the false reassurance of a normal range BMI can lead to lost opportunities for implementing preventive interventions that may benefit a substantial number of people. A growing body of literature has documented the increased risk profile of MONW individuals and demonstrated practical uses for body composition and biochemical analyses to identify this at-risk population. In this review, we survey the current literature on MONW and cancer, summarize pathophysiology and oncogenic mechanisms, highlight potential strategies for diagnosis and treatment, and suggest directions for future research.

The association of body fat composition with risk of breast, endometrial, ovarian and colorectal cancers among normal weight participants in the UK Biobank

BACKGROUND

The association between body fat composition and risk of cancer in normal weight individuals (body mass index (BMI) 18.5-24.9 kg/m2) is unclear.

METHODS

We examined the association of measures of adiposity with risk of incident cancers of the breast (postmenopausal), endometrium, ovary and colon/rectum among 149,928 normal weight individuals (40-70 years) who were enrolled in the UK Biobank cohort between 2006 and 2010.

RESULTS

All of the body fat measures were positively associated with invasive postmenopausal breast cancer risk (hazard ratios (HR) for the uppermost quintile (Q5) versus the lowest quintile (Q1) ranged from 1.32 (95% CI: 1.09-1.60) for waist circumference (WC) to 1.56 (1.28-1.90) for BMI). Trunk fat mass index (HRQ5 vs Q1: 1.72, 95% CI: 1.02-2.89) and WC (HRQ5 vs Q1: 1.65, 95% CI: 1.01-2.70)) were positively associated with risk of endometrial cancer. Among males, trunk fat:trunk fat free mass ratio, trunk fat:leg fat mass ratio and (HRQ5 vs Q1: 1.63, 95% CI: 1.02-2.60; 1.92, 1.20-3.07 and 1.68, 1.05-2.66, respectively) were positively associated with colon cancer risk. None of the body fat measures was associated with risk of ovarian cancer or colorectal cancer in women.

CONCLUSION

The findings of this study suggest that the current normal weight category based on BMI includes individuals who are at increased risk of some obesity-related cancers.

The association of prediagnostic circulating levels of cardiometabolic markers, testosterone and sex hormone-binding globulin with risk of breast cancer among normal weight postmenopausal women in the UK Biobank

Emerging evidence suggests that normal weight postmenopausal women with a relative excess of body fat are at increased breast cancer risk. However, little is known about the associations between obesity-related blood markers and risk of breast cancer among these individuals. In this prospective study comprising 58 629 normal weight postmenopausal women (body mass index between 18.5 kg/m² and 24.9 kg/m² ) who were enrolled in the UK Biobank cohort between 2006 and 2010, we examined the associations of glycated hemoglobin, triglycerides, high-density lipoprotein cholesterol, C-reactive protein (CRP), testosterone and sex hormone-binding globulin (SHBG) with risk of breast cancer. A total of 1268 postmenopausal breast cancer cases were ascertained during a median follow-up period of 7 years. Women with CRP, total testosterone and free testosterone (FT) levels in the highest quintile had increased risk of breast cancer compared to those in the lowest quintile (HR_{Q5 vs Q1} : 1.35, 95% confidence interval [CI]: 1.12-1.63, HR _{Q5 vs Q1} : 1.47, 95% CI: 1.20-1.80 and HR _{Q5 vs Q1} : 1.53, 95% CI: 1.23-1.90, respectively), whereas those with SHBG in the highest quintile had reduced risk (HR _{Q5 vs Q1} : 0.70, 95% CI: 0.56-0.88). These associations were attenuated but persisted after additional adjustment for BMI, fat mass index (whole body fat mass [kg]/height [m² ]) or waist circumference and after mutual adjustment for testosterone, CRP and/or SHBG. Our study suggests that the risk of postmenopausal breast cancer among normal weight women is increased in association with relatively high levels of CRP and testosterone and with relatively low levels of SHBG.

Sugar-containing beverages and their association with risk of breast, endometrial, ovarian and colorectal cancers among Canadian women

BACKGROUND

The association of sugar containing beverages (SCBs) with risk of breast, endometrial, ovarian and colorectal cancers is unclear. Therefore, we investigated these associations in the Canadian Study of Diet, Lifestyle, and Health.

METHODS

The study population comprised an age-stratified subcohort of 3185 women and 848, 161, 91 and 243 breast, endometrial, ovarian and colorectal cancer cases, respectively. We used Cox proportional hazards regression models modified for the case-cohort design to assess the associations of SCBs with risk of the aforementioned cancers.

RESULTS

Compared to SCB intake in the lowest tertile, SCB intake in the highest tertile was positively associated with endometrial cancer risk (HR_{T3 vs T1} = 1.58, 95 % CI = 1.08-2.33 and 1.78, 95 % CI = 1.12-2.81 for overall and Type 1 endometrial cancer, respectively) and ovarian cancer (HR_{T3 vs T1} = 1.76, 95 % CI: 1.09-2.83). Fruit juice intake was also positively associated with risk of Type 1endometrial (HR_{T3 vs T1} = 1.63, 95 % CI = 1.03-2.60). After excluding women with diabetes or cardiovascular diseases, we also observed sugar-sweetened beverages (SSBs) intake in the highest tertile was associated with higher risk of Type 1 endometrial cancer (HR _{T3 vs T1} = 1.65; 95 % CI: 1.03-2.64). None of the beverages was associated with risk of breast or colorectal cancer.

CONCLUSION

We conclude that, in this cohort, relatively high SCB intake was associated with higher risk of endometrial and ovarian cancers, but not of breast or colorectal cancers. Our findings also suggest that relatively high SSB and fruit juice intake are associated with higher risk of Type 1 endometrial cancer.

Genetic Factors, Adherence to Healthy Lifestyle Behavior, and Risk of Invasive Breast Cancer Among Women in the UK Biobank

BACKGROUND

Breast cancer is considered to result from a combination of genetic and lifestyle-related factors, but the degree to which an overall healthy lifestyle may attenuate the impact of multiple genetic variants on invasive breast cancer risk remains equivocal.

METHODS

Using Cox proportional hazards regression models, we examined the association of a modified healthy lifestyle index (HLI) with risk of invasive breast cancer by genetic risk group among 146 326 women from the UK Biobank. We generated an HLI score based on a combination of diet, physical activity, smoking, alcohol consumption and anthropometry, and a polygenic risk score (PRS) using 304 breast cancer-associated genetic loci.

RESULTS

Among premenopausal and postmenopausal women, a favorable lifestyle (highest tertile) was associated with 22% and 31% reductions in invasive breast cancer risk, respectively (hazard ratio [HR]high vs low = 0.78, 95% confidence interval [CI] = 0.64 to 0.94; HRhigh vs low = 0.69, 95% CI = 0.63 to 0.77, respectively), whereas a high PRS (highest tertile) was associated with more than a doubling in the risk in both groups. For premenopausal women, the greatest risk reduction in association with the HLI was seen among those with a high PRS (HRhigh vs low = 0.73, 95% CI = 0.75 to 0.95). In postmenopausal women, those with a favorable lifestyle had 30%, 29%, and 32% reductions in risk of invasive breast cancer in the low, intermediate, and high PRS groups, respectively (HRhigh vs low = 0.70, 95% CI = 0.56 to 0.88; HRhigh vs low = 0.71, 95% CI = 0.59 to 0.84; and HRhigh vs low = 0.68, 95% CI = 0.59 to 0.78, respectively). There was an additive but not multiplicative interaction between the HLI score and PRS for postmenopausal and, to a lesser extent, premenopausal women.

CONCLUSION

Our findings support the view that an overall healthy lifestyle may attenuate the impact of genetic factors on invasive breast cancer risk among women of European ancestry.

Abstract 3483: Measures of overall and central adiposity in relation to risk of obesity-related cancers among normal weight men and women in the UK Biobank

Background: Within the normal BMI (body mass index (BMI) of 18.5-24.9kg/m2) category, some individuals may be at increased risk of developing obesity-related cancers. Towards this end, studies have shown positive associations between body fat, particularly in the abdominal region, and cancer-associated metabolic disturbances among normal weight individuals. However, little is known about the association between body fat distribution and risk of obesity-related cancers among normal weight individuals. Thus, in this study, we examined the association of overall and central adiposity, assessed using bioelectrical impedance (BIA)-derived and anthropometric measures, with risk of selected obesity-related cancers among normal weight persons.

Methods: The study included normal weight individuals aged 40-70 years who were enrolled in the UK Biobank cohort between 2006 and 2010. BIA-derived and anthropometric body fat measures were taken at baseline by trained staff. Incident tumors were ascertained via linkage to UK cancer registries. Multivariable Cox proportional hazards regression models were used to estimate the hazard ratios (HR) and 95% confidence intervals (CI) for the associations of the body fat measures with risk of cancers of the breast, endometrium, ovary, colorectum, pancreas, and kidney, and with multiple myeloma.

Results: The overall incidence of obesity-related cancers was 2.2 per 1000 person-years of follow-up (N= 2364 incident obesity-related cases among 152,489 subjects with a median follow-up time of 7 years). All measures of central and peripheral adiposity demonstrated linear positive dose-response relationships with risk of postmenopausal invasive breast cancer and with endometrial cancer. For all of the body fat measures, postmenopausal women in the highest quartile showed increased invasive breast cancer risk, after adjusting for potential confounders, compared to women in the lowest quartile, with hazard ratios ranging from 1.29 (95% CI: 1.11-1.50) for the ratio of trunk fat to leg fat mass to 1.59 (95% CI: 1.31-1.93) for trunk fat mass index (TFMI; calculated as trunk fat mass (kg)/height (m)2). For endometrial cancer, only the TFMI (HR: 1.80, 95% CI:1.12-2.88) and waist circumference (HR: 1.70, 95% CI: 1.04-2.80) were positively associated with risk. A waist-to-hip ratio in the highest quartile was also positively associated with colorectal cancer risk among males (HR: 1.56, 95% CI: 1.03-2.37). None of the body fat measures were associated with risk colorectal cancer risk among women or with risk of the remaining cancers.

Conclusion: The findings of this study suggest that elevated levels of central and/or overall adiposity may be associated with increased risk of postmenopausal breast cancer, endometrial cancer and probably colorectal cancer (males), among normal weight individuals. Evaluating body composition in those with a normal BMI can potentially identify individuals at increased risk for cancer providing an opportunity for interventions to reduce risk.

Citation Format: Rhonda S. Arthur, Mimi Kim, Andrew Dannenberg, Thomas Rohan. Measures of overall and central adiposity in relation to risk of obesity-related cancers among normal weight men and women in the UK Biobank [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 3483.

Association of Sex Hormones with Risk of Cancers of the Pancreas, Kidney, and Brain in the UK Biobank Cohort Study

BACKGROUND

There is some evidence to suggest that endogenous levels of sex hormones might influence the etiology of cancers of the pancreas, kidney, and brain, but epidemiologic data are lacking.

METHODS

We evaluated the association of circulating levels of total and free testosterone, and of sex hormone-binding globulin (SHBG), with the risk of cancers of the pancreas, kidney, and brain, and of total and free estradiol with the risk of kidney cancer, in the UK Biobank cohort study (n = 425,793; 225 pancreatic cancers, 749 kidney cancers, 467 brain cancers). Multivariable Cox proportional hazards models were used to estimate HRs and 95% confidence intervals for the associations.

RESULTS

Testosterone and SHBG levels were not associated with risk of pancreatic cancer. Most of the associations for the other two anatomic sites were null. There were inverse associations between total testosterone and brain cancer in men and between SHBG and risk of kidney cancer in the total sample and in women. Estradiol was not associated with the risk of kidney cancer.

CONCLUSIONS

The results of this study provide little support for associations between sex hormones/SHBG and risk of cancers of the pancreas, kidney, and brain. Larger studies are warranted.

IMPACT

Although these results provide little support for roles for sex hormones and SHBG in the etiology of cancers of the pancreas, kidney, and brain, there is a need for studies with larger numbers of cases.

The association between DXA-derived body fat measures and breast cancer risk among postmenopausal women in the Women's Health Initiative

Background

Most studies demonstrating an association between excess adiposity and postmenopausal breast cancer have used anthropometric measures, particularly body mass index (BMI). However, more direct body fat measures may more accurately determine the relationship between body fat distribution and breast cancer risk.

Methods

Cox proportional hazards regression models were created to examine the associations of dual‐energy x‐ray absorptiometry (DXA) body fat measures (at baseline and during follow‐up) with breast cancer risk among 10 931 postmenopausal women from the Women's Health Initiative cohort. A total of 639 incident invasive breast cancer cases (including 484 estrogen receptor positive (ER+) cases) were ascertained after a median follow‐up of 15.0 years.

Results

Excess whole body fat mass and trunk fat mass were positively associated with risk invasive breast cancer risk. These associations persisted even after additional adjustment for standard anthropometric measures. In time‐dependent analyses, we observed that both whole body fat mass and trunk fat mass, in the highest versus lowest category, were associated with a doubling of risk of invasive breast cancer overall (HR: 2.17; 95% CI: 1.54‐3.05 and 2.20; 1.55‐3.14, respectively) and of ER+ breast cancer (2.05; 1.37‐3.05 and 2.03; 1.34‐3.07, respectively). The remaining DXA measures were also positively associated with breast cancer risk in baseline and time‐dependent analyses.

Conclusion

These findings suggest that DXA‐derived body fat measures are positively associated with breast cancer risk after adjustment for BMI and other conventional breast cancer risk factors.

Abstract 963: The interplay between lifestyle-related factors and genetics with risk of invasive breast cancer among postmenopausal women from the UK Biobank

Background: Many genetic variants have been associated with increased risk of breast cancer. In contrast, an overall healthy lifestyle has been associated with a reduced risk. However, the degree to which an overall healthy lifestyle may attenuate the impact of genetic variants on risk of breast cancer remains equivocal. In this study, we examined the association of a healthy lifestyle index (HLI) with risk of breast cancer by genetic risk groups.

Methods: The study included 106,814 postmenopausal women of white descent aged 40 to 70 years who were enrolled in the UK Biobank cohort between 2006 and 2010. The HLI was based on a combination of diet, physical activity, smoking, alcohol consumption and anthropometry (ranging from 0 to 20, with the higher scores representing more favorable lifestyle). A polygenic risk score (categorized as low, intermediate and high) was generated as the sum of risk alleles weighted by the logOR of 117 breast cancer associated single nucleotide polymorphisms. A total of 1,949 incident invasive breast cancer cases were ascertained after a median follow-up of 5.7 years. Cox proportional hazards regression models were used to estimate the hazard ratios (HR) and 95% confidence intervals (CI) for the association of a healthy lifestyle risk score with risk of breast cancer by genetic risk groups.

Results: Compared to women with an unfavorable lifestyle (lowest quartile), women with a favorable lifestyle (highest quartile) had a 32% reduced risk of invasive breast cancer (HR: 0.68: 0.59, 0.79). Women with high genetic risk (highest tertile) had an 86% increased risk of invasive breast cancer (1.86: 1.66, 2.08) compared to those with low genetic risk (lowest tertile). Compared with women who had an unfavorable lifestyle, a favorable lifestyle did not significantly reduce risk of invasive breast cancer among women with low genetic risk (0.80: 0.63-1.02), while women with a favorable lifestyle had 32% and 43% reduced risk of invasive breast cancer in the intermediate and high genetic risk categories,

respectively (0.68: 0.53, 0.86 and 0.57; 0.44, 0.74, respectively). However, interaction between the genetic score and the lifestyle score did not achieve statistical significance (pinteraction=0.162).

Conclusion: This study suggests that an overall healthy lifestyle may attenuate the impact of genetics on risk of breast cancer, particularly among women with intermediate and high genetic risk.

Citation Format: Rhonda S. Arthur, Tao Wang, Thomas Rohan. The interplay between lifestyle-related factors and genetics with risk of invasive breast cancer among postmenopausal women from the UK Biobank [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 963.

Dietary B-Vitamin Intake and Risk of Breast, Endometrial, Ovarian and Colorectal Cancer among Canadians

Few studies have explored the associations of thiamin, niacin and riboflavin with risk of cancer despite their role in potentially cancer-associated one-carbon metabolism. Using multivariable Cox proportional hazards regression models modified for the case-cohort design, we examined the associations of dietary intake of the above-mentioned B vitamins, as well as folate, and vitamins B6 and B12, with risk of the breast (n = 922), endometrial (n = 180), ovarian (n = 104) and colorectal (n = 266) cancers among age-stratified subcohorts of 3,185 women who were randomly selected from a cohort of 73,909 participants. None of the B-vitamins were associated with risk of breast or colorectal cancers. However, relatively high dietary intake of folate intake was inversely associated with risk of endometrial (HR_{q4 vs q1}: 0.52; 95% CI: 0.29-0.93) and ovarian (HR_{q3 vs q1}: 0.39; 95% CI: 0.19-0.80) cancers while relatively high dietary intake of vitamin B6 was inversely associated with ovarian cancer risk (HR_{q3 vs q1}: 0.49; 95% CI: 0.24-0.98). These findings suggest that dietary intake of folate may reduce risk of endometrial and ovarian cancers and dietary intake of vitamin B6 may reduce risk of ovarian cancer.

Metabolic syndrome and risk of endometrial cancer in postmenopausal women: a prospective study

BACKGROUND

Obesity is a strong risk factor for endometrial cancer, but it is unclear whether metabolic syndrome (MetS) contributes to endometrial cancer risk over and above the contribution of obesity.

METHODS

We examined the association of MetS and its components with risk of endometrial cancer in a sub-cohort of 24,210 women enrolled in the Women's Health Initiative cohort study. Two variants of the National Cholesterol Education Program Adult Treatment Panel III definition of the MetS were used: one including and one excluding waist circumference (WC). Cox proportional hazards models were used to estimate the association of the study exposures with disease risk.

RESULTS

When WC was included in the definition, MetS showed an approximately two-fold increase in endometrial cancer risk (HR 2.20; 95% CI 1.61-3.02); however, when WC was excluded, MetS was no longer associated with risk. We also observed that women with hyperglycemia, dyslipidemia and hypertension, in combination, had almost a twofold increased risk of endometrial cancer, independent of WC (HR 1.94; 95% CI 1.09, 3.46). Glucose, and, in particular, WC and body mass index were also positively associated with risk.

CONCLUSIONS

Our findings suggest that MetS may predict risk of endometrial cancer independent of obesity among women with the remaining four Mets components.

Assessing facial approximation accuracy: How do resemblance ratings of disparate faces compare to recognition tests?

In the past, the accuracy of facial approximations has been assessed by resemblance ratings (i.e., the comparison of a facial approximation directly to a target individual) and recognition tests (e.g., the comparison of a facial approximation to a photo array of faces including foils and a target individual). Recently, several research studies have indicated that recognition tests hold major strengths in contrast to resemblance ratings. However, resemblance ratings remain popularly employed and/or are given weighting when judging facial approximations, thus indicating that no consensus has been reached. This study aims to further investigate the matter by comparing the results of resemblance ratings and recognition tests for two facial approximations which clearly differed in their morphological appearance. One facial approximation was constructed by an experienced practitioner privy to the appearance of the target individual (practitioner had direct access to an antemortem frontal photograph during face construction), while the other facial approximation was constructed by a novice under blind conditions. Both facial approximations, whilst clearly morphologically different, were given similar resemblance scores even though recognition test results produced vastly different results. One facial approximation was correctly recognized almost without exception while the other was not correctly recognized above chance rates. These results suggest that resemblance ratings are insensitive measures of the accuracy of facial approximations and lend further weight to the use of recognition tests in facial approximation assessment.

Thallium stress testing does not predict cardiovascular risk in diabetic patients with end-stage renal disease undergoing cadaveric renal transplantation

PURPOSE

This study assessed the usefulness of thallium stress testing as a predictor of perioperative cardiovascular risk in diabetic patients with end-stage renal disease undergoing cadaveric renal transplantation. Demographic factors influencing the exercise performance in these patients were also examined.

PATIENTS AND METHODS

The medical records of 189 consecutive patients with diabetic nephropathy who were evaluated for cadaveric renal transplantation were reviewed. Thallium stress testing was the initial examination of cardiovascular status in 141 patients. An adequate examination was one in which at least 70% of maximum heart rate was achieved. A thallium stress test was normal if there were no ST segment depressions on the electrocardiogram and no perfusion abnormalities on the thallium scan. Forty-four patients underwent cardiac catheterization as the initial evaluation (Group C) and four patients underwent transplantation without a formal cardiovascular evaluation (Group D).

RESULTS

Sixty-four of the 141 patients undergoing thallium stress testing had an adequate and normal examination (Group A). The incidence of perioperative cardiac events in this group was 2%. Seventy-seven patients (Group B) had an abnormal (n = 41) or an inadequate (n = 36) thallium stress test and most (n = 61) then underwent coronary angiography. The use of beta-blockers was the only predictor of an abnormal or inadequate thallium stress test (10 of 64 versus 27 of 77, chi 2 = 6.66, p less than or equal to 0.025). Forty-three percent (26 of 61 in Group B) of patients with inadequate or abnormal thallium stress tests had significant coronary artery disease on cardiac catheterization. The perioperative risk of cardiac events was not different in Group A versus Groups B, C, and D combined. Survival of Group A and B patients was not different but was significantly longer than that of Group C patients (p less than 0.001). Thallium stress testing was less expensive than cardiac catheterization ($1,000 versus $4,000 to $5,000).

CONCLUSIONS

Thallium stress testing allowed 45% of patients to avoid cardiac catheterization before renal transplantation. Discontinuing beta-blockers before thallium stress tests may improve exercise performance. The risk of perioperative cardiac events after transplantation was low and not different among patient groups. The relatively low predictive value of thallium stress testing for significant coronary artery disease and perioperative cardiac events in diabetic patients with end-stage renal disease suggests the need for the development of a more cost-effective, noninvasive screening test for this patient population.

Concordance of nutrient information obtained by different methods

Data obtained from two vegetarian and two nonvegetarian populations by 24-h diet recall, 3-day weighed diet diary, analysis of 3-day composite food samples, and measurement of certain biochemical parameters were compared. Correlations for group means (both sexes combined) for values obtained by 24-h recall versus 3-day diet diary were protein, r = 0.96 and total calories r = 0.86. For 3-day diet diary with food analysis, protein r = 0.89, fat r = 0.90 and for reported protein intake with serum prealbumin r = 0.74, with urinary urea nitrogen r = 0.87. Correlations were low for comparisons of means of male groups for most parameters. Individual correlations for reported protein intake and biochemical parameters were lower for males than for females. This suggests that male subjects may require special attention to insure accuracy of reporting and specimen collection. These findings indicate comparability of data from 24-h recall and 3-day diary, and agreement of dietary records with certain biochemical parameters. Protein and fat intake as determined from chemical analysis of a composite food sample correlated well (r = 0.89; r = 0.90) with that calculated from food tables.

Selected biochemical parameters in blood and urine

Selected biochemical parameters (serum protein, albumin, prealbumin, total retinol-binding protein, vitamins A and E, total carotenoids, and urinary urea and creatinine) were determined in healthy, free-living vegetarian and nonvegetarian subjects. The groups studied were composed of Seventh-day Adventist pure vegetarians, Seventh-day Adventist lacto-ovo vegetarians, Seventh-day Adventist nonvegetarians, and general population nonvegetarians. No values indicative of nutritional deficiencies were observed in any of the subjects. Serum carotenoid levels were significantly higher in Seventh-day Adventist pure vegetarians than in members of the other groups. Mean values for serum vitamin A showed no differences between the dietary groups, although 41% of general population nonvegetarian subjects (the group considered at highest risk for colon cancer) had serum vitamin A levels in the upper quartile of the distribution. From these data no conclusions can be drawn relating to the role of dietary habits as determinants of colon cancer risk.

Diet, nutrition intake, and metabolism in populations at high and low risk for colon cancer. Laboratory analysis of 3-day composite of food samples

In a study designed to characterize dietary patterns of vegetarian and nonvegetarian populations, chemical analysis of 3-day composite food samples showed lower fat content of food of vegetarians than that of nonvegetarians; pure vegetarians had the lowest. Unsaturated fatty acids were highest in the food of the pure vegetarian group. No significant difference was seen in percentage protein of the food consumed by male vegetarians and nonvegetarians while the food of female vegetarians was of lower protein content than that of the nonvegetarians. The relationship of these findings to the lower incidence of colon cancer in vegetarian populations remains to be determined.