Prospective cohort studies of bowel movement frequency and laxative use and colorectal cancer incidence in US women and men

Purpose

The associations between bowel movement frequency, laxative use, and colorectal cancer incidence remain uncertain. No published studies have accounted for potential latency between these factors and colorectal cancer onset.

Methods

We prospectively examined these associations among 88,173 women in the Nurses’ Health Study (NHS, 1982–2010) and 23,722 men in the Health Professionals Follow-up Study (HPFS, 2000–2010). Cox proportional hazards regression models were used to estimate multivariable hazard ratios (HRs, 95 % CIs). We conducted time lagged analyses to evaluate the potential latency in the NHS.

Results

We documented 2,012 incident colorectal cancer cases. The HRs (95 % CIs) for infrequent bowel movement relative to daily were 0.86 (95 % CI 0.71–1.04) in women and 0.81 (95 % CI 0.48–1.37) in men. The HRs for weekly to daily relative to never laxative use were 0.98 (95 % CI 0.81–1.20) in women and 1.41 (95 % CI 0.96–2.06) in men. In women, the HRs for every 3 days or less bowel movement relative to daily were 0.87 (95 % CI 0.59–1.27) for colorectal cancers that developed within 10 years of assessment, 1.03 (95 % CI 0.85–1.26) for 11–18 years after assessment, and 0.73 (95 % CI 0.54–1.01) for 19–28 years after assessment. The corresponding HRs for weekly to daily relative to never laxative use were 0.93 (95 % CI 0.63–1.37), 1.03 (95 % CI 0.74–1.44), and 0.98 (95 % CI 0.71–1.35), respectively.

Conclusion

Bowel movement frequency and laxative use appear not to be associated with colorectal cancer risk in this study.     

Racial disparities in advanced-stage colorectal cancer survival

Purpose

African-Americans (AA) have a higher incidence of and lower survival from colorectal cancer (CRC) compared with European Americans (EA). In the present study, statewide, population-based data from South Carolina Central Cancer Registry are used to investigate the relationship between race and age on advanced-stage CRC survival.

Methods

The study population was comprised of 3,865 advanced pathologically documented colon and rectal adenocarcinoma cases diagnosed between 01 January 1996 and 31 December 2006: 2,673 (69 %) EA and 1,192 (31 %) AA. Kaplan–Meier methods were used to generate median survival time and corresponding 95 % confidence intervals (CI) by race, age, and gender. Factors associated with survival were evaluated by fitting Cox proportional hazards regression models to generate hazard ratios (HR) and 95 % CI.

Results

We observed a significant interaction between race and age on CRC survival (p = 0.04). Among younger patients (<50 years), AA race was associated with a 1.34 times (95 % CI 1.06–1.71) higher risk of death compared with EA. Among older patients, we observed a modest increase in risk of death among AA men compared with EA [HR 1.16 (95 % CI 1.01–1.32)] but no difference by race between women [HR 0.94 (95 % CI 0.82–1.08)]. Moreover, we observed that the disparity in survival has worsened over the past 15 years.

Conclusions

Future studies that integrate clinical, molecular, and treatment-related data are needed for advancing understanding of the racial disparity in CRC survival, especially for those <50 years old.     

Body mass index and weight change in men with prostate cancer: progression and mortality

Purpose

Body mass index (BMI) is a modifiable lifestyle factor that has been associated with an increased risk of fatal prostate cancer and biochemical recurrence. The main purpose of the present study was to investigate the association between the exposure BMI at the time of a prostate cancer diagnosis and weight change after diagnosis, and the outcomes of prostate cancer progression and mortality in a large cohort study.

Methods

Data from 4,376 men diagnosed with clinically localized prostate cancer between 1997 and 2002 were analyzed. BMI and weight change were self-reported in 2007. Hazard ratios (HRs) with 95 % confidence intervals (CIs) were estimated in complete-case analysis (n = 3,214) using Cox proportional hazards models.

Results

Progression was experienced among 639 (14.6 %) of the study participants, and in total, 450 (10.3 %) deaths of any cause and 134 (3.1 %) prostate cancer-specific deaths were recorded during follow-up. Obese men had a 47 % increased rate of overall mortality compared to normal weight men (HR 1.47, 95 % CI 1.03–2.10). No statistically significant associations were found for BMI and prostate cancer progression or prostate cancer-specific mortality. A weight loss >5 % after diagnosis almost doubled the rate of overall mortality compared to maintaining a stable weight (HR 1.94, 95 % CI 1.41–2.66), while a weight gain >5 % was associated with an almost doubled increased rate of prostate cancer-specific mortality (HR 1.93, 95 % CI 1.18–3.16).

Conclusions

Being obese was associated with an increased rate of overall mortality, and gaining weight after a prostate cancer diagnosis was associated with an increased rate of prostate cancer-specific mortality.     

Attained height,sex, and risk of cancer at different anatomic sites in the NIH-AARP Diet and Health Study

Purpose

To examine the association of adult height with risk of cancer at different anatomic sites in a cohort of men and women.

Methods

The association of self-reported height with subsequent cancer risk was assessed in 288,683 men and 192,514 women enrolled in the National Institutes of Health-AARP Diet and Health Study. After a median follow-up of 10.5 years, incident cancer was diagnosed in 51,139 men and 23,407 women. Cox proportional hazards models were used to estimate hazard ratios (HRs) and 95 % confidence intervals (95 % CIs) for the association of height with cancer risk.

Results

After adjustment for covariates, height was positively associated with increased risk of all cancers combined in both men [HR_{10 cm increase} = 1.05 (95 % CI 1.04–1.06)] and women [HR_{10 cm increase} = 1.08 (95 % CI 1.06–1.10)]. Several sites common to men and women showed significant positive associations with height: colon, rectum, kidney, melanoma, and non-Hodgkin’s lymphoma. For other shared sites, the association differed by sex. For still other sites, there was no clear association with height. Positive associations were also observed with cancers of the breast, endometrium, and prostate.

Conclusions

Different patterns were observed in the height–cancer association by sex. Studies investigating the biological mechanisms underlying the association of height with cancer risk should focus on those sites that show a reproducible association with attained height.     

Diabetes and colorectal cancer screening among men and women in the USA: National Health Interview Survey: 2008, 2010

Purpose

Adults with diabetes are at increased risk of being diagnosed with and dying from colorectal cancer, but it is unclear whether colorectal cancer screening (CRCS) use is lower in this population. Using the 2008 and 2010 National Health Interview Survey data, we examined whether guideline-concordant CRCS is lower among men and women with self-reported diabetes.

Methods

We calculated the weighted percentage of guideline-concordant CRCS and unadjusted and adjusted prevalence ratios (PR) comparing adults aged 51–75 years with diabetes (n = 6,514) to those without (n = 8,371). We also examined effect modification by age (51–64 and 65–75), race/ethnicity, and number of medical office visits (0–3, ≥4).

Results

The unadjusted prevalence of CRCS among men with diabetes was significantly higher than men without (63.3 vs. 58.0 %; PR = 1.09 95 % CI 1.03–1.16). In adjusted models, this relationship was evident among older [adjusted PR (aPR) = 1.13 95 % CI 1.06–1.21] but not younger men (aPR = 0.99 95 % CI 0.91–1.08; p for interaction term ≤0.01). There was no significant association between diabetes and CRCS among women overall (56.6 vs. 57.9 %; PR = 0.98 95 % CI 0.92–1.04) or by age group. Race/ethnicity and the number of medical visits did not significantly modify the association between diabetes and CRCS for men or women.

Conclusions

Men and women with self-reported diabetes were not less likely to be up to date with CRCS than those without diabetes. Older men with diabetes were more likely to be up to date with CRCS than those without diabetes.     

Reproductive factors and risk of lung cancer in female textile workers in Shanghai, China

Purpose

Hormonal factors may play a role in the development of lung cancer in women. This study examined the relationship between lung cancer and reproductive factors in a large cohort of women, most of whom never smoked (97 %).

Methods

A cohort of 267,400 female textile workers in Shanghai, China, enrolled in a trial of breast self-examination provided information on reproductive history, demographical factors, and cigarette smoking at enrollment in 1989–91. The cohort was followed until July of 2000 for incidence of lung cancer; 824 cases were identified. Hazard ratios (HR) and 95 % confidence intervals (CI) associated with selected reproductive factors were calculated using Cox proportional hazards modeling, adjusting for smoking, age, and also parity when relevant.

Results

Nulliparous women were at increased risk compared to parous women (HR = 1.33, 95 % CI 1.00–1.77). Women who had gone through menopause at baseline were at increased risk compared to women of the same age who were still menstruating. Risk was higher in women with a surgical menopause (HR = 1.64, 95 % CI 0.96–2.79) than in those with a natural menopause (HR = 1.35, 95 % CI 0.84–2.18), and risk was highest in those postmenopausal women with a hysterectomy and bilateral oophorectomy at baseline (HR = 1.39, 95 % CI 0.96–2.00), although the risk estimates were not statistically significant.

Conclusions

These results support experimental data that demonstrate a biological role for hormones in lung carcinogenesis.     

Dietary arsenic intake and subsequent risk of cancer: the Japan Public Health Center-based (JPHC) Prospective Study

Purpose

Arsenic is a known human carcinogen and has been linked to adverse health outcomes, including cancer. However, the effects of arsenic exposure from food on health are still unknown. We researched to examine the association between arsenic exposure from food and incidence of cancer in a Japanese population.

Methods

We conducted a population-based prospective study in 90,378 Japanese men and women aged 45–74 years. Participants responded to a validated questionnaire that included 138 food items. We estimated dietary arsenic intake from 12 food groups (75 items) based on the questionnaire data. During 11 years of follow-up, 7,002 cancer cases were identified. Hazard ratios (HRs) and 95 % confidence intervals (CIs) for cancer were calculated by Cox proportional hazards modeling.

Results

Total arsenic and inorganic arsenic showed no association with the risk of total cancer in both men and women. Total arsenic and inorganic arsenic intake tended to be associated with an increased risk of lung cancer in men. In particular, these positive associations were strengthened in currently smoking men, with HRs (95 % CI) in the highest categories of arsenic and inorganic arsenic intake compared with the lowest of 1.29 (95 % CI = 1.03–1.61) and 1.36 (95 % CI = 1.09–1.70), respectively. We also detected an interaction between arsenic and inorganic arsenic intake and smoking status in men (p _interaction < 0.01 and 0.07, respectively).

Conclusion

A significant dose–response trend was seen in the association of arsenic and inorganic intake with lung cancer risk in currently smoking men.     

Iron metabolism and risk of cancer in the Swedish AMORIS study

Objectives

Pre-clinical studies have shown that iron can be carcinogenic, but few population-based studies investigated the association between markers of the iron metabolism and risk of cancer while taking into account inflammation. We assessed the link between serum iron (SI), total-iron binding capacity (TIBC), and risk of cancer by levels of C-reactive protein (CRP) in a large population-based study (n = 220,642).

Methods

From the Swedish Apolipoprotein Mortality Risk (AMORIS) study, we selected all participants (>20 years old) with baseline measurements of serum SI, TIBC, and CRP. Multivariate Cox proportional hazards regression was carried out for standardized and quartile values of SI and TIBC. Similar analyses were performed for specific cancers (pancreatic, colon, liver, respiratory, kidney, prostate, stomach, and breast cancer). To avoid reverse causation, we excluded those with follow-up <3 years.

Results

We found a positive association between standardized TIBC and overall cancer [HR 1.03 (95 % CI 1.01–1.05)]. No statistically significant association was found between SI and cancer risk except for postmenopausal breast cancer [HR for standardized SI 1.09 (95 % CI 1.02–1.15)]. The association between TIBC and specific cancer was only statistically significant for colon cancer [i.e., HR for standardized TIBC: 1.17 (95 % CI 1.08–1.28)]. A borderline interaction between SI and levels of CRP was observed only in stomach cancer.

Conclusions

As opposed to pre-clinical findings for serum iron and cancer, this population-based epidemiological study showed an inverse relation between iron metabolism and cancer risk. Minimal role of inflammatory markers observed warrants further study focusing on developments of specific cancers.     

The association between television watching time and all-cause mortality after breast cancer

Purpose

Sedentary time is a rapidly emerging independent risk factor for mortality in the general population, but its prognostic effect among cancer survivors is unknown. In a multiethnic, prospective cohort of breast cancer survivors, we hypothesized that television watching time would be independently associated with an increased risk of death from any cause.

Methods

The Health, Eating, Activity, and Lifestyle Study cohort included 687 women diagnosed with local or regional breast cancer. On average 30 (±4) months postdiagnosis, women completed self-report assessments on time spent sitting watching television/videos in a typical day in the previous year. Multivariate Cox proportional hazards models were used to estimate hazard ratios (HR) and 95 % confidence intervals (CI) for death from any cause (n?=?89) during the 7 years of follow-up.

Results

Television time (top tertile vs. bottom tertile) was positively related to risk of death (HR, 1.94; 95 % CI, 1.02, 3.66, p _trend?=?0.024), but the association was attenuated and not statistically significant after adjustment for aerobic moderate-vigorous intensity physical activity (HR, 1.70; 95 % CI, 0.89, 3.22, p _trend?=?0.14) and all covariates (HR, 1.39; 95 % CI, 0.69, 2.82, p _trend?=?0.48).

Conclusion

In this first published investigation on this topic, we did not observe a statistically significant multivariate-adjusted association between television watching time and risk of death among women diagnosed with breast cancer.

Implications for cancer survivors

These results begin an evidence base on this topic that can be built upon to inform lifestyle recommendations for this expanding, aging population.     

Adherence to the WCRF/AICR cancer prevention recommendations and cancer-specific mortality: results from the Vitamins and Lifestyle (VITAL) Study

Purpose

In 2007, the World Cancer Research Fund (WCRF) and American Institute for Cancer Research (AICR) released eight recommendations related to body fatness, physical activity, and diet aimed at preventing the most common cancers worldwide. The purpose of this paper is to estimate the association between meeting these recommendations and cancer-specific mortality.

Methods

We operationalized six recommendations (related to body fatness; physical activity; and consumption of foods that promote weight gain, plant foods, red and processed meat, and alcohol) and examined their association with cancer-specific mortality over 7.7 years of follow-up in the Vitamins and Lifestyle (VITAL) Study cohort. Participants included 57,841 men and women ages 50–76 in 2000–2002 who had not been diagnosed with cancer prior to baseline. Cancer-specific deaths (n = 1,595) were tracked through the Washington State death file.

Results

Meeting the recommendations related to plant foods and foods that promote weight gain were most strongly associated with lower cancer-specific mortality [hazard ratio (HR) 0.82, 95 % confidence interval (CI) 0.67, 1.00 and HR 0.82, 95 % CI 0.70, 0.96, respectively]. Cancer-specific mortality was 61 % lower in respondents who met at least five recommendations compared to those who met none (HR 0.39, 95 % CI 0.24, 0.62). Cancer-specific mortality was 10 % lower on an average with each additional recommendation met (per-recommendation HR 0.90, 95 % CI 0.85, 0.94; p _trend < 0.001). This association did not differ by sex or age but was stronger in non-smokers (HR 0.84, 95 % CI 0.76, 0.92) than in smokers (HR 0.93, 95 % CI 0.87, 0.98; p _interaction = 0.086).

Conclusion

Adherence to the WCRF/AICR cancer prevention recommendations developed to reduce incidence of common cancers could substantially reduce cancer-specific mortality in older adults.     

Prospective cohort study on television viewing time and incidence of lung cancer: findings from the Japan Collaborative Cohort Study

Purpose

To ascertain whether prolonged television viewing time was associated with lung cancer incidence in Japanese adults aged 40–79 years from a nationwide large-scale cohort study.

Methods

A total of 54,258 adults (23,090 men and 31,168 women) without a history of cancer at baseline (1988–1990) were enrolled and followed for a median of 15.6 years. The Cox proportional hazard model was used to calculate hazard ratios (HRs) and 95 % confidence interval (CI) for lung cancer according to television viewing time adjusted for age and other possible confounding factors.

Results

During the study period, 798 participants were diagnosed with lung cancer. The HR of male participants who watched television for more than 4 h daily was 1.36 (95 % CI 1.04–1.80) compared with <2 h/day.

Conclusion

Our findings suggest that reducing the amount of time spent watching television may be beneficial for preventing lung cancer.     

Body mass index, effect modifiers, and risk of pancreatic cancer: a pooled study of seven prospective cohorts

Objective

To investigate whether the positive association of body mass index (BMI, kg/m²) with risk of pancreatic cancer is modified by age, sex, smoking status, physical activity, and history of diabetes.

Methods

In a pooled analysis of primary data of seven prospective cohorts including 458,070 men and 485,689 women, we identified 2,454 patients with incident pancreatic cancer during an average 6.9 years of follow-up. Cox proportional hazard regression models were used in data analysis.

Results

In a random-effects meta-analysis, for every 5 kg/m² increment in BMI, the summary relative risk (RR) was 1.06 (95% confidence interval (CI) 0.99–1.13) for men and 1.12 (95% CI 1.05–1.19) for women. The aggregate analysis showed that compared with normal weight (BMI: 18.5 to <25), the adjusted RR was 1.13 (95% CI 1.03–1.23) for overweight (BMI: 25 to <30) and 1.19 (95% CI 1.05–1.35) for obesity class I (BMI: 30 to <35). Tests of interactions of BMI effects by other risk factors were not statistically significant. Every 5 kg/m² increment in BMI was associated with an increased risk of pancreatic cancer among never and former smokers, but not among current smokers (P-interaction = 0.08).

Conclusion

The present evidence suggests that a high BMI is an independent risk factor of pancreatic cancer.     

Waist circumference,body mass index,and postmenopausal breast cancer incidence in the Cancer Prevention Study-II Nutrition Cohort

Purpose

High body mass index (BMI) is an established risk factor for postmenopausal breast cancer. However, less is known about associations with waist circumference. In particular, it is unclear whether a larger waist circumference is associated with risk more than would be expected based solely on its contribution to BMI.

Methods

We examined the associations of BMI and waist circumference with risk of postmenopausal breast cancer, with and without mutual adjustment, in the Cancer Prevention Study-II Nutrition Cohort. Analyses included 28,965 postmenopausal women who reported weight and waist circumference on a questionnaire in 1997 and were not taking menopausal hormones.

Results

During a median follow-up of 11.58 years, 1,088 invasive breast cancer cases were identified. Hazard ratios (HR) and 95 % confidence intervals (CI) were estimated from multivariable-adjusted Cox proportional hazard regression models. Without adjustment for BMI, a larger waist circumference was associated with higher risk of breast cancer (per 10 cm increase in waist circumference, HR = 1.13, 95 % CI 1.08–1.19). However, adjustment for BMI eliminated the association with waist circumference (per 10 cm HR = 1.00, 95 % CI 0.92–1.08). BMI was associated with risk unadjusted for waist circumference (per 1 kg/m² HR = 1.04, 95 % CI 1.03–1.05) and adjusted for waist circumference (per 1 kg/m² HR = 1.04, 95 % CI 1.02–1.06).

Conclusions

Our study of predominantly white women provides evidence that a larger waist circumference is associated with higher risk of postmenopausal breast cancer, but not beyond its contribution to BMI.     

Colonoscopy reduced distal colorectal cancer risk and excess cancer risk associated with family history

Purpose

Colonoscopy efficacy at preventing proximal colorectal cancer (CRC) is questioned, and little is known about efficacy in high-risk versus medium-risk populations. We investigated the relationship between colonoscopy screening, family history of colorectal cancer (FHCC), and CRC risk by site.

Methods

Among 92,078 women of the E3N prospective cohort, 692 CRCs have been diagnosed after a median follow-up of 15.4 years. Cox proportional hazard models estimated adjusted hazards ratios according to subsites of cancer and FHCC.

Results

A personal history of colonoscopy (PHC; n = 37,470) was associated with decreased rectal and distal colon cancer risks (hazard ratio (HR) = 0.57; 95 % Confidence Interval (CI) = 0.42–0.78 and HR = 0.37; 95 % CI = 0.26–0.52, respectively), but not proximal colon cancer risk (HR = 0.87; 95 % CI = 0.64–1.18). In women with no prior colonoscopy, those with FHCC had a 80 % higher CRC risk than those without FHCC. In women with previous colonoscopy, CRC risk was similar in women with and without FHCC (p for interaction = 0.04).

Conclusions

Results showed colonoscopy ability to prevent distal cancers, but not proximal cancers in women. Colonoscopy screening also reduced the excess risk of women with FHCC to that of women with no FHCC.     

Statins and colorectal cancer risk: a longitudinal study

Purpose

Studies evaluating the association between statins and colorectal cancer (CRC) have used various methods to address bias and have reported mixed findings. We sought to assess the association in a large cohort of residents in Emilia-Romagna, Italy, using multiple methods to address different sources of confounding. We also sought to explore potential effect measure modification by sex.

Methods

We conducted a retrospective cohort study using the 2003–2010 healthcare database of Emilia-Romagna, Italy. We identified all initiators of statins; initiators of glaucoma medications served as the comparison group to account for confounding by healthy user bias. We followed patients longitudinally to identify CRC cases in hospital discharge data. We used multivariable Cox regression analyses to adjust for confounding by CRC risk factors and we conducted a sensitivity analysis using propensity score matching.

Results

After multivariable adjustment, initiators of statins had a lower incidence rate of CRC as compared to initiators of glaucoma drugs [hazard ratio (HR) 0.79; 95 % CI 0.69–0.90]. In sex-stratified analyses we observed a protective effect in men (HR 0.77; 95 % CI 0.67–0.88) but not in women (HR 0.96; 95 % CI 0.82–1.1). Results were similar in propensity score analyses.

Conclusions

After adjusting for observed risk factors, statin initiation versus glaucoma drug initiation was associated with a reduced risk of CRC in men but not in women. While this study is subject to many limitations, it corroborates a previous study that found sex differences in the association between statins and CRC.     

Bilateral oophorectomy and risk of cancer in African American women

Purpose

African American women are more likely to undergo hysterectomy, with or without bilateral oophorectomy, at younger ages than white women. It is well established that women who have a bilateral oophorectomy at younger ages are at reduced risk of breast cancer, and there is some evidence of an increased risk of colorectal and lung cancer.

Methods

Using data from 44,514 women in the Black Women’s Health Study, we prospectively investigated the relation of hysterectomy and oophorectomy to incidence of breast, colorectal, and lung cancer and to mortality from cancer. Hazard ratios (HRs) and 95 % confidence intervals (CIs) were estimated using Cox proportional hazards regression with control for confounding factors.

Results

During 16 years of follow-up, hysterectomy alone, relative to no hysterectomy, was not associated with risk of breast, lung, or colorectal cancer. Bilateral oophorectomy, relative to hysterectomy with ovarian conservation, was inversely associated with risk of estrogen receptor-positive (ER+) breast cancer (HR 0.62; 95 % CI 0.45–0.85) but not with ER-negative breast cancer; age at surgery and menopausal hormone use did not modify the associations. HRs for the association of bilateral oophorectomy with incidence of colorectal and lung cancer were nonsignificantly increased for women who had surgery before age 40 years and had used menopausal hormones for less than 2 years (HR 1.65; 95 % CI 0.73–3.73 for colorectal cancer and HR 1.71; 95 % CI 0.68–4.31 for lung cancer). Bilateral oophorectomy was not associated with cancer mortality.

Conclusions

Bilateral oophorectomy was associated with reduced risk of ER+ breast cancer regardless of age at surgery and use of menopausal hormones. There were nonsignificant increases in risk of colorectal and lung cancer for women with oophorectomy at younger ages and short duration of menopausal hormone use.     

A prospective cohort study of shift work and the risk of death from pancreatic cancer in Japanese men

Purpose

There is mounting evidence that shift work involving night work increases cancer risk. We examined the relationship between working rotating shifts and the risk of death from pancreatic cancer on the basis of data from the Japanese Collaborative Cohort Study (JACC Study).

Methods

The present analysis was restricted to 22,224 men who were 40–65 years of age at baseline (1988–1990) and who reported working full time or were self-employed in the JACC Study. The subjects were followed through 31 December 2009. Information on occupation and lifestyle factors was collected using a self-administered questionnaire. The Cox proportional hazards model was used to estimate the relative risk (RR) and 95 % confidence interval (CI) for the risk of death from pancreatic cancer in relation to shift work.

Results

During the follow-up period, 127 pancreatic cancer deaths were observed. Overall, we found no statistically significant increase in the risk of death from pancreatic cancer associated with rotating shift work. As compared to day-shift workers, the RRs were 0.83 (95 % CI 0.43–1.60) for rotating shift workers and 0.61 (95 % CI 0.22–1.60) for fixed night-shift workers, after adjustment for potential confounding factors. The multivariable-adjusted RR was 1.34 (95 % CI 0.66–2.75) among rotating shift workers in the analysis restricted to men who reported working full time at baseline.

Conclusions

Our data did not support the hypothesis that shift work is significantly associated with the risk of death from pancreatic cancer in this cohort of Japanese men.     

Body size in early life and breast cancer risk in African American and European American women

Purpose

There is growing evidence that body size in early life influences lifetime breast cancer risk, but little is known for African American (AA) women.

Methods

We evaluated body size during childhood and young adulthood and breast cancer risk among 1,751 cases [979 AA and 772 European American (EA)] and 1,673 controls (958 AA and 715 EA) in the Women’s Circle of Health Study. Odds ratio (OR) and 95 % confidence intervals (CI) were computed using logistic regression models while adjusting for potential covariates.

Results

Among AA women, being shorter at 7–8 years compared to peers was associated with increased postmenopausal breast cancer risk (OR 1.68, 95 % CI 1.02–2.74), and being heavier at menarche with decreased postmenopausal breast cancer risk, although of borderline significance (OR 0.45, 95 % CI 0.20–1.02). For EA women, being shorter from childhood through adolescence, particularly at menarche, was associated with reduced premenopausal breast cancer risk (OR 0.55, 95 % CI 0.31–0.98). After excluding hormone replacement therapy users, an inverse association with postmenopausal breast cancer was found among EA women reporting to be heavier than their peers at menarche (OR 0.18, 95 % CI 0.04–0.79). The inverse relationship between BMI at age 20 and breast cancer risk was stronger and only statistically significant in EA women. No clear association with weight gain since age 20 was found.

Conclusions

Findings suggest that the impact of childhood height on breast cancer risk may differ for EA and AA women and confirm the inverse association previously reported in EA populations with adolescent body fatness, in AA women.     

Garlic consumption and colorectal cancer risk in the CPS-II Nutrition Cohort

Purpose

The World Cancer Research Fund/American Institute for Cancer Research identified a probable role for garlic in colorectal cancer prevention based on preclinical evidence and epidemiologic studies, but prospective data are limited. The purpose of this paper was to contribute additional evidence on this topic for men and women in a large prospective cohort study.

Methods

In 1999, 42,824 men and 56,876 women in the Cancer Prevention Study II Nutrition Cohort completed a questionnaire with information on dietary garlic consumption. Garlic supplement use was assessed in 2001. Cox proportional hazards regression was used to estimate multivariable-adjusted hazard rate ratios (HRs) and 95?% confidence intervals (CIs).

Results

During 7?years of follow-up, 579 men and 551 women were diagnosed with colorectal cancer. Among men, daily garlic consumption was associated with a non-significant higher colorectal cancer risk (HR?=?1.04, 95?% CI 0.99–1.08 for each additional clove or “4 shakes” of garlic per week), whereas the association was borderline inverse in women (HR?=?0.95, 95?% CI 0.91–1.00, p heterogeneity by sex?=?0.03). Garlic supplement use was not related to a lower risk of colorectal cancer, and in men, former use was associated with a higher risk of colorectal cancer (HR?=?1.85, 95?% CI 1.13–3.03).

Conclusions

These results provide weak support for a role of dietary garlic consumption in colorectal cancer prevention in women, but a possible increased risk in men. Further research is needed to confirm different associations by sex.