Racial disparities in red meat and poultry intake and breast cancer risk

Purpose

Research on the role of red meat and poultry consumption in breast carcinogenesis is inconclusive, but the evidence in African-American (AA) women is lacking. The association between consuming meat and breast cancer risk was examined in the Women’s Circle of Health Study involving 803 AA cases, 889 AA controls, 755 Caucasian cases, and 701 Caucasian controls.

Methods

Dietary information was collected using a Food Frequency Questionnaire. Odds ratios (OR) and 95 % confidence intervals (CI) were obtained from logistic regression models adjusting for potential covariates.

Results

Comparing the fourth versus the first quartiles, among Caucasian women, processed meat (OR = 1.48; 95 % CI 1.07–2.04), unprocessed red meat (OR = 1.40; 95 % CI 1.01–1.94), and poultry intakes (OR = 1.42; 95 % CI 1.01–1.99) increased breast cancer risk. Risk associated with poultry intake was more dominant in premenopausal women (OR = 2.33; 95 % CI 1.44–3.77) and for women with ER? tumors (OR = 2.55; 95 % CI 1.29–5.03) in the Caucasian group. Associations in AA women were mostly null except for a significant increased risk trend with processed meat consumption for ER+ tumors (OR = 1.36; 95 % CI 0.94–1.97, p trend = 0.04).

Conclusions

Overall, associations between breast cancer risk and consumption of red meat and poultry were of different magnitude in AA and Caucasian women, with further differences noted by menopausal and hormone receptor status in Caucasian women. This is the first study to examine racial differences in meat and breast cancer risk and represents some of the first evidence in AA women.     

Legume intake and the risk of cancer: a multisite case–control study in Uruguay

Background

Previous studies have suggested that a high intake of legumes may decrease the risk of stomach and prostate cancer and some other cancers. However, the evidence is still limited. To further explore the association between legume intake and cancer risk we conducted a case–control study of 11 cancer sites in Uruguay between 1996 and 2004, including 3,539 cancer cases and 2,032 hospital controls.

Results

The highest versus the lowest tertile of legume intake was associated with a significant decrease in the risk of cancers of the oral cavity and pharynx (OR = 0.48, 95% CI: 0.34–0.68), esophagus (OR = 0.54, 95% CI: 0.38–0.77), larynx (OR = 0.55, 95% CI: 0.40–0.77), upper aerodigestive tract (OR = 0.50, 95% CI: 0.40–0.63), stomach (OR = 0.69, 95% CI: 0.49–0.97), colorectum (OR = 0.43, 95% CI: 0.32–0.59), kidney (OR = 0.41, 95% CI: 0.24–0.71), and all sites combined (OR = 0.68, 95% CI: 0.59–0.78). No significant association was observed between legume intake and cancers of the lung (OR = 1.03, 95% CI: 0.83–1.27), breast (OR = 0.89, 95% CI: 0.65–1.20), prostate (OR = 0.87, 95% CI: 0.64–1.18) or bladder (OR = 0.82, 95% CI: 0.57–1.17). Similar results were found for both beans and lentils.

Conclusion

Higher intake of legumes was associated with a decreased risk of several cancers including those of the upper aerodigestive tract, stomach, colorectum, and kidney, but not lung, breast, prostate or bladder. Further investigations of these associations in prospective cohort studies are warranted.     

Allergy and brain tumors in the INTERPHONE study: pooled results from Australia, Canada, France, Israel, and New Zealand

Purpose

A history of allergy has been inversely associated with several types of cancer although the evidence is not entirely consistent. We examined the association between allergy history and risk of glioma, meningioma, acoustic neuroma, and parotid gland tumors using data on a large number of cases and controls from five INTERPHONE study countries (Australia, Canada, France, Israel, New Zealand), to better understand potential sources of bias in brain tumor case–control studies and to examine associations between allergy and tumor sites where few studies exist.

Methods

A total of 793 glioma, 832 meningioma, 394 acoustic neuroma, and 84 parotid gland tumor cases were analyzed with 2,520 controls recruited during 2000–2004. Conditional logistic regression models were used to obtain odds ratios (ORs) and 95 % confidence intervals (CIs) for associations between self-reported allergy and tumor risk.

Results

A significant inverse association was observed between a history of any allergy and glioma (OR = 0.73, 95 % CI 0.60–0.88), meningioma (OR = 0.77, 95 % CI 0.63–0.93), and acoustic neuroma (OR = 0.64, 95 % CI 0.49–0.83). Inverse associations were also observed with specific allergic conditions. However, inverse associations with asthma and hay fever strengthened with increasing age of allergy onset and weakened with longer time since onset. No overall association was observed for parotid gland tumors (OR = 1.21, 95 % CI 0.73–2.02).

Conclusions

While allergy history might influence glioma, meningioma, and acoustic neuroma risk, the observed associations could be due to information or selection bias or reverse causality.     

Physical activity and other lifestyle factors in relation to the prevalence of colorectal adenoma: a colonoscopy-based study in asymptomatic Koreans

Purpose

To evaluate physical activity and other lifestyle risk factors in relation to the prevalence of colorectal adenomas in asymptomatic Koreans.

Methods

A total of 1,526 asymptomatic subjects who underwent a colonoscopy were enrolled. Lifestyle factors such as physical activity and smoking data were obtained using a questionnaire. The subjects were grouped into three exposure levels by tertiles of metabolic equivalent hours per week. We evaluated the risk factors in subjects with adenomas by risk stratification (low-risk adenoma group vs. high-risk adenoma group) and by anatomic location (proximal colon, distal colon, rectum, and multiple locations). The high-risk adenoma group was defined as subjects with advanced adenomas or multiple (≥3) adenomas.

Results

A total of 456 participants had colorectal adenomas, and 861 had no polyps. In multivariate analyses, higher levels of physical activity were associated with a significantly decreased risk of colorectal adenomas (OR = 0.56, 95 % CI 0.40–0.79). This inverse association was stronger for the risk of high-risk adenomas (OR = 0.39, 95 % CI 0.21–0.73) than for low-risk adenomas (OR = 0.62, 95 % CI 0.43–0.89). The negative relation of physical activity was significant for distal colon adenomas (OR = 0.54, 95 % CI 0.30–0.95) and the adenomas with multiple locations (OR = 0.39, 95 % CI 0.21–0.72).

Conclusions

Increased physical activity is associated with a reduced prevalence of colorectal adenomas. The inverse association between physical activity and adenoma was stronger for the risk of advanced or multiple adenomas.     

Polymorphism of A118G in μ-opioid receptor gene is associated with risk of esophageal squamous cell carcinoma in a Chinese population

Background

Previous studies have indicated a direct effect of μ-opioid receptors on tumor progression or recurrence. An A118G polymorphism in the μ-opioid receptor gene was believed to play an important role in this carcinogenic process. The aim of the present study was to investigate the association between the A118G polymorphism and the risk of esophageal squamous cell carcinoma (ESCC) in a Chinese population.

Method

The case–control study included 260 cancer patients and 291 controls from a Chinese Han and Chinese TuJia population in Enshi region, China. Genotypes were determined by TaqMan platform. Odds ratios (ORs) and 95 % confidence intervals (CIs) were calculated using multivariate unconditional logistic regression.

Results

Compared with the G/G genotype, the A/A genotype exhibited a significantly elevated risk for ESCC (OR = 3.12, 95 % CI [1], 1.11–6.01). A significant interaction between the A118G polymorphism and age, smoking status, and family history of cancer was also found (OR = 2.25, 95 % CI 1.36–4.12; OR = 1.75, 95 % CI 1.23–2.32; OR = 3.14, 95 % CI 1.31–7.28, respectively).

Conclusion

The A118G polymorphism in the μ-opioid receptor gene might be associated with the risk of ESCC in Chinese population.     

Dietary consumption and diet diversity and risk of developing bladder cancer: results from the South and East China case–control study

Background

The epidemiologic evidence on the role of dietary consumption on the risk of bladder cancer in the Chinese population is limited. We investigated the role of dietary consumption and diet diversity on the risk of developing bladder cancer within a Chinese population.

Methods

A case–control study of 487 cases and 469 controls was conducted in four hospitals in China. A food frequency questionnaire was used to gather information on the consumption of 35 food items. Unconditional logistic regression models were used to derive odds ratios (ORs) and corresponding 95 % confidence intervals (95 % CI) for the relationship between dietary factors, dietary diversity scores, and bladder cancer.

Results

The ORs of bladder cancer for red meat (OR = 1.8, 95 % CI:1.1–3.0;p _trend = 0.01), organ meat (OR = 1.6, 95 % CI:0.9–2.9;p _trend = 0.04), leafy vegetables (OR = 2.9, 95 % CI:1.6–5.4;p _trend = 0.003), bulb vegetables (OR = 2.3, 95 % CI:1.3–4.0;p _trend = 0.003), and preserved vegetables (OR = 2.3, 95 % CI:1.2–4.2;p _trend = 0.02) were significantly increased when comparing the highest to lowest level of consumption. The ORs for white fresh fish (OR = 0.5, 95 % CI:0.3–0.9;p _trend = 0.004), citrus fruits (OR = 0.4, 95 % CI:0.3–0.8;p _trend = 0.007), stone fruits (OR = 0.4, 95 % CI:0.2–0.6;p _trend < 0.001), vine fruits (OR = 0.5, 95 % CI:0.2–1.0;p _trend = 0.02), flower vegetables (OR = 0.3, 95 % CI:0.2–0.6;p _trend < 0.001), potatoes (OR = 0.4, 95 % CI:0.2–0.9;p _trend = 0.005), or dairy products (OR = 0.4, 95 % CI:0.3–0.7;p _trend < 0.001) were significantly decreased when comparing the highest to lowest level of consumption. Subjects with the highest total diet diversity (OR = 0.4, 95 % CI:0.2–1.1;p _trend = 0.02) and fruit diversity (OR = 0.1, 95 % CI:0.0–0.3;p _trend < 0.001) had reduced ORs of and compared to subjects with the lowest diversity.

Conclusion

Our results indicate that a diet with higher total diet diversity and in particular fruit diversity may reduce the risk of bladder cancer.     

Association of MTHFR C677T polymorphisms and colorectal cancer risk in Asians: evidence of 12,255 subjects

Objectives

To investigate the relationship of the MTHFR polymorphisms (C677T) and the risk of CRC by meta-analysis.

Methods

Relevant literatures concerning the association between the MTHFR C677T polymorphism and the risk of CRC were searched using the electronic database PubMed, EMBASE, Cochrane and China National Knowledge Infrastructure (CNKI). Odds ratio (ORs) and 95 % confidence intervals (CIs) were determined to assess the gene–disease association using fixed or random effect models, according to the heterogeneity among included studies.

Results

The study shows that the MTHFR 677 TT homozygous genotype significantly decreases the risk of CRC in Asians (TT vs. CC: OR = 0.82, 95 % CI 0.73–0.92; TT vs. CT: OR = 0.84, 95 % CI 0.75–0.94; TT vs. CC+TT: OR = 0.83, 95 % CI 0.75–0.93).

Conclusion

This meta-analysis indicated that the MTHFR 677 TT homozygous genotype decreased the risk of CRC in Asians, while the MTHFR 677 CT heterozygous genotype did not contribute to CRC susceptibility.     

ABO blood group and esophageal carcinoma risk: from a case–control study in Chinese population to meta-analysis

Purpose

The association between ABO blood group and the risk of esophageal carcinoma (EC) in previously published studies is uncertain and conflicting. The aim of the current study was to determine the correlation of ABO blood group with EC risk via a case–control study and meta-analysis.

Methods

We performed a population-based case–control study of 3,595 cases and 41,788 controls in Chinese population to evaluate the association between ABO blood group and EC risk. Then, a comprehensive meta-analysis combining our original data and previously published data was conducted to clearly discern the real relationship. The strength of association was measured by odds ratios (ORs) with 95 % confidence intervals (CI).

Results

In our case–control study, the risk of EC in blood group B was significantly higher than that in non-B groups (A, O, and AB) (OR = 1.15, 95 % CI 1.09–1.21). Compared with non-O groups (A, B, and AB), individuals with blood group O demonstrated a reduced risk of EC (OR = 0.90, 95 % CI 0.85–0.94). The meta-analysis also indicated that blood group B was associated with significantly higher EC risk (OR = 1.20, 95 % CI 1.10–1.31), and people with blood group O had a decreased EC risk (OR = 0.94, 95 % CI 0.90–0.99). Neither the case–control study nor the meta-analysis produced any significant association of blood group A or AB with EC risk.

Conclusion

Results from our case–control study and the followed meta-analysis confirmed that there was an increased risk of EC in blood group B individuals, whereas a decreased risk of EC was observed in blood group O individuals.     

Inverse associations between serum concentrations of zeaxanthin and other carotenoids and colorectal neoplasm in Japanese

Background

To investigate the associations between serum concentrations of carotenoids and the presence of colorectal polyps and cancers in Japanese using a cross-sectional study.

Methods

893 subjects who underwent colorectal endoscopy between 2001 and 2002 provided serum samples and information on lifestyle factors. Serum concentrations of six carotenoids were compared among patients with polyps, cancers, and controls.

Results

In males, high serum zeaxanthin was associated with decreased rates of polyps [odds ratio (OR) = 0.48, 95 % confidence interval (CI) 0.27–0.87] and cancer (OR = 0.35, 95 % CI 0.12–1.06), adjusting for age, body mass index, serum cholesterol, smoking status, and alcohol intake. In females, zeaxanthin (OR = 0.25, 95 % CI 0.07–0.82), lutein (OR = 0.30, 95 % CI 0.10–0.94), alpha-carotene (OR = 0.30, 95 % CI 0.10–0.90), and beta-carotene (OR = 0.27, 95 % CI 0.09–0.85) showed significant inverse associations with cancer development. These associations were consistent with findings of inverse associations between the ingestion of green–yellow vegetables (OR = 0.44, 95 % CI 0.23–0.84), carrots and pumpkins (OR = 0.46, 95 % CI 0.25–0.86), and fruits (OR = 0.53, 95 % CI 0.30–0.94) and polyp in males, and between carrots and pumpkins (OR = 0.30, 95 % CI 0.09–0.99), legumes (OR = 0.14, 95 % CI 0.04–0.44), and seaweed (OR = 0.23, 95 % CI 0.07–0.75) and cancer development in females.

Conclusions

These results provide further support for the protective effects of carotenoids contained in green–yellow vegetables and fruits against colorectal neoplasm in Japanese.

     

Consumption of flaxseed, a rich source of lignans, is associated with reduced breast cancer risk

Purpose

To investigate the association between intake of flaxseed—the richest source of dietary lignans (a class of phytoestrogens)—and breast cancer risk.

Methods

A food frequency questionnaire was used to measure the consumption of flaxseed and flax bread by 2,999 women with breast cancer and 3,370 healthy control women who participated in the Ontario Women’s Diet and Health Study (2002–2003). Logistic regression was used to investigate associations between consumption of flaxseed and flax bread and breast cancer risk. Confounding by established and suspected breast cancer risk factors, as well as dietary factors, was assessed.

Results

Flaxseed or flax bread was consumed at least weekly by 21 % of control women. None of the 19 variables assessed were identified as confounders of the associations between flaxseed or flax bread and breast cancer risk. Consumption of flaxseed was associated with a significant reduction in breast cancer risk (odds ratio (OR) = 0.82, 95 % confidence interval (CI) 0.69–0.97), as was consumption of flax bread (OR = 0.77, 95 % CI 0.67–0.89).

Conclusions

This Canadian study is, to our knowledge, the first to report on the association between flaxseed alone and breast cancer risk and has found that flaxseed intake is associated with a reduction in breast cancer risk. As dietary intake of flaxseed is modifiable, this finding may be of public health importance with respect to breast cancer prevention.     

Periodontal disease and mouthwash use are risk factors for head and neck squamous cell carcinoma

Purpose

The purpose of this study was to examine associations between oral hygiene, including history of periodontal disease and mouthwash use, and risk of head and neck squamous cell carcinoma (HNSCC).

Methods

We measured history of oral hygiene and dental care on 513 HNSCC cases and 567 controls from a population-based study of HNSCC. Logistic regression was used to estimate odds ratios (ORs) and 95 % confidence intervals (95 % CI).

Results

Periodontal disease was associated with a slightly elevated risk of HNSCC (OR = 1.09, 95 % CI: 1.02, 1.16). Using any type of mouthwash at least once per day was associated with increased risk compared to never using mouthwash (OR = 1.11, 95 % CI: 1.02, 1.20). HNSCC was associated with frequent use of non-alcoholic mouthwash compared to using any kind of mouthwash rarely or never (OR = 1.24, 95 % CI: 1.05, 1.47).

Conclusions

Our results support an association between periodontal disease and HNSCC. Our data suggest that mouthwash use is associated with HNSCC, but we noted no difference between the effects of alcohol-containing and non-alcoholic mouthwashes.     

Assessing environmental and occupational risk factors for lung cancer in Mexican–Americans

Background

We investigated environmental and occupational exposures and smoking history (while controlling for demographics) in a population of Mexican–American lung cancer cases and controls from the Houston metropolitan area.

Methods

Data were collected between 1991 and 2005 as part of an on-going multi-racial/ethnic, lung cancer case–control study. Cases included 212 Mexican–American lung cancer cases from UT MD Anderson Cancer Center. Controls (n = 328) were recruited from Houston’s largest multispecialty group practice and frequency matched to the cases by age (±5 years), sex, and ethnicity. Environmental and occupational factors were analyzed and odds ratios and 95% confidence intervals were calculated using logistic regression.

Results

We detected elevated risks of lung cancer associated with pesticide exposure and found conventional and antimicrobial (e.g., sterilizers, disinfectants, antiseptics) pesticides were associated with an increased risk of lung cancer in Mexican–Americans (conventional pesticides and antimicrobial pesticides combined: OR = 1.80, 95% CI 1.13–2.86; conventional pesticides: OR = 2.05, 95% CI 1.23–2.39; antimicrobial pesticides: OR = 2.48, 95% CI 1.46–4.21).

Conclusions

Although we found over a two-fold increased risk of lung cancer among Mexican–Americans for pesticides, we could not identify individual pesticides. Our findings are an important preliminary step in identifying factors that are specifically associated with lung cancer risk among Mexican Americans.     

Toenail iron, genetic determinants of iron status, and the risk of glioma

Purpose

Iron is essential for oxygen transport and oxidative metabolism; however, elevated iron stores can trigger overproduction of reactive oxygen species and induce DNA damage. Little is known about the association between body iron stores and glioma risk. This study examined the associations of iron levels measured in toenails and genetic variants linked to body iron stores with risk of glioma in a clinic-based case–control study.

Methods

Samples were collected a median of 24 days following glioma diagnosis in the cases (10th–90th percentile, range: 10–44 days). Nail iron levels were measured in 300 cases and 300 controls using neutron activation analysis. A total of 24 genetic variants associated with iron status were genotyped in 622 cases and 628 controls. Logistic regression was used to estimate odds ratios (OR) and 95 % confidence intervals (CI) for glioma risk according to toenail iron and the examined genotypes.

Results

No association was observed between toenail iron and glioma risk when restricting to cases with nails collected within ~3 weeks of diagnosis (OR = 0.93; 95 % CI 0.46, 1.87 comparing those with high (≥14 μg/g) vs. low (<6 μg/g) iron levels). In contrast, an inverse association with increasing iron was observed after restricting to cases with a delay of 3 weeks or greater (OR = 0.42; 95 % CI 0.19, 0.95), reflecting potentially insidious effects of advancing disease on iron levels among the cases. No associations were observed for any of the examined genetic variants.

Conclusion

The results do not support a role for body iron stores as a determinant of glioma risk.     

Do reproductive and hormonal risk factors for breast cancer associate with attendance at mammography screening?

Purpose

To determine whether reproductive and hormonal risk factors for breast cancer associate with mammography attendance.

Methods

We linked data from the Malmö Diet and Cancer Study to the Malmö mammography register (Sweden, 1992–2009). We analyzed 11,409 women (age 44–72) who were free of breast cancer at study entry and a total of 69,746 screening invitations. Generalized Estimating Equations were used to account for repeated measures within subjects. Models were adjusted for age and other sociodemographic factors.

Results

In this study cohort, mammography screening attendance ranged from 87.6 to 94.5 % between calendar years, with an average attendance of 92 %. Higher attendance was found among women who had given birth to fewer than three children (ORs ranging between 1.15 and 1.37) and had used oral contraceptives (OC) within the last decade (OR = 1.22, 95 % CI 1.07–1.38) and for a longer period (OR = 1.13, 95 % CI 1.01–1.27). A lower odds of attendance was found among post-menopausal women (OR = 0.86, 95 % CI 0.77–0.96). Age <13 at menarche, age ≥30 at first childbirth, age ≥55 at menopause, age <20 at first OC use, nulliparity, breastfeeding, and hormone replacement therapy were not associated with mammography attendance.

Conclusion

Reproductive and hormonal risk factors for breast cancer have little effect on mammography screening attendance. This may indicate a potential for under-screening of some women at higher risk.     

Pelvic inflammatory disease and risk of invasive ovarian cancer and ovarian borderline tumors

Purpose

The aim of the study was to examine the potential association between a history of pelvic inflammatory disease (PID) and risk of epithelial ovarian cancer or ovarian borderline tumors.

Methods

In a population-based case–control study in Denmark, we included 554 women with invasive ovarian cancer, 202 with ovarian borderline tumors, and 1,564 controls aged 35–79 years. The analyses were performed in multiple logistic regression models.

Results

We found a significantly increased risk of ovarian borderline tumors among women with a history of PID (OR = 1.50; 95 % CI 1.08–2.08) but no apparent association between PID and risk of invasive ovarian cancer (OR = 0.83; 95 % CI 0.65–1.05). We found no effect of age at time of first PID or time since first PID on the risk for either condition.

Conclusion

Our results suggest that a history of PID is associated with an increased risk of ovarian borderline tumors, which may support the hypothesis that inflammation is an etiological factor. The lack of an association between previous PID and invasive ovarian cancer may indicate an etiological difference between ovarian borderline tumors and invasive ovarian cancer. However, an important limitation of the study is the use of self-reported PID.     

Role of one-carbon metabolizing pathway genes and gene–nutrient interaction in the risk of non-Hodgkin lymphoma

Purpose

Genetic polymorphisms in one-carbon metabolizing pathway genes have been associated with risk of malignant lymphoma. However, the results have been inconsistent. The objectives of this study were to examine the potential relationship between gene–nutrient interactions and the risk of non-Hodgkin lymphoma (NHL).

Methods

We examined 25 polymorphisms in 16 one-carbon metabolism genes for their main effect and gene–nutrient interactions in relation to NHL risk among 518 incident cases and 597 population-based controls of Connecticut women enrolled between 1996 and 2000.

Results

A significantly reduced risk of NHL was associated with the homozygous TT genotype in CBS (rs234706, Ex9+33C>T) (OR = 0.51, 95 % CI 0.31–0.84), the homozygous CC genotype in MBD2 (rs603097, ?2176C>T) (OR = 0.37, 95 % CI 0.17–0.79), the heterozygote AG genotype in FTHFD (rs1127717, Ex21+31A>G) (OR = 0.73, 95 % CI 0.55–0.98), and a borderline significantly reduced risk of NHL was observed for the homozygous CC genotype in MTRR (rs161870, Ex5+136T>C) (OR = 0.23, 95 % CI 0.05–1.04). The reduced risk of NHL associated with these genotypes was predominately in those with higher dietary vitamin B6 and methionine intakes, as well as with higher dietary folate intake although results were less stable. A borderline significantly increased risk of NHL was also observed for CBS (rs1801181, Ex13+41C>T), FTHFD (rs2305230, Ex10?40G>T), SHMT1 (rs1979277, Ex12+138C>T), and SHMT1 (rs1979276, Ex12+236T>C), and these associations appeared to be contingent on dietary nutrient intakes.

Conclusion

Our results suggest that variation in several one-carbon metabolizing pathway genes may influence the risk of NHL through gene–nutrient interactions involving dietary nutrient intakes.     

A prospective study of socioeconomic status, prostate cancer screening and incidence among men at high risk for prostate cancer

Purpose

Higher socioeconomic status (SES) men are at higher risk of prostate cancer (PCa) diagnosis, an association commonly interpreted as a function of higher rates of prostate screening among higher SES men. However, the extent to which screening explains this association has not been well quantified.

Methods

Within a Detroit area cohort of 6,692 men followed up after a benign prostate procedure, a case–control study was conducted of 494 PCa cases and controls matched on age, race, duration of follow-up, and date of initial benign finding; 2000 Census data were used in a principal component analysis to derive a single factor, labeled the neighborhood SES index (NSESI), representing zip code-level SES.

Results

Among cases, higher SES was associated with a younger age at initial biopsy: ?1.48 years (95 % CI, ?2.32, ?0.64) per unit NSESI. After adjustment for confounders and duration of follow-up, higher SES was associated with more PSA tests and DRE during follow-up; 9 % (95 % CI, 2, 16) and 8 % (95 % CI, 1, 15) more respectively, per unit NSESI. Higher SES was associated with a higher risk of PCa diagnosis during follow-up, multivariable adjusted OR = 1.26 per unit increase in NSESI (95 % CI, 1.04, 1.49). Further adjustment for screening frequency somewhat reduced the association between SES and PCa risk (OR = 1.19 per unit NSESI, 95 % CI, 0.98, 1.44).

Conclusions

Differences in screening frequency only partially explained the association between higher zip code SES and PCa risk; other health care-related factors should also be considered as explanatory factors.     

Contribution of clinical and socioeconomic factors to differences in breast cancer subtype and mortality between Hispanic and non-Hispanic white women

Purpose

To assess tumor subtype distribution and the relative contribution of clinical and sociodemographic factors on breast cancer survival between Hispanic and non-Hispanic whites (NHWs).

Methods

We analyzed data from the California Cancer Registry, which included 29,626 Hispanic and 99,862 NHW female invasive breast cancer cases diagnosed from 2004 to 2014. Logistic regression was used to assess ethnic differences in tumor subtype, and Cox proportional hazard modeling to assess differences in breast cancer survival.

Results

Hispanics compared to NHWs had higher odds of having triple-negative (OR = 1.29; 95% CI 1.23–1.35) and HER2-overexpressing tumors (OR = 1.19; 95% CI 1.14–1.25 [HR?] and OR = 1.39; 95% CI 1.31–1.48 [HR+]). In adjusted models, Hispanic women had a higher risk of breast cancer mortality than NHW women (mortality rate ratio [MRR] = 1.24; 95% CI 1.19–1.28). Clinical factors accounted for most of the mortality difference (MRR = 1.05; 95% CI 1.01–1.09); however, neighborhood socioeconomic status (SES) and health insurance together accounted for all of the mortality difference (MRR = 1.01; 95% CI 0.97–1.05).

Conclusions

Addressing SES disparities, including increasing access to health care, may be critical to overcoming poorer breast cancer outcomes in Hispanics.

     

Meta-analyses of colorectal cancer risk factors

Purpose

Demographic, behavioral, and environmental factors have been associated with increased risk of colorectal cancer (CRC). We reviewed the published evidence and explored associations between risk factors and CRC incidence.

Methods

We identified 12 established non-screening CRC risk factors and performed a comprehensive review and meta-analyses to quantify each factor’s impact on CRC risk. We used random-effects models of the logarithms of risks across studies: inverse-variance weighted averages for dichotomous factors and generalized least squares for dose–response for multi-level factors.

Results

Significant risk factors include inflammatory bowel disease (RR = 2.93, 95 % CI 1.79–4.81); CRC history in first-degree relative (RR = 1.80, 95 % CI 1.61–2.02); body mass index (BMI) to overall population (RR = 1.10 per 8 kg/m² increase, 95 % CI 1.08–1.12); physical activity (RR = 0.88, 95 % CI 0.86–0.91 for 2 standard deviations increased physical activity score); cigarette smoking (RR = 1.06, 95 % CI 1.03–1.08 for 5 pack-years); and consumption of red meat (RR = 1.13, 95 % CI 1.09–1.16 for 5 servings/week), fruit (RR = 0.85, 95 % CI 0.75–0.96 for 3 servings/day), and vegetables (RR = 0.86, 95 % CI 0.78–0.94 for 5 servings/day).

Conclusions

We developed a comprehensive risk modeling strategy that incorporates multiple effects to predict an individual’s risk of developing CRC. Inflammatory bowel disease and history of CRC in first-degree relatives are associated with much higher risk of CRC. Increased BMI, red meat intake, cigarette smoking, low physical activity, low vegetable consumption, and low fruit consumption were associated with moderately increased risk of CRC.     

A case–control study of lifetime occupational sitting and likelihood of breast cancer

Purpose

Sedentary behavior may be a unique risk factor for some cancers, including breast cancer. The objective of this study was to determine the association between lifetime occupational sitting and likelihood of breast cancer.

Methods

A case–control study of 2,452 women was conducted in Alberta, Canada, between 1995 and 1997. A comprehensive measure of lifetime physical activity assessed frequency and duration of sedentary jobs. Logistic regression estimated the odds of being diagnosed with breast cancer across quartiles of lifetime occupational sitting, by menopausal status and family history of breast cancer, and within body mass index categories and physical activity quartiles.

Results

There was no association between occupational sitting and breast cancer among pre-menopausal women and women with a family history of breast cancer. Unexpectedly, higher amounts of occupational sitting were associated with lower odds of breast cancer in post-menopausal women (top versus bottom categories of occupational sitting OR = 0.71, 95 % CI 0.52, 0.97), women without a family history of breast cancer (OR = 0.77, 95 % CI 0.60, 1.00), and women in the third highest quartile of total lifetime physical activity (OR = 0.57, 95 % CI 0.33, 0.97).

Conclusion

Occupational sitting levels were lower than would be expected in a contemporary study. Exposures may have been insufficient to make a determinable contribution to breast cancer risk.