Mediating effects of cancer risk factors on the association between race and cancer incidence: analysis of the NIH-AARP Diet and Health Study

Associations of Albumin and BMI with Colorectal Cancer Risk in the Southern Community Cohort Study: a Prospective Cohort Study

BACKGROUND

Obesity may increase colorectal cancer (CRC) risk through mechanisms of increased inflammation. Although BMI is the most used adiposity indicator, it may less accurately measure adiposity in Black populations. Herein, we investigate associations between BMI, low albumin as an inflammation biomarker, and CRC risk in a racially diverse cohort.

METHODS

Participant data arise from 71,141 participants of the Southern Community Cohort Study, including 724 incident CRC cases. Within the cohort, 69% are Black. Blood serum albumin concentrations, from samples taken at enrollment, were available for 235 cases and 567 controls. Controls matched by age, sex, and race were selected through incidence density sampling. Cox proportional hazards calculated BMI and CRC risk associations (hazard ratios [HRs]; 95% confidence intervals [CIs]. Conditional logistic regression calculated albumin and CRC risk associations (odds ratios [ORs]; 95%CIs).

RESULTS

Underweight, but not overweight or obese, compared to normal BMI was associated with increased CRC risk (HR:1.75, 95%CI:1.00-3.09). Each standard deviation increase of albumin was associated with decreased CRC risk, particularly for those who self-identified as non-Hispanic Black (OR: 0.56, 95%CI:0.34-0.91), or female (OR:0.54, 95%CI:0.30-0.98), but there was no evidence for interaction by these variables (p-interactions > 0.05). Moreover, albumin concentration was lower in Black than White participants. Mediation analysis suggested that the relation between albumin and CRC was not mediated by BMI.

CONCLUSIONS

Null associations of overweight/obesity with CRC risk demonstrates limited utility of BMI, especially among Black populations. Low albumin may indicate CRC risk. In Black individuals, albumin may better predict adiposity related risks than BMI.

Impact of Alcohol Consumption on Breast Cancer Incidence and Mortality: The Women's Health Study

Background: Alcohol intake is associated with breast cancer (BC) risk, but estimates of greatest public health relevance have not been quantified in large studies with long duration. Materials and Methods: In this prospective cohort study of 39,811 women (median 25 years follow-up), we examined the association between alcohol consumption and BC incidence and mortality with adjusted hazard ratios (HRs), cubic splines, absolute risks, number needed to harm (NNH), and population-attributable fractions. Results: We documented 2,830 cases of BC, including 237 BC deaths. Each additional alcoholic drink/day was associated with a 10% higher rate (HR = 1.10, 95% confidence intervals [CIs]: 1.04-1.16) of total BC in a linear manner (p = 0.0004). The higher rate was apparent for estrogen receptor (ER)+ (HR = 1.12, 95% CI: 1.06-1.18) but not ER- tumors (HR = 0.95, 95% CI: 0.82-1.10), with a statistically significant difference between these associations (p = 0.03). We constructed models comparing BC incidence among 100,000 women followed for 10 years. Compared to a scenario where all women rarely or never consumed alcohol, we expect 63.79 (95% CI: 58.35-69.24) more cases (NNH = 1,567) had all women consumed alcohol at least monthly and 278.66 (95% CI: 268.70-288.62) more cases (NNH = 358) had all women consumed >1 drink/day. Approximately 4.1% of BC cases were attributable to consumption exceeding one drink/month. Conclusion: Alcohol consumption is associated with a linear dose-response increase in BC incidence even within recommended limits of up to one alcoholic drink/day, at least for ER+ tumors. Our estimates of risk differences, attributable fraction, and NNH quantify the burden that alcohol consumption imposes on women in the general population. ClinicalTrials.gov Identifier: NCT00000479.

Neighborhood Disadvantage, African Genetic Ancestry, Cancer Subtype, and Mortality Among Breast Cancer Survivors

Importance

Racial disparities in breast cancer (BC) survival arise from multilevel causes, which may exert influence at different stages of BC progression. Clarifying the importance of genetic and social factors could help prioritize interventions.

Objective

To jointly examine associations between African genetic ancestry, social environment, and mortality from any cause and BC in Black BC survivors.

Design, Setting, and Participants

This population-based cohort study enrolled self-identified Black women aged 20 to 75 years with histologically confirmed BC from June 2005 to May 2019 and followed them up until death or censoring in September 2021. Participants lived in 10 New Jersey counties. Data were analyzed between December 2022 and April 2023.

Exposures

A neighborhood socioeconomic status (nSES) index composed of census tract measures (education, income, wealth, employment status, and occupation) was linked to residential addresses at diagnosis. Percentage African ancestry was estimated using the ADMIXTURE program.

Main Outcomes and Measures

Sequentially adjusted (age adjusted: age and interview year; fully adjusted: age adjusted with individual SES, lifestyle factors, and comorbidities) logistic regression models were fit to estimate associations with tumor subtypes (estrogen receptor-negative [ER-] vs estrogen receptor-positive [ER+]; triple-negative breast cancer [TNBC] vs luminal A), and Cox models were fit for associations with all-cause mortality (ACM) and breast cancer-specific mortality (BCSM). Models for BCSM were fit using Fine-Gray competing risks models, and robust standard errors were used to account for census tract-level clustering.

Results

Among 1575 participants, median (IQR) African ancestry was 85% (76%-90%), and median (IQR) age was 55 (46-63) years. A 10-percentage point increase in African ancestry was associated with higher odds of ER- vs ER+ (adjusted odds ratio [aOR], 1.08; 95% CI, 0.98-1.18) and TNBC vs luminal (aOR, 1.15; 95% CI, 1.02-1.31) tumors, but not with ACM or BCSM. A 1-IQR increase in nSES was associated with lower ACM (adjusted hazard ratio [aHR], 0.76; 95% CI, 0.63-0.93), and the HR for BCSM was less than 1 but not statistically significant (aHR, 0.81; 95% CI, 0.62-1.04) in age-adjusted models, but associations attenuated following further adjustment for potential mediators (individual SES, lifestyles, comorbidities).

Conclusions and Relevance

In this cohort study of Black female BC survivors, higher African ancestry was associated with aggressive tumor subtypes. Compared with genetic ancestry, mediating pathways related to social environments may be more important for survival in these patients.

Serum markers, obesity and prostate cancer risk: results from the prostate cancer prevention trial

Molecular mechanisms linking obesity to prostate cancer involve steroid hormone and insulin/insulin-like growth factor 1 (IGF1) pathways. We investigated the association of circulating serum markers (e.g. androgens and IGFs/IGFBPs) with BMI and in modifying the association of obesity with prostate cancer risk. Data and specimens for this nested case-control study are from the Prostate Cancer Prevention Trial, a randomized, placebo-controlled trial of finasteride for prostate cancer prevention. Presence or absence of cancer was determined by prostate biopsy. Serum samples were assayed for sex steroid hormone concentrations and IGF1 axis analytes. Logistic regression estimated odds ratio and 95% CIs for risk of overall, low-grade (Gleason 2-6), and high-grade (Gleason 7-10) cancers. We found significant associations between BMI with serum steroids and IGFs/IGFBPs; the IGF1 axis was significantly associated with several serum steroids. Serum steroid levels did not affect the association of BMI with prostate cancer risk; however, IGFBP2 and IGFs modified the association of obesity with low- and high-grade disease. While serum steroids and IGFs/IGFBPs are associated with BMI, only the IGF1 axis contributed to obesity-related prostate cancer risk. Understanding the biological mechanisms linking obesity to prostate cancer risk as it relates to circulating serum markers will aid in developing effective prostate cancer prevention strategies and treatments.

The Cancer Prevention Study-3 FFQ Is a Reliable and Valid Measure of Nutrient Intakes among Racial/Ethnic Subgroups, Compared with 24-Hour Recalls and Biomarkers

BACKGROUND

Valid assessment of dietary intake in diverse populations is important for studies of chronic disease risk in the United States.

OBJECTIVES

We evaluated the reproducibility and validity of a food frequency questionnaire (FFQ) modified for the American Cancer Society's Cancer Prevention Study-3 (CPS-3) prospective cohort, among a racially/ethnically diverse subgroup.

METHODS

The Diet Assessment Substudy included 677 CPS-3 participants (64% women; 61% non-Hispanic white, 24% non-Hispanic black, 15% Hispanic), aged 31-70 y, who completed 2 FFQs 1 y apart (FFQ1, FFQ2), 4-6 telephone-administered 24-h dietary recalls (24HRs), and 2 fasting blood samples and 24-h urine collections ∼6 mo apart in the interim. Spearman rank correlation coefficients (ρ) were used to evaluate FFQ reproducibility and validity compared with 24HRs for 67 nutrient exposures. For 18 of these nutrients, we used the method of triads to calculate validity coefficients (VCs, ρ) from pairwise correlations of FFQ2, 24HRs, and biomarkers. Analyses were stratified by sex, race/ethnicity, education, and BMI.

RESULTS

Mean (range) FFQ reproducibility correlations were ρ = 0.65 (0.50-0.91) for men and ρ = 0.63 (0.37-0.89) for women; mean (range) energy-adjusted, deattenuated correlations of FFQ2 with 24HRs were ρ = 0.60 (0.33-0.84) for men and ρ = 0.55 (0.21-0.79) for women. FFQ2 VCs (ρ) among men ranged from 0.42 for β-cryptoxanthin to 0.91 for omega-3 (n-3) fatty acids and, among women, from 0.41 for sodium to 0.79 for total vitamin D. Mean FFQ reproducibility and validity were highest among whites (ρ = 0.68, ρ = 0.58, respectively) and slightly lower among blacks (ρ = 0.57, ρ = 0.49, respectively) and Hispanics (ρ = 0.59, 0.55, respectively). FFQ reproducibility and validity were slightly lower among those with less than a 4-y college degree, and those with a BMI ≥30 kg/m2.

CONCLUSIONS

Reproducibility and validity of the CPS-3 FFQ were comparable with similar studies for most nutrients, among all subgroups. These findings support future dietary analyses in the contemporary CPS-3 cohort and other similar cohorts.

Effects of socioeconomic status on cancer patient survival: counterfactual event-based mediation analysis

PURPOSE

This study investigated the direct and indirect effects of socioeconomic status (SES) on the survival time of cancer patients by using cancer stage to create a pathway from SES to health outcomes and facilitate a mechanistic inference.

METHODS

Both a traditional mediation analysis and a counterfactual event-based mediation analysis were applied to SEER (The Surveillance, Epidemiology, and End Results) data from the National Cancer Institute of the United States. A Cox proportional hazards model for survival analysis was performed in the mediation analysis.

RESULTS

The counterfactual event-based mediation analysis showed that the effect of SES on survival time was partially mediated by stage at diagnosis in lung (12%), liver (14.33%), and colorectal (9%) cancers. Investigation of the fundamental mechanism involved thus established the direct effect of SES on survival time and the indirect effect of SES on survival time through stage at diagnosis. Moreover, the mediation analysis also revealed that the disparity in timely diagnosis (i.e., stage at diagnosis) caused by SES was slightly significant.

CONCLUSIONS

SES can either affect cancer survival directly or indirectly through stage at diagnosis. Opportunities to reduce cancer disparity exist in the design of early detection policies or mechanisms for patients with varying resources.

Cancer risk in a large inception SLE cohort: Effects of demographics, smoking, and medications

OBJECTIVE

To assess cancer risk factors in incident SLE.

METHODS

Clinical variables and cancer outcomes were assessed annually among incident SLE patients. Multivariate hazard regression models (over-all risk, and most common cancers) included demographics and time-dependent medications (corticosteroids, antimalarial drugs, immunosuppressants), smoking, and adjusted mean SLE Disease Activity Index-2K.

RESULTS

Among 1668 patients (average 9 years follow-up), 65 cancers occurred: 15 breast, 10 non-melanoma skin, seven lung, six hematological, six prostate, five melanoma, three cervical, three renal, two each gastric, head and neck, and thyroid, and one each rectal, sarcoma, thymoma, and uterine cancers. Half of cancers (including all lung cancers) occurred in past/current smokers, versus one-third of patients without cancer. Multivariate analyses indicated over-all cancer risk was related primarily to male sex and older age at SLE diagnosis. In addition, smoking was associated with lung cancer. For breast cancer risk, age was positively and anti-malarial drugs were negatively associated. Anti-malarial drugs and higher disease activity were also negatively associated with non-melanoma skin cancer (NMSC) risk, whereas age and cyclophosphamide were positively associated. Disease activity was associated positively with hematologic and negatively with NMSC risk.

CONCLUSIONS

Smoking is a key modifiable risk factor, especially for lung cancer, in SLE. Immunosuppressive medications were not clearly associated with higher risk except for cyclophosphamide and NMSC. Antimalarials were negatively associated with breast cancer and NMSC risk. SLE activity was associated positively with hematologic cancer and negatively with NMSC. Since the absolute number of cancers was small, additional follow-up will help consolidate these findings.