Risk factors and health behaviors associated with loneliness among cancer survivors during the COVID-19 pandemic

Loneliness may exacerbate poor health outcomes particularly among cancer survivors during the COVID-19 pandemic. Little is known about the risk factors of loneliness among cancer survivors. We evaluated the risk factors of loneliness in the context of COVID-19 pandemic-related prevention behaviors and lifestyle/psychosocial factors among cancer survivors. Cancer survivors (n = 1471) seen at Huntsman Cancer Institute completed a survey between August-September 2020 evaluating health behaviors, medical care, and psychosocial factors including loneliness during COVID-19 pandemic. Participants were classified into two groups: 'lonely' (sometimes, usually, or always felt lonely in past month) and 'non-lonely' (never or rarely felt lonely in past month). 33% of cancer survivors reported feeling lonely in the past month. Multivariable logistic regression showed female sex, not living with a spouse/partner, poor health status, COVID-19 pandemic-associated lifestyle factors including increased alcohol consumption and marijuana/CBD oil use, and psychosocial stressors such as disruptions in daily life, less social interaction, and higher perceived stress and financial stress were associated with feeling lonely as compared to being non-lonely (all p < 0.05). A significant proportion of participants reported loneliness, which is a serious health risk among vulnerable populations, particularly cancer survivors. Modifiable risk factors such as unhealthy lifestyle behaviors and psychosocial stress were associated with loneliness. These results highlight the need to screen for unhealthy lifestyle factors and psychosocial stressors to identify cancer survivors at increased risk of loneliness and to develop effective management strategies.

Genetic risk impacts the association of menopausal hormone therapy with colorectal cancer risk

BACKGROUND

Menopausal hormone therapy (MHT), a common treatment to relieve symptoms of menopause, is associated with a lower risk of colorectal cancer (CRC). To inform CRC risk prediction and MHT risk-benefit assessment, we aimed to evaluate the joint association of a polygenic risk score (PRS) for CRC and MHT on CRC risk.

METHODS

We used data from 28,486 postmenopausal women (11,519 cases and 16,967 controls) of European descent. A PRS based on 141 CRC-associated genetic variants was modeled as a categorical variable in quartiles. Multiplicative interaction between PRS and MHT use was evaluated using logistic regression. Additive interaction was measured using the relative excess risk due to interaction (RERI). 30-year cumulative risks of CRC for 50-year-old women according to MHT use and PRS were calculated.

RESULTS

The reduction in odds ratios by MHT use was larger in women within the highest quartile of PRS compared to that in women within the lowest quartile of PRS (p-value = 2.7 × 10-8). At the highest quartile of PRS, the 30-year CRC risk was statistically significantly lower for women taking any MHT than for women not taking any MHT, 3.7% (3.3%-4.0%) vs 6.1% (5.7%-6.5%) (difference 2.4%, P-value = 1.83 × 10-14); these differences were also statistically significant but smaller in magnitude in the lowest PRS quartile, 1.6% (1.4%-1.8%) vs 2.2% (1.9%-2.4%) (difference 0.6%, P-value = 1.01 × 10-3), indicating 4 times greater reduction in absolute risk associated with any MHT use in the highest compared to the lowest quartile of genetic CRC risk.

CONCLUSIONS

MHT use has a greater impact on the reduction of CRC risk for women at higher genetic risk. These findings have implications for the development of risk prediction models for CRC and potentially for the consideration of genetic information in the risk-benefit assessment of MHT use.

Age-related differences in employment, insurance, and financial hardship among colorectal cancer patients: a report from the ColoCare Study

PURPOSE

Employment and financial hardships are common issues for working-age colorectal cancer patients. We surveyed colorectal cancer survivors to investigate employment, insurance, and financial outcomes by age at diagnosis.

METHODS

Cross-sectional survey of six ColoCare Study sites regarding employment, insurance, and financial hardship outcomes. Eligible participants were 1 to 5 years from colorectal cancer diagnosis. Diagnosis age (18-49, 50-64, 65+ years) with outcomes of interest were compared using chi-square and t-tests. Multivariable logistic and Poisson regressions were fit to examine association of demographic factors with any material/psychological hardship (yes/no) and the count of hardships.

RESULTS

N = 202 participants completed the survey (age: 18-49 (n = 42, 20.8%), 50-64 (n = 79, 39.1%), 65+ (n = 81, 40.1%)). Most diagnosed age < 65 worked at diagnosis (18-49: 83%; 50-64: 64%; 65+ : 14%, p < 0.001) and continued working after diagnosis (18-49: 76%; 50-64: 59%; 65+ : 13%; p < 0.001). Participants age 18-49 reported cancer-related difficulties with mental (81.3%) and physical (89%) tasks at work more than those working in the older age groups (45%-61%). In regression models, among those reporting any hardship, the rates of material and psychological hardships were higher among those age 18-64 (Incidence Rate Ratios (IRR) range 1.5-2.3 vs. age 65+) and for those with < college (IRR range 1.3-1.6 vs. college +).

CONCLUSIONS

Younger colorectal cancer patients are more likely to work after a cancer diagnosis and during cancer treatment, but report higher levels of financial hardship than older patients.

IMPLICATIONS FOR CANCER SURVIVORS

Younger colorectal cancer patients may encounter financial hardship, thus may feel a need to work during and after treatment.

Metabolic basis of cardiac dysfunction in cancer patients

PURPOSE OF REVIEW

The relationship between metabolism and cardiovascular diseases is complex and bidirectional. Cardiac cells must adapt metabolic pathways to meet biosynthetic demands and energy requirements to maintain contractile function. During cancer, this homeostasis is challenged by the increased metabolic demands of proliferating cancer cells.

RECENT FINDINGS

Tumors have a systemic metabolic impact that extends beyond the tumor microenvironment. Lipid metabolism is critical to cancer cell proliferation, metabolic adaptation, and increased cardiovascular risk. Metabolites serve as signals which provide insights for diagnosis and prognosis in cardio-oncology patients.

SUMMARY

Metabolic processes demonstrate a complex relationship between cancer cell states and cardiovascular remodeling with potential for therapeutic interventions.

Fine-mapping analysis including over 254,000 East Asian and European descendants identifies 136 putative colorectal cancer susceptibility genes

Genome-wide association studies (GWAS) have identified more than 200 common genetic variants independently associated with colorectal cancer (CRC) risk, but the causal variants and target genes are mostly unknown. We sought to fine-map all known CRC risk loci using GWAS data from 100,204 cases and 154,587 controls of East Asian and European ancestry. Our stepwise conditional analyses revealed 238 independent association signals of CRC risk, each with a set of credible causal variants (CCVs), of which 28 signals had a single CCV. Our cis-eQTL/mQTL and colocalization analyses using colorectal tissue-specific transcriptome and methylome data separately from 1299 and 321 individuals, along with functional genomic investigation, uncovered 136 putative CRC susceptibility genes, including 56 genes not previously reported. Analyses of single-cell RNA-seq data from colorectal tissues revealed 17 putative CRC susceptibility genes with distinct expression patterns in specific cell types. Analyses of whole exome sequencing data provided additional support for several target genes identified in this study as CRC susceptibility genes. Enrichment analyses of the 136 genes uncover pathways not previously linked to CRC risk. Our study substantially expanded association signals for CRC and provided additional insight into the biological mechanisms underlying CRC development.

Tissue-specific genetic variation suggests distinct molecular pathways between body shape phenotypes and colorectal cancer

It remains unknown whether adiposity subtypes are differentially associated with colorectal cancer (CRC). To move beyond single-trait anthropometric indicators, we derived four multi-trait body shape phenotypes reflecting adiposity subtypes from principal components analysis on body mass index, height, weight, waist-to-hip ratio, and waist and hip circumference. A generally obese (PC1) and a tall, centrally obese (PC3) body shape were both positively associated with CRC risk in observational analyses in 329,828 UK Biobank participants (3728 cases). In genome-wide association studies in 460,198 UK Biobank participants, we identified 3414 genetic variants across four body shapes and Mendelian randomization analyses confirmed positive associations of PC1 and PC3 with CRC risk (52,775 cases/45,940 controls from GECCO/CORECT/CCFR). Brain tissue-specific genetic instruments, mapped to PC1 through enrichment analysis, were responsible for the relationship between PC1 and CRC, while the relationship between PC3 and CRC was predominantly driven by adipose tissue-specific genetic instruments. This study suggests distinct putative causal pathways between adiposity subtypes and CRC.

Functional quality of life among newly diagnosed young adult colorectal cancer survivors compared to older adults: results from the ColoCare Study

PURPOSE

Colorectal cancer (CRC) incidence and mortality are increasing among young adults (YAs) aged 18-39. This study compared quality of life (QOL) between YA and older adult CRC survivors in the ColoCare Study.

METHODS

Participants were grouped by age (years) as follows: 18-39 (YA), 40-49, 50-64, and 65 + . Functional QOL (physical, social, role, emotional, cognitive) and global QOL were assessed with the EORTC-QLQ-C30 at enrollment, 3, 6, and 12 months. Average scores were compared between groups over time using longitudinal mixed-effect modeling. Proportions with clinically meaningful QOL impairment were calculated using age-relevant thresholds and compared between groups over time using logistic regression with mixed effects.

RESULTS

Participants (N = 1590) were n = 81 YAs, n = 196 aged 40-49, n = 627 aged 50-64, and n = 686 aged 65 + . Average physical function was better among YAs than participants aged 50-64 (p = 0.010) and 65 + (p < 0.001), and average social function was worse among YAs than aged 65 + (p = 0.046). Relative to YAs, all age groups were less likely to report clinically meaningful social dysfunction (aged 40-49 OR = 0.13, 95%CI = 0.06-0.29; aged 50-64 OR = 0.10, 95%CI = 0.05-0.21; aged 65 + OR = 0.07, 95%CI = 0.04-0.15) and role dysfunction (aged 40-49 OR = 0.36, 95%CI = 0.18-0.75; aged 50-64 OR = 0.41, 95%CI = 0.22-0.78; aged 65 + OR = 0.32, 95%CI = 0.17-0.61). Participants aged 40-49 were also less likely to report physical dysfunction (OR = 0.42, 95%CI = 0.19-0.93).

CONCLUSION

YA CRC survivors reported better physical and worse social function compared to older CRC survivors, and YA CRC survivors were more likely to report clinically meaningful social, role, and physical disfunction. Future work should further investigate QOL using age-relevant benchmarks to inform best practices for CRC survivorship care.

TRIAL REGISTRATION

NCT02328677, registered December 2014.

Epidemiologic Factors in Relation to Colorectal Cancer Risk and Survival by Genotoxic Colibactin Mutational Signature

BACKGROUND

The genotoxin colibactin causes a tumor single-base substitution (SBS) mutational signature, SBS88. It is unknown whether epidemiologic factors' association with colorectal cancer risk and survival differs by SBS88.

METHODS

Within the Genetic Epidemiology of Colorectal Cancer Consortium and Colon Cancer Family Registry, we measured SBS88 in 4,308 microsatellite stable/microsatellite instability low tumors. Associations of epidemiologic factors with colorectal cancer risk by SBS88 were assessed using multinomial regression (N = 4,308 cases, 14,192 controls; cohort-only cases N = 1,911), and with colorectal cancer-specific survival using Cox proportional hazards regression (N = 3,465 cases).

RESULTS

392 (9%) tumors were SBS88 positive. Among all cases, the highest quartile of fruit intake was associated with lower risk of SBS88-positive colorectal cancer than SBS88-negative colorectal cancer [odds ratio (OR) = 0.53, 95% confidence interval (CI) 0.37-0.76; OR = 0.75, 95% CI 0.66-0.85, respectively, Pheterogeneity = 0.047]. Among cohort studies, associations of body mass index (BMI), alcohol, and fruit intake with colorectal cancer risk differed by SBS88. BMI ≥30 kg/m2 was associated with worse colorectal cancer-specific survival among those SBS88-positive [hazard ratio (HR) = 3.40, 95% CI 1.47-7.84], but not among those SBS88-negative (HR = 0.97, 95% CI 0.78-1.21, Pheterogeneity = 0.066).

CONCLUSIONS

Most epidemiologic factors did not differ by SBS88 for colorectal cancer risk or survival. Higher BMI may be associated with worse colorectal cancer-specific survival among those SBS88-positive; however, validation is needed in samples with whole-genome or whole-exome sequencing available.

IMPACT

This study highlights the importance of identification of tumor phenotypes related to colorectal cancer and understanding potential heterogeneity for risk and survival.

Spectrum of somatic mutational features of colorectal tumors in ancestrally diverse populations

Ancestrally diverse and admixed populations, including the Hispanic/Latino/a/x/e community, are underrepresented in cancer genetic and genomic studies. Leveraging the Latino Colorectal Cancer Consortium, we analyzed whole exome sequencing data on tumor/normal pairs from 718 individuals with colorectal cancer (128 Latino, 469 non-Latino) to map somatic mutational features by ethnicity and genetic ancestry. Global proportions of African, East Asian, European, and Native American ancestries were estimated using ADMIXTURE. Associations between global genetic ancestry and somatic mutational features across genes were examined using logistic regression. TP53 , APC , and KRAS were the most recurrently mutated genes. Compared to non-Latino individuals, tumors from Latino individuals had fewer KRAS (OR=0.64, 95%CI=0.41-0.97, p=0.037) and PIK3CA mutations (OR=0.55, 95%CI=0.31-0.98, p=0.043). Genetic ancestry was associated with presence of somatic mutations in 39 genes (FDR-adjusted LRT p<0.05). Among these genes, a 10% increase in African ancestry was associated with significantly higher odds of mutation in KNCN (OR=1.34, 95%CI=1.09-1.66, p=5.74×10 -3 ) and TMEM184B (OR=1.53, 95%CI=1.10-2.12, p=0.011). Among RMGs, we found evidence of association between genetic ancestry and mutation status in CDC27 (LRT p=0.0084) and between SMAD2 mutation status and AFR ancestry (OR=1.14, 95%CI=1.00-1.30, p=0.046). Ancestry was not associated with tumor mutational burden. Individuals with above-average Native American ancestry had a lower frequency of microsatellite instable (MSI-H) vs microsatellite stable tumors (OR=0.45, 95%CI=0.21-0.99, p=0.048). Our findings provide new knowledge about the relationship between ancestral haplotypes and somatic mutational profiles that may be useful in developing precision medicine approaches and provide additional insight into genomic contributions to cancer disparities.

Significance

Our data in ancestrally diverse populations adds essential information to characterize mutational features in the colorectal cancer genome. These results will help enhance equity in the development of precision medicine strategies.

Relationships Among Physical Activity, Sleep, and Cancer-related Fatigue: Results From the International ColoCare Study

BACKGROUND

Risk factors for cancer-related fatigue are understudied in colorectal cancer.

PURPOSE

This study aimed to address this critical gap in the literature by (a) describing changes in colorectal cancer-related fatigue and health behavior (physical activity, sleep problems) and (b) examining if physical activity and sleep problems predict fatigue trajectories from baseline (approximately at the time of diagnosis), to 6- and 12 months after enrollment.

METHODS

Patients participating in the international ColoCare Study completed self-report measures at baseline (approximately time of diagnosis), 6-, and 12 months assessing physical activity using the International Physical Activity Questionnaire (IPAQ) and fatigue and sleep using the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire (EORTC-QLQ-C30). Mixed-effect models examined changes in physical activity, sleep problems, and fatigue. Cross-lagged panel models examined bidirectional relationships between physical activity or sleep and fatigue across time.

RESULTS

Colorectal cancer patients (n = 649) had a mean age of 61 ± 13 years. Most were male (59%), non-Hispanic White (91%), diagnosed with Stages III-IV (56%) colon cancer (58%), and treated with surgery (98%). Within-person cross-lagged models indicated higher physical activity at Month 6 was associated with higher fatigue at Month 12 (β = 0.26, p = .016). When stratified by cancer stage (I-II vs. III-IV), the relationship between physical activity at Month 6 and fatigue at Month 12 existed only for patients with advanced cancer (Stages III and IV, β = 0.43, p = .035). Cross-lagged associations for sleep and fatigue from baseline to Month 6 were only observed in patients with Stages III or IV cancer, however, there was a clear cross-sectional association between sleep problems and fatigue at baseline and Month 6.

CONCLUSIONS

Within-person and cross-lagged association models suggest fatiguability may become increasingly problematic for patients with advanced colorectal cancer the first year after diagnosis. In addition, sleep problems were consistently associated with higher fatigue in the first year, regardless of cancer stage.

TRIAL REGISTRATION

The international ColoCare Study was registered on clinicaltrials.gov, NCT02328677, in December 2014.

Causal relationships between risk of venous thromboembolism and 18 cancers: a bidirectional Mendelian randomization analysis

BACKGROUND

People with cancer experience high rates of venous thromboembolism (VTE). Risk of subsequent cancer is also increased in people experiencing their first VTE. The causal mechanisms underlying this association are not completely understood, and it is unknown whether VTE is itself a risk factor for cancer.

METHODS

We used data from large genome-wide association study meta-analyses to perform bidirectional Mendelian randomization analyses to estimate causal associations between genetic liability to VTE and risk of 18 different cancers.

RESULTS

We found no conclusive evidence that genetic liability to VTE was causally associated with an increased incidence of cancer, or vice versa. We observed an association between liability to VTE and pancreatic cancer risk [odds ratio for pancreatic cancer: 1.23 (95% confidence interval: 1.08-1.40) per log-odds increase in VTE risk, P = 0.002]. However, sensitivity analyses revealed this association was predominantly driven by a variant proxying non-O blood group, with inadequate evidence to suggest a causal relationship.

CONCLUSIONS

These findings do not support the hypothesis that genetic liability to VTE is a cause of cancer. Existing observational epidemiological associations between VTE and cancer are therefore more likely to be driven by pathophysiological changes which occur in the setting of active cancer and anti-cancer treatments. Further work is required to explore and synthesize evidence for these mechanisms.

Genotoxic colibactin mutational signature in colorectal cancer is associated with clinicopathological features, specific genomic alterations and better survival

Background and Aims

The microbiome has long been suspected of a role in colorectal cancer (CRC) tumorigenesis. The mutational signature SBS88 mechanistically links CRC development with the strain of Escherichia coli harboring the pks island that produces the genotoxin colibactin, but the genomic, pathological and survival characteristics associated with SBS88-positive tumors are unknown.

Methods

SBS88-positive CRCs were identified from targeted sequencing data from 5,292 CRCs from 17 studies and tested for their association with clinico-pathological features, oncogenic pathways, genomic characteristics and survival.

Results

In total, 7.5% (398/5,292) of the CRCs were SBS88-positive, of which 98.7% (392/398) were microsatellite stable/microsatellite instability low (MSS/MSI-L), compared with 80% (3916/4894) of SBS88 negative tumors (p=1.5x10-28). Analysis of MSS/MSI-L CRCs demonstrated that SBS88 positive CRCs were associated with the distal colon (OR=1.84, 95% CI=1.40-2.42, p=1x10-5) and rectum (OR=1.90, 95% CI=1.44-2.51, p=6x10-6) tumor sites compared with the proximal colon. The top seven recurrent somatic mutations associated with SBS88-positive CRCs demonstrated mutational contexts associated with colibactin-induced DNA damage, the strongest of which was the APC:c.835-8A>G mutation (OR=65.5, 95%CI=39.0-110.0, p=3x10-80). Large copy number alterations (CNAs) including CNA loss on 14q and gains on 13q, 16q and 20p were significantly enriched in SBS88-positive CRCs. SBS88-positive CRCs were associated with better CRC-specific survival (p=0.007; hazard ratio of 0.69, 95% CI=0.52-0.90) when stratified by age, sex, study, and by stage.

Conclusion

SBS88-positivity, a biomarker of colibactin-induced DNA damage, can identify a novel subtype of CRC characterized by recurrent somatic mutations, copy number alterations and better survival. These findings provide new insights for treatment and prevention strategies for this subtype of CRC.

Leisure time television watching, computer use and risks of breast, colorectal and prostate cancer: A Mendelian randomisation analysis

BACKGROUND

Sedentary behaviours have been associated with increased risks of some common cancers in epidemiological studies; however, it is unclear if these associations are causal.

METHODS

We used univariable and multivariable two-sample Mendelian randomisation (MR) to examine potential causal relationships between sedentary behaviours and risks of breast, colorectal and prostate cancer. Genetic variants associated with self-reported leisure television watching and computer use were identified from a recent genome-wide association study (GWAS). Data related to cancer risk were obtained from cancer GWAS consortia. A series of sensitivity analyses were applied to examine the robustness of the results to the presence of confounding.

RESULTS

A 1-standard deviation (SD: 1.5 h/day) increment in hours of television watching increased risk of breast cancer (OR per 1-SD: 1.15, 95% confidence interval [CI]: 1.05-1.26) and colorectal cancer (OR per 1-SD: 1.32, 95% CI: 1.16-1.49) while there was little evidence of an association for prostate cancer risk (OR per 1-SD: 0.94, 95% CI: 0.84-1.06). After adjusting for years of education, the effect estimates for television watching were attenuated (breast cancer, OR per 1-SD: 1.08, 95% CI: 0.92-1.27; colorectal cancer, OR per 1-SD: 1.08, 95% CI: 0.90-1.31). Post hoc analyses showed that years of education might have a possible confounding and mediating role in the association between television watching with breast and colorectal cancer. Consistent results were observed for each cancer site according to sex (colorectal cancer), anatomical subsites and cancer subtypes. There was little evidence of associations between genetically predicted computer use and cancer risk.

CONCLUSIONS

Our univariable analysis identified some positive associations between hours of television watching and risks of breast and colorectal cancer. However, further adjustment for additional lifestyle factors especially years of education attenuated these results. Future studies using objective measures of exposure can provide new insights into the possible role of sedentary behaviour in cancer development.

Identifying metabolic features of colorectal cancer liability using Mendelian randomization

Background

Recognizing the early signs of cancer risk is vital for informing prevention, early detection, and survival.

Methods

To investigate whether changes in circulating metabolites characterize the early stages of colorectal cancer (CRC) development, we examined the associations between a genetic risk score (GRS) associated with CRC liability (72 single-nucleotide polymorphisms) and 231 circulating metabolites measured by nuclear magnetic resonance spectroscopy in the Avon Longitudinal Study of Parents and Children (N = 6221). Linear regression models were applied to examine the associations between genetic liability to CRC and circulating metabolites measured in the same individuals at age 8 y, 16 y, 18 y, and 25 y.

Results

The GRS for CRC was associated with up to 28% of the circulating metabolites at FDR-P < 0.05 across all time points, particularly with higher fatty acids and very-low- and low-density lipoprotein subclass lipids. Two-sample reverse Mendelian randomization (MR) analyses investigating CRC liability (52,775 cases, 45,940 controls) and metabolites measured in a random subset of UK Biobank participants (N = 118,466, median age 58 y) revealed broadly consistent effect estimates with the GRS analysis. In conventional (forward) MR analyses, genetically predicted polyunsaturated fatty acid concentrations were most strongly associated with higher CRC risk.

Conclusions

These analyses suggest that higher genetic liability to CRC can cause early alterations in systemic metabolism and suggest that fatty acids may play an important role in CRC development.

Funding

This work was supported by the Elizabeth Blackwell Institute for Health Research, University of Bristol, the Wellcome Trust, the Medical Research Council, Diabetes UK, the University of Bristol NIHR Biomedical Research Centre, and Cancer Research UK. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. This work used the computational facilities of the Advanced Computing Research Centre, University of Bristol - http://www.bristol.ac.uk/acrc/.

Association Between COVID-19 During Pregnancy and Preterm Birth by Trimester of Infection: A Retrospective Cohort Study Using Longitudinal Social Media Data

Background

Preterm birth, defined as birth at <37 weeks of gestation, is the leading cause of neonatal death globally and, together with low birthweight, the second leading cause of infant mortality in the United States. There is mounting evidence that COVID-19 infection during pregnancy is associated with an increased risk of preterm birth; however, data remain limited by trimester of infection. The ability to study COVID-19 infection during the earlier stages of pregnancy has been limited by available sources of data. The objective of this study was to use self-reports in large-scale, longitudinal social media data to assess the association between trimester of COVID-19 infection and preterm birth.

Methods

In this retrospective cohort study, we used natural language processing and machine learning, followed by manual validation, to identify pregnant Twitter users and to search their longitudinal collection of publicly available tweets for reports of COVID-19 infection during pregnancy and, subsequently, a preterm birth or term birth (i.e., a gestational age ≥37 weeks) outcome. Among the users who reported their pregnancy on Twitter, we also identified a 1:1 age-matched control group, consisting of users with a due date prior to January 1, 2020-that is, without COVID-19 infection during pregnancy. We calculated the odds ratios (ORs) with 95% confidence intervals (CIs) to compare the overall rates of preterm birth for pregnancies with and without COVID-19 infection and by timing of infection: first trimester (weeks 1-13), second trimester (weeks 14-27), or third trimester (weeks 28-36).

Results

Through August 2022, we identified 298 Twitter users who reported COVID-19 infection during pregnancy, a preterm birth or term birth outcome, and maternal age: 94 (31.5%) with first-trimester infection, 110 (36.9%) second-trimester infection, and 95 (31.9%) third-trimester infection. In total, 26 (8.8%) of these 298 users reported preterm birth: 8 (8.5%) were infected during the first trimester, 7 (6.4%) were infected during the second trimester, and 12 (12.6%) were infected during the third trimester. In the 1:1 age-matched control group, 13 (4.4%) of the 298 users reported preterm birth. Overall, the risk of preterm birth was significantly higher for pregnancies with COVID-19 infection compared to those without (OR 2.1, 95% CI 1.06-4.16). In particular, the risk of preterm birth was significantly higher for pregnancies with COVID-19 infection during the third trimester (OR 3.17, CI 1.39-7.21).

Conclusion

The results of our study suggest that COVID-19 infection particularly during the third trimester is associated with an increased risk of preterm birth.

Identifying metabolic features of colorectal cancer liability using Mendelian randomization

Background

Recognizing the early signs of cancer risk is vital for informing prevention, early detection, and survival.

Methods

To investigate whether changes in circulating metabolites characterise the early stages of colorectal cancer (CRC) development, we examined associations between a genetic risk score (GRS) associated with CRC liability (72 single nucleotide polymorphisms) and 231 circulating metabolites measured by nuclear magnetic resonance spectroscopy in the Avon Longitudinal Study of Parents and Children (N=6,221). Linear regression models were applied to examine associations between genetic liability to colorectal cancer and circulating metabolites measured in the same individuals at age 8, 16, 18 and 25 years.

Results

The GRS for CRC was associated with up to 28% of the circulating metabolites at FDR-P<0.05 across all time points, particularly with higher fatty acids and very-low- and low-density lipoprotein subclass lipids. Two-sample reverse Mendelian randomization (MR) analyses investigating CRC liability (52,775 cases, 45,940 controls) and metabolites measured in a random subset of UK Biobank participants (N=118,466, median age 58y) revealed broadly consistent effect estimates with the GRS analysis. In conventional (forward) MR analyses, genetically predicted polyunsaturated fatty acid concentrations were most strongly associated with higher CRC risk.

Conclusions

These analyses suggest that higher genetic liability to CRC can cause early alterations in systemic metabolism, and suggest that fatty acids may play an important role in CRC development.

Funding

This work was supported by the Elizabeth Blackwell Institute for Health Research, University of Bristol, the Wellcome Trust, the Medical Research Council, Diabetes UK, the University of Bristol NIHR Biomedical Research Centre, and Cancer Research UK. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. This work used the computational facilities of the Advanced Computing Research Centre, University of Bristol - http://www.bristol.ac.uk/acrc/.

Genome-wide interaction analysis of folate for colorectal cancer risk

BACKGROUND

Epidemiological and experimental evidence suggests that higher folate intake is associated with decreased colorectal cancer (CRC) risk; however, the mechanisms underlying this relationship are not fully understood. Genetic variation that may have a direct or indirect impact on folate metabolism can provide insights into folate's role in CRC.

OBJECTIVES

Our aim was to perform a genome-wide interaction analysis to identify genetic variants that may modify the association of folate on CRC risk.

METHODS

We applied traditional case-control logistic regression, joint 3-degree of freedom, and a 2-step weighted hypothesis approach to test the interactions of common variants (allele frequency >1%) across the genome and dietary folate, folic acid supplement use, and total folate in relation to risk of CRC in 30,550 cases and 42,336 controls from 51 studies from 3 genetic consortia (CCFR, CORECT, GECCO).

RESULTS

Inverse associations of dietary, total folate, and folic acid supplement with CRC were found (odds ratio [OR]: 0.93; 95% confidence interval [CI]: 0.90, 0.96; and 0.91; 95% CI: 0.89, 0.94 per quartile higher intake, and 0.82 (95% CI: 0.78, 0.88) for users compared with nonusers, respectively). Interactions (P-interaction < 5×10-8) of folic acid supplement and variants in the 3p25.2 locus (in the region of Synapsin II [SYN2]/tissue inhibitor of metalloproteinase 4 [TIMP4]) were found using traditional interaction analysis, with variant rs150924902 (located upstream to SYN2) showing the strongest interaction. In stratified analyses by rs150924902 genotypes, folate supplementation was associated with decreased CRC risk among those carrying the TT genotype (OR: 0.82; 95% CI: 0.79, 0.86) but increased CRC risk among those carrying the TA genotype (OR: 1.63; 95% CI: 1.29, 2.05), suggesting a qualitative interaction (P-interaction = 1.4×10-8). No interactions were observed for dietary and total folate.

CONCLUSIONS

Variation in 3p25.2 locus may modify the association of folate supplement with CRC risk. Experimental studies and studies incorporating other relevant omics data are warranted to validate this finding.

Low booster uptake in cancer patients despite health benefits

Patients with cancer are at increased risk of death from COVID-19 and have reduced immune responses to SARS-CoV2 vaccines, necessitating regular boosters. We performed comprehensive chart reviews, surveys of patients attitudes, serology for SARS-CoV-2 antibodies and T-cell receptor (TCR) β sequencing for cellular responses on a cohort of 982 cancer patients receiving active cancer therapy accrued between November-3-2020 and Mar-31-2023. We found that 92·3% of patients received the primer vaccine, 70·8% received one monovalent booster, but only 30·1% received a bivalent booster. Booster uptake was lower under age 50, and among African American or Hispanic patients. Nearly all patients seroconverted after 2+ booster vaccinations (>99%) and improved cellular responses, demonstrating that repeated boosters could overcome poor response to vaccination. Receipt of booster vaccinations was associated with a lower risk of all-cause mortality (HR=0·61, P=0·024). Booster uptake in high-risk cancer patients remains low and strategies to encourage booster uptake are needed.

Highlights

COVID-19 booster vaccinations increase antibody levels and maintain T-cell responses against SARS-CoV-2 in patients receiving various anti-cancer therapiesBooster vaccinations reduced all-cause mortality in patientsA significant proportion of patients remain unboosted and strategies are needed to encourage patients to be up-to-date with vaccinations.

Prospective and Mendelian randomization analyses on the association of circulating fatty acid binding protein 4 (FABP-4) and risk of colorectal cancer

BACKGROUND

Fatty acid binding protein 4 (FABP-4) is a lipid-binding adipokine upregulated in obesity, which may facilitate fatty acid supply for tumor growth and promote insulin resistance and inflammation and may thus play a role in colorectal cancer (CRC) development. We aimed to investigate the association between circulating FABP-4 and CRC and to assess potential causality using a Mendelian randomization (MR) approach.

METHODS

The association between pre-diagnostic plasma measurements of FABP-4 and CRC risk was investigated in a nested case-control study in 1324 CRC cases and the same number of matched controls within the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort. A two-sample Mendelian randomization study was conducted based on three genetic variants (1 cis, 2 trans) associated with circulating FABP-4 identified in a published genome-wide association study (discovery n = 20,436) and data from 58,131 CRC cases and 67,347 controls in the Genetics and Epidemiology of Colorectal Cancer Consortium, Colorectal Cancer Transdisciplinary Study, and Colon Cancer Family Registry.

RESULTS

In conditional logistic regression models adjusted for potential confounders including body size, the estimated relative risk, RR (95% confidence interval, CI) per one standard deviation, SD (8.9 ng/mL) higher FABP-4 concentration was 1.01 (0.92, 1.12) overall, 0.95 (0.80, 1.13) in men and 1.09 (0.95, 1.25) in women. Genetically determined higher FABP-4 was not associated with colorectal cancer risk (RR per FABP-4 SD was 1.10 (0.95, 1.27) overall, 1.03 (0.84, 1.26) in men and 1.21 (0.98, 1.48) in women). However, in a cis-MR approach, a statistically significant association was observed in women (RR 1.56, 1.09, 2.23) but not overall (RR 1.23, 0.97, 1.57) or in men (0.99, 0.71, 1.37).

CONCLUSIONS

Taken together, these analyses provide no support for a causal role of circulating FABP-4 in the development of CRC, although the cis-MR provides some evidence for a positive association in women, which may deserve to be investigated further.

Combining Asian and European genome-wide association studies of colorectal cancer improves risk prediction across racial and ethnic populations

Polygenic risk scores (PRS) have great potential to guide precision colorectal cancer (CRC) prevention by identifying those at higher risk to undertake targeted screening. However, current PRS using European ancestry data have sub-optimal performance in non-European ancestry populations, limiting their utility among these populations. Towards addressing this deficiency, we expand PRS development for CRC by incorporating Asian ancestry data (21,731 cases; 47,444 controls) into European ancestry training datasets (78,473 cases; 107,143 controls). The AUC estimates (95% CI) of PRS are 0.63(0.62-0.64), 0.59(0.57-0.61), 0.62(0.60-0.63), and 0.65(0.63-0.66) in independent datasets including 1681-3651 cases and 8696-115,105 controls of Asian, Black/African American, Latinx/Hispanic, and non-Hispanic White, respectively. They are significantly better than the European-centric PRS in all four major US racial and ethnic groups (p-values < 0.05). Further inclusion of non-European ancestry populations, especially Black/African American and Latinx/Hispanic, is needed to improve the risk prediction and enhance equity in applying PRS in clinical practice.

Trajectories and risk factors of fatigue following colorectal cancer diagnosis

AIM

This study sought to identify groups of colorectal cancer patients based upon trajectories of fatigue and examine how demographic, clinical and behavioural risk factors differentiate these groups.

METHOD

Patients were from six cancer centres in the United States and Germany. Fatigue was measured using the fatigue subscale of the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire (EORTC QLQ-C30) at five time points (baseline/enrolment and 3, 6, 12 and 24 months after diagnosis). Piecewise growth mixture models identified latent trajectories of fatigue. Logistic regression models examined differences in demographic, clinical and behavioural characteristics between fatigue trajectory groups.

RESULTS

Among 1615 participants (57% men, 86% non-Hispanic White, mean age 61 ± 13 years at diagnosis), three distinct groups were identified. In the high fatigue group (36%), fatigue significantly increased in the first 6 months after diagnosis and then showed statistically and clinically significant improvement from 6 to 24 months (P values < 0.01). Throughout the study period, average fatigue met or exceeded cutoffs for clinical significance. In the moderate (34%) and low (30%) fatigue groups, fatigue levels remained below or near population norms across the study period. Patients who were diagnosed with Stage II-IV disease and/or current smokers were more likely to be in the high fatigue than in the moderate fatigue group (P values < 0.05).

CONCLUSION

A large proportion of colorectal cancer patients experienced sustained fatigue after initiation of cancer treatment. Patients with high fatigue at the time of diagnosis may benefit from early supportive care.

A Paratope-Enhanced Method to Determine Breadth and Depth TCR Clonal Metrics of the Private Human T-Cell Vaccine Response after SARS-CoV-2 Vaccination

Quantitative metrics for vaccine-induced T-cell responses are an important need for developing correlates of protection and their use in vaccine-based medical management and population health. Molecular TCR analysis is an appealing strategy but currently requires a targeted methodology involving complex integration of ex vivo data (antigen-specific functional T-cell cytokine responses and TCR molecular responses) that uncover only public antigen-specific metrics. Here, we describe an untargeted private TCR method that measures breadth and depth metrics of the T-cell response to vaccine challenge using a simple pre- and post-vaccine subject sampling, TCR immunoseq analysis, and a bioinformatic approach using self-organizing maps and GLIPH2. Among 515 subjects undergoing SARS-CoV-2 mRNA vaccination, we found that breadth and depth metrics were moderately correlated between the targeted public TCR response and untargeted private TCR response methods. The untargeted private TCR method was sufficiently sensitive to distinguish subgroups of potential clinical significance also observed using public TCR methods (the reduced T-cell vaccine response with age and the paradoxically elevated T-cell vaccine response of patients on anti-TNF immunotherapy). These observations suggest the promise of this untargeted private TCR method to produce T-cell vaccine-response metrics in an antigen-agnostic and individual-autonomous context.

Elevated EVL Methylation Level in the Normal Colon Mucosa Is a Potential Risk Biomarker for Developing Recurrent Adenomas

BACKGROUND

Individuals with adenomatous colorectal polyps undergo repeated colonoscopy surveillance to identify and remove metachronous adenomas. However, many patients with adenomas do not develop recurrent adenomas. Better methods to evaluate who benefits from increased surveillance are needed. We evaluated the use of altered EVL methylation as a potential biomarker for risk of recurrent adenomas.

METHODS

Patients with ≥1 colonoscopy had EVL methylation (mEVL) measured with an ultra-accurate methylation-specific droplet digital PCR assay on normal colon mucosa. The association between EVL methylation levels and adenoma or colorectal cancer was evaluated using three case/control definitions in three models: unadjusted (model 1), adjusting for baseline characteristics (model 2), and an adjusted model excluding patients with colorectal cancer at baseline (model 3).

RESULTS

Between 2001 and 2020, 136 patients were included; 74 healthy patients and 62 patients with a history of colorectal cancer. Older age, never smoking, and baseline colorectal cancer were associated with higher levels of mEVL (P ≤ 0.05). Each log base 10 difference in mEVL was associated with an increased risk of adenoma(s) or cancer at/after baseline for model 1 [OR, 2.64; 95% confidence interval (CI), 1.09-6.36], and adenoma(s) or cancer after baseline for models 1 (OR, 2.01; 95% CI, 1.04-3.90) and model 2 (OR, 3.17; 95% CI, 1.30-7.72).

CONCLUSIONS

Our results suggest that EVL methylation level detected in the normal colon mucosa has the potential to be a biomarker for monitoring the risk for recurrent adenomas.

IMPACT

These findings support the potential utility of EVL methylation for improving the accuracy for assigning risk for recurrent colorectal adenomas and cancer.

Using DEPendency of Association on the Number of Top Hits (DEPTH) as a Complementary Tool to Identify Novel Colorectal Cancer Susceptibility Loci

BACKGROUND

DEPendency of association on the number of Top Hits (DEPTH) is an approach to identify candidate susceptibility regions by considering the risk signals from overlapping groups of sequential variants across the genome.

METHODS

We applied a DEPTH analysis using a sliding window of 200 SNPs to colorectal cancer data from the Colon Cancer Family Registry (CCFR; 5,735 cases and 3,688 controls), and Genetics and Epidemiology of Colorectal Cancer Consortium (GECCO; 8,865 cases and 10,285 controls) studies. A DEPTH score > 1 was used to identify candidate susceptibility regions common to both analyses. We compared DEPTH results against those from conventional genome-wide association study (GWAS) analyses of these two studies as well as against 132 published susceptibility regions.

RESULTS

Initial DEPTH analysis revealed 2,622 (CCFR) and 3,686 (GECCO) candidate susceptibility regions, of which 569 were common to both studies. Bootstrapping revealed 40 and 49 candidate susceptibility regions in the CCFR and GECCO data sets, respectively. Notably, DEPTH identified at least 82 regions that would not be detected using conventional GWAS methods, nor had they been identified by previous colorectal cancer GWASs. We found four reproducible candidate susceptibility regions (2q22.2, 2q33.1, 6p21.32, 13q14.3). The highest DEPTH scores were in the human leukocyte antigen locus at 6p21 where the strongest associated SNPs were rs762216297, rs149490268, rs114741460, and rs199707618 for the CCFR data, and rs9270761 for the GECCO data.

CONCLUSIONS

DEPTH can identify candidate susceptibility regions for colorectal cancer not identified using conventional analyses of larger datasets.

IMPACT

DEPTH has potential as a powerful complementary tool to conventional GWAS analyses for discovering susceptibility regions within the genome.

Probing the diabetes and colorectal cancer relationship using gene - environment interaction analyses

BACKGROUND

Diabetes is an established risk factor for colorectal cancer. However, the mechanisms underlying this relationship still require investigation and it is not known if the association is modified by genetic variants. To address these questions, we undertook a genome-wide gene-environment interaction analysis.

METHODS

We used data from 3 genetic consortia (CCFR, CORECT, GECCO; 31,318 colorectal cancer cases/41,499 controls) and undertook genome-wide gene-environment interaction analyses with colorectal cancer risk, including interaction tests of genetics(G)xdiabetes (1-degree of freedom; d.f.) and joint testing of Gxdiabetes, G-colorectal cancer association (2-d.f. joint test) and G-diabetes correlation (3-d.f. joint test).

RESULTS

Based on the joint tests, we found that the association of diabetes with colorectal cancer risk is modified by loci on chromosomes 8q24.11 (rs3802177, SLC30A8 - ORAA: 1.62, 95% CI: 1.34-1.96; ORAG: 1.41, 95% CI: 1.30-1.54; ORGG: 1.22, 95% CI: 1.13-1.31; p-value3-d.f.: 5.46 × 10-11) and 13q14.13 (rs9526201, LRCH1 - ORGG: 2.11, 95% CI: 1.56-2.83; ORGA: 1.52, 95% CI: 1.38-1.68; ORAA: 1.13, 95% CI: 1.06-1.21; p-value2-d.f.: 7.84 × 10-09).

DISCUSSION

These results suggest that variation in genes related to insulin signaling (SLC30A8) and immune function (LRCH1) may modify the association of diabetes with colorectal cancer risk and provide novel insights into the biology underlying the diabetes and colorectal cancer relationship.

A Genetic Locus within the FMN1/GREM1 Gene Region Interacts with Body Mass Index in Colorectal Cancer Risk

Colorectal cancer risk can be impacted by genetic, environmental, and lifestyle factors, including diet and obesity. Gene-environment interactions (G × E) can provide biological insights into the effects of obesity on colorectal cancer risk. Here, we assessed potential genome-wide G × E interactions between body mass index (BMI) and common SNPs for colorectal cancer risk using data from 36,415 colorectal cancer cases and 48,451 controls from three international colorectal cancer consortia (CCFR, CORECT, and GECCO). The G × E tests included the conventional logistic regression using multiplicative terms (one degree of freedom, 1DF test), the two-step EDGE method, and the joint 3DF test, each of which is powerful for detecting G × E interactions under specific conditions. BMI was associated with higher colorectal cancer risk. The two-step approach revealed a statistically significant G×BMI interaction located within the Formin 1/Gremlin 1 (FMN1/GREM1) gene region (rs58349661). This SNP was also identified by the 3DF test, with a suggestive statistical significance in the 1DF test. Among participants with the CC genotype of rs58349661, overweight and obesity categories were associated with higher colorectal cancer risk, whereas null associations were observed across BMI categories in those with the TT genotype. Using data from three large international consortia, this study discovered a locus in the FMN1/GREM1 gene region that interacts with BMI on the association with colorectal cancer risk. Further studies should examine the potential mechanisms through which this locus modifies the etiologic link between obesity and colorectal cancer.

SIGNIFICANCE

This gene-environment interaction analysis revealed a genetic locus in FMN1/GREM1 that interacts with body mass index in colorectal cancer risk, suggesting potential implications for precision prevention strategies.

Efforts to Grow Genomic Research in Ancestrally Diverse and Admixed Populations

Recent initiatives by the research community to characterize the genomic and molecular landscapes of tumors in ancestrally diverse and admixed populations, including the publication by Ding and colleagues in this issue of Cancer Research, represent important efforts to improve our understanding of the entire spectrum of cancer genomic variation with potential clinical consequences. Ding and colleagues confirmed a similar prevalence of mutations in established breast cancer driver genes including PIK3CA, TP53, GATA3, MAP3K1, CDH1, CBFB, PTEN, and RUNX1 and recurrent amplifications in breast cancer drivers including MYC, FGFR1, CCND1, and ERBB2 in tumors from Hispanic/Latina women as compared with non-Hispanic White women. Importantly, they also identified Catalogue of Somatic Mutations in Cancer (COSMIC) signature 16 in a significant fraction of tumors from Hispanic/Latina women and a novel recurrent amplification on 17q11.2. This study highlights the potential for inclusion of participants from diverse populations to accelerate discoveries and advance equity in genomic medicine, as well as the need for even larger collaborative initiatives. See related article by Ding et al., p. 2600.

Physical Activity, Sedentary Behavior, and Risk of Coronavirus Disease 2019

INTRODUCTION

Data on the associations of prepandemic physical activity and sedentary behavior with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and coronavirus disease 2019 (COVID-19) severity, particularly milder illness, have been limited.

METHODS

We used data from 43,913 participants within the Nurses' Health Study II and Health Professionals Follow-Up Study who responded to periodic COVID-related surveys from May 2020 through March 2021. History of physical activity from the prepandemic period was assessed as the metabolic equivalents of task (MET)-hours per week of various activities of different intensity and sedentary behavior assessed from reports of time spent sitting from questionnaires completed 2016-2017. Multivariable logistic regression models were fitted to calculate the odds ratios (ORs) and 95% confidence intervals (CIs) for risk of SARS-CoV-2 infection and COVID-19 severity, as well as predicted COVID-19 defined using a validated symptom-based algorithm.

RESULTS

Higher levels of prepandemic physical activity were associated with a lower risk for SARS-CoV-2 infection. Compared to participants with <3 MET-hours per week, the multivariable-adjusted OR was 0.86 (95% CI: 0.74, 0.99; P trend =.07) for those with ≥27 MET-hours per week. Higher physical activity levels were also associated with lower risk of symptomatic SARS-CoV-2 infection (OR: 0.84; 95% CI: 0.72, 0.99; P trend = .05) and predicted COVID-19 (OR: 0.87; 95% CI: 0.78, 0.97; P trend = .01). Longer time sitting at home watching TV (OR: 0.85; 95% CI: 0.73, 0.97) or for other tasks (OR: 0.78; 95% CI: 0.66, 0.92) was associated with a lower risk of SARS-CoV-2 infection.

CONCLUSIONS

Our findings support a protective association between prepandemic physical activity and lower risk and severity of COVID-19.

Causal relationships between risk of venous thromboembolism and 18 cancers: a bidirectional Mendelian randomisation analysis

Background

People with cancer experience high rates of venous thromboembolism (VTE). Additionally, risk of subsequent cancer is increased in people experiencing their first VTE. The causal mechanisms underlying this association are not completely understood, and it is unknown whether VTE is itself a risk factor for cancer.

Methods

We used data from large genome-wide association study meta-analyses to perform bi-directional Mendelian randomisation analyses to estimate causal associations between genetically-proxied lifetime risk of VTE and risk of 18 different cancers.

Results

We found no conclusive evidence that genetically-proxied lifetime risk of VTE was causally associated with an increased incidence of cancer, or vice-versa. We observed an association between VTE and pancreatic cancer risk (odds ratio for pancreatic cancer 1.23 (95% confidence interval 1.08 - 1.40) per log-odds increase in risk of VTE, P = 0.002). However, sensitivity analyses revealed this association was predominantly driven by a variant proxying non-O blood group, with inadequate evidence from Mendelian randomisation to suggest a causal relationship.

Conclusions

These findings do not support the hypothesis that genetically-proxied lifetime risk of VTE is a cause of cancer. Existing observational epidemiological associations between VTE and cancer are therefore more likely to be driven by pathophysiological changes which occur in the setting of active cancer and anti-cancer treatments. Further work is required to explore and synthesise evidence for these mechanisms.

Application of Mendelian randomization to explore the causal role of the human gut microbiome in colorectal cancer

The role of the human gut microbiome in colorectal cancer (CRC) is unclear as most studies on the topic are unable to discern correlation from causation. We apply two-sample Mendelian randomization (MR) to estimate the causal relationship between the gut microbiome and CRC. We used summary-level data from independent genome-wide association studies to estimate the causal effect of 14 microbial traits (n = 3890 individuals) on overall CRC (55,168 cases, 65,160 controls) and site-specific CRC risk, conducting several sensitivity analyses to understand the nature of results. Initial MR analysis suggested that a higher abundance of Bifidobacterium and presence of an unclassified group of bacteria within the Bacteroidales order in the gut increased overall and site-specific CRC risk. However, sensitivity analyses suggested that instruments used to estimate relationships were likely complex and involved in many potential horizontal pleiotropic pathways, demonstrating that caution is needed when interpreting MR analyses with gut microbiome exposures. In assessing reverse causality, we did not find strong evidence that CRC causally affected these microbial traits. Whilst our study initially identified potential causal roles for two microbial traits in CRC, importantly, further exploration of these relationships highlighted that these were unlikely to reflect causality.

Abstract 355: Examination of systemic myokine concentrations with risk of cachexia in non-metastatic colorectal cancer patients - Results from the ColoCare Study

BACKGROUND: Cachexia is a multifactorial metabolic syndrome associated with higher risk of mortality. The precise molecular mechanisms and biological pathways involved remain poorly characterized. A specific criterion of cachexia is loss of muscle mass. Myokines affect muscle mass and have profound effects on glucose and lipid metabolism, thus contributing to energy homeostasis and potentially cachexia. Only sparse data for patients with non-metastatic colorectal cancer exist. This study aims to investigate associations of systemic myokine concentrations with onset of cachexia in non-metastatic colorectal cancer patients.

METHODS: Serum samples from n=125 colorectal cancer patients (stage I-III) recruited from the ColoCare Study site at Huntsman Cancer Institute were collected prior to surgery (baseline). Assays were run with the Milliplex Human Myokine Magnetic panel containing beads such as FABP3, Oncostatin M, and FGF21. Patients were defined as cachectic, pre-cachectic, or non-cachectic based on the criteria by Fearon et al. based on sex, BMI, and weight loss over a period of six months. ANOVA were applied to analyze associations of myokines with cachexia at 12 month after surgery, adjusted by age at diagnosis, sex, tumor stage, and tumor site.

RESULTS: At the 12 months follow-up, 11% of patients were diagnosed with cachexia (n=14), 14% of patients with pre-cachexia (n=18), and 74% of patients were defined as non-cachectic. Patients with cachexia were more likely to be diagnosed with rectal cancer (57%) compared to pre-cachectic (17%) or non-cachectic patients (42%; p&lt;0.01). Patients who received neo-adjuvant treatment were more likely to be cachectic compared to pre-cachectic or non-cachectic patients (36% vs 11% vs 26%, respectively, p&lt;0.01). FABP3 at baseline was significantly different across the three groups, e.g., FABP3 was 11.4 pg/ml for cachectic patients, 10.5 pg/ml for pre-cachectic patients, and 10.4 pg/ml for non-cachectic patients (p=0.02). FABP3 was associated with 65% increased risk of cachexia in unadjusted models, e.g., Odds ratio 1.65, 95% Confidence Intervals 1.05-2.61; p=0.03). After additional adjustment for age, sex, tumor site, and tumor stage the result was non-significant (p=0.26). There were no statistically significant differences in FGF21 and Oncostatin M concentrations across cachexia stages. C

ONCLUSIONS: Cachectic patients presented higher FABP3 concentrations (p=0.02) which were associated with increased risk of cachexia, however these results were not significant after adjustment. In this study, cachectic patients were more likely to be diagnosed with rectal cancer. In summary, larger studies are needed to further evaluate FABP3 and other myokines as potential prognostic biomarkers for cachexia and consider differences by tumor site.

Citation Format: Jennifer Ose, Ellen Beswick, Simon Ta Van, Richard H. Viskochil, Christy A. Warby, Jeffrey T. Yap, Matthew F. Covington, Anne H. Nguyen, Jordan W. Stanford, Tengda Lin, Anita R. Peoples, Sheetal Hardikar, Christopher I. Li, William M. Grady, David Shibatta, Adetunji T. Toriola, Martin Schneider, Jane C. Figueiredo, Daniel Jeong, Erin M. Siegel, Cornelia M. Ulrich, Biljana Gigic. Examination of systemic myokine concentrations with risk of cachexia in non-metastatic colorectal cancer patients - Results from the ColoCare Study [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 355.

Associations of combined physical activity and body mass index groups with colorectal cancer survival outcomes

BACKGROUND

Physical activity and BMI have been individually associated with cancer survivorship but have not yet been studied in combinations in colorectal cancer patients. Here, we investigate individual and combined associations of physical activity and BMI groups with colorectal cancer survival outcomes.

METHODS

Self-reported physical activity levels (MET hrs/wk) were assessed using an adapted version of the International Physical Activity Questionnaire (IPAQ) at baseline in 931 patients with stage I-III colorectal cancer and classified into 'highly active' and'not-highly active'(≥ / < 18 MET hrs/wk). BMI (kg/m2) was categorized into 'normal weight', 'overweight', and 'obese'. Patients were further classified into combined physical activity and BMI groups. Cox-proportional hazard models with Firth correction were computed to assess associations [hazard ratio (HR), 95% profile HR likelihood confidence interval (95% CI) between individual and combined physical activity and BMI groups with overall and disease-free survival in colorectal cancer patients.

RESULTS

'Not-highly active' compared to 'highly active' and 'overweight'/ 'obese' compared to 'normal weight' patients had a 40-50% increased risk of death or recurrence (HR: 1.41 (95% CI: 0.99-2.06), p = 0.03; HR: 1.49 (95% CI: 1.02-2.21) and HR: 1.51 (95% CI: 1.02-2.26), p = 0.04, respectively). 'Not-highly active' patients had worse disease-free survival outcomes, regardless of their BMI, compared to 'highly active/normal weight' patients. 'Not-highly active/obese' patients had a 3.66 times increased risk of death or recurrence compared to 'highly active/normal weight' patients (HR: 4.66 (95% CI: 1.75-9.10), p = 0.002). Lower activity thresholds yielded smaller effect sizes.

CONCLUSION

Physical activity and BMI were individually associated with disease-free survival among colorectal cancer patients. Physical activity seems to improve survival outcomes in patients regardless of their BMI.

Leisure time sedentary behaviour and risks of breast, colorectal, and prostate cancer: A Mendelian randomization analysis

Sedentary behaviours have been associated with increased risks of some common cancers in epidemiological studies; however, it is unclear if these associations are causal. We examined potential causal associations between self-reported leisure television watching and computer use and risks of breast, colorectal, and prostate cancer using a two-sample Mendelian randomization framework. Genetic variants were identified from a recent genome-wide association study (GWAS). Cancer data were obtained from cancer GWAS consortia. Additional sensitivity analyses were applied to examine the robustness of the results. A 1-standard deviation increment in hours of television watching increased risk of breast (OR: 1.15, 95% confidence interval [CI]: 1.05,1.26) and colorectal cancer (OR: 1.32, 95%CI: 1.16,1.49) with little evidence of an association for prostate cancer risk. In multivariable models adjusted for years of education, the effect estimates for television watching were attenuated (breast cancer, OR: 1.08, 95%CI: 0.92,1.27; colorectal cancer, OR: 1.08, 95%CI: 0.90,1.31). Post-hoc analyses showed that years of education might have a possible confounding and mediating role in the association between television watching with breast and colorectal cancer. Consistent results were observed by sex (colorectal cancer), anatomical subsites, and cancer subtypes. There was little evidence of associations between computer use and cancer risk. We found evidence of positive associations between hours of television watching and risks of breast and colorectal cancer. However, these findings should be interpreted cautiously given the complex role of education. Future studies using objective measures of exposure can provide new insights into the possible role of sedentary behaviour in cancer development.

Novelty and impact

Evidence from observational studies that examined associations between sedentary behaviours and common cancers is mixed and causality is uncertain. In our Mendelian randomization analyses, higher levels of leisure television watching were found to increase the risks of breast and colorectal cancer, suggesting that the that the promotion of lowering sedentary behaviour time could be an effective strategy in the primary prevention of these commonly diagnosed cancers.

Article category

Cancer Epidemiology.

Investigation of liquid biopsy analytes in peripheral blood of individuals after SARS-CoV-2 infection

BACKGROUND

Post-acute COVID-19 syndrome (PACS) is linked to severe organ damage. The identification and stratification of at-risk SARS-CoV-2 infected individuals is vital to providing appropriate care. This exploratory study looks for a potential liquid biopsy signal for PACS using both manual and machine learning approaches.

METHODS

Using a high definition single cell assay (HDSCA) workflow for liquid biopsy, we analysed 100 Post-COVID patients and 19 pre-pandemic normal donor (ND) controls. Within our patient cohort, 73 had received at least 1 dose of vaccination prior to SARS-CoV-2 infection. We stratified the COVID patients into 25 asymptomatic, 22 symptomatic COVID-19 but not suspected for PACS and 53 PACS suspected. All COVID-19 patients investigated in this study were diagnosed between April 2020 and January 2022 with a median 243 days (range 16-669) from diagnosis to their blood draw. We did a histopathological examination of rare events in the peripheral blood and used a machine learning model to evaluate predictors of PACS.

FINDINGS

The manual classification found rare cellular and acellular events consistent with features of endothelial cells and platelet structures in the PACS-suspected cohort. The three categories encompassing the hypothesised events were observed at a significantly higher incidence in the PACS-suspected cohort compared to the ND (p-value < 0.05). The machine learning classifier performed well when separating the NDs from Post-COVID with an accuracy of 90.1%, but poorly when separating the patients suspected and not suspected of PACS with an accuracy of 58.7%.

INTERPRETATION

Both the manual and the machine learning model found differences in the Post-COVID cohort and the NDs, suggesting the existence of a liquid biopsy signal after active SARS-CoV-2 infection. More research is needed to stratify PACS and its subsyndromes.

FUNDING

This work was funded in whole or in part by Fulgent Genetics, Kathy and Richard Leventhal and Vassiliadis Research Fund. This work was also supported by the National Cancer InstituteU54CA260591.

Pre-Surgery Inflammatory and Angiogenesis Biomarkers as Predictors of 12-Month Cancer-Related Distress: Results from the ColoCare Study

BACKGROUND

Patients with colorectal cancer commonly suffer from complex psychological distress. Elevated distress may be linked to systemic biomarkers. We investigated associations of biomarkers of inflammation and angiogenesis with cancer-related distress (CTXD) score.

METHODS

N = 315 patients (stage I-IV) from 2 centers of the ColoCare Study were included: Huntsman Cancer Institute and University of Heidelberg. Biomarkers (e.g., IL6, VEGF-A, VEGF-D) were measured in serum collected pre-surgery and 12 months thereafter. The CTXD overall score and 4 subscales were collected 12 months after surgery and dichotomized to investigate biomarkers as predictors of distress 12 months after surgery; adjusted for age, sex, body mass index, tumor stage, center, and baseline levels of biomarkers.

RESULTS

Doubling of IL6 predicted future increased risk of overall distress [odds ratio (OR), 1.20; 95% confidence interval (CI), 1.02-1.41; P = 0.03]. VEGF-A-predicted future increased risk of high family strain (VEGF-A: OR, 1.21; 95% CI, 1.01-1.44; P = 0.04) and VEGF-D was associated with medical and financial demands (OR, 1.34; 95% CI, 1.01-1.74; P = 0.03).

CONCLUSIONS

This is the first study to show that systemic biomarkers are significantly associated with future CTXD score. Distress was not measured at baseline; we cannot rule out ongoing associations of inflammation and distress throughout treatment versus a direct effect of inflammation on distress. Nonetheless, these data add to evidence that biobehavioral processes interact and that systemic biomarkers are associated with cancer-related distress one year after surgery.

IMPACT

Exercise and diet interventions that lower systemic cytokine levels may impact longer-term CTXD score and improve quality of life of patients with colorectal cancer.

Validation of a Genetic-Enhanced Risk Prediction Model for Colorectal Cancer in a Large Community-Based Cohort

BACKGROUND

Polygenic risk scores (PRS) which summarize individuals' genetic risk profile may enhance targeted colorectal cancer screening. A critical step towards clinical implementation is rigorous external validations in large community-based cohorts. This study externally validated a PRS-enhanced colorectal cancer risk model comprising 140 known colorectal cancer loci to provide a comprehensive assessment on prediction performance.

METHODS

The model was developed using 20,338 individuals and externally validated in a community-based cohort (n = 85,221). We validated predicted 5-year absolute colorectal cancer risk, including calibration using expected-to-observed case ratios (E/O) and calibration plots, and discriminatory accuracy using time-dependent AUC. The PRS-related improvement in AUC, sensitivity and specificity were assessed in individuals of age 45 to 74 years (screening-eligible age group) and 40 to 49 years with no endoscopy history (younger-age group).

RESULTS

In European-ancestral individuals, the predicted 5-year risk calibrated well [E/O = 1.01; 95% confidence interval (CI), 0.91-1.13] and had high discriminatory accuracy (AUC = 0.73; 95% CI, 0.71-0.76). Adding the PRS to a model with age, sex, family and endoscopy history improved the 5-year AUC by 0.06 (P < 0.001) and 0.14 (P = 0.05) in the screening-eligible age and younger-age groups, respectively. Using a risk-threshold of 5-year SEER colorectal cancer incidence rate at age 50 years, adding the PRS had a similar sensitivity but improved the specificity by 11% (P < 0.001) in the screening-eligible age group. In the younger-age group it improved the sensitivity by 27% (P = 0.04) with similar specificity.

CONCLUSIONS

The proposed PRS-enhanced model provides a well-calibrated 5-year colorectal cancer risk prediction and improves discriminatory accuracy in the external cohort.

IMPACT

The proposed model has potential utility in risk-stratified colorectal cancer prevention.

Genome-wide Interaction Study with Smoking for Colorectal Cancer Risk Identifies Novel Genetic Loci Related to Tumor Suppression, Inflammation, and Immune Response

BACKGROUND

Tobacco smoking is an established risk factor for colorectal cancer. However, genetically defined population subgroups may have increased susceptibility to smoking-related effects on colorectal cancer.

METHODS

A genome-wide interaction scan was performed including 33,756 colorectal cancer cases and 44,346 controls from three genetic consortia.

RESULTS

Evidence of an interaction was observed between smoking status (ever vs. never smokers) and a locus on 3p12.1 (rs9880919, P = 4.58 × 10-8), with higher associated risk in subjects carrying the GG genotype [OR, 1.25; 95% confidence interval (CI), 1.20-1.30] compared with the other genotypes (OR <1.17 for GA and AA). Among ever smokers, we observed interactions between smoking intensity (increase in 10 cigarettes smoked per day) and two loci on 6p21.33 (rs4151657, P = 1.72 × 10-8) and 8q24.23 (rs7005722, P = 2.88 × 10-8). Subjects carrying the rs4151657 TT genotype showed higher risk (OR, 1.12; 95% CI, 1.09-1.16) compared with the other genotypes (OR <1.06 for TC and CC). Similarly, higher risk was observed among subjects carrying the rs7005722 AA genotype (OR, 1.17; 95% CI, 1.07-1.28) compared with the other genotypes (OR <1.13 for AC and CC). Functional annotation revealed that SNPs in 3p12.1 and 6p21.33 loci were located in regulatory regions, and were associated with expression levels of nearby genes. Genetic models predicting gene expression revealed that smoking parameters were associated with lower colorectal cancer risk with higher expression levels of CADM2 (3p12.1) and ATF6B (6p21.33).

CONCLUSIONS

Our study identified novel genetic loci that may modulate the risk for colorectal cancer of smoking status and intensity, linked to tumor suppression and immune response.

IMPACT

These findings can guide potential prevention treatments.

Seeing the unseen: how can we best identify transgender women within the Veterans Affairs healthcare system's electronic medical record?

BACKGROUND

One challenge in transgender research is reliably identifying patients through electronic medical records data, as there is no universal transgender International Classification of Diseases (ICD) code, but rather multiple ICD codes that can be used.

AIM

To explore the sensitivity and specificity of 5 commonly used ICD codes to identify transgender patients overall and transgender women specifically (assigned male sex at birth) by using data from the Veterans Affairs (VA), the largest integrated health system in the United States.

METHODS

Patients aged ≥18 years were identified via ICD-9 codes 302.5 and 302.6 (Ninth Revision) and ICD-10 codes F64.0, F64.8, and F64.9 (Tenth Revision) using VA health records from 2000 to 2021 and stratified by bilateral orchiectomy status.

OUTCOMES

Detailed chart review was performed on 32 randomly selected patients for each code (half with and half without orchiectomy) to confirm transgender status and to perform descriptive analyses.

RESULTS

For each ICD code, rates of confirmed transgender status ranged from 88% to 100% for those with and without an orchiectomy, with the majority being transgender women (consistent with most veterans being assigned male sex at birth). Most transgender women (66%-100%) were undergoing estrogen gender-affirming therapy. The majority of provider-driven entries of transgender status took place from 2011 to 2020, with 75% of entries made from 2011 to 2020, consistent with increased recognition and societal acceptance of this population. False negatives were detected at a rate of 15%. Based upon these 5 ICD codes alone, we estimate that the VA has records for 9,449 to 10,738 transgender individuals.

CLINICAL IMPLICATIONS

All 5 codes are very sensitive in identifying transgender patients, and the combination of these codes with orchiectomy is extremely sensitive in identifying transgender women, specifically.

STRENGTHS AND LIMITATIONS

Major strengths of the study are the use of universal ICD codes and a large patient sample size that spans health records nationally and across multiple decades, potentially making our data more generalizable. The main limitation of this study is that subanalyses were performed on a limited number of patients, which prevented us from capturing all false positives and thus from calculating specificity for each code. Similarly, our true negatives were derived from a small, random subset of the population; as such, our calculation for specificity is an estimate.

CONCLUSION

This study highlights a novel method to identify transgender women and paves the way for further research.

Combining Asian-European Genome-Wide Association Studies of Colorectal Cancer Improves Risk Prediction Across Race and Ethnicity

Polygenic risk scores (PRS) have great potential to guide precision colorectal cancer (CRC) prevention by identifying those at higher risk to undertake targeted screening. However, current PRS using European ancestry data have sub-optimal performance in non-European ancestry populations, limiting their utility among these populations. Towards addressing this deficiency, we expanded PRS development for CRC by incorporating Asian ancestry data (21,731 cases; 47,444 controls) into European ancestry training datasets (78,473 cases; 107,143 controls). The AUC estimates (95% CI) of PRS were 0.63(0.62-0.64), 0.59(0.57-0.61), 0.62(0.60-0.63), and 0.65(0.63-0.66) in independent datasets including 1,681-3,651 cases and 8,696-115,105 controls of Asian, Black/African American, Latinx/Hispanic, and non-Hispanic White, respectively. They were significantly better than the European-centric PRS in all four major US racial and ethnic groups (p-values<0.05). Further inclusion of non-European ancestry populations, especially Black/African American and Latinx/Hispanic, is needed to improve the risk prediction and enhance equity in applying PRS in clinical practice.

Separating the effects of early and later life adiposity on colorectal cancer risk: a Mendelian randomization study

BACKGROUND

Observational studies have linked childhood obesity with elevated risk of colorectal cancer; however, it is unclear if this association is causal or independent from the effects of obesity in adulthood on colorectal cancer risk.

METHODS

We conducted Mendelian randomization (MR) analyses to investigate potential causal relationships between self-perceived body size (thinner, plumper, or about average) in early life (age 10) and measured body mass index in adulthood (mean age 56.5) with risk of colorectal cancer. The total and independent effects of body size exposures were estimated using univariable and multivariable MR, respectively. Summary data were obtained from a genome-wide association study of 453,169 participants in UK Biobank for body size and from a genome-wide association study meta-analysis of three colorectal cancer consortia of 125,478 participants.

RESULTS

Genetically predicted early life body size was estimated to increase odds of colorectal cancer (odds ratio [OR] per category change: 1.12, 95% confidence interval [CI]: 0.98-1.27), with stronger results for colon cancer (OR: 1.16, 95% CI: 1.00-1.35), and distal colon cancer (OR: 1.25, 95% CI: 1.04-1.51). After accounting for adult body size using multivariable MR, effect estimates for early life body size were attenuated towards the null for colorectal cancer (OR: 0.97, 95% CI: 0.77-1.22) and colon cancer (OR: 0.97, 95% CI: 0.76-1.25), while the estimate for distal colon cancer was of similar magnitude but more imprecise (OR: 1.27, 95% CI: 0.90-1.77). Genetically predicted adult life body size was estimated to increase odds of colorectal (OR: 1.27, 95% CI: 1.03, 1.57), colon (OR: 1.32, 95% CI: 1.05, 1.67), and proximal colon (OR: 1.57, 95% CI: 1.21, 2.05).

CONCLUSIONS

Our findings suggest that the positive association between early life body size and colorectal cancer risk is likely due to large body size retainment into adulthood.

Abstract P010: Molecular mediators of the energy balance-colorectal cancer link: evaluating the gut microbiome and pro-inflammatory biomarkers

Background: Physical activity and BMI are convincingly associated with colorectal cancer risk, yet the underlying molecular mediators and their interplay in the energy balance-cancer link remain unclear. Possible counteracting effects of physical activity on obesity-induced metabolic changes, including systemic inflammation and changes in the gut microbiome, have yet to be studied. Here, we investigated associations of several combinations of physical activity and BMI with pro-inflammatory biomarkers and the gut microbiome and relationships between these two mediators among patients with colorectal cancer. Methods: N=579 patients with newly diagnosed colorectal cancer (stages I-IV) were included. Physical activity at baseline was assessed using an adapted International Physical Activity Questionnaire (IPAQ) and participants were classified as being ‘active’ or ‘inactive’ based on physical activity guidelines. BMI at baseline was abstracted from medical records and categorized into ‘normal weight’ and ‘overweight/obese’. Pro-inflammatory biomarkers (CRP, SAA, IL-6, IL-8, and TNF-α) were measured in pre-surgery serum samples. In a subset of patients (n=179), 16S rRNA gene sequencing was additionally performed in pre-surgery stool samples. Relative abundances were determined for each taxonomic level and used to calculate diversity metrics. Analyses were adjusted for sex, stage at diagnosis, neoadjuvant treatment, and study site. Results: ‘Obese’ patients had 88% and 17% higher CRP and TNF-α levels compared to ‘normal weight’ patients (p=0.03 and 0.02, respectively). Highest CRP levels were observed among ‘overweight or obese/inactive’ compared to ‘normal weight/active’ patients (p=0.03). Lower gut microbial diversity was observed among ‘inactive’ vs. ‘active’ patients (Shannon index: p=0.01, Simpson: p=0.03), ‘obese’ vs. ‘normal weight’ patients (Shannon index, Simpson, and Observed species: p=0.02, respectively), and ‘overweight or obese/inactive’ vs. ‘normal weight/active’ patients (Shannon index: p=0.02, Observed species: p=0.04). Two phyla and 12 genera (e.g., Actinobacteria and Fusobacteria, and Ruminococcus, Succinivibrio, Succiniclasticum) were differentially abundant across physical activity and BMI groups. High CRP and TNF-α levels were statistically significantly associated with lower alpha diversity metrics (p=0.02-0.05). Conclusions: This is the first evidence indicating that the gut microbiome may be a molecular mediator of the energy balance-colorectal cancer link. We further provide evidence of associations between physical activity and BMI groups with pro-inflammatory biomarkers. While BMI was identified as the key driver of inflammation, biomarker levels were higher among ‘inactive’ patients across BMI groups. Physical activity may offset obesity-induced inflammation and gut microbiome dysbiosis. Our results further provide new insights into the host-microbiome interactions with respect to systemic inflammation.

Citation Format: Caroline Himbert, W. Zac Stephens, Biljana Gigic, Tengda Lin, Jennifer Ose, Anjelica Ashworth, Christy Warby, David Nix, Jolanta Jedrzkiewicz, Anita R Peoples, Mary Bronner, Bartley Pickron, Courtney Scaife, Jessica N. Cohan, William M. Grady, Stacey A. Cohen, Mukta Krane, Petra Schrotz-King, Jane C. Figueiredo, Adetunji T. Toriola, Erin M. Siegel, Christopher I. Li, Alexis Ulrich, David Shibata, June L. Round, Lyen C. Huang, Martin Schneider, Sheetal Hardikar, Cornelia M Ulrich. Molecular mediators of the energy balance-colorectal cancer link: evaluating the gut microbiome and pro-inflammatory biomarkers. [abstract]. In: Proceedings of the AACR Special Conference: Precision Prevention, Early Detection, and Interception of Cancer; 2022 Nov 17-19; Austin, TX. Philadelphia (PA): AACR; Can Prev Res 2023;16(1 Suppl): Abstract nr P010.

Abstract PR008: Evaluation of intra-tumoral pathogenic bacteria pks+ E. coli, enterotoxigenic B. fragilis and fusobacterium nucleatum in 3695 colorectal cancer cases

Background: The microbiome in colorectal cancer (CRC) tumors is now recognized as a potent facilitator of tumorigenesis. Identification of the intra-tumoral microbiome may provide an avenue to enhance prediction of adverse outcomes and ultimately lead to improved survival of CRC, the second leading cause of cancer death. Methods: We performed targeted sequencing of tumor and matched normal DNA samples for 3695 colorectal cancer cases within the Genetics and Colorectal Cancer Consortium (GECCO) and the Colon Cancer Family Registry (CCFR). Tumor DNA was extracted primarily from formalin fixed paraffin embedded (FFPE) or from fresh frozen tissue. FFPE slides were dissected to ensure &gt;70% tumor content. Normal DNA was primarily extracted from blood and otherwise normal surrounding colorectal tissue. We designed probes for bacterial pathogens including Bacteroides fragilis (ETBF), polyketide synthase positive E. coli (pks+ EC), enterotoxigenic and Fusobacterium nucleatum (Fn). Logistic regression was used to assess tumor-associated bacteria and various clinical parameters, tumor molecular characteristics, and tumor stage adjusted for age, sex, and study and a Cox promotional hazard to assess association with CRC-specific survival adjusted for age at diagnosis, sex, mutational burden and microsatellite instability (MSI) and stratified baseline hazards by study. Survival data were available for 2357 patients. Results: The prevalence of patients with bacteria in tumors varied for ETBF (5.2%), pks+ EC (12.9%), and Fn (10.4%). Men had a lower probability of tumors with Fn (odds ratio (OR)=0.8, 95% confidence interval (CI)=0.64-0.99,p=0.04) but higher odds of tumors with pks+ EC (OR=1.38, CI=1.14-1.68,p=0.001). Patients with proximal tumors had higher odds of carrying Fn (OR=1.76, CI=1.38-2.26, p&lt;0.001) as did patients with MSI high tumors (OR 2.79, CI=2.08-3.74) p&lt;0.001). Patients with MSI-high tumors had lower odds of carrying pks+ EC (OR=0.63, CI=0.44-0.88, p=0.008) when compared to patients with microsatellite stable tumors. Among non-hypermutated tumors, we observed that tumors positive for pks+ EC were associated with better CRC-specific survival (OR=0.73, CI=0.57-0.93,p=0.01 whereas in patients with ETBF positive tumors had shorter survival (OR=1.99,CI=1,18-3.36,p=0.009) as did patients with tumors positive for Fn (OR=1.33, CI=1.04-1.72, p=0.03). Conclusions: In this largest investigation of intra-tumoral bacteria in CRC, we demonstrate that inclusion of pathogenic intra-tumoral microbiome may enhance prediction of survival and can identify a subset of patients with CRC that may benefit from targeted therapies that modulate the tumor microbiome.

Citation Format: Meredith A. J. Hullar, Keith R. Curtis, Tabitha A. Harrison, Yi Lin, Robert S. Steinfelder, Sonja I. Berndt, Daniel D. Buchanan, Andrew T. Chan, David Drew, Jane C. Figueiredo, Amy J. French, Ellen L. Goode, Mark A. Jenkins, Yohannes A. Melaku, Victor Moreno, Shuji Ogino, Stephen N. Thibideau, Amanda I. Phipps, Ulrike Peters. Evaluation of intra-tumoral pathogenic bacteria pks+ E. coli, enterotoxigenic B. fragilis and fusobacterium nucleatum in 3695 colorectal cancer cases [abstract]. In: Proceedings of the AACR Special Conference on Colorectal Cancer; 2022 Oct 1-4; Portland, OR. Philadelphia (PA): AACR; Cancer Res 2022;82(23 Suppl_1):Abstract nr PR008.

Exploring Latino Promotores/a de Salud (Community Health Workers) knowledge, attitudes, and perceptions of COVID-19 vaccines

Promotoras/promotores (i.e., community health workers) are uniquely positioned to provide much needed COVID-19 education and outreach in Latino communities, particularly in areas with disparities in vaccination rates. This study used qualitative methods to explore promotoras perspectives on COVID-19 vaccines, with a focus on understanding how vaccine knowledge and viewpoints among Latino communities can formulate recommendations to improve uptake of vaccination. Promotoras (N=22) were recruited to participate in semi-structured focus groups conducted virtually. Reflexive thematic analysis identified three overarching themes: (1) prevalence of misinformation (related to lack of trustworthy information, mistrust in the government, immigration status concerns, and conspiracy theories); (2) hesitancy (related to health concerns and eligibility confusion); and (3) recommendations for improving vaccine uptake. Delays in vaccination were not strictly due to doubts or fears but were also related to access barriers. The themes provide insight into the Latino communities' perceptions of COVID-19 vaccines and reasons why some remain unvaccinated. Promotoras' perspectives are integral to the development of strategies and approaches to address COVID-19 vaccine hesitancy, uptake, and implementation among underserved communities.

Interactions between folate intake and genetic predictors of gene expression levels associated with colorectal cancer risk

Observational studies have shown higher folate consumption to be associated with lower risk of colorectal cancer (CRC). Understanding whether and how genetic risk factors interact with folate could further elucidate the underlying mechanism. Aggregating functionally relevant genetic variants in set-based variant testing has higher power to detect gene-environment (G × E) interactions and may provide information on the underlying biological pathway. We investigated interactions between folate consumption and predicted gene expression on colorectal cancer risk across the genome. We used variant weights from the PrediXcan models of colon tissue-specific gene expression as a priori variant information for a set-based G × E approach. We harmonized total folate intake (mcg/day) based on dietary intake and supplemental use across cohort and case-control studies and calculated sex and study specific quantiles. Analyses were performed using a mixed effects score tests for interactions between folate and genetically predicted expression of 4839 genes with available genetically predicted expression. We pooled results across 23 studies for a total of 13,498 cases with colorectal tumors and 13,918 controls of European ancestry. We used a false discovery rate of 0.2 to identify genes with suggestive evidence of an interaction. We found suggestive evidence of interaction with folate intake on CRC risk for genes including glutathione S-Transferase Alpha 1 (GSTA1; p = 4.3E-4), Tonsuko Like, DNA Repair Protein (TONSL; p = 4.3E-4), and Aspartylglucosaminidase (AGA: p = 4.5E-4). We identified three genes involved in preventing or repairing DNA damage that may interact with folate consumption to alter CRC risk. Glutathione is an antioxidant, preventing cellular damage and is a downstream metabolite of homocysteine and metabolized by GSTA1. TONSL is part of a complex that functions in the recovery of double strand breaks and AGA plays a role in lysosomal breakdown of glycoprotein.

Differences in the gut microbiome by physical activity and BMI among colorectal cancer patients

Associations of energy balance components, including physical activity and obesity, with colorectal cancer risk and mortality are well established. However, the gut microbiome has not been investigated as underlying mechanism. We investigated associations of physical activity, BMI, and combinations of physical activity/BMI with gut microbiome diversity and differential abundances among colorectal cancer patients. N=179 patients with colorectal cancer (stages I-IV) were included in the study. Pre-surgery stool samples were used to perform 16S rRNA gene sequencing (Illumina). Physical activity (MET hrs/wk) during the year before diagnosis was assessed by questionnaire and participants were classified as being active vs. inactive based on guidelines. BMI at baseline was abstracted from medical records. Patients were classified into four combinations of physical activity levels/BMI. Lower gut microbial diversity was observed among 'inactive' vs. 'active' patients (Shannon: P=0.01, Simpson: P=0.03), 'obese' vs. 'normal weight' patients (Shannon, Simpson, and Observed species: P=0.02, respectively), and 'overweight/obese/inactive' vs. 'normal weight/active' patients (Shannon: P=0.02, Observed species: P=0.04). Results differed by sex and tumor site. Two phyla and 12 genera (Actinobacteria and Fusobacteria, Adlercreutzia, Anaerococcus, Clostridium, Eubacterium, Mogibacteriaceae, Olsenella, Peptinophilus, Pyramidobacter, RFN20, Ruminococcus, Succinivibrio, Succiniclasticum) were differentially abundant across physical activity and BMI groups. This is the first evidence for associations of physical activity with gut microbiome diversity and abundances, directly among colorectal cancer patients. Our results indicate that physical activity may offset gut microbiome dysbiosis due to obesity. Alterations in gut microbiota may contribute mechanistically to the energy balance-colorectal cancer link and impact clinical outcomes.

A validation of models for prediction of pathogenic variants in mismatch repair genes

PURPOSE

Models used to predict the probability of an individual having a pathogenic homozygous or heterozygous variant in a mismatch repair gene, such as MMRpro, are widely used. Recently, MMRpro was updated with new colorectal cancer penetrance estimates. The purpose of this study was to evaluate the predictive performance of MMRpro and other models for individuals with a family history of colorectal cancer.

METHODS

We performed a validation study of 4 models, Leiden, MMRpredict, PREMM5, and MMRpro, using 784 members of clinic-based families from the United States. Predicted probabilities were compared with germline testing results and evaluated for discrimination, calibration, and predictive accuracy. We analyzed several strategies to combine models and improve predictive performance.

RESULTS

MMRpro with additional tumor information (MMRpro+) and PREMM5 outperformed the other models in discrimination and predictive accuracy. MMRpro+ was the best calibrated with an observed to expected ratio of 0.98 (95% CI = 0.89-1.08). The combination models showed improvement over PREMM5 and performed similar to MMRpro+.

CONCLUSION

MMRpro+ and PREMM5 performed well in predicting the probability of having a pathogenic homozygous or heterozygous variant in a mismatch repair gene. They serve as useful clinical decision tools for identifying individuals who would benefit greatly from screening and prevention strategies.

Associations of individual and combined physical activity and body mass index groups with pro-inflammatory biomarkers among colorectal cancer patients

BACKGROUND

Physical activity and obesity are well-established factors of colorectal cancer (CRC) risk and prognosis. Here, we investigate associations of individual and combined physical activity and BMI groups with pro-inflammatory biomarkers in CRC patients.

METHODS

Self-reported physical activity levels were classified as 'active' (≥8.75 MET-hrs/wk) vs. 'inactive' (<8.75 MET-hrs/wk) in n=579 stage I-IV CRC patients enrolled in the ColoCare Study. BMI [normal weight (≥18.5-<25kg/m2), overweight (≥25-<30kg/m2), and obese (≥30kg/m2)] was abstracted from medical records. Patients were classified into four combinations of physical activity levels and BMI. Biomarkers (CRP, SAA, IL-6, IL-8, and TNF-α) in pre-surgery serum samples were measured using Meso-Scale-Discovery platform. Regression models were used to compute relative percent differences in biomarker levels by physical activity and BMI groups.

RESULTS

'Inactive' patients had non-statistically significant higher IL-6 levels compared to 'active' patients (+36%, p=0.10). 'Obese' patients had 88% and 17% higher CRP and TNF-α levels compared to 'normal weight' patients (p=0.03 and 0.02, respectively). Highest CRP levels were observed among 'overweight or obese/inactive' compared to 'normal weight/active' patients (p=0.03).

CONCLUSION

We provide evidence of associations between individual and combined physical activity and BMI groups with pro-inflammatory biomarkers. While BMI was identified as the key driver of inflammation, biomarker levels were higher among 'inactive' patients across BMI groups.

IMPACT

This is the largest study in CRC patients investigating associations of energy balance components with inflammatory biomarkers. Our results suggest that physical activity may reduce obesity-induced inflammation in CRC patients and support the design of randomized controlled trials testing this hypothesis.

The mental health burden of racial and ethnic minorities during the COVID-19 pandemic

Racial/ethnic minorities have been disproportionately impacted by COVID-19. The effects of COVID-19 on the long-term mental health of minorities remains unclear. To evaluate differences in odds of screening positive for depression and anxiety among various racial and ethnic groups during the latter phase of the COVID-19 pandemic, we performed a cross-sectional analysis of 691,473 participants nested within the prospective smartphone-based COVID Symptom Study in the United States (U.S.) and United Kingdom (U.K). from February 23, 2021 to June 9, 2021. In the U.S. (n=57,187), compared to White participants, the multivariable odds ratios (ORs) for screening positive for depression were 1·16 (95% CI: 1·02 to 1·31) for Black, 1·23 (1·11 to 1·36) for Hispanic, and 1·15 (1·02 to 1·30) for Asian participants, and 1·34 (1·13 to 1·59) for participants reporting more than one race/other even after accounting for personal factors such as prior history of a mental health disorder, COVID-19 infection status, and surrounding lockdown stringency. Rates of screening positive for anxiety were comparable. In the U.K. (n=643,286), racial/ethnic minorities had similarly elevated rates of positive screening for depression and anxiety. These disparities were not fully explained by changes in leisure time activities. Racial/ethnic minorities bore a disproportionate mental health burden during the COVID-19 pandemic. These differences will need to be considered as health care systems transition from prioritizing infection control to mitigating long-term consequences.

Genome-Wide Interaction Analysis of Genetic Variants With Menopausal Hormone Therapy for Colorectal Cancer Risk

BACKGROUND

The use of menopausal hormone therapy (MHT) may interact with genetic variants to influence colorectal cancer (CRC) risk.

METHODS

We conducted a genome-wide, gene-environment interaction between single nucleotide polymorphisms and the use of any MHT, estrogen only, and combined estrogen-progestogen therapy with CRC risk, among 28 486 postmenopausal women (11 519 CRC patients and 16 967 participants without CRC) from 38 studies, using logistic regression, 2-step method, and 2- or 3-degree-of-freedom joint test. A set-based score test was applied for rare genetic variants.

RESULTS

The use of any MHT, estrogen only and estrogen-progestogen were associated with a reduced CRC risk (odds ratio [OR] = 0.71, 95% confidence interval [CI] = 0.64 to 0.78; OR = 0.65, 95% CI = 0.53 to 0.79; and OR = 0.73, 95% CI = 0.59 to 0.90, respectively). The 2-step method identified a statistically significant interaction between a GRIN2B variant rs117868593 and MHT use, whereby MHT-associated CRC risk was statistically significantly reduced in women with the GG genotype (OR = 0.68, 95% CI = 0.64 to 0.72) but not within strata of GC or CC genotypes. A statistically significant interaction between a DCBLD1 intronic variant at 6q22.1 (rs10782186) and MHT use was identified by the 2-degree-of-freedom joint test. The MHT-associated CRC risk was reduced with increasing number of rs10782186-C alleles, showing odds ratios of 0.78 (95% CI = 0.70 to 0.87) for TT, 0.68 (95% CI = 0.63 to 0.73) for TC, and 0.66 (95% CI = 0.60 to 0.74) for CC genotypes. In addition, 5 genes in rare variant analysis showed suggestive interactions with MHT (2-sided P < 1.2 × 10-4).

CONCLUSION

Genetic variants that modify the association between MHT and CRC risk were identified, offering new insights into pathways of CRC carcinogenesis and potential mechanisms involved.