Citrus-Gene interaction and melanoma risk in the UK Biobank.

High citrus consumption may increase melanoma risk; however, little is known about the biological mechanisms of this association, or whether it is modified by genetic variants. We conducted a genome-wide analysis of gene-citrus consumption interactions on melanoma risk among 1563 melanoma cases and 193 296 controls from the UK Biobank. Both the 2-degrees-of-freedom (df) joint test of genetic main effect and gene-environment (G-E) interaction and the standard 1-df G-E interaction test were performed. Three index SNPs (lowest P-value SNP among highly correlated variants [r2 > .6]) were identified from among the 365 genome-wide significant 2-df test results (rs183783391 on chromosome 3 [MITF], rs869329 on chromosome 9 [MTAP] and rs11446223 on chromosome 16 [DEF8]). Although all three were statistically significant for the 2-df test (4.25e-08, 1.98e-10 and 4.93e-13, respectively), none showed evidence of interaction according to the 1-df test (P = .73, .24 and .12, respectively). Eight nonindex, 2-df test significant SNPs on chromosome 16 were significant (P < .05) according to the 1-df test, providing evidence of citrus-gene interaction. Seven of these SNPs were mapped to AFG3L1P (rs199600347, rs111822773, rs113178244, rs3803683, rs73283867, rs78800020, rs73283871), and one SNP was mapped to GAS8 (rs74583214). We identified several genetic loci that may elucidate the association between citrus consumption and melanoma risk. Further studies are needed to confirm these findings.

Maximum and Time-Dependent Body Mass Index and Breast Cancer Incidence Among Postmenopausal Women in the Black Women's Health Study.

While excess weight is an established risk factor for postmenopausal breast cancer, consideration of maximum body mass index (maxBMI; BMI is calculated as weight (kg)/height (m)2) or BMI at a point in time relevant for breast carcinogenesis may offer new insights. We prospectively evaluated maxBMI and time-dependent BMI in relation to breast cancer incidence among 31,028 postmenopausal women in the Black Women's Health Study. During 1995-2015, a total of 1,384 diagnoses occurred, including 787 estrogen-receptor (ER)-positive (ER+) cases and 310 ER-negative (ER-) cases. BMI was assessed at baseline and 2, 4, 6, and 8 years before diagnosis. Cox proportional hazards regression was used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs). Compared with women with BMI <25, those with BMI ≥35 had increased risk of ER+ breast cancer but not ER- breast cancer. For BMI assessed 2 years before diagnosis, the HRs for ER+ breast cancer associated with maxBMI ≥35 and time-dependent BMI ≥35 were 1.42 (95% confidence interval (CI): 1.10, 1.84) and 1.63 (95% CI: 1.25, 2.13), respectively. The corresponding HR for time-dependent BMI assessed 6 years before diagnosis was 1.95 (95% CI: 1.45, 2.62). These findings suggest strong associations of BMI with risk of ER+ breast cancer in postmenopausal women, regardless of timing of BMI assessment.

Citrus Consumption and Risk of Non-Melanoma Skin Cancer in the UK Biobank.

Background: Non-melanoma skin cancer (NMSC) incidence has been dramatically increasing worldwide. Psoralen, a known photocarcinogen, is naturally abundant in citrus products, leading to the hypothesis that high citrus consumption may increase NMSC risk.Methods: We fitted age- and multivariable-adjusted logistic regression models to evaluate the association between citrus consumption and NMSC risk among 197,372 UKBB participants. A total of 9,613 NMSC cases were identified using International Classification of Disease 10 codes. Citrus consumption data were collected via five rounds of 24-hour recall questionnaires.Results: We found no association between high total citrus consumption and NMSC risk, although a slightly elevated NMSC risk was observed among participants who consumed >0 to half a serving of total citrus per day (OR [95% CI] = 1.08 [1.01-1.16]). There was no association between individual citrus products and NMSC risk.Conclusion: High citrus consumption was not associated with an increased risk of NMSC in our UKBB sample. Further studies are needed to clarify these associations.Supplemental data for this article is available online at https://doi.org/10.1080/01635581.2021.1952439 .

Perinatal folate levels do not influence tumor latency or multiplicity in a model of NF1 associated plexiform-like neurofibromas.

OBJECTIVE: In epidemiological and experimental research, high folic acid intake has been demonstrated to accelerate tumor development among populations with genetic and/or molecular susceptibility to cancer. Neurofibromatosis type 1 (NF1) is a common autosomal dominant disorder predisposing affected individuals to tumorigenesis, including benign plexiform neurofibromas; however, understanding of factors associated with tumor risk in NF1 patients is limited. Therefore, we investigated whether pregestational folic acid intake modified plexiform-like peripheral nerve sheath tumor risk in a transgenic NF1 murine model. RESULTS: We observed no significant differences in overall survival according to folate group. Relative to controls (180 days), median survival did not statistically differ in deficient (174 days, P = 0.56) or supplemented (177 days, P = 0.13) folate groups. Dietary folate intake was positively associated with RBC folate levels at weaning, (P = 0.023, 0.0096, and 0.0006 for deficient vs. control, control vs. supplemented, and deficient vs. supplemented groups, respectively). Dorsal root ganglia (DRG), brachial plexi, and sciatic nerves were assessed according to folate group. Mice in the folate deficient group had significantly more enlarged DRG relative to controls (P = 0.044), but no other groups statistically differed. No significant differences for brachial plexi or sciatic nerve enlargement were observed according to folate status.

Maternal obesity and acute lymphoblastic leukemia risk in offspring: A summary of trends, epidemiological evidence, and possible biological mechanisms.

Acute lymphoblastic leukemia, a heterogenous malignancy characterized by uncontrolled proliferation of lymphoid progenitors and generally initiated in utero, is the most common pediatric cancer. Although incidence of ALL has been steadily increasing in recent decades, no clear reason for this trend has been identified. Rising concurrently with ALL incidence, increasing maternal obesity rates may be partially contributing to increasing ALL prevelance. Epidemiological studies, including a recent meta-analysis, have found an association between maternal obesity and leukemogenesis in offspring, although mechanisms underlying this association remain unknown. Therefore, the purpose of this review is to propose possible mechanisms connecting maternal obesity to ALL risk in offspring, including changes to fetal/neonatal epigenetics, altered insulin-like growth factor profiles and insulin resistance, modified adipokine production and secretion, changes to immune cell populations, and impacts on birthweight and childhood obesity/adiposity. We describe how each proposed mechanism is biologically plausible due to their connection with maternal obesity, presence in neonatal and/or fetal tissue, observation in pediatric ALL patients at diagnosis, and association with leukemogenesis, A description of ALL and maternal obesity trends, a summary of epidemiological evidence, a discussion of the pathway from intrauterine environment to subsequent malignancy, and propositions for future directions are also presented.

Maternal Body Mass Index, Diabetes, and Gestational Weight Gain and Risk for Pediatric Cancer in Offspring: A Systematic Review and Meta-Analysis.

BACKGROUND: Pediatric cancer incidence has steadily increased concurrent with rising adult obesity, but associations between maternal obesity and associated comorbidities and pediatric cancer risk remain understudied. We aimed to quantitatively characterize associations of pediatric cancer risk with maternal prepregnancy body mass index (BMI), gestational weight gain, and maternal diabetes. METHODS: We performed a comprehensive and systematic literature search in Ovid and EMBASE from their inception to March 15, 2021. Eligible studies reported risk estimates and sample sizes and provided sufficient description of outcome and exposure ascertainment. Random effects models were used to estimate pooled effects. RESULTS: Thirty-four studies were included in the analysis. Prepregnancy BMI was positively associated with leukemia risk in offspring (odds ratio [OR] per 5-unit BMI increase =1.07, 95% confidence intervals [CI] = 1.04 to 1.11; I2 = 0.0%). Any maternal diabetes was positively associated with acute lymphoblastic leukemia risk (OR = 1.46, 95% CI = 1.28 to 1.67; I2 = 0.0%), even after restricting to birthweight-adjusted analyses (OR = 1.74, 95% CI = 1.29 to 2.34; I2 = 0.0%), and inversely associated with risk of central nervous system tumors (OR = 0.73, 95% CI = 0.55 to 0.97; I2 = 0.0%). Pregestational diabetes (OR = 1.57, 95% CI = 1.11 to 2.24; I2 = 26.8%) and gestational diabetes (OR = 1.40, 95% CI = 1.12 to 1.75; I2 = 0.0%) were also positively associated with acute lymphoblastic leukemia risk. No statistically significant associations were observed for gestational weight gain. CONCLUSIONS: Maternal obesity and diabetes may be etiologically linked to pediatric cancer, particularly leukemia and central nervous system tumors. Our findings support weight management and glycemic control as important components of maternal and offspring health. Further validation is warranted.

A comprehensive literature review and meta-analysis of the prevalence of pan-cancer BRCA mutations, homologous recombination repair gene mutations, and homologous recombination deficiencies.

There is significant improvement in the outcomes following treatment with PARP inhibitors among patients with certain tumors that have BRCA mutations (BRCAm), homologous recombination repair (HRR) gene mutations, or homologous recombination deficiency (HRD) positivity. We performed a literature review and meta-analysis to evaluate the prevalence of BRCA1/2m, HRR gene mutations, and HRD positivity across multiple cancers. There were 265 publications on BRCA1/2 mutation prevalence, 189 on HRR gene mutation prevalence, and 7 on HRD positivity prevalence. The prevalences of germline BRCA1m and BRCA2m were 7.8% and 5.7% for breast cancer, 13.5% and 6.6% for ovarian cancer, 0.5% and 3.5% for prostate cancer, and 1.1% and 4.1% for pancreatic cancer, respectively. The prevalences of somatic BRCA1m and BRCA2m were 3.4% and 2.7% for breast cancer, 4.7% and 2.9% for ovarian cancer, 5.7% and 3.2% for prostate cancer, and 1.2% and 2.9% for pancreatic cancer, respectively. We identified 189 studies with over 418,649 samples across 25 tumor types that examined mutations in one or more HRR genes other than BRCA1/2. The prevalence of mutations among HRR genes remained low (less than 1%), with ATM (5.2%), CHEK2 (1.6%), and PALB2 (0.9%) exhibiting the highest prevalence. Seven studies evaluated HRD positivity in breast, ovarian, and prostate cancer patients. The prevalence of HRD positivity was 56% overall (95% CI = 48%-64%). The understanding of biomarker prevalence across tumor types and standardization of biomarker assays could have important clinical implications.

A Systematic Review and Meta-Analysis on the Prognostic Value of BRCA Mutations, Homologous Recombination Gene Mutations, and Homologous Recombination Deficiencies in Cancer.

Patients with BRCA1/2 mutations (BRCAm), loss-of-function mutations in other homologous recombination repair (HRRm) genes, or tumors that are homologous recombination deficiency positivity (HRD+) demonstrate a robust response to PARPi therapy. We conducted a systematic literature review and meta-analysis to evaluate the prognostic value of BRCAm, HRRm, and HRD+ on overall survival (OS) among those treated by chemotherapy or targeted therapy other than PARPi across tumor types. A total of 135 eligible studies were included. Breast cancer (BC) patients with BRCA1/2m had a similar overall survival (OS) to those with wild-type BRCA1/2 (BRCA1/2 wt) across 18 studies. Ovarian cancer (OC) patients with BRCA1/2m had a significantly longer OS than those with BRCA1/2 wt across 24 studies reporting BRCA1m and BRCA2m, with an HR of 0.7 (0.6-0.8). Less OS data were reported for other tumors: 6 studies for BRCA2m compared with BRCA2 wt in prostate cancer with an HR of 1.9 (1.1-3.2) and 2 studies for BRCA1/2m compared with BRCA1/2 wt in pancreatic cancer with an HR of 1.5 (0.8-3.1). Only 4 studies reported HRD+ by either BRCA m or genomic instability score (GIS) ≥ 42 and OS by HRD status. The HR was 0.67 (0.43-1.02) for OS with HRD+ vs. HRD-. A total of 15 studies reported the association between HRRm and OS of cancers in which one or more HRR genes were examined. The HR was 1.0 (0.7-1.4) comparing patients with HRRm to those with HRR wild-type across tumors. Our findings are useful in improving the precision and efficacy of treatment selection in clinical oncology.

Intake of methyl-related nutrients and risk of pancreatic cancer in a population-based case-control study in Minnesota.

BACKGROUND/OBJECTIVES: Folate, vitamin B6, vitamin B12, and methionine are involved in DNA synthesis and methylation and thus may modulate pancreatic cancer risk. We investigated these associations in a population-based case-control study conducted in 1994-1998. SUBJECTS/METHODS: Cases (n = 150) were identified from all hospitals in the metropolitan areas of the Twin Cities and the Mayo Clinic, Minnesota. Controls (n = 459) were selected randomly from the general population and were frequency matched to cases by age, sex, and race. Logistic regression was used to estimate odds ratios (OR) and 95% confidence intervals (95% CI) for risk of pancreatic cancer in relation to intake of nutrients considered. RESULTS: Dietary intake of folate was associated with a reduced pancreatic cancer risk [OR (95% CI) for quartile (Q) 4 vs. Q1: 0.31 (0.12-0.78)]. A composite score (range from 2 to 8), reflecting combined dietary intake of folate and vitamin B6, was also inversely associated with pancreatic cancer risk [OR (95% CI) for Q4 vs. Q1: 0.24 (0.08-0.70)]. Null associations were found for intake of vitamin B12 and methionine. CONCLUSIONS: Dietary folate intake was associated with a reduced pancreatic cancer risk, and this association became stronger when dietary intake of folate and vitamin B6 was combined in analysis.

A Randomized Trial to Compare a Tailored Web-Based Intervention and Tailored Phone Counseling to Usual Care for Increasing Colorectal Cancer Screening.

BACKGROUND: Colorectal cancer mortality could be decreased with risk-appropriate cancer screening. We examined the efficacy of three tailored interventions compared with usual care for increasing screening adherence. METHODS: Women (n = 1,196) ages 51 to 74, from primary care networks and nonadherent to colorectal cancer guidelines, were randomized to (1) usual care, (2) tailored Web intervention, (3) tailored phone intervention, or (4) tailored Web + phone intervention. Average-risk women could select either stool test or colonoscopy, whereas women considered at higher than average risk received an intervention that supported colonoscopy. Outcome data were collected at 6 months by self-report, followed by medical record confirmation (attrition of 23%). Stage of change for colorectal cancer screening (precontemplation or contemplation) was assessed at baseline and 6 months. RESULTS: The phone (41.7%, P < 0.0001) and combined Web + phone (35.8%, P < 0.001) interventions significantly increased colorectal cancer screening by stool test compared with usual care (11.1%), with ORs ranging from 5.4 to 6.8 in models adjusted for covariates. Colonoscopy completion did not differ between groups except that phone significantly increased colonoscopy completion compared with usual care for participants in the highest tertile of self-reported fear of cancer. CONCLUSIONS: A tailored phone with or without a Web component significantly increased colorectal cancer screening compared with usual care, primarily through stool testing, and phone significantly increased colonoscopy compared with usual care but only among those with the highest levels of baseline fear. IMPACT: This study supports tailored phone counseling with or without a Web program for increasing colorectal cancer screening in average-risk women.

Epidemiology of colorectal cancer.

Colorectal cancer is currently the third deadliest cancer in the United States and will claim an estimated 49,190 U.S. lives in 2016. The purpose of this review is to summarize our current understanding of this disease, based on nationally published statistics and information presented in peer-reviewed journal articles. Specifically, this review will cover the following topics: descriptive epidemiology (including time and disease trends both in the United States and abroad), risk factors (environmental, genetic, and gene-environment interactions), screening, prevention and control, and treatment. Landmark discoveries in colorectal cancer risk factor research will also be presented. Based on the information reviewed for this report, we suggest that future U.S. public health efforts aim to increase colorectal cancer screening among African American communities, and that future worldwide colorectal cancer epidemiology studies should focus on researching nutrient-gene interactions towards the goal of improving personalized treatment and prevention strategies.