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Background: Colorectal cancer (CRC) is a leading cause of death worldwide. Despite its preventability through screening, compliance still needs to improve due to the invasiveness of current tools. There is a growing demand for validated molecular biomarker panels for minimally invasive blood-based CRC screening. This study assessed the diagnostic accuracy of four promising blood-based CRC biomarkers, individually and in combination. Methods: This case-control study involved plasma samples from 124 CRC cases and 124 age- and sex-matched controls. Biomarkers tested included methylated DNA encoding the Septin-9 gene ( mSEPT9 ) using Epi proColon ® 2.0 CE, insulin-like growth factor binding protein 2 (IGFBP2), dickkopf-3 (DKK3), and pyruvate kinase M2 (PKM2) by ELISA. Diagnostic accuracy was measured using the receiver operating characteristic (ROC), area under the curve (AUC), as well as sensitivity and specificity. Results: Diagnostic accuracy for mSEPT9 , IGFBP2, DKK3, and PKM2 was 62.9% (95% CI: 56.8-62.9%), 69.7% (95% CI: 63.1-69.7%), 61.6% (95% CI: 54.6-61.6%), and 50.8% (95% CI: 43.4-50.8%), respectively. The combined biomarkers yielded an AUC of 74.4% (95% CI: 68.1-80.6%), outperforming all biomarkers except IGFBP2. Conclusions: These biomarkers show potential for developing a minimally invasive CRC detection tool as an alternative to existing approaches, potentially increasing adherence, early detection, and survivorship.

Gastric adenocarcinoma (GAC) is the fourth leading global cause of cancer mortality and leading infection-associated cancer. High-incidence regions of GAC include Latin America and Eastern Asia. Immigrants from high-incidence regions maintain their GAC risk. GAC is a major U.S. cancer disparity, and its incidence rates are 2 to 10 times higher in non-White populations. Emerging guidelines recommend 3-year surveillance endoscopy for patients with high-risk gastric premalignant conditions (GPMC). Clinical trials of GPMC chemoprevention agents are lacking. We conducted a NCI Division of Cancer Prevention-funded, phase II placebo-controlled chemoprevention trial in patients with GPMCs (atrophic gastritis and intestinal metaplasia) with a highly bioavailable preparation of curcuminoids (Meriva). The trial sites in Puerto Rico and rural Honduras had important characteristics: (i) representative Caribbean and Mesoamerican populations, linked to large U.S. immigrant populations; (ii) high prevalence of Helicobacter pylori infection and GPMCs; (iii) the absence of turmeric and curcuminoids in local diets; and (iv) proven bidirectional collaboration with U.S. academic institutions. H. pylori-negative patients with GPMCs were randomized to the study drug (500 mg po bid) or placebo for 180 days (NCT02782949), with primary outcomes based upon histologic parameters. Principal study challenges included (i) an international regulatory environment; (ii) research infrastructure strengthening, particularly in Central America; (iii) participant recruitment in Honduras, wherein only 10% to 15% are H. pylori negative; (iv) the COVID-19 pandemic; and (v) natural disasters (three hurricanes). There were no losses to follow-up related to the pandemic or natural disasters. In conclusion, the south-south partnership provides a model for chemoprevention and translational studies in Latino populations with prevalent cancers, such as GAC., (©2024 American Association for Cancer Research.)

Background and Aims: Gastric cancer is the 5 th leading cause of cancer mortality worldwide and the leading infection-associated cancer. Helicobacter pylori is the most common chronic bacterial infection in humans and the major predisposing factor for the development of gastric intestinal metaplasia (GIM), the principal preneoplastic lesion in the gastric carcinogenesis pathway. GIM surveillance is now recommended for individuals among high-risk subgroups by three major gastroenterology societies in Europe, England, and U.S. Our objective was to provide the initial epidemiologic data for GIM among Hispanics in Puerto Rico., Methods: Using a cross-sectional study design, we analyzed an extensive pathology database ( n = 43,993) that captured approximately 50% of all endoscopy biopsies taken during 2012-2014 at academic, public, and private sectors in Puerto Rico. Prevalence estimates of GIM, GIM subgroups, and H. pylori status were estimated using logistic regression models., Results: A total of 4,707 GIM cases were identified during the study period for a prevalence rate of 10.7%. H. pylori was detected in 26.9% (95% CI: 25.7-28.2) of the GIM cases. The majority of the pathology reports lacked information regarding the high-risk subtypes (99.6%) and extension (71.2%)., Conclusions: The prevalence of GIM among Hispanics living in Puerto Rico may be higher than in U.S. mainland non-Hispanic populations. The prevalence of H. pylori detected in our study population was comparable to the rates reported in the mainland U.S. Standardization of the endoscopy biopsy protocol and pathology reporting is needed to characterize and risk stratify GIM surveillance programs in Puerto Rico., Competing Interests: Marcia Cruz-Correa is in the advisory board of Exact Sciences. All authors declared no conflict of interests., (Copyright © 2021 Jorge J. Cruz-Cruz et al.)

Gut bacterial toxins are thought to contribute to the development of colorectal cancer (CRC). This study examines the presence of specific gut bacterial toxin genes in stool samples from individuals with colorectal neoplasia (adenomas and/or CRC). The presence of bacterial genes encoding genotoxic or pro-inflammatory factors ( pks , tcpC , gelE , cnf-1 , AMmurB , and usp ) was established by PCR of stool samples from individuals from mainland US ( n = 30; controls = 10, adenoma = 10, CRC = 10) and from Puerto Rico (PR) ( n = 33; controls = 13; adenomas = 8; CRC = 12). Logistic regression models and multinomial logistic regression models were used to estimate the magnitude of association. Distinct bacterial gene profiles were observed in each sample cohort. In individuals with CRC, AMmurB was detected more frequently in samples from the US and gelE in samples from PR. In samples from PR, individuals with ≥2 gut bacterial toxin genes in stool had higher odds of having colorectal neoplasia (OR = 11.0, 95%: CI 1.0⁻637.1): however, no significant association between bacterial genes and colorectal neoplasia was observed in the US cohort. Further analyses are warranted in a larger cohort to validate these preliminary findings, but these encouraging results highlight the importance of developing bacterial markers as tools for CRC diagnosis or risk stratification.

Objective: Colorectal cancer (CRC) is a leading causes of cancer death among men and women. The purpose of this study was to determine the prevalence of oligopolyposis (≥20 synchronous colorectal adenomas) and its associated clinicopathological characteristics in Hispanics with incident CRC., Methods: Pathology reports from individuals diagnosed with CRC (2007 to 2011) were obtained from the PR Central Cancer Registry. Colorectal polyp burden was calculated using pathology reports and the data was normalized to colon segment size. Comparisons of demographic and clinicopathological characteristics by synchronous oligopolyposis status (<20 vs. <= *20) were performed using the chi-square or Fisher's exact test. Multivariate logistic regression models were fitted to estimate the adjusted prevalence odds ratios (aPOR), with 95% confidence intervals (CI). All analyses were performed using Stata (v.12.0)., Results: Analyses of 1,573 colectomy specimens was performed. Oligopolyposis was observed in 9.47% (149 of 1,573) of the subjects with incident CRC. Increasing age (aPOR50-64 = 1.72, 95% CI: 0.59-5.02; aPOR65-74 = 1.83, 95% CI: 0.64-5.27; aPOR≥75 = 2.67, 95% CI: 0.93-7.64) and proximal CRC tumor location (POR = 2.91, 95% CI:1.98-4.30) were significantly associated with having oligopolyposis at CRC diagnosis. However, subjects diagnosed with CRC at a regional stage (aPORRegional = 0.50, 95% CI: 0.32-0.79) or distant stage (aPORDistant = 0.45, 95% CI: 0.29-0.69) were less likely to have synchronous oligopolyposis (p<0.05)., Conclusion: Our findings suggest that genetic syndromes associated with colorectal polyposis may be implicated in a higher than expected number of CRC cases. Individuals with CRC and synchronous oligopolyposis should receive genetic counseling.

Background: Helicobacter pylori is an important etiologic factor for peptic ulcers and gastric cancer, one of the top ten leading causes of cancer death in Puerto Rico. However, the prevalence of H. pylori infections in this population was previously unknown. The aim of this study was to examine the seroprevalence of H. pylori and its associated risk factors in Puerto Rico., Materials and Methods: A cross-sectional study was designed using an existing population-based biorepository. Seropositivity was determined using the Premier ™ H. pylori immunoassay. Helicobacter pylori seroprevalence was estimated with 95% confidence using marginal standardization following logistic regression. To assess the risk factors associated with H. pylori seropositivity, a multivariable log-binomial model was fitted to estimate the prevalence ratio (PR) and its 95% confidence interval (95% CI)., Results: A total of 528 population-based serum samples were analyzed. The mean age of the study population was 41 ± 12 years, of whom 55.3% were females. The overall seroprevalence of H. pylori was 33.0% (95% CI = 28.3%-38.1%). Increasing age and having <12 years of education were significantly (P < .05) associated with H. pylori seropositivity in the multivariable model; however, residing in counties with low population density reached marginal significance (P = .085)., Conclusions: We report that H. pylori infection is common among Hispanics living in Puerto Rico. The H. pylori seroprevalence observed in Puerto Rico is similar to the seroprevalence reported in the overall population of the United States. The association between H. pylori seroprevalence and the risk factors analyzed offers insight into the epidemiology of gastric cancer in Puerto Rico and warrants further investigation., (© 2017 The Authors. Helicobacter Published by John Wiley & Sons Ltd.)

Gastric cancer (GC) is third leading cause of cancer-related death. Only 28.3% of new GC cases survive more than 5 years. Although incidence has declined in the United States, an increase is estimated for 2016. Risk factors include sex (risk is higher in men), Helicobacter pylori infection, heredity, and lifestyle. GC is usually diagnosed between the ages of 60-80 years. Prognosis of GC is largely dependent on the tumor stage at diagnosis and classification as intestinal or diffuse type; diffuse-type GC has worse prognosis. Chemoprevention has been shown to decrease risk, but is currently not used clinically., Competing Interests: The authors have no conflict of interest to disclose., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Familial adenomatous polyposis (FAP) is an inherited form of colorectal cancer characterized by hundreds of adenomatous polyps in the colon and rectum. FAP is also associated with thyroid cancer (TC), but the lifetime risk is still unclear. This study reports the standardized incidence ratio (SIR) of TC in Hispanic FAP patients. TC incidence rates in patients with FAP between the periods of January 1, 2006 to December 31, 2013 were compared with the general population through direct database linkage from the Puerto Rico Central Cancer Registry (PRCCR) and the Puerto Rico Familial Colorectal Cancer Registry (PURIFICAR). The study population consisted of 51 Hispanic patients with FAP and 3239 with TC from the general population. The SIR was calculated using the Indirect Method, defined as observed TC incidence among patients with FAP in PURIFICAR's cohort (2006-2013) divided by the expected TC incidence based on the PR population rates (2006-2010). SIR values were estimated by sex (male, female, and overall). This study received IRB approval (protocol #A2210207). In Hispanic patients with FAP, the SIR (95% CI) for TC was 251.73 (51.91-735.65), with higher risk for females 461.18 (55.85-1665.94) than males 131.91 (3.34-734.95). Hispanic FAP patients are at a high risk for TC compared to the general population. Our incidence rates are higher than previous studies, suggesting that this community may be at a higher risk for TC than previously assumed. Implementation of clinical surveillance guidelines and regular ultrasound neck screening in Hispanic FAP patients is recommended.

Multidrug resistance-associated proteins (MRPs) belong to the C-family of ATP-binding cassette (ABC) transport proteins and are known to transport a variety of physiologically important compounds and to be involved in the extrusion of pharmaceuticals. Rodent malaria parasites encode a single ABC transporter subfamily C protein, whereas human parasites encode two: MRP1 and MRP2. Although associated with drug resistance, their biological function and substrates remain unknown. To elucidate the role of MRP throughout the parasite life cycle, Plasmodium berghei and Plasmodium falciparum mutants lacking MRP expression were generated. P. berghei mutants lacking expression of the single MRP as well as P. falciparum mutants lacking MRP1, MRP2 or both proteins have similar blood stage growth kinetics and drug-sensitivity profiles as wild type parasites. We show that MRP1-deficient parasites readily invade primary human hepatocytes and develop into mature liver stages. In contrast, both P. falciparum MRP2-deficient parasites and P. berghei mutants lacking MRP protein expression abort in mid to late liver stage development, failing to produce mature liver stages. The combined P. berghei and P. falciparum data are the first demonstration of a critical role of an ABC transporter during Plasmodium liver stage development., (© 2015 John Wiley & Sons Ltd.)

Aims: There is inconclusive evidence regarding the potential link between diabetes mellitus (DM) and colorectal cancer (CRC). Associations between type 2 DM and colorectal neoplasia (CRN; colorectal cancer and/or adenomas) have not been well studied in Hispanics, an ethnic minority at high risk for type 2 DM. This study aims to assess the association between type 2 DM and CRN in Hispanics., Methods: Hispanics with incident CRN and colonoscopy-negative controls from 2005 to 2009 were evaluated. Diagnosis of type 2 DM was established by previous medical diagnosis and/or use of DM treatments. Unconditional logistic regression was performed to estimate odds ratios for the association between type 2 DM and CRN., Results: A total of 451 participants (mean age 61.1±11.9years, 59.6 % men) were evaluated (218 with incident CRC, 77 with colorectal adenomas, and 156 colonoscopy-negative controls). The prevalence of type 2 DM in this study was 25.1%. After adjusting for potential confounding variables, women with type 2 DM were 2.74 (95% CI: 0.94-7.99) times more likely to have CRN and 4.83 times more likely to present with proximal colonic CRN (95% CI: 1.25-18.58) than women without type 2 DM. No statistically significant associations were found between type 2 DM and CRN among men., Conclusions: An increased odds for CRN and proximal location of CRN was observed among Hispanic women with type 2 DM. Since DM is a highly prevalent disease in this population, adherence to routine CRC screening is of outmost importance., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Background: The ATP-binding cassette (ABC) superfamily is one of the largest evolutionarily conserved families of proteins. ABC proteins play key roles in cellular detoxification of endobiotics and xenobiotics. Overexpression of certain ABC proteins, among them the multidrug resistance associated protein (MRP), contributes to drug resistance in organisms ranging from human neoplastic cells to parasitic protozoa. In the present study, the Plasmodium berghei mrp gene (pbmrp) was partially characterized and the predicted protein was classified using bioinformatics in order to explore its putative involvement in drug resistance., Methods: The pbmrp gene from the P. berghei drug sensitive, N clone, was sequenced using a PCR strategy. Classification and domain organization of pbMRP were determined with bioinformatics. The Plasmodium spp. MRPs were aligned and analysed to study their conserved motifs and organization. Gene copy number and organization were determined via Southern blot analysis in both N clone and the chloroquine selected line, RC. Chromosomal Southern blots and RNase protection assays were employed to determine the chromosomal location and expression levels of pbmrp in blood stages., Results: The pbmrp gene is a single copy, intronless gene with a predicted open reading frame spanning 5820 nucleotides. Bioinformatic analyses show that this protein has distinctive features characteristic of the ABCC sub-family. Multiple sequence alignments reveal a high degree of conservation in the nucleotide binding and transmembrane domains within the MRPs from the Plasmodium spp. analysed. Expression of pbmrp was detected in asexual blood stages. Gene organization, copy number and mRNA expression was similar in both lines studied. A chromosomal translocation was observed in the chloroquine selected RC line, from chromosome 13/14 to chromosome 8, when compared to the drug sensitive N clone., Conclusion: In this study, the pbmrp gene was sequenced and classified as a member of the ABCC sub-family. Multiple sequence alignments reveal that this gene is homologous to the Plasmodium y. yoelii and Plasmodium knowlesi mrp, and the Plasmodium vivax and Plasmodium falciparum mrp2 genes. There were no differences in gene organization, copy number, or mRNA expression between N clone and the RC line, but a chromosomal translocation of pbmrp from chromosome 13/14 to chromosome 8 was detected in RC.