Flexible sigmoidoscopy in the randomized prostate, lung, colorectal, and ovarian (PLCO) cancer screening trial: added yield from a second screening examination

Developing an optimal stratification model for colorectal cancer screening and reducing racial disparities in multi-center population-based studies

BACKGROUND

Early detection of colorectal neoplasms can reduce the colorectal cancer (CRC) burden by timely intervention for high-risk individuals. However, effective risk prediction models are lacking for personalized CRC early screening in East Asian (EAS) population. We aimed to develop, validate, and optimize a comprehensive risk prediction model across all stages of the dynamic adenoma-carcinoma sequence in EAS population.

METHODS

To develop precision risk-stratification and intervention strategies, we developed three trans-ancestry PRSs targeting colorectal neoplasms: (1) using 148 previously identified CRC risk loci (PRS148); (2) SNPs selection from large-scale meta-analysis data by clumping and thresholding (PRS183); (3) PRS-CSx, a Bayesian approach for genome-wide risk prediction (PRSGenomewide). Then, the performance of each PRS was assessed and validated in two independent cross-sectional screening sets, including 4600 patients with advanced colorectal neoplasm, 4495 patients with non-advanced adenoma, and 21,199 normal individuals from the ZJCRC (Zhejiang colorectal cancer set; EAS) and PLCO (the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial; European, EUR) studies. The optimal PRS was further incorporated with lifestyle factors to stratify individual risk and ultimately tested in the PLCO and UK Biobank prospective cohorts, totaling 350,013 participants.

RESULTS

Three trans-ancestry PRSs achieved moderately improved predictive performance in EAS compared to EUR populations. Remarkably, the PRSs effectively facilitated a thorough risk assessment across all stages of the dynamic adenoma-carcinoma sequence. Among these models, PRS183 demonstrated the optimal discriminatory ability in both EAS and EUR validation datasets, particularly for individuals at risk of colorectal neoplasms. Using two large-scale and independent prospective cohorts, we further confirmed a significant dose-response effect of PRS183 on incident colorectal neoplasms. Incorporating PRS183 with lifestyle factors into a comprehensive strategy improves risk stratification and discriminatory accuracy compared to using PRS or lifestyle factors separately. This comprehensive risk-stratified model shows potential in addressing missed diagnoses in screening tests (best NPV = 0.93), while moderately reducing unnecessary screening (best PPV = 0.32).

CONCLUSIONS

Our comprehensive risk-stratified model in population-based CRC screening trials represents a promising advancement in personalized risk assessment, facilitating tailored CRC screening in the EAS population. This approach enhances the transferability of PRSs across ancestries and thereby helps address health disparity.

Single nucleotide polymorphisms in FOXP1 and RORA of the lymphocyte activation-related pathway affect survival of lung cancer patients

Background

Lymphocyte activation is part of a complex microenvironment that affects the development and progression of solid tumors. The present study analyzed the associations between genetic variants in lymphocyte activation-related genes and survival of patients with non-small cell lung cancer (NSCLC).

Methods

Our study evaluated the associations of 14,400 (1,599 genotyped and 12,801 imputed) single-nucleotide polymorphisms (SNPs) in 176 lymphocyte activation pathway-related genes with survival of 1,185 NSCLC patients in the Prostate, Lung, Colorectal and Ovarian (PLCO) Cancer Screening Trial and validated the results in another independent dataset of 984 NSCLC patients from the Harvard Lung Cancer Susceptibility (HLCS) trial.

Results

Multivariable Cox proportional hazards regression analyses identified two distinct and possibly functional variants in forkhead box P1 (FOXP1; rs2568847 G>C) and RAR-related orphan receptor A (RORA; rs922782 T>G) that were significantly and independently associated with overall survival (OS) [adjusted hazards ratios (HRs) of 1.21 and 0.82, respectively; 95% confidence intervals (CI), 1.11 to 1.32 and 0.76 to 0.88, respectively; P=5.38×10-6 and 2.68×10-2, respectively]. Combined analysis of the unfavorable genotypes showed a significant correlation with both OS and disease-specific survival (DSS) in patients with NSCLC patients from PLCO trial (both Ptrend<0.0001). Further expression quantitative trait loci (eQTL) analysis using RORA mRNA expression and genotype data in the 1000 Genomes Project demonstrated that the RORA rs922782 G allele predicted mRNA expression levels.

Conclusions

Genetic variants in FOXP1 and RORA of the lymphocyte activation pathway may be promising predictors of NSCLC survival. The RORA rs922782 G allele may predict NSCLC survival, possibly by controlling RORA mRNA expression.

Diagnostic utility of upper and lower gastrointestinal endoscopy for the diagnosis of acute graft-versus-host disease in children following stem cell transplantation: A 12-year experience

BACKGROUND

Endoscopically obtained mucosal biopsies are the gold standard for diagnosing acute graft-versus-host disease of the gastrointestinal tract (GI-GVHD). There is no consensus on the ideal endoscopic approach in children. We aimed to ascertain which gastrointestinal sites and endoscopic approaches were most helpful for diagnosing acute GVHD and whether clinical symptoms can guide the endoscopic approach.

METHOD

A single-center retrospective review of all pediatric stem cell transplants (SCT) between January 1, 2007, and December 31, 2018. Of those with histologically diagnosed GI-GVHD, sensitivities of individual GI sites for making the diagnosis were calculated. Clinical symptoms were compared with GI site yielding diagnosis.

RESULTS

216 allogeneic SCTs were performed in 199 patients. 37 of 52 suspected GI-GHVD cases underwent endoscopy. There was marked variability in the endoscopic approaches chosen. 82% of these cases had lower gastrointestinal symptoms. 21 cases had histologically proven GI-GVHD. 19 (90%) of these had GVHD of non-gastrointestinal sites; 10 (48%) had concurrent infections. The most-sensitive GI sites were the rectosigmoid and duodenum (86% and 76%, respectively). Overall sensitivity of upper GI endoscopy (UGIE) and lower GI endoscopy (LGIE) was 86% and 90%, respectively. There was no statistically significant association between clinical symptoms and site at which histological diagnosis was obtained.

CONCLUSION

We observed variability in the endoscopic approach used by clinicians. UGIE and sigmoidoscopy had high sensitivities for diagnosing GVHD, regardless of symptoms. LGIE had minimal additional diagnostic value. This would support a standardized approach with UGIE and sigmoidoscopy for all children with suspected GI-GVHD.

Aspirin, ibuprofen, and reduced risk of advanced colorectal adenoma incidence and recurrence and colorectal cancer in the PLCO Cancer Screening Trial

BACKGROUND

Studying the differential impact of aspirin and other nonsteroidal anti-inflammatory drugs across the stages of colorectal neoplasia from early adenoma to cancer is critical for understanding the benefits of these widely used drugs.

METHODS

With 13 years of follow-up, the authors prospectively evaluated the association between aspirin and ibuprofen use and incident distal adenoma (1221 cases), recurrent adenoma (862 cases), and incident colorectal cancer (CRC; 2826 cases) among men and women in the population-based Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial. With multivariable-adjusted models, odds ratio (ORs) and 95% confidence intervals (CIs) for adenoma incidence and recurrence and hazard ratios (HRs) and 95% CIs for incident CRC were determined.

RESULTS

The authors observed a significantly reduced risk of incident adenoma with ibuprofen use (≥30 vs <4 pills per month: OR, 0.76 [95% CI, 0.60-0.95]; Ptrend = .04), particularly advanced adenoma (OR, 0.48 [95% CI, 0.28-0.83]; Ptrend = .005). Among those with a previous adenoma detected through screening, aspirin use was associated with a decreased risk of advanced recurrent adenoma (≥30 vs <4 pills per month: OR, 0.56 [95% CI, 0.36-0.87]; Ptrend = 0.006). Both aspirin (HR, 0.88 [95% CI, 0.81-0.96]; Ptrend <.0001) and ibuprofen use (HR, 0.81 [95% CI, 0.70-0.93); Ptrend = 0.003) ≥30 versus <4 pills per month were significantly associated with reduced CRC risk.

CONCLUSIONS

In this large prospective study with long-term follow-up, a beneficial role for not only aspirin, but also ibuprofen, in preventing advanced adenoma and curbing progression to recurrence and cancer among older adults was observed.

Genetic variants of CHEK1, PRIM2 and CDK6 in the mitotic phase-related pathway are associated with nonsmall cell lung cancer survival

The mitotic phase is a vital step in cell division and may be involved in cancer progression, but it remains unclear whether genetic variants in mitotic phase-related pathways genes impact the survival of these patients. Here, we investigated associations between 31 032 single nucleotide polymorphisms (SNPs) in 368 mitotic phase-related pathway genes and overall survival (OS) of patients with nonsmall cell lung cancer (NSCLC). We assessed the associations in a discovery data set of 1185 NSCLC patients from the Prostate, Lung, Colorectal and Ovarian (PLCO) Cancer Screening Trial and validated the findings in another data set of 984 patients from the Harvard Lung Cancer Susceptibility Study. As a result, we identified three independent SNPs (ie, CHEK1 rs76744140 T>C, PRIM2 rs6939623 G>T and CDK6 rs113181986 G>C) to be significantly associated with NSCLC OS with an adjusted hazard ratio of 1.29 (95% confidence interval = 1.11-1.49, P = 8.26 × 10^-4 ), 1.26 (1.12-1.42, 1.10 × 10^-4 ) and 0.73 (0.63-0.86, 1.63 × 10^-4 ), respectively. Moreover, the number of combined unfavorable genotypes of these three SNPs was significantly associated with NSCLC OS and disease-specific survival in the PLCO data set (P_trend  < .0001 and .0003, respectively). Further expression quantitative trait loci analysis showed that the rs76744140C allele predicted CHEK1 mRNA expression levels in normal lung tissues and that rs113181986C allele predicted CDK6 mRNA expression levels in whole blood tissues. Additional analyses indicated CHEK1, PRIM2 and CDK6 may impact NSCLC survival. Taken together, these findings suggested that these genetic variants may be prognostic biomarkers of patients with NSCLC.

Genetic variants of DOCK2, EPHB1 and VAV2 in the natural killer cell-related pathway are associated with non-small cell lung cancer survival

Although natural killer (NK) cells are a known major player in anti-tumor immunity, the effect of genetic variation in NK-associated genes on survival in patients with non-small cell lung cancer (NSCLC) remains unknown. Here, in 1,185 with NSCLC cases of a discovery dataset, we evaluated associations of 28,219 single nucleotide polymorphisms (SNPs) in 276 NK-associated genes with their survival. These patients were from the reported genome-wide association study (GWAS) from the Prostate, Lung, Colorectal and Ovarian (PLCO) Cancer Screening Trial. We further validated the findings in an additional 984 cases from the Harvard Lung Cancer Susceptibility (HLCS) Study. We identified three SNPs (i.e., DOCK2 rs261083 G>C, VAV2 rs2519996 C>T and EPHB1 rs36215 A>G) to be independently associated with overall survival (OS) in NSCLC cases with adjusted hazards ratios (HRs) of 1.16 (95% confidence interval [CI] = 1.07-1.26, P = 3.34×10^-4), 1.28 (1.12-1.47, P = 4.57×10^-4) and 0.75 (0.67-0.83, P = 1.50×10^-7), respectively. Additional joint assessment of the unfavorable genotypes of the three SNPs showed significant associations with OS and disease-specific survival of NSCLC cases in the PLCO dataset (P _trend<0.0001 and <0.0001, respectively). Moreover, the survival-associated DOCK2 rs261083 C allele had a significant correlation with reduced DOCK2 transcript levels in lung adenocarcinoma (LUAD), while the rs36215 G allele was significantly correlated with reduced EPHB1 transcript levels in lymphoblastoid cell lines in the 1000 Genomes Project. These results revealed that DOCK2 and EPHB1 genetic variants may be prognostic biomarkers of NSCLC survival, likely via transcription regulation of respective genes.

Potentially functional genetic variants in PLIN2, SULT2A1 and UGT1A9 genes of the ketone pathway and survival of nonsmall cell lung cancer

The ketone metabolism pathway is a principle procedure in physiological homeostasis and induces cancer cells to switch between glycolysis and oxidative phosphorylation for energy production. We conducted a two-phase analysis for associations between genetic variants in the ketone metabolism pathway genes and survival of nonsmall cell lung cancer (NSCLC) by analyzing genotyping data from two published genome-wide association studies (GWASs). In the discovery, we used a genotyping dataset from the Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial in the multivariable Cox proportional hazards regression analysis. We used Bayesian false discovery probability (≤0.80) for multiple testing correction to evaluate associations between 25,819 (2,176 genotyped and 23,643 imputed) single-nucleotide polymorphisms (SNPs) in 162 genes and survival of 1,185 NSCLC patients. Subsequently, we validated the identified significant SNPs with an additional 984 NSCLC patients from the Harvard Lung Cancer Susceptibility GWAS study. Finally, we found that three independent and potentially functional SNPs in three different genes (i.e., PLIN2 rs7867814 G>A, SULT2A1 rs2547235 C>T and UGT1A9 rs2011404 C>T) were independently associated with risk of death from NSCLC, with a combined hazards ratio of 1.22 [95% confidence interval = 1.09-1.36 and p = 0.0003], 0.82 (0.74-0.91 and p = 0.0002) and 1.21 (1.10-1.33 and p = 0.0001), respectively. Additional expression quantitative trait loci analysis found that the survival-associated PLIN2 rs7867814 GA + AA genotypes, but not the genotypes of other two SNPs, were significantly associated with increased mRNA expression levels (p = 0.005). These results indicated that PLIN2 variants may be potential predictors of NSCLC survival through regulating the PLIN2 expression.

Genetic variants of BIRC3 and NRG1 in the NLRP3 inflammasome pathway are associated with non-small cell lung cancer survival

The nod-like receptor protein 3 (NLRP3) is one of the most characterized inflammasomes, and its genetic variation and functional dysregulation are involved in pathogenesis of several cancers. To systematically evaluate the role of NLRP3 in predicting outcomes of patients with non-small cell lung cancer (NSCLC), we performed a two-phase analysis for associations between genetic variants in NLRP3 inflammasome pathway genes and NSCLC survival by using a published genome-wide association study (GWAS) dataset from the Prostate, Lung, Colorectal and Ovarian (PLCO) Cancer Screening Trial. We used multivariate Cox proportional hazards regression analysis with Bayesian false discovery probability (≤0.80) for multiple testing correction to evaluate associations between 20,730 single-nucleotide polymorphisms (SNPs) in 176 genes and overall survival of 1,185 NSCLC patients from the PLCO trial. We further validated the identified significant SNPs in another GWAS dataset with survival data from 984 NSCLC patients of the Harvard Lung Cancer Susceptibility (HLCS) study. The results showed that two independent SNPs in two different genes (i.e., BIRC3 rs11225211 and NRG1 rs4733124) were significantly associated with the NSCLC overall survival, with a combined hazards ratio (HR) of 0.83 [95% confidence interval (CI) = 0.74-0.93 and P = 0.0009] and 1.18 (95% CI = 1.06-1.31) and P = 0.002], respectively. However, further expression quantitative trait loci (eQTL) analysis showed no evidence for correlations between the two SNPs and mRNA expression levels of corresponding genes. These results indicated that genetic variants in the NLRP3 imflammasome pathway gene-sets might be predictors of NSCLC survival, but the molecular mechanisms underlying the observed associations warrant further investigations.

MiR-19a-3p regulates the Forkhead box F2-mediated Wnt/β-catenin signaling pathway and affects the biological functions of colorectal cancer cells

BACKGROUND

Colorectal cancer (CRC) is one of the most common malignancies worldwide.

AIM

To explore the expression of microRNA miR-19a-3p and Forkhead box F2 (FOXF2) in patients with CRC and the relevant mechanisms.

METHODS

Sixty-two CRC patients admitted to the hospital were enrolled into the study group, and sixty healthy people from the same period were assigned to the control group. Elbow venous blood was sampled from the patients and healthy individuals, and blood serum was saved for later analysis. MiR-19a-3p mimics, miR-19a-3p inhibitor, miR-negative control, small interfering-FOXF2, and short hairpin-FOXF2 were transfected into HT29 and HCT116 cells. Then quantitative polymerase chain reaction was performed to quantify the expression of miR-19a-3p and FOXF2 in HT29 and HCT116 cells, and western blot (WB) analysis was conducted to evaluate the levels of FOXF2, glycogen synthase kinase 3 beta (GSK-3β), phosphorylated GSK-3β (p-GSK-3β), β-catenin, p-β-catenin, α-catenin, N-cadherin, E-cadherin, and vimentin. The MTT, Transwell, and wound healing assays were applied to analyze cell proliferation, invasion, and migration, respectively, and the dual luciferase reporter assay was used to determine the correlation of miR-19a-3p with FOXF2.

RESULTS

The patients showed high serum levels of miR-19a-3p and low levels of FOXF2, and the area under the curves of miR-19a-3p and FOXF2 were larger than 0.8. MiR-19a-3p and FOXF2 were related to sex, tumor size, age, tumor-node-metastasis staging, lymph node metastasis, and differentiation of CRC patients. Silencing of miR-19a-3p and overexpression of FOXF2 suppressed the epithelial-mesenchymal transition, invasion, migration, and proliferation of cells. WB analysis revealed that silencing of miR-19a-3p and FOXF2 overexpression significantly suppressed the expression of p-GSK-3β, β-catenin, N-cadherin, and vimentin; and increased the levels of GSK-3β, p-β-catenin, α-catenin, and E-cadherin. The dual luciferase reporter assay confirmed that there was a targeted correlation of miR-19a-3p with FOXF2. In addition, a rescue experiment revealed that there were no differences in cell proliferation, invasion, and migration in HT29 and HCT116 cells co-transfected with miR-19a-3p-mimics+sh-FOXF2 and miR-19a-3p-inhibitor+si-FOXF2 compared to the miR-negative control group.

CONCLUSION

Inhibiting miR-19a-3p expression can upregulate the FOXF2-mediated Wnt/β-catenin signaling pathway, thereby affecting the epithelial-mesenchymal transition, proliferation, invasion, and migration of cells. Thus, miR-19a-3p is likely to be a therapeutic target in CRC.

Novel genetic variants in HDAC2 and PPARGC1A of the CREB-binding protein pathway predict survival of non-small-cell lung cancer

The CREB-binding protein (CBP) pathway plays an important role in transcription and activity of acetyltransferase that acetylates lysine residues of histones and nonhistone proteins. In the present study, we hypothesized that genetic variants in the CBP pathway genes played a role in survival of non-small-cell lung cancer (NSCLC). We tested this hypothesis using the genotyping data from the genome-wide association study (GWAS) dataset from the Prostate, Lung, Colorectal, and Ovarian (PLCO) Cancer Screening Trial. In the single-locus analysis, we evaluated associations between 13 176 (1107 genotyped and 12 069 imputed) single-nucleotide polymorphisms (SNPs) in 72 genes and survival of 1185 patients with NSCLC. The identified 106 significant SNPs in the discovery were further validated in additional genotyping data from another GWAS dataset of 984 patients with NSCLC in the Harvard Lung Cancer Susceptibility Study. The combined results of two datasets showed that two independent, potentially functional SNPs (i.e., HDAC2 rs13213007G>A and PPARGC1A rs60571065T>A) were significantly associated with NSCLC overall survival, with a combined hazards ratio (HR) of 1.26 (95% confidence interval (CI), 1.09-1.45; P = .002) and 1.23 (1.04-1.47; P = .017), respectively. Furthermore, we performed an expression quantitative trait loci analysis and found that the survival-associated HDAC2 rs13213007A allele (GA+AA), but not PPARGC1A rs60571065A allele (TA+AA), was significantly associated with increased messenger RNA expression levels of HDAC2 in 373 lymphoblastoid cell lines. These results indicate that the HDAC2 rs13213007A allele is a potential predictor of NSCLC survival, likely by altering the HDAC2 expression.

Association of Race and Socioeconomic Status With Colorectal Cancer Screening, Colorectal Cancer Risk, and Mortality in Southern US Adults

IMPORTANCE

Colorectal cancer (CRC) screening is rarely studied in populations who may face additional barriers to participate in cancer screening, such as African American individuals and individuals with low socioeconomic status (SES).

OBJECTIVE

To examine the associations of CRC screening and modalities with CRC incidence and mortality by race and SES.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study used data from the Southern Community Cohort Study, which enrolled more than 85 000 participants from community health centers or stratified random sampling of the general population in 12 states in the southeastern United States. The present study included data from cohort members who were eligible for CRC screening as recommended by expert organizations based on age and family history. Participants completed questionnaires from 2002 to 2009 and were contacted again from 2008 to 2012. Linkages to state cancer registries and the National Death Index as of December 31, 2016, identified incident CRC and vital status. Data analysis was performed from January 1, 2018, to October 30, 2019.

MAIN OUTCOMES AND MEASURES

Incident CRC (n = 632) and mortality (n = 10 003). Cox proportional hazards regression models evaluated associations between screening modalities and CRC risk and mortality. Information on fecal occult blood test use was only obtained on the follow-up questionnaire. Self-identified race was measured as African American/black, white, or other, and SES was defined by household income.

RESULTS

This study included 47 596 participants (median baseline age, 54 years [interquartile range, 10 years]; 32 185 [67.6%] African American; 28 884 [60.7%] female; and 26 075 [54.8%] with household income <$15 000). A total of 24 432 participants (63.9%) had never undergone CRC testing at baseline. The CRC testing assessed at baseline and follow-up interviews was associated with significant CRC risk reduction (hazard ratio [HR], 0.55; 95% CI, 0.44-0.70 for ever colonoscopy at baseline). Results were similar in analyses stratified by race (African American: HR, 0.65; 95% CI, 0.50-0.85; white: HR, 0.44; 95% CI, 0.27-0.70) and household income (<$15 000: HR, 0.63; 95% CI, 0.46-0.86, ≥$15 000: HR, 0.49; 95% CI, 0.35-0.69). Ever sigmoidoscopy at baseline was associated with CRC risk reduction (HR, 0.66; 95% CI, 0.51-0.87), and undergoing fecal occult blood test in the interval between baseline and follow-up interview was associated with CRC risk reduction (HR, 0.75; 95% CI, 0.57-0.98). Inverse associations were also observed between CRC mortality and receipt of colonoscopy (HR for women, 0.39; 95% CI, 0.21-0.73; HR for men, 0.69; 95% CI, 0.40-1.18) and sigmoidoscopy (HR for women, 0.37; 95% CI, 0.16-0.85; HR for men, 0.82; 95% CI, 0.46-1.47); however, the association did not extend to fecal occult blood test (HR for women, 1.02; 95% CI, 0.62-1.70; HR for men, 1.03; 95% CI, 0.55-1.93).

CONCLUSIONS AND RELEVANCE

In this study, CRC test rates were low among African American individuals and those with low SES. The findings suggest that screening, particularly with colonoscopy, is significantly associated with reduced risk of CRC and mortality. The CRC disparities experienced by individuals with low SES and African American individuals may be lessened by improving access to and uptake of CRC screening.

Enhancing bowel screening: Preventing colorectal cancer by flexible sigmoidoscopy in New Zealand

OBJECTIVES

The prevention of colorectal cancer (CRC) attainable from introducing once-in-a-lifetime flexible sigmoidoscopy (FSIG) screening was assessed.

STUDY DESIGN

This is a review of relevant available information for the assessment of the impact and resource demands of FSIG in New Zealand.

METHODS

The reduction in bowel cancer incidence achievable by one-off FSIG screening from 50 to 59 years of age, an age group for which bowel screening is not currently offered, was reviewed. The prevention of CRC attainable from an offer of screening at 55 years of age in New Zealand was also estimated. The number and cost of the FSIG screening procedures required and referrals for colonoscopies and the savings in treatment were calculated.

RESULTS

Annually, about 27,500 FSIG screening procedures would be required if 50% of those turning 55 years of age accepted an offer of once-in-a-lifetime FSIG screening. This would result in three-four-fold fewer people being referred for colonoscopy than in the national 2-yearly faecal immunochemical test (FIT) screening programme and subsequently reduce demand for colonoscopy from a false-positive FIT. The number of CRC cases prevented would increase over 17 years to more than 300 per year by 2033. After 10-15 years of screening, the annual savings in health service costs, primarily from CRC prevented, were sufficient to completely fund the FSIG screening.

CONCLUSIONS

Inclusion of FSIG screening in the national bowel screening programme would significantly reduce both the incidence and mortality of CRC in New Zealand, reduce the colonoscopy demand of current bowel screening and reduce long-term health service costs.

Effect of flexible sigmoidoscopy screening on colorectal cancer incidence and mortality: long-term follow-up of the randomised US PLCO cancer screening trial

BACKGROUND

Screening flexible sigmoidoscopy reduces incidence and mortality of colorectal cancer. Previously reported results from the Prostate, Lung, Colorectal, and Ovarian Cancer (PLCO) screening trial had a median follow-up of 12 years. Whether the benefit is sustained over the long term and remains so in both sexes and all age groups is uncertain. We report long-term results after an additional 5 years of follow-up.

METHODS

Participants in the PLCO trial were recruited from the general population in the catchment areas of ten screening centres across the USA, without previous diagnosis of a prostate, lung, colorectal, or ovarian cancer or current cancer treatment. From 1993 to 2001, participants aged 55-74 years were randomly assigned to usual care or flexible sigmoidoscopy at baseline and again at 3 years or 5 years. Randomisation was done within blocks and stratified by centre, age, and sex. The primary endpoint was cause-specific mortality and secondary endpoints included incidence and tumour staging; cause of death was determined without knowledge of study arm. In this analysis, we assessed incidence and mortality rates overall, by time-period, and by combinations of sex, age at baseline (55-64 years/65-74 years), location (distal/proximal), and stage, on an intent-to-treat basis. This trial is registered with ClinicalTrials.gov, number NCT00002540.

FINDINGS

After a median follow-up of 15·8 years (IQR 13·2-18·0) for incidence and 16·8 years (14·4-18·9) for mortality, the incidence of colorectal cancer was significantly lower in the intervention arm (1461 cases; 12·55 per 10 000 person-years) than with usual care (1761 cases; 15·33 per 10 000 person-years; relative risk [RR] 0·82, 95% CI 0·76-0·88). Similarly, mortality was lower in the intervention arm (417 deaths; 3·37 per 10 000 person-years) than the usual care arm (549; 4·48 per 10 000 person-years; RR 0·75, 95% CI 0·66-0·85). The reduction in mortality was limited to the distal colon, with no significant effect in the proximal colon. Reductions in incidence were significantly larger in men than women (pinteraction=0·04) and reductions in mortality were significantly larger in the older age group (65-74 years vs 55-64 years at baseline; pinteraction=0·01).

INTERPRETATION

Reductions in colorectal cancer incidence and mortality from flexible sigmoidoscopy screening are sustained over the long term. Differences by sex and age should be examined in other ongoing trials of colorectal cancer screening to help clarify if different screening strategies would achieve greater risk reduction.

FUNDING

Extended follow-up was funded under NIH contract HHSN261201600007I.

Modifiable Failures in the Colorectal Cancer Screening Process and Their Association With Risk of Death

BACKGROUND & AIMS

Colorectal cancer (CRC) deaths occur when patients do not receive screening or have inadequate follow-up of abnormal results or when the screening test fails. We have few data on the contribution of each to CRC-associated deaths or factors associated with these events.

METHODS

We performed a retrospective cohort study of patients in the Kaiser Permanente Northern and Southern California systems (55-90 years old) who died of CRC from 2006 through 2012 and had ≥5 years of enrollment before diagnosis. We compared data from patients with those from a matched cohort of cancer-free patients in the same system. Receipt, results, indications, and follow-up of CRC tests in the 10-year period before diagnosis were obtained from electronic databases and chart audits.

RESULTS

Of 1750 CRC deaths, 75.9% (n = 1328) occurred in patients who were not up to date in screening and 24.1% (n = 422) occurred in patients who were up to date. Failure to screen was associated with fewer visits to primary care physicians. Of 3486 cancer-free patients, 44.6% were up to date in their screening. Patients who were up to date in their screening had a lower risk of CRC death (odds ratio, 0.38; 95% confidence interval, 0.33-0.44). Failure to screen, or failure to screen at appropriate intervals, occurred in a 67.8% of patients who died of CRC vs 53.2% of cancer-free patients; failure to follow-up on abnormal results occurred in 8.1% of patients who died of CRC vs 2.2% of cancer-free patients. CRC death was associated with higher odds of failure to screen or failure to screen at appropriate intervals (odds ratio, 2.40; 95% confidence interval, 2.07-2.77) and failure to follow-up on abnormal results (odds ratio, 7.26; 95% confidence interval, 5.26-10.03).

CONCLUSIONS

Being up to date on screening substantially decreases the risk of CRC death. In 2 health care systems with high rates of screening, most people who died of CRC had failures in the screening process that could be rectified, such as failure to follow-up on abnormal findings; these significantly increased the risk for CRC death.

Association of Colonoscopy Adenoma Findings With Long-term Colorectal Cancer Incidence

IMPORTANCE

Individuals with adenomatous polyps are advised to undergo repeated colonoscopy surveillance to prevent subsequent colorectal cancer (CRC), but the relationship between adenomas at colonoscopy and long-term CRC incidence is unclear.

OBJECTIVE

To compare long-term CRC incidence by colonoscopy adenoma findings.

DESIGN, SETTING, AND PARTICIPANTS

Multicenter, prospective cohort study of participants in the Prostate, Lung, Colorectal, and Ovarian (PLCO) Cancer randomized clinical trial of flexible sigmoidoscopy (FSG) beginning in 1993 with follow-up for CRC incidence to 2013 across the United States. Participants included 154 900 men and women aged 55 to 74 years enrolled in PLCO of whom 15 935 underwent colonoscopy following their first positive FSG screening result. The final day of follow-up was December 31, 2013.

EXPOSURES

Enrolled participants had been randomized to FSG or usual care. Participants who underwent FSG and had abnormal findings were referred for follow-up. Subsequent colonoscopy findings were categorized as advanced adenoma (≥1 cm, high-grade dysplasia, or tubulovillous or villous histology), nonadvanced adenoma (<1 cm without advanced histology), or no adenoma.

MAIN OUTCOMES AND MEASURES

The primary outcome was CRC incidence within 15 years of the baseline colonoscopy. The secondary outcome was CRC mortality.

RESULTS

There were 15 935 participants who underwent colonoscopy (men, 59.7%; white, 90.7%; median age, 64 y [IQR, 61-68]). On initial colonoscopy, 2882 participants (18.1%) had an advanced adenoma, 5068 participants (31.8%) had a nonadvanced adenoma, and 7985 participants (50.1%) had no adenoma; median follow-up for CRC incidence was 12.9 years. CRC incidence rates per 10 000 person-years of observation were 20.0 (95% CI, 15.3-24.7; n = 70) for advanced adenoma, 9.1 (95% CI, 6.7-11.5; n = 55) for nonadvanced adenoma, and 7.5 (95% CI, 5.8-9.7; n = 71) for no adenoma. Participants with advanced adenoma were significantly more likely to develop CRC compared with participants with no adenoma (rate ratio [RR], 2.7 [95% CI, 1.9-3.7]; P < .001). There was no significant difference in CRC risk between participants with nonadvanced adenoma compared with no adenoma (RR, 1.2 [95% CI, 0.8-1.7]; P = .30). Compared with participants with no adenoma, those with advanced adenoma were at significantly increased risk of CRC death (RR, 2.6 [95% CI, 1.2-5.7], P = .01), but mortality risk in participants with nonadvanced adenoma was not significantly different (RR, 1.2 [95% CI, 0.5-2.7], P = .68).

CONCLUSIONS AND RELEVANCE

Over a median of 13 years of follow-up, participants with an advanced adenoma at diagnostic colonoscopy prompted by a positive flexible sigmoidoscopy result were at significantly increased risk of developing colorectal cancer compared with those with no adenoma. Identification of nonadvanced adenoma may not be associated with increased colorectal cancer risk.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT00002540.

Development and clinical testing of individual immunoassays for the quantification of serum glycoproteins to diagnose prostate cancer

Prostate Cancer (PCa) diagnosis is currently hampered by the high false-positive rate of PSA evaluations, which consequently may lead to overtreatment. Non-invasive methods with increased specificity and sensitivity are needed to improve diagnosis of significant PCa. We developed and technically validated four individual immunoassays for cathepsin D (CTSD), intercellular adhesion molecule 1 (ICAM1), olfactomedin 4 (OLFM4), and thrombospondin 1 (THBS1). These glycoproteins, previously identified by mass spectrometry using a Pten mouse model, were measured in clinical serum samples for testing the capability of discriminating PCa positive and negative samples. The development yielded 4 individual immunoassays with inter and intra-variability (CV) <15% and linearity on dilution of the analytes. In serum, ex vivo protein stability (<15% loss of analyte) was achieved for a duration of at least 24 hours at room temperature and 2 days at 4°C. The measurement of 359 serum samples from PCa positive (n = 167) and negative (n = 192) patients with elevated PSA (2-10 ng/ml) revealed a significantly improved accuracy (P <0.001) when two of the glycoproteins (CTSD and THBS1) were combined with %fPSA and age (AUC = 0.8109; P <0.0001; 95% CI = 0.7673-0.8545). Conclusively, the use of CTSD and THBS1 together with commonly used parameters for PCa diagnosis such as %fPSA and age has the potential to improve the diagnosis of PCa.

Clinicopathologic review of polyps biopsied at colonoscopy in Lagos, Nigeria

Introduction

Colorectal polyps are known precursors of colorectal cancers. The increase in utilization of colonoscopy in Nigeria has meant a rise in the recently reported incidence of these lesions. The aim of this study is to evaluate the clinicopathological profile of colorectal polyps biopsied during the inaugural 12 month period of colonoscopy from a private endoscopy suite in Nigeria.

Methods

This is a retrospective review of all the clients who had polyps diagnosed at colonoscopy over a 12 month period (August 2014 –July 2015) at a private endoscopy suite in Lagos, Nigeria. This analysis of prospectively collected data was performed using clinical information from the endoscopy logs and pathology database system of a private endoscopy suite based in Lagos, Nigeria.

Results

A total of 125 colonoscopies were carried out over the stated period. Of these, 14 individuals had a total of 18 polyps- 4 clients (28.6% of the persons with polyps) had two polyps each. The polyp detection rate was 11.2% while the polyp per colonoscopy rate was 14.4%. Of these clients, males were 10 in number; giving a male to female ratio of 2.5:1. Their ages ranged from 37 to 77 years (mean= 57.3 years). The presenting complaint at colonoscopy was hematochezia in 11 (78.6%), new onset constipation in 2 (14.2%) and peri-anal pain in 1 patient (7.1%). The polyps were distributed as follows; 2 (11.1%) in the ascending colon, 1 (5.6%) each in the transverse and descending colons, 8 (44.4%) in the sigmoid colon, 6(33.3%) located in the rectum. Hence, there was left sided (15 of 18= 83.3%) preponderance. Pathologically, tubular (adenomatous) polyp with or without low grade dysplastic changes was diagnosed in 6 of the 18 polyps (giving an adenoma detection rate of 4.8%), 4 (22.2%) were inflammatory polyps, 1 (5.6%) was malignant and another had the rare inflammatory fibroid polyp. Five (27.8%) of the specimens were reported as non-specific colitis.

Conclusion

The study supports the present wisdom that polyps are clearly less prevalent in our environment when compared to the Western world. The increased prevalence with advancing age, in male subjects and of left sided lesions, is also in keeping with previous results from our environment. A case is also advanced for the increased deployment of endoscopy as a tool for the detection of these polyps and ultimately, the reduction of colorectal cancer in our population.

Occurrence of Distal Colorectal Neoplasia Among Whites and Blacks Following Negative Flexible Sigmoidoscopy: An Analysis of PLCO Trial

BACKGROUND

It is unclear whether the higher rate of colorectal cancer (CRC) among non-Hispanic blacks (blacks) is due to lower rates of CRC screening or greater biologic risk.

OBJECTIVE

We aimed to evaluate whether blacks are more likely than non-Hispanic whites (whites) to develop distal colon neoplasia (adenoma and/or cancer) after negative flexible sigmoidoscopy (FSG).

DESIGN

We analyzed data of participants with negative FSGs at baseline in the Prostate, Lung, Colorectal, and Ovarian (PLCO) cancer screening trial who underwent repeat FSGs 3 or 5 years later. Subjects with polyps or masses were referred to their physicians for diagnostic colonoscopy. We collected and reviewed the records of diagnostic evaluations.

PARTICIPANTS

Our analytic cohort consisted of 21,550 whites and 975 blacks.

MAIN MEASURES

We did a comparison by race (whites vs. blacks) in the findings of polyps or masses at repeat FSG, the follow-up of abnormal test results and the detection of colorectal neoplasia at diagnostic colonoscopy.

KEY RESULTS

At the follow-up FSG examination, 304 blacks (31.2 %) and 4183 whites (19.4 %) had abnormal FSG, [adjusted relative risk (RR) = 1.00; 95 % confidence interval (CI), 0.90-1.10]. However, blacks were less likely to undergo diagnostic colonoscopy (76.6 % vs. 83.1 %; RR = 0.90; 95 % CI, 0.84-0.96). Among all included patients, blacks had similar risk of any distal adenoma (RR = 0.86; 95 % CI, 0.65-1.14) and distal advanced adenoma (RR = 1.01; 95 % CI, 0.60-1.68). Similar results were obtained when we restricted our analysis to compliant subjects who underwent diagnostic colonoscopy (RR = 1.01; 95 % CI, 0.80-1.29) for any distal adenoma and (RR = 1.18; 95 % CI, 0.73-1.92) for distal advanced adenoma.

CONCLUSIONS

We did not find any differences between blacks and whites in the risk of distal colorectal adenoma 3-5 years after negative FSG. However, follow-up evaluations were lower among blacks.

Heterogeneous demographic and cultural profiles of Chinese American patients nonadherent to colorectal cancer screening: a latent class analysis

BACKGROUND

Colorectal cancer (CRC) is one of the leading causes of cancer death in Chinese Americans, but their CRC screening rates remain low.

OBJECTIVE

We examined subgroups of Chinese American patients nonadherent to CRC screening guidelines to better inform clinical practices to effectively promote screening.

METHODS

Using latent class analysis of data from 327 participants recruited from 18 primary care clinics, we classified nonadherent patients based on sociodemographics, screening barriers, and attitudinal and clinical factors for CRC screening.

RESULTS

The best-fitting latent class analysis model described 3 distinctive classes: Western healthcare class (36%), Eastern healthcare class (18%), and mixed healthcare class (46%). Western healthcare class patients were highly educated, with average US residency of 20 years, a high level of English proficiency, the least Eastern cultural views of care, and the greatest exposure to physician recommendations, but reported having no time for screenings. Eastern healthcare class patients were highly educated seniors and recent immigrants with the least CRC knowledge and the most Eastern cultural views. Mixed healthcare class patients had low level of education, resided in the United States for 20 years, and half had sought services of their physicians for at least 3 years, but their knowledge and cultural views were similar to those of Eastern healthcare class patients.

CONCLUSIONS

Nonadherent Chinese American patients are heterogeneous. It is essential to have future intervention programs tailored to address specific screening beliefs and barriers for subtypes of nonadherent patients.

IMPLICATIONS FOR PRACTICE

Training primary care physicians to recognize patients' different demographic characteristics and healthcare beliefs may facilitate physicians' communication with patients to overcome their barriers and improve screening behaviors.

Using the Cancer Risk Management Model to evaluate colorectal cancer screening options for Canada

BACKGROUND

Several screening methods for colorectal cancer (crc) are available, and some have been shown by randomized trials to be effective. In the present study, we used a well-developed population health simulation model to compare the risks and benefits of a variety of screening scenarios. Tests considered were the fecal occult blood test (fobt), the fecal immunochemical test (fit), flexible sigmoidoscopy, and colonoscopy. Outcomes considered included years of life gained, crc cases and deaths prevented, and direct health system costs.

METHODS

A natural history model of crc was implemented and calibrated to specified targets within the framework of the Cancer Risk Management Model (crmm) from the Canadian Partnership Against Cancer. The crmm-crc permits users to enter their own parameter values or to use program-specified base values. For each of 23 screening scenarios, we used the crmm-crc to run 10 million replicate simulations.

RESULTS

Using base parameter values and some user-specified values in the crmm-crc, and comparing our screening scenarios with no screening, all screening scenarios were found to reduce the incidence of and mortality from crc. The fobt was the least effective test; it was not associated with lower net cost. Colonoscopy screening was the most effective test; it had net costs comparable to those for several other strategies considered, but required more than 3 times the colonoscopy resources needed by other approaches. After colonoscopy, strategies based on the fit were predicted to be the most effective. In sensitivity analyses performed for the fobt and fit screening strategies, fobt parameter values associated with high-sensitivity formulations were associated with a substantial increase in test effectiveness. The fit was more cost-effective at the 50 ng/mL threshold than at the 100 ng/mL threshold.

CONCLUSIONS

The crmm-crc provides a sophisticated and flexible environment in which to evaluate crc control options. All screening scenarios considered in this study effectively reduced crc mortality, although sensitivity analyses demonstrated some uncertainty in the magnitude of the improvements. Where possible, local data should be used to reduce uncertainty in the parameters.

A comparison of colorectal cancer screening uptake among average-risk insured American Indian/Alaska Native and white women

INTRODUCTION

American Indian and Alaska Native (AI/AN) women have among the lowest rates of colorectal cancer (CRC) screening. Whether screening disparities persist with equal access to health care is unknown.

METHODS

Using administrative data from 1996-2007, we compared CRC screening events for 286 AI/AN and 14,042 White women aged 50 years and older from a health maintenance organization in the Pacific Northwest of the U.S.

RESULTS

The proportion of AI/AN and White women screened for CRC at age 50 was similar (13.3% vs. 14.0%, p =.74). No differences were seen in the type of screening test. Time elapsed to first screening among AI/AN women who were not screened at age 50 did not differ from White women (hazard ratio 1.0, 95% confidence interval 0.8-1.3).

CONCLUSIONS

Uptake for CRC screening was similar among insured AI/AN and White women, suggesting that when access to care is equal, racial disparities in screening diminish.

22-year longitudinal study of repetitive colonoscopy in patients with a family history of colorectal cancer

INTRODUCTION

We report the outcomes of a long-term surveillance programme for individuals with a family history of colorectal cancer.

METHODS

The details of patients undergoing a colonoscopy having been referred on the basis of family history of colorectal cancer were entered prospectively into a database. Further colonoscopy was arranged on the basis of the findings. The outcomes assessed included incidence of cancer and adenoma identification at initial and subsequent colonoscopy.

RESULTS

The records of 2,293 patients (917 men; median patient age: 51 years) were entered over 22 years, giving data on 3,982 colonoscopies. Eight adverse events (0.2%) were recorded. Twenty-seven cancers were found at first colonoscopy and thirteen developed during the follow-up period. There were significantly more cancers identified in those with more than one first-degree relative with cancer than in other groups (p=0.01). The number of adenomas identified at subsequent surveillance colonoscopies remained constant with between 9.3% and 12.0% of patients having adenomas that were removed. Two-thirds (68%) of patients with cancer and three-quarters (77%) with adenomas fell outside the British Society of Gastroenterology (BSG) 2006 guidelines.

CONCLUSIONS

Repeated colonoscopy continues to yield significant pathology including new cancers. These continue to occur despite removal of adenomas at prior colonoscopies. The majority of patients with cancers and adenomas fell outside the BSG 2006 guidelines; more would have fallen outside the 2010 guidelines.

22-year longitudinal study of repetitive colonoscopy in patients with a family history of colorectal cancer

Introduction

We report the outcomes of a long-term surveillance programme for individuals with a family history of colorectal cancer.

Methods

The details of patients undergoing a colonoscopy having been referred on the basis of family history of colorectal cancer were entered prospectively into a database. Further colonoscopy was arranged on the basis of the findings. The outcomes assessed included incidence of cancer and adenoma identification at initial and subsequent colonoscopy.

Results

The records of 2,293 patients (917 men; median patient age: 51 years) were entered over 22 years, giving data on 3,982 colonoscopies. Eight adverse events (0.2%) were recorded. Twenty-seven cancers were found at first colonoscopy and thirteen developed during the follow-up period. There were significantly more cancers identified in those with more than one first-degree relative with cancer than in other groups (p=0.01). The number of adenomas identified at subsequent surveillance colonoscopies remained constant with between 9.3% and 12.0% of patients having adenomas that were removed. Two-thirds (68%) of patients with cancer and three-quarters (77%) with adenomas fell outside the British Society of Gastroenterology (BSG) 2006 guidelines.

Conclusions

Repeated colonoscopy continues to yield significant pathology including new cancers. These continue to occur despite removal of adenomas at prior colonoscopies. The majority of patients with cancers and adenomas fell outside the BSG 2006 guidelines; more would have fallen outside the 2010 guidelines.

Colorectal cancer screening--optimizing current strategies and new directions

The first evidence that screening for colorectal cancer (CRC) could effectively reduce mortality dates back 20 years. However, actual population screening has, in many countries, halted at the level of individual testing and discussions on differences between screening tests. With a wealth of new evidence from various community-based studies looking at test uptake, screening-programme organization and the importance of quality assurance, population screening for CRC is now moving into a new realm, promising better results in terms of reducing CRC-specific morbidity and mortality. Such a shift in the paradigm requires a change from opportunistic, individual testing towards organized population screening with comprehensive monitoring and full-programme quality assurance. To achieve this, a combination of factors--including test characteristics, uptake, screenee autonomy, costs and capacity--must be considered. Thus, evidence from randomized trials comparing different tests must be supplemented by studies of acceptance and uptake to obtain the full picture of the effectiveness (in terms of morbidity, mortality and cost) the different strategies have. In this Review, we discuss a range of screening modalities and describe the factors to be considered to achieve a truly effective population CRC screening programme.

Concerns and challenges in flexible sigmoidoscopy screening

In 1992, two well-conducted case-control studies used data from two different health maintenance organizations and demonstrated a 59-79% reduction in mortality from colorectal cancer (CRC) following exposure to sigmoidoscopy. These studies highlight the possibility of reducing mortality from CRC using population-based endoscopic screening. The development of fiber optics improved the technology, and the ease of performing flexible sigmoidoscopy (FS) with widespread adoption of this screening modality. To date, FS is the only endoscopic screening modality that has been shown to reduce mortality in randomized clinical trials. This article reviews the development of sigmoidoscopy, its use in CRC screening and the current reduced role of this proven screening modality, and explores new frontiers for population-based FS screening.

Colorectal-cancer incidence and mortality with screening flexible sigmoidoscopy

BACKGROUND

The benefits of endoscopic testing for colorectal-cancer screening are uncertain. We evaluated the effect of screening with flexible sigmoidoscopy on colorectal-cancer incidence and mortality.

METHODS

From 1993 through 2001, we randomly assigned 154,900 men and women 55 to 74 years of age either to screening with flexible sigmoidoscopy, with a repeat screening at 3 or 5 years, or to usual care. Cases of colorectal cancer and deaths from the disease were ascertained.

RESULTS

Of the 77,445 participants randomly assigned to screening (intervention group), 83.5% underwent baseline flexible sigmoidoscopy and 54.0% were screened at 3 or 5 years. The incidence of colorectal cancer after a median follow-up of 11.9 years was 11.9 cases per 10,000 person-years in the intervention group (1012 cases), as compared with 15.2 cases per 10,000 person-years in the usual-care group (1287 cases), which represents a 21% reduction (relative risk, 0.79; 95% confidence interval [CI], 0.72 to 0.85; P<0.001). Significant reductions were observed in the incidence of both distal colorectal cancer (479 cases in the intervention group vs. 669 cases in the usual-care group; relative risk, 0.71; 95% CI, 0.64 to 0.80; P<0.001) and proximal colorectal cancer (512 cases vs. 595 cases; relative risk, 0.86; 95% CI, 0.76 to 0.97; P=0.01). There were 2.9 deaths from colorectal cancer per 10,000 person-years in the intervention group (252 deaths), as compared with 3.9 per 10,000 person-years in the usual-care group (341 deaths), which represents a 26% reduction (relative risk, 0.74; 95% CI, 0.63 to 0.87; P<0.001). Mortality from distal colorectal cancer was reduced by 50% (87 deaths in the intervention group vs. 175 in the usual-care group; relative risk, 0.50; 95% CI, 0.38 to 0.64; P<0.001); mortality from proximal colorectal cancer was unaffected (143 and 147 deaths, respectively; relative risk, 0.97; 95% CI, 0.77 to 1.22; P=0.81).

CONCLUSIONS

Screening with flexible sigmoidoscopy was associated with a significant decrease in colorectal-cancer incidence (in both the distal and proximal colon) and mortality (distal colon only). (Funded by the National Cancer Institute; PLCO ClinicalTrials.gov number, NCT00002540.).