Colorectal cancer in the setting of pregnancy and familial risk

BACKGROUND AND AIMS

Women are at risk of colorectal cancer (CRC) during pregnancy but this fact is underappreciated. We performed a population-based study to evaluate the rate, predictors, and familial risk for pregnancy associated CRC in Utah.

METHODS

All newly diagnosed cases of CRC between 1973 and 2014 were obtained from the Utah Cancer Registry and linked to pedigrees from the Utah Population Database.

RESULTS

Of the 12,886 females diagnosed with CRC, 73 were diagnosed with CRC (0.57%) during the period of obstetric delivery/childbirth. Pregnancy associated CRC was diagnosed at a mean age of 31.9 years, and cancers were less frequently located in the proximal colon compared with women with non-pregnancy associated CRC. First-degree relatives of cases with pregnancy associated CRC had a nearly threefold higher risk of CRC (OR, 2.76; 95% CI, 1.26-6.01) compared with relatives of CRC-free individuals.

CONCLUSIONS

Of women diagnosed with CRC, less than 1% were diagnosed during or soon after obstetric delivery/childbirth. Relatives of these patients have a nearly threefold greater risk of CRC than those without a family history of CRC. These results provide physicians with data to guide the care of patients and their relatives with pregnancy associated CRC.

Use of Family History and Genetic Testing to Determine Risk of Colorectal Cancer

Approximately 35% of patients with colorectal cancer (CRC) have a family history of the disease attributed to genetic factors, common exposures, or both. Some families with a history of CRC carry genetic variants that cause CRC with high or moderate penetrance, but these account for only 5% to 10% of CRC cases. Most families with a history of CRC and/or adenomas do not carry genetic variants associated with cancer syndromes; this is called common familial CRC. Our understanding of familial predisposition to CRC and cancer syndromes has increased rapidly due to advances in next-generation sequencing technologies. As a result, there has been a shift from genetic testing for specific inherited cancer syndromes based on clinical criteria alone, to simultaneous testing of multiple genes for cancer-associated variants. We summarize current knowledge of common familial CRC, provide an update on syndromes associated with CRC (including the nonpolyposis and polyposis types), and review current recommendations for CRC screening and surveillance. We also provide an approach to genetic evaluation and testing in clinical practice. Determination of CRC risk based on family cancer history and results of genetic testing can provide a personalized approach to cancer screening and prevention, with optimal use of colonoscopy to effectively decrease CRC incidence and mortality.

Clinical and Molecular Features of Post-Colonoscopy Colorectal Cancers

BACKGROUND & AIMS

Post-colonoscopy colorectal cancers (PCCRCs) may arise from missed lesions or due to molecular features of tumors that allow them to grow rapidly. We aimed to compare clinical, pathology, and molecular features of PCCRCs (those detected within 6-60 months of colonoscopy) and detected CRCs (those detected within 6 months of a colonoscopy).

METHODS

Within a population-based cross-sectional study of incident CRC cases in Utah (from 1995 through 2009), we identified PCCRCs (those cancers that developed within 5 years of a colonoscopy) and matched the patients by age, sex, and hospital site to patients with detected CRC. Archived specimens were retrieved and tested for microsatellite instability (MSI), CpG island methylation, and mutations in KRAS and BRAF. There were 2659 cases of CRC diagnosed within the study window; 6% of these (n = 159) were defined as PCCRCs; 84 of these cases had tissue available and were matched to 84 subjects with detected CRC.

RESULTS

Higher proportions of PCCRCs than detected CRCs formed in the proximal colon (64% vs 44%; P = .016) and were of an early stage (86% vs 69%; P = .040). MSI was observed in 32% of PCCRCs compared with 13% of detected CRCs (P = .005). The other molecular features were found in similar proportions of PCCRCs and detected CRCs. In a multivariable logistic regression, MSI (odds ratio, 4.20; 95% CI, 1.58-11.14) was associated with PCCRC. There was no difference in 5-year survival between patients with PCCRCs vs detected CRCs.

CONCLUSION

In this population-based cross-sectional study of incident CRC cases in Utah, we found PCCRCs to be more likely to arise in the proximal colon and demonstrate MSI, so PCCRCs and detected CRC appear to have different features or processes of tumorigenesis. Additional studies are needed to determine if post-colonoscopy cancers arise through a specific genetic pathway.

Familial pancreatic cancer risk: a population-based study in Utah

INTRODUCTION

Pancreas adenocarcinoma (PC) has an undefined hereditary component. We quantified the familial risk of PC among relatives of patients diagnosed with PC and stratified it based on anatomic location of PC and age and sex of the proband.

METHODS

This is a retrospective, population-based, case-control study of PC diagnosed in Utah between 1980 and 2011. The Utah population database and cancer registry were used to identify index patients with PC. The risk of PC in first-degree relatives (FDRs), second-degree relatives (SDRs), and first cousins (FCs) of probands was compared with randomly selected sex- and age-matched population controls.

RESULTS

A total of 4,095 patients and 40,933 controls were identified. The relative risk (RR) of PC was 1.76 (95% CI 1.35-2.29) in FDRs, 1.42 (95% CI 1.18-1.7) in SDRs and 1.08 (95% CI 0.95-1.23) in FCs of probands compared to relatives of PC-free controls. The RR were elevated in FDRs (1.96, 95% CI 1.45-2.65), SDRs (1.54, 95% CI 1.19-1.98) and FCs (1.18, 95% CI 1.0-1.64) of female probands. Among probands diagnosed as < 65 years, RR was 2.12 (95% CI 1.37-3.28) in FDRs, 1.94 (95% CI 1.44-2.62) in SDRs, and 1.28 (95% CI 1.0-1.64) in FCs. Overall, the RR for PC was elevated in FDRs regardless of the anatomic location of PC.

DISCUSSION

There is an increased risk of PC in FDR and more distant relatives of patients with PC. Relatives of female patients with PC and patients diagnosed at age < 65 years are at a significantly increased risk of PC.

Association of Sulindac and Erlotinib vs Placebo With Colorectal Neoplasia in Familial Adenomatous Polyposis: Secondary Analysis of a Randomized Clinical Trial

Importance

Patients with familial adenomatous polyposis (FAP) are at markedly increased risk for colorectal polyps and cancer. A combination of sulindac and erlotinib led to a 71% reduction in duodenal polyp burden in a phase 2 trial.

Objective

To evaluate effect of sulindac and erlotinib on colorectal adenoma regression in patients with FAP.

Design, Setting, and Participants

Prespecified secondary analysis for colorectal adenoma regression was carried out using data from a double-blind, randomized, placebo-controlled trial, enrolling 92 patients with FAP, conducted from July 2010 to June 2014 in Salt Lake City, Utah.

Interventions

Patients were randomized to sulindac, 150 mg twice daily, and erlotinib, 75 mg daily (n = 46), vs placebo (n = 46) for 6 months.

Main Outcomes and Measurements

The total number of polyps in the intact colorectum, ileal pouch anal anastomosis, or ileo-rectum were recorded at baseline and 6 months. The primary outcomes were change in total colorectal polyp count and percentage change in colorectal polyps, following 6 months of treatment.

Results

Eighty-two randomized patients (mean [SD] age, 40 [13] years; 49 [60%] women) had colorectal polyp count data available for this secondary analysis: 22 with intact colon, 44 with ileal pouch anal anastomosis and 16 with ileo-rectal anastomosis; 41 patients received sulindac/erlotinib and 41 placebo. The total colorectal polyp count was significantly different between the placebo and sulindac-erlotinib group at 6 months in patients with net percentage change of 69.4% in those with an intact colorectum compared with placebo (95% CI, 28.8%-109.2%; P = .009).

Conclusion and Relevance

In this double-blind, placebo-controlled, randomized trial we showed that combination treatment with sulindac and erlotinib compared with placebo resulted in significantly lower colorectal polyp burden after 6 months of treatment. There was a reduction in polyp burden in both those with an entire colorectum and those with only a rectal pouch or rectum.

Trial Registration

clinicaltrials.gov Identifier: NCT01187901.

Family History Associates With Increased Risk of Colorectal Cancer in Patients With Inflammatory Bowel Diseases

BACKGROUND & AIMS

Individuals with inflammatory bowel diseases (IBDs) have an increased risk of developing colorectal cancer (CRC). Although family history of CRC is a well-established risk factor in healthy individuals, its role in patients with IBD is less clear. We aimed to estimate the risk of CRC in a cohort of patients with IBD from Utah and the significance of family history of CRC in a first-degree relative (FDR).

METHODS

We identified Utah residents with IBD, using the Intermountain Healthcare and University of Utah Health Sciences databases, from January 1, 1996, through December 31, 2011. CRCs were identified using the Utah Cancer Registry and linked to pedigrees from the Utah Population Database. CRC incidence was compared with that of the state population by standardized incidence ratios (SIRs).

RESULTS

A cohort of 9505 individuals with IBD was identified and 101 developed CRC during the study period. The SIR for CRC in patients with Crohn's disease was 3.4 (95% CI, 2.3-4.4), and in patients with ulcerative colitis was 5.2 (95% CI, 3.9-6.6). Patients with IBD and a concurrent diagnosis of primary sclerosing cholangitis had the greatest risk of CRC (SIR, 14.8; 95% CI, 8.3-21.2). A history of CRC in a FDR was associated with a nearly 8-fold increase in risk of CRC in patients with IBD (SIR, 7.9; 95% CI, 1.6-14.3), compared with the state population.

CONCLUSIONS

Patients with IBD have a 3- to 5-fold increase in risk of CRC, and those with CRC in a FDR have an almost 8-fold increase in risk. Family history may act as a simple measure to identify individuals with IBD at highest risk for CRC and indicates the need for enhanced surveillance in this population.

Cancer Risk in Families Fulfilling the Amsterdam Criteria for Lynch Syndrome

Importance

The data describing cancer risks associated with Lynch syndrome are variable.

Objectives

To quantify the prevalence of families that fulfill the Amsterdam I or II criteria for Lynch syndrome in the Utah population and investigate the risk of colonic and extracolonic cancers in family members and their relatives.

Design, Setting, and Participants

In a population-based study, 202 families with Amsterdam I and II criteria–positive pedigrees in the Utah Population Database were identified. Of these, all cancer diagnoses in members of families with Amsterdam criteria and their first-degree, second-degree, and first-cousin relatives were located through linkage to the Utah Cancer Registry. The study was conducted from May 1 to June 30, 2016.

Main Outcomes and Measures

Standardized morbidity ratios (SMRs) were estimated by comparing the observed rates of cancer in relatives with population-expected rates estimated internally from the Utah Population Database.

Results

A total of 202 families meeting Amsterdam criteria for Lynch syndrome accounted for 2.6% of all colorectal cancers in the state; of these, 59 met both the Amsterdam I and Amsterdam II criteria. Cancers observed in significant excess in the first-degree relatives of Amsterdam criteria pedigrees included colorectal (SMR, 10.10; 95% CI, 9.43-10.81), endometrial (SMR, 5.89; 95% CI, 5.09-6.78), stomach (SMR, 2.90; 95% CI, 2.02-4.03), small intestine (SMR, 7.72; 95% CI, 5.17-11.08), prostate (SMR, 1.94; 95% CI, 1.73-2.17), kidney (SMR, 3.22; 95% CI, 2.45-4.16), urinary bladder (SMR, 1.62; 95% CI, 1.22-2.12), thyroid (SMR, 2.26; 95% CI, 1.55-3.17), and non-Hodgkin lymphoma (SMR, 2.10; 95% CI, 1.64-2.65). Risks of colorectal and endometrial cancers were also found to be elevated in second-degree (SMR, 4.31; 95% CI, 3.98-4.65 and SMR, 2.70; 95% CI, 2.30-3.14, respectively) and first-cousin (SMR, 1.85; 95% CI, 1.70-2.00 and SMR, 1.50; 95% CI, 1.29-1.73, respectively) relatives of families with Amsterdam criteria.

Conclusions and Relevance

In this population-based study of cancer risk in families fulfilling the Amsterdam criteria, many of the cancers previously reported to be associated with Lynch syndrome were observed, several previously unreported cancer associations were noted, and the risk of colorectal and endometrial cancer were markedly increased in first-, second-, and even third-degree relatives of these families. This study provides clinicians with population-based, unbiased data to counsel members of families meeting the Amsterdam criteria regarding their elevated risks of cancer and the importance of cancer screening.

Small RNA sequencing of sessile serrated polyps identifies microRNA profile associated with colon cancer

Sessile serrated adenoma/polyps (SSA/Ps) of the colon account for 20-30% of all colon cancers. Small non-coding RNAs, including microRNAs (miRNAs), may function as oncogenes or tumor suppressor genes involved in cancer development. Small RNA sequencing (RNA-seq) was used to characterize miRNA profiles in SSA/Ps, hyperplastic polyps (HPs), adenomatous polyps and paired uninvolved colon. Our 108 small RNA-seq samples' results were compared to small RNA-seq data from 212 colon cancers from the Cancer Genome Atlas. Twenty-three and six miRNAs were differentially expressed in SSA/Ps compared to paired uninvolved colon and HPs, respectively. Differential expression of MIR31-5p, MIR135B-5p and MIR378A-5p was confirmed by RT-qPCR. SSA/P-specific miRNAs are similarly expressed in colon cancers containing genomic aberrations described in serrated cancers. Correlation of miRNA expression with consensus molecular subtypes suggests more than one subtype is associated with the serrated neoplasia pathway. Canonical pathway analysis suggests many of these miRNAs target growth factor signaling pathways.

Variables affecting penetrance of gastric and duodenal phenotype in familial adenomatous polyposis patients

BACKGROUND

Patients with familial adenomatous polyposis (FAP) frequently undergo colectomy to reduce the 70 to 90% lifetime risk of colorectal cancer. After risk-reducing colectomy, duodenal cancer and complications from duodenal surgeries are the main cause of morbidity. Our objective was to prospectively describe the duodenal and gastric polyp phenotype in a cohort of 150 FAP patients undergoing pre-screening for a chemoprevention trial and analyze variables that may affect recommendations for surveillance.

METHODS

Individuals with a diagnosis of FAP underwent prospective esophagogastroduodenoscopy using a uniform system of mapping of size and number of duodenal polyps for a 10 cm segment. Gastric polyps were recorded as the total number.

RESULTS

The distribution of the count and sum diameter of duodenal polyps were statistically different in two genotype groups, those with APC mutations associated with classic FAP had a greater count (median 17) and sum diameter of polyps (median 32 mm) than those with APC mutations associated with attenuated FAP (median count 4 and median sum diameter of 7 mm) (p < 0.0001). The number of gastric polyps did not differ based on genotype (p = 0.67) but advancing age correlated with severity of gastric polyposis (p = 0.019). Spigelman (modified) staging of II or greater was found in 88% of classic FAP patients and 48% attenuated FAP patients. Examples of severe and mild upper GI phenotype are observed in patients with identical APC mutations, showing that the APC mutation location is not absolutely predictive of an upper GI phenotype.

CONCLUSIONS

Most FAP patients have duodenal and gastric polyps which become more prevalent and advanced with age. Standard upper endoscopic surveillance is recommended based on personal history independent of APC mutation location.

TRIAL REGISTRATION

NCT 01187901 registered August 24, 2010, prospective to enrollment.

Active BRAF-V600E is the key player in generation of a sessile serrated polyp-specific DNA methylation profile

BACKGROUND

Sessile serrated polyps (SSPs) have emerged as important precursors for a large number of sporadic colorectal cancers. They are difficult to detect during colonoscopy due to their flat shape and the excessive amounts of secreted mucin that cover the polyps. The underlying genetic and epigenetic basis for the emergence of SSPs is largely unknown with existing genetic studies confined to a limited number of oncogenes and tumor suppressors. A full characterization of the genetic and epigenetic landscape of SSPs would provide insight into their origin and potentially offer new biomarkers useful for detection of SSPs in stool samples.

METHODS

We used a combination of genome-wide mutation detection, exome sequencing and DNA methylation profiling (via methyl-array and whole-genome bisulfite sequencing) to analyze multiple samples of sessile serrated polyps and compared these to familial adenomatous polyps.

RESULTS

Our analysis revealed BRAF-V600E as the sole recurring somatic mutation in SSPs with no additional major genetic mutations detected. The occurrence of BRAF-V600E was coincident with a unique DNA methylation pattern revealing a set of DNA methylation markers showing significant (~3 to 30 fold) increase in their methylation levels, exclusively in SSP samples. These methylation patterns effectively distinguished sessile serrated polys from adenomatous polyps and did so more effectively than parallel gene expression profiles.

CONCLUSIONS

This study provides an important example of a single oncogenic mutation leading to reproducible global DNA methylation changes. These methylated markers are specific to SSPs and could be of important clinical relevance for the early diagnosis of SSPs using non-invasive approaches such as fecal DNA testing.

A role for the vitamin D pathway in non-intestinal lesions in genetic and carcinogen models of colorectal cancer and in familial adenomatous polyposis

Vitamin D is implicated in the etiology of cancers of the gastrointestinal tract, usually characterized by alteration in the APC/β-catenin/TCF tumor suppressor pathway. The vitamin D receptor (VDR) is also implicated in cardiovascular and skin diseases as well as in immunity. Activated VDR can indirectly alter β-catenin nuclear localization and directly suppress β-catenin/TCF mediated transcriptional activity. We treated VDR null mice with the carcinogen azoxymethane (AOM) and generated mice bearing a mutated APC (hypomorph) on a VDR null background (Apc^1638N/+Vdr^−/−). VDR null mice do not develop GI or extra-colonic tumors but loss of VDR decreased intestinal tumor latency and increased progression to adenocarcinoma in both models. AOM treatment of VDR null mice also caused squamous cell carcinoma of the anus. Although levels and distribution of total or activated β-catenin in the epithelial component of tumors were unaffected by loss of VDR, β-catenin dependent cyclin D1 expression was affected suggesting a direct VDR effect on β-catenin co-activator activity. Extra-colonic mucosa manifestations in Apc^1638N/+Vdr^−/− animals included increased nuclear β-catenin in submucosal stromal cells, spleno- and cardiomegaly and large epidermoid cysts characteristic of the FAP variant, Gardner's syndrome. Consistent with this, SNPs in the VDR, vitamin D binding protein and CYP24 as well as mutations in APC distal to codon 850 were strongly associated with Gardners syndrome in a cohort of 457 FAP patients, This work suggests that alterations in the vitamin D/VDR axis are important in Gardner's syndrome, as well as in the etiology of anal cancer.

Chemoprevention with Cyclooxygenase and Epidermal Growth Factor Receptor Inhibitors in Familial Adenomatous Polyposis Patients: mRNA Signatures of Duodenal Neoplasia

To identify gene expression biomarkers and pathways targeted by sulindac and erlotinib given in a chemoprevention trial with a significant decrease in duodenal polyp burden at 6 months (P < 0.001) in familial adenomatous polyposis (FAP) patients, we biopsied normal and polyp duodenal tissues from patients on drug versus placebo and analyzed the RNA expression. RNA sequencing was performed on biopsies from the duodenum of FAP patients obtained at baseline and 6-month endpoint endoscopy. Ten FAP patients on placebo and 10 on sulindac and erlotinib were selected for analysis. Purity of biopsied polyp tissue was calculated from RNA expression data. RNAs differentially expressed between endpoint polyp and paired baseline normal were determined for each group and mapped to biological pathways. Key genes in candidate pathways were further validated by quantitative RT-PCR. RNA expression analyses of endpoint polyp compared with paired baseline normal for patients on placebo and drug show that pathways activated in polyp growth and proliferation are blocked by this drug combination. Directly comparing polyp gene expression between patients on drug and placebo also identified innate immune response genes (IL12 and IFNγ) preferentially expressed in patients on drug. Gene expression analyses from tissue obtained at endpoint of the trial demonstrated inhibition of the cancer pathways COX2/PGE2, EGFR, and WNT. These findings provide molecular evidence that the drug combination of sulindac and erlotinib reached the intended tissue and was on target for the predicted pathways. Furthermore, activation of innate immune pathways from patients on drug may have contributed to polyp regression. Cancer Prev Res; 11(1); 4-15. ©2017 AACRSee related editorial by Shureiqi, p. 1.

Gastrointestinal Polyposis in Cowden Syndrome

GOALS

To further characterize the gastrointestinal manifestations of Cowden syndrome in clinically well-annotated patients to improve the diagnosis of this syndrome.

BACKGROUND

The gastrointestinal manifestations of Cowden Syndrome, an important heritable and multiorgan cancer syndrome, are not well defined. Proper diagnosis is essential for effective cancer surveillance and prevention in these patients.

STUDY

Cowden patients with gastrointestinal polyps were selected for medical record and pathologic slide review.

RESULTS

Of 19 total patients, genetic testing revealed pathogenic PTEN mutations in 12. Pan-colonic (11-patients, 58%) and pan-gastrointestinal (8-patients, 42%) polyp distributions were common. Inflammatory (juvenile) polyps were the most common of the hamartomatous polyp (18 patients, 95%), along with expansive lymphoid follicle polyps (12 patients, 63%), ganglioneuromatous polyps (10 patients, 53%), and intramucosal lipomas (5 patients, 26%). The findings of 2 or more hamartomatous polyp types per patient emerged as a newly described and highly prevalent (79%) feature of Cowden syndrome. Ganglioneuromatous polyps, rare in the general population, and intramucosal lipomas, which may be unique to Cowden syndrome, should both prompt further evaluation. Colonic adenomas and adenocarcinomas were common; 10 patients (53%) had single and 3 (16%) had ≥3 adenomas, whereas 2 (11%) had colonic adenocarcinoma, strengthening the emerging association of colorectal cancer with Cowden syndrome.

CONCLUSIONS

The clinical phenotypes and gastrointestinal manifestations in Cowden syndrome are quite variable but this series adds the following new considerations for this syndromic diagnosis: multiple gastrointestinal hamartomas, especially 2 or more hamartoma types, and any intramucosal lipomas or ganglioneuromas. These features should warrant consideration of Cowden syndrome.

Colorectal Cancer in Inflammatory Bowel Diseases: A Population-Based Study in Utah

BACKGROUND AND AIMS

The molecular, endoscopic, and histological features of IBD-associated CRC differ from sporadic CRC. The objective of this study was to describe the prevalence, clinical features, and prognosis of IBD-associated CRC compared to patients with sporadic CRC in a US statewide population-based cohort.

METHODS

All newly diagnosed cases of CRC between 1996 and 2011 were obtained from Utah Cancer Registry. IBD was identified using a previously validated algorithm, from statewide databases of Intermountain Healthcare, University of Utah Health Sciences, and the Utah Population Database. Logistic regression was performed to identify risk factors associated with IBD-associated cancer and Cox regression for differences in survival.

RESULTS

Among 12,578 patients diagnosed with CRC, 101 (0.8%) had a prior history of IBD (61 ulcerative colitis and 40 Crohn's disease). The mean age at CRC diagnosis was greater for patients without IBD than those with IBD (67.1 vs 52.8 years, P < 0.001). Individuals with IBD-associated CRC were more likely to be men (odds ratio [OR] 1.90, 95% CI 1.23-2.92), aged less than 65 years (OR 6.77, 95% CI 4.06-11.27), and have CRC located in the proximal colon (OR 2.79, 95% CI 1.85-4.20) than those with sporadic CRC. Nearly 20% of the IBD-associated CRCs had evidence of primary sclerosing cholangitis. After adjustment for age, gender, and stage at diagnosis, the excess hazard of death after CRC diagnosis was 1.7 times higher in IBD than in non-IBD patients (95% CI 1.27-2.33).

CONCLUSIONS

The features of patients with CRC and IBD differ significantly from those without IBD and may be associated with increased mortality.

Reducing the polyp burden in serrated polyposis by serial colonoscopy: the impact of nationally coordinated community surveillance

BACKGROUND

Serrated polyposis syndrome (SPS) is associated with an increased risk of colorectal cancer (CRC) and an evolving management approach. The aims of this study were to assess the polyp burden reduction over time, and the incidence of CRC in serrated polyposis patients undergoing community surveillance.

METHODS

This is an observational study based on prospectively collected data. A total of 96 SPS patients with no personal history of CRC were prospectively enrolled in a surveillance program under the guidance of a tertiary center. Patients underwent surveillance colonoscopy in multiple centres across New Zealand.

RESULTS

Patients underwent a median of four colonoscopies with a median interval of 15 months over a median follow-up period of 4.8 years. Five of 96 patients (5%) were referred for surgery, and the remaining 91 were managed by colonoscopy alone. In patients referred for surgery, 92% of the surveillance intervals to the fourth colonoscopy had been ≤12 months compared to 33% (P<0.001) in the colonoscopy only group, and all five (100%) had ≥20 pancolonic polyps after four procedures compared with only 5/91 (5%) in those managed by colonoscopy alone. In patients successfully managed by colonoscopy, 86% had <10 pancolonic polyps, >75% no longer had polyps ≥10mm and >90% no longer had proximal serrated polyps ≥10mm after the fourth colonoscopy. No patients were found to develop CRC during the study time period.

CONCLUSIONS

Patients with SPS were managed by proactive surveillance colonoscopy in wider hospital settings under tertiary centre guidance, with only 5% requiring surgical management. No CRC was diagnosed in any patient during surveillance.

Understanding the contribution of family history to colorectal cancer risk and its clinical implications: A state-of-the-science review

Persons with a family history (FH) of colorectal cancer (CRC) or adenomas that are not due to known hereditary syndromes have an increased risk for CRC. An understanding of these risks, screening recommendations, and screening behaviors can inform strategies for reducing the CRC burden in these families. A comprehensive review of the literature published within the past 10 years has been performed to assess what is known about cancer risk, screening guidelines, adherence and barriers to screening, and effective interventions in persons with an FH of CRC and to identify FH tools used to identify these individuals and inform care. Existing data show that having 1 affected first-degree relative (FDR) increases the CRC risk 2-fold, and the risk increases with multiple affected FDRs and a younger age at diagnosis. There is variability in screening recommendations across consensus guidelines. Screening adherence is <50% and is lower in persons under the age of 50 years. A provider's recommendation, multiple affected relatives, and family encouragement facilitate screening; insufficient collection of FH, low knowledge of guidelines, and poor family communication are important barriers. Effective interventions incorporate strategies for overcoming barriers, but these have not been broadly tested in clinical settings. Four strategies for reducing CRC in persons with familial risk are suggested: 1) improving the collection and utilization of the FH of cancer, 2) establishing a consensus for screening guidelines by FH, 3) enhancing provider-patient knowledge of guidelines and communication about CRC risk, and 4) encouraging survivors to promote screening within their families and partnering with existing screening programs to expand their reach to high-risk groups. Cancer 2016. © 2016 American Cancer Society. Cancer 2016;122:2633-2645. © 2016 American Cancer Society.

Familial Risk in Patients With Carcinoma of Unknown Primary

IMPORTANCE

Carcinoma of unknown primary (CUP) accounts for 3% to 5% of all cancers and is associated with poor prognosis. Familial clustering of different cancer sites with CUP is unknown and may provide information regarding etiology, as well as elevated cancer risks in relatives.

OBJECTIVE

To quantify the risk of cancer by site in first- and second-degree relatives and first cousins of individuals with CUP.

DESIGN, SETTING, AND PARTICIPANTS

Nested case-control study of patients who received a diagnosis of CUP between 1980 and 2010 identified from the Utah Cancer Registry. Population controls with no CUP diagnosis were sex and age matched 10:1 to patients with CUP. Data about relatives were drawn from the Utah Population Database.

MAIN OUTCOMES AND MEASURES

Familial aggregation of cancer risk in relatives of cases compared with controls using Cox regression analysis.

RESULTS

For the 4160 index patients (median [interquartile range] age, 72 [62-81] years; 47.6% male) who had received a diagnosis of CUP, first-degree relatives were at an elevated risk of CUP themselves (hazard ratio [HR], 1.35 [95% CI, 1.07-1.70]), as well as lung (HR, 1.37 [95% CI, 1.22-1.54]), pancreatic (HR, 1.28 [95% CI, 1.06-1.54]), myeloma (HR, 1.28 [95% CI, 1.01-1.62]), and non-Hodgkin lymphoma (HR, 1.16 [95% CI, >1.00-1.35]) cancers compared with controls without CUP. When the analysis was restricted to relatives of cancer-free controls, additional increased risks for colon (HR, 1.19 [95% CI, 1.06-1.33]) and bladder (HR, 1.18 [95% CI, >1.00-1.38]) cancers were observed. Second-degree relatives of patients with CUP were at a slight increased risk of lung (HR, 1.14 [95% CI, 1.03-1.26]), pancreatic (HR, 1.17 [95% CI, 1.01-1.37]), breast (HR, 1.09 [95% CI, 1.02-1.16]), melanoma (HR, 1.09 [95% CI, >1.00-1.19]), and ovarian (HR, 1.19 [95% CI, 1.02-1.39]) cancers.

CONCLUSIONS AND RELEVANCE

Relatives of patients with CUP are at increased risk of CUP and several other malignant neoplasms, including lung, pancreatic, and colon cancer. The present data may suggest sites of origin for CUP and provide cancer risk information for relatives of patients with CUP that can lead to effective intervention. Relatives of patients with CUP should be aware of the elevated risks for lung, pancreatic, and colon cancer and encouraged to modify risk factors and adhere to site-specific population cancer screening.

Abstract LB-074: Regression of duodenal neoplasia in familial adenomatous polyposis patients using COX and EGFR inhibition: A randomized placebo-controlled trial

The objective of this trial was to test the effect of a combination of COX and EGFR inhibition on duodenal adenoma progression in patients with familial adenomatous polyposis (FAP). FAP is caused by mutations in the APC gene and is characterized by the development of hundreds of colorectal adenomas and colorectal cancer. FAP patients are also at increased risk for duodenal neoplasia with a ∼10% lifetime risk of duodenal carcinoma. Surgical and endoscopic management of duodenal neoplasia is difficult and chemoprevention has not been successful. Preclinical data has illustrated that a combination of cyclooxygenase (COX) and epidermal growth factor (EGFR) inhibition diminishes small intestinal adenoma development by 87% in mice with germline Apc mutations. Therefore, we conducted a double blind, randomized, placebo-controlled trial in which FAP patients received combination therapy with 150 mg sulindac twice per day and 75 mg erlotinib daily or placebo for 6 months (NCT01187901). The total number and diameter of polyps in a 10cm segment of the proximal duodenum were mapped at baseline and 6 months. The primary outcome was change in total polyp burden, calculated as the sum of the diameters of polyps. We also evaluated RNA expression in duodenal tissue and polyps at endpoint from 10 patients on drug and 10 patients on placebo by RNA sequencing. Seventy-three randomized patients were included in the intention to treat analysis. Over six months, the median change in total duodenal polyp burden was an increase of 8.0 mm from baseline burden in the placebo group (23.0 to 31.0 mm) and the median change in the sulindac-erlotinib group was a decrease of 8.5 mm (29.0 to 19.5 mm). The estimated net difference in change between the two groups was -19.0 mm (95% CI: -32.0, -10.9; P&lt;0.001). Grade 1 and 2 adverse events were more common in the sulindac-erlotinib group, with an acne-like rash observed in 87% of patients receiving treatment and 20% of patients receiving placebo (P&lt;0.001). We identified ∼ 750 differentially expressed genes (fold ≥ 2, false discovery rate &lt; 0.05) in polyps from patients on placebo as compared with patient-matched normal duodenum which were unchanged in polyps from patients on drug. These differentially expressed genes suggested increased EGFR, prostaglandin E2 (PGE2 or COX2) and WNT signaling in duodenal polyps from patients on placebo but not on drug. In duodenal tissue from patients on drug when compared to tissue from patients on placebo, we identified differentially expressed genes suggestive of a reactivated immune response including interferon gamma and interleukin 12 signaling; a possible mechanism for the regression of duodenal polyps observed in drug treated patients. In conclusion, combined chemoprevention with sulindac and erlotinib in FAP patients is effective to lower duodenal polyp burden, block COX2 and EGFR activity, and may reactivate immune surveillance. At the doses tested, however, frequent adverse events may limit the use of these medications.

Part of this abstract was presented as part of a preliminary presentation.

Citation Format: Deborah W. Neklason, Don A. Delker, Kenneth M. Boucher, Priyanka Kanth, Kathryn Byrne, Philip Bernard, Wade Samowitz, Michelle W. Done, Therese Berry, Lisa Pappas, Laurel Smith, Danielle Sample, Rian Davis, Matthew K. Topham, Randall W. Burt, Scott K. Kuwada, N Jewel Samadder. Regression of duodenal neoplasia in familial adenomatous polyposis patients using COX and EGFR inhibition: A randomized placebo-controlled trial. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr LB-074.

Gene Signature in Sessile Serrated Polyps Identifies Colon Cancer Subtype

Sessile serrated colon adenoma/polyps (SSA/P) are found during routine screening colonoscopy and may account for 20% to 30% of colon cancers. However, differentiating SSA/Ps from hyperplastic polyps (HP) with little risk of cancer is challenging and complementary molecular markers are needed. In addition, the molecular mechanisms of colon cancer development from SSA/Ps are poorly understood. RNA sequencing (RNA-Seq) was performed on 21 SSA/Ps, 10 HPs, 10 adenomas, 21 uninvolved colon, and 20 control colon specimens. Differential expression and leave-one-out cross-validation methods were used to define a unique gene signature of SSA/Ps. Our SSA/P gene signature was evaluated in colon cancer RNA-Seq data from The Cancer Genome Atlas (TCGA) to identify a subtype of colon cancers that may develop from SSA/Ps. A total of 1,422 differentially expressed genes were found in SSA/Ps relative to controls. Serrated polyposis syndrome (n = 12) and sporadic SSA/Ps (n = 9) exhibited almost complete (96%) gene overlap. A 51-gene panel in SSA/P showed similar expression in a subset of TCGA colon cancers with high microsatellite instability. A smaller 7-gene panel showed high sensitivity and specificity in identifying BRAF-mutant, CpG island methylator phenotype high, and MLH1-silenced colon cancers. We describe a unique gene signature in SSA/Ps that identifies a subset of colon cancers likely to develop through the serrated pathway. These gene panels may be utilized for improved differentiation of SSA/Ps from HPs and provide insights into novel molecular pathways altered in colon cancer arising from the serrated pathway. Cancer Prev Res; 9(6); 456-65. ©2016 AACR.

Effect of Sulindac and Erlotinib vs Placebo on Duodenal Neoplasia in Familial Adenomatous Polyposis: A Randomized Clinical Trial

IMPORTANCE

Patients with familial adenomatous polyposis (FAP) are at markedly increased risk for duodenal polyps and cancer. Surgical and endoscopic management of duodenal neoplasia is difficult and chemoprevention has not been successful.

OBJECTIVE

To evaluate the effect of a combination of sulindac and erlotinib on duodenal adenoma regression in patients with FAP.

DESIGN, SETTING, AND PARTICIPANTS

Double-blind, randomized, placebo-controlled trial, enrolling 92 participants with FAP, conducted from July 2010 through June 2014 at Huntsman Cancer Institute in Salt Lake City, Utah.

INTERVENTIONS

Participants with FAP were randomized to sulindac (150 mg) twice daily and erlotinib (75 mg) daily (n = 46) vs placebo (n = 46) for 6 months.

MAIN OUTCOMES AND MEASURES

The total number and diameter of polyps in the proximal duodenum were mapped at baseline and 6 months. The primary outcome was change in total polyp burden at 6 months. Polyp burden was calculated as the sum of the diameters of polyps. The secondary outcomes were change in total duodenal polyp count, change in duodenal polyp burden or count stratified by genotype and initial polyp burden, and percentage of change from baseline in duodenal polyp burden.

RESULTS

Ninety-two participants (mean age, 41 years [range, 24-55]; women, 56 [61%]) were randomized when the trial was stopped by the external data and safety monitoring board because the second preplanned interim analysis met the prespecified stopping rule for superiority. Grade 1 and 2 adverse events were more common in the sulindac-erlotinib group, with an acne-like rash observed in 87% of participants receiving treatment and 20% of participants receiving placebo (P < .001). Only 2 participants experienced grade 3 adverse events. [table: see text].

CONCLUSIONS AND RELEVANCE

Among participants with FAP, the use of sulindac and erlotinib compared with placebo resulted in a lower duodenal polyp burden after 6 months. Adverse events may limit the use of these medications at the doses used in this study. Further research is necessary to evaluate these preliminary findings in a larger study population with longer follow-up to determine whether the observed effects will result in improved clinical outcomes.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT 01187901.

Risk of Incident Colorectal Cancer and Death After Colonoscopy: A Population-based Study in Utah

BACKGROUND & AIMS

Colonoscopy is widely recommended for colorectal (CRC) screening in the United States, but evidence of effectiveness is limited. We examined whether exposure to colonoscopy decreases the odds of incident CRC and death from CRC in Utah.

METHODS

We performed a case-control study of Utah residents, 54 to 90 years old, who received a CRC diagnosis from 2000 through 2010 (cases). Age- and sex-matched controls with no history of CRC (controls) were selected for each case. We determined receipt of colonoscopy 6 months to 10 years before the reference date for each case and control through administrative claims data. Colonoscopy exposure was compared by using conditional logistic regression.

RESULTS

We identified 5128 cases and 20,512 controls; 741 cases (14%) and 5715 controls (28%) received a colonoscopy. Exposure to colonoscopy reduced the odds for a diagnosis of CRC; the odds ratios (ORs) were 0.41 for any CRC (95% confidence interval [CI], 0.38-0.44), 0.58 for proximal colon cancer (95% CI, 0.51-0.65), and 0.29 for distal colon or rectal cancer (95% CI, 0.25-0.33). This finding was consistent among sexes, age groups, and cancer stages. Similarly, in a subgroup analysis, colonoscopy was associated with decreased odds of death from CRC (OR, 0.33; 95% CI, 0.28-0.39) in both the proximal colon (OR, 0.43; 95% CI, 0.34-0.55) and distal colon or rectum (OR, 0.23; 95% CI, 0.18-0.30).

CONCLUSIONS

In the population of Utah, colonoscopy is associated with a large reduction in risk of new-onset CRC and death from CRC. This reduction in risk for CRC was greatest for the distal colon and rectum, with a more modest reduction for proximal colon cancer.

Increased Risk of Colorectal Cancer Among Family Members of All Ages, Regardless of Age of Index Case at Diagnosis

BACKGROUND & AIMS

It is not clear whether familial risk of colorectal cancer (CRC) varies with age of index CRC patients or their relatives. We quantified the risk of CRC in first-degree relatives (FDRs), second-degree relatives, and first-cousin relatives of individuals with CRC, stratified by ages and sexes of index patients and ages of relatives.

METHODS

CRCs diagnosed between 1980 and 2010 were identified from the Utah Cancer Registry and linked to pedigrees from the Utah Population Database. Age- and sex-matched CRC-free individuals were selected to form the comparison group. CRC risk in relatives was determined by Cox regression analysis.

RESULTS

Of 18,208 index patients diagnosed with CRC, the highest familial risk was observed in FDRs of index CRC patients who were diagnosed at an age younger than 40 years (hazard ratio [HR], 2.53; 95% confidence interval [CI], 1.7-3.79). However, familial risk was increased in FDRs even when the index case was diagnosed with cancer at an advanced age (>80 years; HR, 1.76; 95% CI, 1.59-1.94). Ages of relatives and ages of index cases of CRC each affected familial cancer risk; the highest risk was found in young relatives (<50 years) of individuals with early-onset CRC (<40 years; HR, 7.0; 95% CI, 2.86-17.09).

CONCLUSIONS

All relatives of individuals with CRC are at increased risk for this cancer, regardless of the age of diagnosis of the index patient. Although risk is greatest among young relatives of early-onset CRC cases, relatives of patients diagnosed at advanced ages also have an increased risk.

Effectiveness of the extended parallel process model in promoting colorectal cancer screening

OBJECTIVE

Relatives of colorectal cancer (CRC) patients are at increased risk for the disease, yet screening rates still remain low. Guided by the Extended Parallel Process Model, we examined the impact of a personalized, remote risk communication intervention on behavioral intention and colonoscopy uptake in relatives of CRC patients, assessing the original additive model and an alternative model in which each theoretical construct contributes uniquely.

METHODS

We collected intention-to-screen and medical record-verified colonoscopy information on 218 individuals who received the personalized intervention.

RESULTS

Structural equation modeling showed poor main model fit (root mean square error of approximation (RMSEA) = 0.109; standardized root mean residual (SRMR) = 0.134; comparative fit index (CFI) = 0.797; Akaike information criterion (AIC) = 11,601; Bayesian information criterion (BIC) = 11,884). However, the alternative model (RMSEA = 0.070; SRMR = 0.105; CFI = 0.918; AIC = 11,186; BIC = 11,498) showed good fit. Cancer susceptibility (B = 0.319, p < 0.001) and colonoscopy self-efficacy (B = 0.364, p < 0.001) perceptions predicted intention to screen, which was significantly associated with colonoscopy uptake (B = 0.539, p < 0.001).

CONCLUSIONS

Our findings provide support of the utility of Extended Parallel Process Model for designing effective interventions to motivate CRC screening in persons at increased risk when individual elements of the model are considered. Copyright © 2015 John Wiley & Sons, Ltd.

The Genetics of Colorectal Cancer

The hereditary colorectal cancer syndromes comprise a heterogeneous group of conditions with varying cancer risks, gastrointestinal polyp types, nonmalignant findings, and inheritance patterns. Although each one is unique in its own right, these syndromes often have overlapping features, making diagnoses difficult in select cases. Obtaining accurate polyp history (histologic type, number, location, and age of onset), cancer history (location, type, and age of onset), and other nonmalignant features is imperative in determining the likely disease diagnosis and thereby the appropriate genetic tests for precise diagnosis in a timely fashion. This process often necessitates collaboration among surgical oncology team members and genetic counselors.

Hereditary and common familial colorectal cancer: evidence for colorectal screening

Colorectal cancer (CRC) is the fourth most common cancer among men and women. Between 3 and 6% of all CRCs are attributed to well-defined inherited syndromes, including Lynch syndrome, familial adenomatous polyposis, MUTYH-associated polyposis and several hamartomatous conditions. Up to 30% of CRC cases exhibit common familial risk, likely related to a combination of inherited factors and environment. Identification of these patients through family history and appropriate genetic testing can provide estimates of cancer risk that inform appropriate cancer screening, surveillance and/or preventative interventions. This article examines the colon cancer syndromes, their genetic basis, clinical management and evidence supporting colorectal screening. It also deals with the category of common (non-syndromic) familial risk including risk determination and screening guidelines.

Familial colorectal cancer risk by subsite of primary cancer: a population-based study in Utah

BACKGROUND

Familial occurrence is common in colorectal cancer (CRC), but whether this increased familial risk differs by colonic subsite of the index patients CRC is not well understood.

AIM

To quantify the risk of CRC in first-degree (FDR), second-degree (SDR) and first cousin (FC) relatives of individuals with CRC, stratified by subsite in the colorectum and age at diagnosis.

METHODS

Colorectal cancers diagnosed between 1980 and 2010 were identified from the Utah Cancer Registry and linked to pedigrees from the Utah Population Database. Age and gender-matched CRC-free controls were selected to form the comparison group for determining CRC risk in relatives using Cox regression analysis.

RESULTS

Of the 18,208 index patients diagnosed with CRC, 6584 (36.2%) were located in the proximal colon, 5986 (32.9%) in the distal colon and 5638 (31%) in the rectum. The elevated risk of CRC in relatives was similar in analysis stratified for CRC colorectal subsites in the index cases. FDR had similarly elevated risk of all site CRC, whether the index patient had cancer in the proximal colon [hazards ratio (HR): 1.85; 95% CI: 1.70-2.02], distal colon (HR: 1.90; 95% CI: 1.73-2.08) or rectum (HR: 1.83; 95% CI: 1.66-2.02) compared to relatives of controls. This risk was consistently greater for FDR when cases developed CRC below the age of 60 years.

CONCLUSIONS

Relatives of CRC patients have a similarly elevated risk of CRC regardless of colonic tumour subsite in the index patient, and it is greatest for relatives of younger age index cases.

Intention to undergo colonoscopy screening among relatives of colorectal cancer cases: a theory-based model

BACKGROUND

It is recommended that persons having familial risk of colorectal cancer begin regular colonoscopy screening at an earlier age than those in the general population. However, many individuals at increased risk do not adhere to these screening recommendations.

PURPOSE

The goal of this study was to examine cognitive, affective, social, and behavioral motivators of colonoscopy intention among individuals at increased risk of familial colorectal cancer.

METHODS

Relatives of colorectal cancer cases (N = 481) eligible for colonoscopy screening completed a survey assessing constructs from several theoretical frameworks including fear appeal theories.

RESULTS

Structural equation modeling indicated that perceived colorectal cancer risk, past colonoscopy, fear of colorectal cancer, support from family and friends, and health-care provider recommendation were determinants of colonoscopy intention.

CONCLUSIONS

Future interventions to promote colonoscopy in this increased risk population should target the factors we identified as motivators. (ClinicalTrials.gov number NCT01274143).

Epidemiology and familial risk of synchronous and metachronous colorectal cancer: a population-based study in Utah

BACKGROUND & AIMS

Patients diagnosed with colorectal cancer (CRC) are at risk for synchronous and metachronous lesions at the time of diagnosis or during follow-up evaluation. We performed a population-based study to evaluate the rate, predictors, and familial risk for synchronous and metachronous CRC in Utah.

METHODS

All newly diagnosed cases of CRC between 1980 and 2010 were obtained from the Utah Cancer Registry and linked to pedigrees from the Utah Population Database.

RESULTS

Of the 18,782 patients diagnosed with CRC, 134 were diagnosed with synchronous CRC (0.71%) and 300 were diagnosed with metachronous CRC (1.60%). The risk for synchronous CRC was significantly higher in men (odds ratio [OR], 1.45; 95% confidence interval [CI], 1.02-2.06) and in patients aged 65 years or older (OR, 1.50; 95% CI, 1.02-2.21). Synchronous CRCs were located more often in the proximal colon (OR, 1.70; 95% CI, 1.20-2.41). First-degree relatives of cases with synchronous (OR, 1.86; 95% CI, 1.37-2.53), metachronous (OR, 2.34; 95% CI, 1.62-3.36), or solitary CRC (OR, 1.75; 95% CI, 1.63-1.88) were at increased risk for developing CRC, compared with relatives of CRC-free individuals. Four percent of first-degree relatives of patients with synchronous or metachronous cancer developed CRC at younger ages than the age recommended for initiating CRC screening (based on familial risk), and therefore would not have been screened.

CONCLUSIONS

Of patients diagnosed with CRC, 2.3% are found to have synchronous lesions or develop metachronous CRC during follow-up evaluation. Relatives of these patients have a greater risk of CRC than those without a family history of CRC. These results highlight the importance of obtaining a thorough family history and adhering strictly to surveillance guidelines during management of high-risk patients.

APC promoter 1B deletion in seven American families with familial adenomatous polyposis

Familial adenomatous polyposis (FAP) is a colorectal cancer predisposition syndrome caused by mutations in the adenomatous polyposis coli (APC) gene. Clinical genetic testing fails to identify disease causing mutations in up to 20% of clinically apparent FAP cases. Following the inclusion of multiplex ligation-dependent probe amplification (MLPA) probes specific for APC promoter 1B, seven probands were identified with a deletion of promoter 1B. Using haplotype analysis spanning the APC locus, the seven families appear to be identical by descent from a common founder. The clinical phenotype of 19 mutation carriers is classical FAP with colectomy at an average age of 24. The majority of cases had a large number of duodenal and gastric polyps. Measurements of allele-specific expression of APC mRNA using TaqMan assay confirmed that relative expression in the allele containing the promoter 1B deletion was reduced 42-98%, depending on tissue type. This study confirms the importance of APC promoter deletions as a cause of FAP and identifies a founder mutation in FAP patients from the United States.

Increased risk of colorectal neoplasia among family members of patients with colorectal cancer: a population-based study in Utah

BACKGROUND & AIMS

Colorectal cancer (CRC) frequently develops in multiple members of the same families, but more data are needed to prepare effective screening guidelines. We quantified the risk of CRC and adenomas in first-degree relatives (FDRs) and second-degree relatives and first cousins of individuals with CRC, and stratified risk based on age at cancer diagnosis.

METHODS

We performed a case-control study of Utah residents, 50-80 years old, who underwent colonoscopy from 1995 through 2009. Index cases (exposed to colonoscopy) were colonoscopy patients with a CRC diagnosis. Age- and sex-matched individuals, unexposed to colonoscopy (controls) were selected to form the comparison groups for determining risk in relatives. Colonoscopy results were linked to cancer and pedigree information from the Utah Population Database to investigate familial aggregation of colorectal neoplasia using Cox regression analysis.

RESULTS

Of 126,936 patients who underwent a colonoscopy, 3804 were diagnosed with CRC and defined the index cases. FDRs had an increased risk of CRC (hazard rate ratio [HRR], 1.79; 95% confidence interval [CI],1.59-2.03), as did second-degree relatives (HRR, 1.32; 95% CI, 1.19-1.47) and first cousins (HRR, 1.15; 95% CI, 1.07-1.25), compared with relatives of controls. This risk was greater for FDRs when index patients developed CRC at younger than age 60 years (HRR, 2.11; 95% CI, 1.70-2.63), compared with older than age 60 years (HRR, 1.77; 95% CI, 1.58-1.99). The risk of adenomas (HRR, 1.82; 95% CI, 1.66-2.00) and adenomas with villous histology (HRR, 2.43; 95% CI, 1.96-3.01) also were increased in FDRs. Three percent of CRCs in FDRs would have been missed if the current guidelines, which stratify screening recommendations by the age of the proband, were strictly followed.

CONCLUSIONS

FDRs, second-degree relatives, and first cousins of patients who undergo colonoscopy and are found to have CRC have a significant increase in the risk of colorectal neoplasia. These data should be considered when establishing CRC screening guidelines for individuals and families.

Guidelines on genetic evaluation and management of Lynch syndrome: a consensus statement by the US Multi-Society Task Force on colorectal cancer

The Multi-Society Task Force, in collaboration with invited experts, developed guidelines to assist health care providers with the appropriate provision of genetic testing and management of patients at risk for and affected with Lynch syndrome as follows: Figure 1 provides a colorectal cancer risk assessment tool to screen individuals in the office or endoscopy setting; Figure 2 illustrates a strategy for universal screening for Lynch syndrome by tumor testing of patients diagnosed with colorectal cancer; Figures 3-6 provide algorithms for genetic evaluation of affected and at-risk family members of pedigrees with Lynch syndrome; Table 10 provides guidelines for screening at-risk and affected persons with Lynch syndrome; and Table 12 lists the guidelines for the management of patients with Lynch syndrome. A detailed explanation of Lynch syndrome and the methodology utilized to derive these guidelines, as well as an explanation of, and supporting literature for, these guidelines are provided.

Guidelines on genetic evaluation and management of Lynch syndrome: a consensus statement by the US Multi-society Task Force on colorectal cancer

The Multi-Society Task Force, in collaboration with invited experts, developed guidelines to assist health care providers with the appropriate provision of genetic testing and management of patients at risk for and affected with Lynch syndrome as follows: Figure 1 provides a colorectal cancer risk assessment tool to screen individuals in the office or endoscopy setting; Figure 2 illustrates a strategy for universal screening for Lynch syndrome by tumor testing of patients diagnosed with colorectal cancer; Figures 3,4,5,6 provide algorithms for genetic evaluation of affected and at-risk family members of pedigrees with Lynch syndrome; Table 10 provides guidelines for screening at-risk and affected persons with Lynch syndrome; and Table 12 lists the guidelines for the management of patients with Lynch syndrome. A detailed explanation of Lynch syndrome and the methodology utilized to derive these guidelines, as well as an explanation of, and supporting literature for, these guidelines are provided.

Characteristics of missed or interval colorectal cancer and patient survival: a population-based study

BACKGROUND & AIMS

Colorectal cancers (CRCs) diagnosed within a few years after an index colonoscopy can arise from missed lesions or the development of a new tumor. We investigated the proportion, characteristics, and factors that predict interval CRCs that develop within 6-60 months of colonoscopy.

METHODS

We performed a population-based cohort study of Utah residents who underwent colonoscopy examinations from 1995 through 2009 at Intermountain Healthcare or the University of Utah Health System, which provide care to more than 85% of state residents. Colonoscopy results were linked with cancer histories from the Utah Population Database to identify patients who underwent colonoscopy 6-60 months before a diagnosis of CRC (interval cancer). Logistic regression was performed to identify risk factors associated with interval cancers.

RESULTS

Of 126,851 patients who underwent colonoscopies, 2659 were diagnosed with CRC; 6% of these CRCs (159 of 2659) developed within 6 to 60 months of a colonoscopy. Sex and age were not associated with interval CRCs. A higher percentage of patients with interval CRC were found to have adenomas at their index colonoscopy (57.2%), compared with patients found to have CRC detected at colonoscopy (36%) or patients who did not develop cancer (26%) (P < .001). Interval CRCs tended to be earlier-stage tumors than those detected at index colonoscopy, and to be proximally located (odds ratio, 2.24; P < .001). Patients with interval CRC were more likely to have a family history of CRC (odds ratio, 2.27; P = .008) and had a lower risk of death than patients found to have CRC at their index colonoscopy (hazard ratio, 0.63; P < .001).

CONCLUSIONS

In a population-based study in Utah, 6% of all patients with CRC had interval cancers (cancer that developed within 6 to 60 months of a colonoscopy). Interval CRCs were associated with the proximal colon, earlier-stage cancer, lower risk of death, higher rate of adenoma, and family history of CRC. These findings indicate that interval colorectal tumors may arise as the result of distinct biologic features and/or suboptimal management of polyps at colonoscopy.

Telehealth personalized cancer risk communication to motivate colonoscopy in relatives of patients with colorectal cancer: the family CARE Randomized controlled trial

PURPOSE

The rate of adherence to regular colonoscopy screening in individuals at increased familial risk of colorectal cancer (CRC) is suboptimal, especially among rural and other geographically underserved populations. Remote interventions may overcome geographic and system-level barriers. We compared the efficacy of a telehealth-based personalized risk assessment and communication intervention with a mailed educational brochure for improving colonoscopy screening among at-risk relatives of patients with CRC.

METHODS

Eligible individuals age 30 to 74 years who were not up-to-date with risk-appropriate screening and were not candidates for genetic testing were recruited after contacting patients with CRC or their next of kin in five states. Enrollees were randomly assigned as family units to either an active, personalized intervention that incorporated evidence-based risk communication and behavior change techniques, or a mailed educational brochure. The primary outcome was medically verified colonoscopy within 9 months of the intervention.

RESULTS

Of the 481 eligible and randomly assigned at-risk relatives, 79.8% completed the outcome assessments within 9 months; 35.4% of those in the personalized intervention group and 15.7% of those in the comparison group obtained a colonoscopy. In an intent-to-treat analysis, the telehealth group was almost three times as likely to get screened as the low-intensity comparison group (odds ratio, 2.83; 95% CI, 1.87 to 4.28; P < .001). Persons residing in rural areas and those with lower incomes benefitted at the same level as did urban residents.

CONCLUSION

Remote personalized interventions that consider family history and incorporate evidence-based risk communication and behavior change strategies may promote risk-appropriate screening in close relatives of patients with CRC.

RNA sequencing of sessile serrated colon polyps identifies differentially expressed genes and immunohistochemical markers

BACKGROUND

Sessile serrated adenomas/polyps (SSA/Ps) may account for 20-30% of colon cancers. Although large SSA/Ps are generally recognized phenotypically, small (<1 cm) or dysplastic SSA/Ps are difficult to differentiate from hyperplastic or small adenomatous polyps by endoscopy and histopathology. Our aim was to define the comprehensive gene expression phenotype of SSA/Ps to better define this cancer precursor.

RESULTS

RNA sequencing was performed on 5' capped RNA from seven SSA/Ps collected from patients with the serrated polyposis syndrome (SPS) versus eight controls. Highly expressed genes were analyzed by qPCR in additional SSA/Ps, adenomas and controls. The cellular localization and level of gene products were examined by immunohistochemistry in syndromic and sporadic SSA/Ps, adenomatous and hyperplastic polyps and controls. We identified 1,294 differentially expressed annotated genes, with 106 increased ≥10-fold, in SSA/Ps compared to controls. Comparing these genes with an array dataset for adenomatous polyps identified 30 protein coding genes uniquely expressed ≥10-fold in SSA/Ps. Biological pathways altered in SSA/Ps included mucosal integrity, cell adhesion, and cell development. Marked increased expression of MUC17, the cell junction protein genes VSIG1 and GJB5, and the antiapoptotic gene REG4 were found in SSA/Ps, relative to controls and adenomas, were verified by qPCR analysis of additional SSA/Ps (n = 21) and adenomas (n = 10). Immunohistochemical staining of syndromic (n≥11) and sporadic SSA/Ps (n≥17), adenomatous (n≥13) and hyperplastic (n≥10) polyps plus controls (n≥16) identified unique expression patterns for VSIG1 and MUC17 in SSA/Ps.

CONCLUSION

A subset of genes and pathways are uniquely increased in SSA/Ps, compared to adenomatous polyps, thus supporting the concept that cancer develops by different pathways in these phenotypically distinct polyps with markedly different gene expression profiles. Immunostaining for a subset of these genes differentiates both syndromic and sporadic SSA/Ps from adenomatous and hyperplastic polyps.

Colorectal cancer screening

Mortality from colorectal cancer can be reduced by early diagnosis and by cancer prevention through polypectomy. These NCCN Guidelines for Colorectal Cancer Screening describe various colorectal screening modalities and recommended screening schedules for patients at average or increased risk of developing colorectal cancer. In addition, the guidelines provide recommendations for the management of patients with high-risk colorectal cancer syndromes, including Lynch syndrome. Screening approaches for Lynch syndrome are also described.

Risk of colorectal cancer and adenomas in the families of patients with adenomas: a population-based study in Utah

BACKGROUND

Guidelines recommend that individuals with a first-degree relative (FDR) diagnosed with colorectal cancer (CRC) or advanced adenoma before age 60 years should undergo colonoscopy starting at age 40 years. The authors quantified the risk of adenomas and CRC in FDRs, second-degree relatives (SDRs), and third-degree relatives (TDRs) of patients diagnosed with adenomas and advanced adenomas.

METHODS

A population-based, retrospective, case-control study was performed of residents of the state of Utah aged 50 years to 80 years who underwent colonoscopy between 1995 and 2009 at Intermountain Healthcare or the University of Utah. Controls were selected from the population of colonoscopy patients who were free of adenomas or CRC and matched to each case based on sex and birth year. Colonoscopy results were linked with cancer and pedigree information from the Utah Population Database to investigate the familial aggregation of adenomas and CRC using Cox regression analysis. The unit of analysis was the relatives of cases and controls.

RESULTS

Of 126,936 patients who underwent colonoscopy, 43,189 had adenomas and 5563 had advanced adenomas and defined the case population. An elevated risk of CRC was found in FDRs (relative risk [RR], 1.35; 95% confidence interval [95% CI], 1.25-1.46), SDRs (RR, 1.15; 95% CI, 1.07-1.23) of adenoma cases, and in FDRs of advanced adenoma cases (RR, 1.68; 95% CI, 1.29-2.18) compared with controls. Approximately 10% of CRCs diagnosed in relatives would have been missed if the current screening guidelines were strictly adhered to.

CONCLUSIONS

Relatives of colonoscopy patients with adenomas and advanced adenomas appear to have a significantly elevated risk of developing colorectal neoplasia. These data should be considered when establishing CRC screening guidelines for individuals and their families.

Immunodepletion plasma proteomics by tripleTOF 5600 and Orbitrap elite/LTQ-Orbitrap Velos/Q exactive mass spectrometers

Plasma proteomic experiments performed rapidly and economically using several of the latest high-resolution mass spectrometers were compared. Four quantitative hyperfractionated plasma proteomics experiments were analyzed in replicates by two AB SCIEX TripleTOF 5600 and three Thermo Scientific Orbitrap (Elite/LTQ-Orbitrap Velos/Q Exactive) instruments. Each experiment compared two iTRAQ isobaric-labeled immunodepleted plasma proteomes, provided as 30 labeled peptide fractions, and 480 LC-MS/MS runs delivered >250 GB of data in 2 months. Several analysis algorithms were compared. At 1% false discovery rate, the relative comparative findings concluded that the Thermo Scientific Q Exactive Mass Spectrometer resulted in the highest number of identified proteins and unique sequences with iTRAQ quantitation. The confidence of iTRAQ fold-change for each protein is dependent on the overall ion statistics (Mascot Protein Score) attainable by each instrument. The benchmarking also suggested how to further improve the mass spectrometry parameters and HPLC conditions. Our findings highlight the special challenges presented by the low abundance peptide ions of iTRAQ plasma proteome because the dynamic range of plasma protein abundance is uniquely high compared with cell lysates, necessitating high instrument sensitivity.

Examining the challenges of family recruitment to behavioral intervention trials: factors associated with participation and enrollment in a multi-state colonoscopy intervention trial

BACKGROUND

Colonoscopy is one of the most effective methods of cancer prevention and detection, particularly for individuals with familial risk. Recruitment of family members to behavioral intervention trials remains uniquely challenging, owing to the intensive process required to identify and contact them. Recruiting at-risk family members involves contacting the original cancer cases and asking them to provide information about their at-risk relatives, who must then be contacted for study enrollment. Though this recruitment strategy is common in family trials, few studies have compared influences of patient and relative participation to nonparticipation. Furthermore, although use of cancer registries to identify initial cases has increased, to our knowledge no study has examined the relationship between registries and family recruitment outcomes.

METHODS

This study assessed predictors of case participation and relative enrollment in a recruitment process that utilized state cancer registries. Participation characteristics were analyzed with separate multivariable logistic regressions in three stages: (1) cancer registry-contacted colorectal cancer (CRC) cases who agreed to study contact; (2) study-contacted CRC cases who provided at-risk relative information; and (3) at-risk relatives contacted for intervention participation.

RESULTS

Cancer registry source was predictive of participation for both CRC cases and relatives, though relative associations (odds ratios) varied across registries. Cases were less likely to participate if they were Hispanic or nonwhite, and were more likely to participate if they were female or younger than 50 at cancer diagnosis. At-risk relatives were more likely to participate if they were from Utah, if another family member was also participating in the study, or if they had previously had a colonoscopy. The number of eligible cases who had to be contacted to enroll one eligible relative varied widely by registry, from 7 to 81.

CONCLUSIONS

Family recruitment utilizing cancer registry-identified cancer cases is feasible, but highly dependent on both the strategies and protocols of those who are recruiting and on participant characteristics such as sex, race, or geography. Devising comprehensive recruitment protocols that specifically target those less likely to enroll may help future research meet recruitment goals.

TRIAL REGISTRATION

Family Colorectal Cancer Awareness and Risk Education Project NCT01274143.

Shared genomic segment analysis: the power to find rare disease variants

Shared genomic segment (SGS) analysis uses dense single nucleotide polymorphism genotyping in high-risk (HR) pedigrees to identify regions of sharing between cases. Here, we illustrate the power of SGS to identify dominant rare risk variants. Using simulated pedigrees, we consider 12 disease models based on disease prevalence, minor allele frequency and penetrance to represent disease loci that explain 0.2-99.8% of total disease risk. Pedigrees were required to contain ≥ 15 meioses between all cases and to be HR based on significant excess of disease (P < 0.001 or P < 0.00001). Across these scenarios, the power for a single pedigree ranged widely. Nonetheless, fewer than 10 pedigrees were sufficient for excellent power in the majority of models. Power increased with the risk attributable to the disease locus, penetrance and the excess of disease in the pedigree. Sharing allowing for one sporadic case was uniformly more powerful than sharing using all cases. Furthermore, an SGS analysis using a large attenuated familial adenomatous polyposis pedigree identified a 1.96 Mb region containing the known causal APC gene with genome-wide significance. SGS is a powerful method for detecting rare variants and a valuable complement to genome-wide association studies and linkage analysis.

Serrated lesions of the colorectum: review and recommendations from an expert panel

Serrated lesions of the colorectum are the precursors of perhaps one-third of colorectal cancers (CRCs). Cancers arising in serrated lesions are usually in the proximal colon, and account for a disproportionate fraction of cancer identified after colonoscopy. We sought to provide guidance for the clinical management of serrated colorectal lesions based on current evidence and expert opinion regarding definitions, classification, and significance of serrated lesions. A consensus conference was held over 2 days reviewing the topic of serrated lesions from the perspectives of histology, molecular biology, epidemiology, clinical aspects, and serrated polyposis. Serrated lesions should be classified pathologically according to the World Health Organization criteria as hyperplastic polyp, sessile serrated adenoma/polyp (SSA/P) with or without cytological dysplasia, or traditional serrated adenoma (TSA). SSA/P and TSA are premalignant lesions, but SSA/P is the principal serrated precursor of CRCs. Serrated lesions have a distinct endoscopic appearance, and several lines of evidence suggest that on average they are more difficult to detect than conventional adenomatous polyps. Effective colonoscopy requires an endoscopist trained in the endoscopic appearance of serrated lesions. We recommend that all serrated lesions proximal to the sigmoid colon and all serrated lesions in the rectosigmoid > 5 mm in size, be completely removed. Recommendations are made for post-polypectomy surveillance of serrated lesions and for surveillance of serrated polyposis patients and their relatives.

Serrated lesions of the colorectum: review and recommendations from an expert panel

Serrated lesions of the colorectum are the precursors of perhaps one-third of colorectal cancers (CRCs). Cancers arising in serrated lesions are usually in the proximal colon, and account for a disproportionate fraction of cancer identified after colonoscopy. We sought to provide guidance for the clinical management of serrated colorectal lesions based on current evidence and expert opinion regarding definitions, classification, and significance of serrated lesions. A consensus conference was held over 2 days reviewing the topic of serrated lesions from the perspectives of histology, molecular biology, epidemiology, clinical aspects, and serrated polyposis. Serrated lesions should be classified pathologically according to the World Health Organization criteria as hyperplastic polyp, sessile serrated adenoma/polyp (SSA/P) with or without cytological dysplasia, or traditional serrated adenoma (TSA). SSA/P and TSA are premalignant lesions, but SSA/P is the principal serrated precursor of CRCs. Serrated lesions have a distinct endoscopic appearance, and several lines of evidence suggest that on average they are more difficult to detect than conventional adenomatous polyps. Effective colonoscopy requires an endoscopist trained in the endoscopic appearance of serrated lesions. We recommend that all serrated lesions proximal to the sigmoid colon and all serrated lesions in the rectosigmoid > 5 mm in size, be completely removed. Recommendations are made for post-polypectomy surveillance of serrated lesions and for surveillance of serrated polyposis patients and their relatives.

Diagnosing Lynch syndrome: more light at the end of the tunnel

Since the recognition of Lynch syndrome, which confers a high risk of colorectal, uterine, and other cancers, approaches to its diagnosis have included a family history of associated cancers and web-based algorithms. Identification of causative genes now allows a precise diagnosis, thus focusing present efforts on who should have genetic testing. Testing for cancer tissue changes can determine who should have germline genetic testing. Indeed, such tumor testing is now generally recommended for all newly diagnosed colorectal cancer cases. As reported in this issue of the journal by Yurgelun and colleagues (beginning on page 574), large colorectal adenomatous polyps (≥10 mm) from patients with Lynch syndrome exhibit findings similar to those in Lynch syndrome colorectal cancer tissues. This finding indicates that testing larger adenomas in persons at a significant risk for Lynch syndrome can now determine the need for germline genetic testing. Although further study is needed for general application, the present study justifies large polyp testing in high-risk families when cancer tissue is unavailable, albeit negative polyp tissue would not rule out Lynch syndrome, as would negative cancer tissue.