Pancreatic cyst features predict future development of pancreatic cancer: results of a nested case-control study

BACKGROUND AND AIMS

Risk factors for pancreatic cancer among patients with pancreatic cysts are incompletely characterized. The primary aim of this study was to evaluate risk factors for development of pancreatic cancer among patients with pancreatic cysts.

METHODS

We conducted a retrospective case-control study of U.S. veterans with a suspected diagnosis of branch-duct intraductal papillary mucinous neoplasm from 1999 to 2013.

RESULTS

Age (hazard ratio [HR], 1.03 per year; 95% confidence interval [CI], 1.00-1.06), larger cyst size at cyst diagnosis (HR, 1.03 per mm; 95% CI, 1.01-1.04), cyst growth rate (HR, 1.22 per mm/y; 95% CI, 1.14-1.31), and pancreatic duct dilation (5-9.9 mm: HR, 3.78; 95% CI, 1.90-7.51; ≥10 mm: HR, 13.57; 95% CI, 5.49-33.53) were found to be significant predictors for pancreatic cancer on multivariable analysis.

CONCLUSIONS

Age, cyst size, cyst growth rate, and high-risk or worrisome features were associated with a higher risk of developing pancreatic cancer. Applying current and developing novel strategies is required to optimize early detection of pancreatic cancer after cyst diagnosis.

Risk of Incident and Fatal Colorectal Cancer After Young-Onset Adenoma Diagnosis: A National Cohort Study

INTRODUCTION

Colorectal cancer (CRC) incidence and mortality rates are increasing in adults aged <50 years. Young-onset adenoma (YOA)-adenoma detected in adults younger than 50 years-may signify increased CRC risk, but this association has not been widely studied. Our aim was to compare the risk of incident and fatal CRC in adults aged <50 years with YOA diagnosis compared with those with a normal colonoscopy.

METHODS

We conducted a cohort study of US Veterans aged 18-49 years who received colonoscopy between 2005 and 2016. The primary exposure of interest was YOA. Primary outcomes included incident and fatal CRC. We used Kaplan-Meier curves to calculate cumulative incident and fatal CRC risk and Cox models to examine relative CRC risk.

RESULTS

The study cohort included 54,284 Veterans aged <50 years exposed to colonoscopy, among whom 13% (n = 7,233) had YOA at start of follow-up. Cumulative 10-year CRC incidence was 0.11% (95% confidence interval [CI]: 0.00%-0.27%) after any adenoma diagnosis, 0.18% (95% CI: 0.02%-0.53%) after advanced YOA diagnosis, 0.10% (95% CI: 0.00%-0.28%) after nonadvanced adenoma diagnosis, and 0.06% (95% CI: 0.02%-0.09%) after normal colonoscopy. Veterans with advanced adenoma had 8-fold greater incident CRC risk than those with normal colonoscopy (hazard ratio: 8.0; 95% CI: 1.8-35.6). Across groups, no differences in fatal CRC risk were observed.

DISCUSSION

Young-onset advanced adenoma diagnosis was associated with 8-fold increased incident CRC risk compared with normal colonoscopy. However, cumulative CRC incidence and mortality at 10 years among individuals with either young onset non-advanced or advanced adenoma diagnosis were both relatively low.

Baseline Characteristics and Longitudinal Outcomes of Traditional Serrated Adenomas: A Cohort Study

BACKGROUND AND AIMS

Traditional serrated adenomas (TSAs) may confer increased risk for colorectal cancer (CRC). Our objective with this study was to examine clinical characteristics and long-term outcomes associated with TSA diagnosis.

METHODS

We conducted a retrospective cohort study of U.S. Veterans ≥18 years of age with ≥1 TSA between 1999 and 2018. Baseline characteristics, colonoscopy findings, and diagnosis of incident and fatal CRC were abstracted. Advanced neoplasia was defined by CRC or adenoma with high-grade dysplasia, villous histology, or size ≥1 cm. Follow-up was through CRC diagnosis, death, or end of study (December 31, 2018).

RESULTS

A total of 853 Veterans with a baseline TSA were identified; 74% were ≥60 years of age, 96% were men, 14% were Black, and 73% were non-Hispanic White. About 64% were current or former smokers. Over 2044 total person-years at follow-up, there were 11 incident CRC cases and 1 CRC death. Cumulative CRC incidence was 1.34% (95% confidence interval [CI], 0.67%-2.68%), and cumulative CRC death was 0.12% (95% CI, 0.00%-0.35%). Among the subset of 378 TSA patients with ≥1 surveillance colonoscopy, 65.1% had high-risk neoplasia on follow-up. CRC incidence among TSA patients was significantly higher than in a comparison cohort of patients with normal baseline colonoscopy at baseline (hazard ratio, 3.70; 95% CI, 1.63-8.41) and similar to a comparison cohort with baseline conventional advanced adenoma (hazard ratio, 0.86; 95% CI, 0.45-1.64).

CONCLUSION

Individuals with TSA have substantial risk for CRC based on their cumulative CRC incidence, as well as significant risk of developing other high-risk neoplasia at follow-up surveillance colonoscopy. These data underscore importance of current recommendations for close colonoscopy surveillance after TSA diagnosis.

Adenoma Detection Rate and Clinical Characteristics Influence Advanced Neoplasia Risk After Colorectal Polypectomy

BACKGROUND AND AIMS

Postpolypectomy risk stratification for subsequent metachronous advanced neoplasia (MAN) is imprecise and does not account for colonoscopist adenoma detection rate (ADR). Our aim was to assess association of ADR with MAN and create a prediction model for postpolypectomy risk stratification incorporating ADR and other factors.

METHODS

We conducted a retrospective cohort study of individuals with baseline polypectomy and subsequent surveillance colonoscopy from 2004 to 2016 within the U.S. Department of Veterans Affairs (VA). Clinical factors, polyp findings, and baseline colonoscopist ADR were considered for the model. Model performance (sensitivity, specificity, and area under the curve) for identifying individuals with MAN was compared with 2020 U.S. Multi-Society Task Force on Colorectal Cancer (USMSTF) surveillance recommendations.

RESULTS

A total of 30,897 individuals were randomly assigned 2:1 into independent model training and validation sets. Increasing age, male sex, diabetes, current smoking, adenoma number, polyp location, adenoma ≥10 mm or with tubulovillous/villous features, and decreasing colonoscopist ADR were independently associated with MAN. A range of 1.48- to 1.66-fold increased risk for MAN was observed for ADR in the lowest 3 quintiles (ADR <19.7%-39.3%) vs the highest quintile (ADR >47.0%). When the final model selected based on the training set was applied to the validation set, improved sensitivity and specificity over 2020 USMSTF risk stratification were achieved (P = .001), with an area under the curve of 0.62 (95% confidence interval, 0.60-0.64).

CONCLUSIONS

Colonoscopist ADR is associated with MAN. Combining clinical factors and ADR for risk stratification has potential to improve postpolypectomy risk stratification. Improving ADR is likely to improve postpolypectomy outcomes.

Pancreas Cancer Incidence and Pancreas Cancer-Associated Mortality Are Low in National Cohort of 7211 Pancreas Cyst Patients

BACKGROUND AND AIMS

Pancreatic cancer incidence and mortality among patients with pancreas cysts are unclear. The aims of this study are to evaluate incidence of pancreatic cancer and cause-specific mortality among patients with pancreatic cysts using a large national cohort over a long follow-up period.

METHODS

We conducted a retrospective cohort study of US Veterans diagnosed with a pancreatic cyst 1999-2013, based on International Classification of Diseases, 9th edition (ICD9) coding within national Department of Veterans Affairs (VA) data. Pancreatic cancer incidence was ascertained using VA cancer registry data, ICD-9 codes, and the National Death Index, a national centralized database of death records, including cause-specific mortality.

RESULTS

Among 7211 Veterans with pancreatic cysts contributing 31,501 person-years of follow-up (median follow-up 4.4 years), 79 (1.1%) developed pancreatic cancer. A total of 1982 patients (27.5%) died during the study follow-up period. Sixty-three patients (3.2% of deaths; 0.9% of pancreas cyst cohort) died from pancreatic cancer, but the leading causes of death in the cohort were non-pancreatic cancer (n = 498, 25% of deaths) and cardiovascular disease (n = 398, 20% of deaths).

CONCLUSIONS

Pancreas cancer incidence and pancreatic cancer-associated mortality are very low in a large national cohort of VA pancreatic cyst patients with long-term follow-up. Most deaths were from non-pancreas cancers and cardiovascular causes, and only a minority (3.2%) were attributable to pancreas cancer. Given death from pancreas cancer is rare, future research should focus on identifying criteria for selecting individuals at high risk for death from pancreatic cancer for pancreatic cyst surveillance.

A strategy for validation of variables derived from large-scale electronic health record data

Purpose:

Standardized approaches for rigorous validation of phenotyping from large-scale electronic health record (EHR) data have not been widely reported. We proposed a methodologically rigorous and efficient approach to guide such validation, including strategies for sampling cases and controls, determining sample sizes, estimating algorithm performance, and terminating the validation process, hereafter referred to as the San Diego Approach to Variable Validation (SDAVV).

Methods:

We propose sample size formulae which should be used prior to chart review, based on pre-specified critical lower bounds for positive predictive value (PPV) and negative predictive value (NPV). We also propose a stepwise strategy for iterative algorithm development/validation cycles, updating sample sizes for data abstraction until both PPV and NPV achieve target performance.

Results:

We applied the SDAVV to a Department of Veterans Affairs study in which we created two phenotyping algorithms, one for distinguishing normal colonoscopy cases from abnormal colonoscopy controls and one for identifying aspirin exposure. Estimated PPV and NPV both reached 0.970 with a 95% confidence lower bound of 0.915, estimated sensitivity was 0.963 and specificity was 0.975 for identifying normal colonoscopy cases. The phenotyping algorithm for identifying aspirin exposure reached a PPV of 0.990 (a 95% lower bound of 0.950), an NPV of 0.980 (a 95% lower bound of 0.930), and sensitivity and specificity were 0.960 and 1.000.

Conclusions:

A structured approach for prospectively developing and validating phenotyping algorithms from large-scale EHR data can be successfully implemented, and should be considered to improve the quality of “big data” research.

Systematic Review of Prevalence, Risk Factors, and Risk for Metachronous Advanced Neoplasia in Patients With Young-Onset Colorectal Adenoma

BACKGROUND & AIMS

The incidence and mortality of early-onset colorectal cancer (CRC) are increasing. Adenoma detection, removal, and subsequent endoscopic surveillance might modify risk of CRC diagnosed before age 50 years (early-onset CRC). We conducted a systematic review of young-onset adenoma (YOA) prevalence, associated risk factors, and rate of metachronous advanced neoplasia after YOA diagnosis.

METHODS

We performed a systematic search of multiple electronic databases through February 12, 2019 and identified studies of individuals 18 to 49 years old that reported prevalence of adenoma, risk factors for adenoma, and/or risk for metachronous advanced neoplasia. Summary estimates were derived using random effects meta-analysis, when feasible.

RESULTS

The pooled overall prevalence of YOA was 9.0% (95% CI, 7.1%-11.4%), based on 24 studies comprising 23,142 individuals. On subgroup analysis, the pooled prevalence of YOA from autopsy studies was 3.9% (95% CI, 1.9%-7.6%), whereas the prevalence from colonoscopy studies was 10.7% (95% CI, 8.5%-13.5). Only advancing age was identified as a consistent risk factor for YOA, based on 4 studies comprising 78,880 individuals. Pooled rate of metachronous advanced neoplasia after baseline YOA diagnosis was 6.0% (95% CI, 4.1%-8.6%), based on 3 studies comprising 1493 individuals undergoing follow-up colonoscopy, with only 1 CRC case reported. Overall, few studies reported metachronous advanced neoplasia and no studies evaluated whether routine surveillance colonoscopy decreases risk of CRC.

CONCLUSIONS

In a systematic review, we estimated the prevalence of YOA to be 9% and to increase with age. Risk for metachronous advanced neoplasia after YOA diagnosis is estimated to be 6%. More research is needed to understand the prevalence, risk factors, and risk of CRC associated with YOA.

Risk Factors for Early-Onset Colorectal Cancer

BACKGROUND & AIMS

Colorectal cancer (CRC) incidence and mortality are increasing among persons younger than 50 years old in the United States, but risk factors associated with early-onset CRC (EOCRC) have not been widely studied.

METHODS

We conducted a case-control study of US veterans 18 to 49 years old who underwent colonoscopy examinations from 1999 through 2014. EOCRC cases were identified from a national cancer registry; veterans who were free of CRC at their baseline colonoscopy through 3 years of follow-up were identified as controls. We collected data on age, sex, race/ethnicity, body weight, body mass index (BMI), diabetes, smoking status, and aspirin use. Multivariate-adjusted EOCRC odds were estimated for each factor, with corresponding 95% confidence interval (CI) values.

RESULTS

Our final analysis included 651 EOCRC cases and 67,416 controls. Median age was 45.3 years, and 82.3% were male. Higher proportions of cases were older, male, current smokers, nonaspirin users, and had lower BMIs, compared with controls (P < .05). In adjusted analyses, increasing age and male sex were significantly associated with increased risk of EOCRC, whereas aspirin use and being overweight or obese (relative to normal BMI) were significantly associated with decreased odds of EOCRC. In post hoc analyses, weight loss of 5 kg or more within the 5-year period preceding colonoscopy was associated with higher odds of EOCRC (odds ratio 2.23; 95% CI 1.76-2.83).

CONCLUSIONS

In a case-control study of veterans, we found increasing age and male sex to be significantly associated with increased risk of EOCRC, and aspirin use to be significantly associated with decreased risk; these factors also affect risk for CRC onset after age 50. Weight loss may be an early clinical sign of EOCRC. More intense efforts are required to identify the factors that cause EOCRC and signs that can be used to identify individuals at highest risk.

Metformin Is Associated With Reduced Odds for Colorectal Cancer Among Persons With Diabetes

INTRODUCTION

Metformin may be associated with reduced colorectal cancer (CRC) risk, but findings from previous studies have been inconsistent and had insufficient sample sizes to examine whether the association differs by anatomic site. This study examined whether metformin was associated with reduced CRC risk, both overall and stratified by anatomic site, in a large sample of persons with diabetes who underwent colonoscopy.

METHODS

We performed a case-control study of US Veterans with prevalent diabetes who underwent colonoscopy between 1999 and 2014 using Department of Veterans Affairs electronic health record data. Cases were defined by presence of CRC at colonoscopy, while controls had normal colonoscopy. The primary exposure was metformin use at time of colonoscopy (yes/no). Association of metformin exposure with CRC (further stratified by proximal, distal, or rectal subsite) was examined using multivariable and multinomial logistic regression and summarized by odds ratios (ORs) with 95% confidence intervals (CIs).

RESULTS

We included 6,650 CRC patients and 454,507 normal colonoscopy patients. CRC cases were older and had lower metformin exposure. Metformin was associated with 8% relative reduction in CRC odds (OR: 0.92, 95% CI: 0.87-0.96). By subsite, metformin was associated with a 14% statistically significant reduced rectal cancer odds (OR: 0.86, 95% CI: 0.78-0.94) but no reduced distal or proximal cancer odds.

DISCUSSION

Metformin was associated with reduced CRC odds-particularly rectal cancer-in a large sample of persons with diabetes undergoing colonoscopy.

Structured Approach for Evaluating Strategies for Cancer Ascertainment Using Large-Scale Electronic Health Record Data

PURPOSE

Cancer ascertainment using large-scale electronic health records is a challenge. Our aim was to propose and apply a structured approach for evaluating multiple candidate approaches for cancer ascertainment using colorectal cancer (CRC) ascertainment within the US Department of Veterans Affairs (VA) as a use case.

METHODS

The proposed approach for evaluating cancer ascertainment strategies includes assessment of individual strategy performance, comparison of agreement across strategies, and review of discordant diagnoses. We applied this approach to compare three strategies for CRC ascertainment within the VA: administrative claims data consisting of International Classification of Diseases, Ninth Revision (ICD9) diagnosis codes; the VA Central Cancer Registry (VACCR); and the newly accessible Oncology Domain, consisting of cases abstracted by local cancer registrars. The study sample consisted of 1,839,043 veterans with index colonoscopy performed from 1999 to 2014. Strategy-specific performance was estimated based on manual record review of 100 candidate CRC cases and 100 colonoscopy controls. Strategies were further compared using Cohen's κ and focused review of discordant CRC diagnoses.

RESULTS

A total of 92,197 individuals met at least one CRC definition. All three strategies had high sensitivity and specificity for incident CRC. However, the ICD9-based strategy demonstrated poor positive predictive value (58%). VACCR and Oncology Domain had almost perfect agreement with each other (κ, 0.87) but only moderate agreement with ICD9-based diagnoses (κ, 0.51 and 0.57, respectively). Among discordant cases reviewed, 15% of ICD9-positive but VACCR- or Oncology Domain-negative cases had incident CRC.

CONCLUSION

Evaluating novel strategies for identifying cancer requires a structured approach, including validation against manual record review, agreement among candidate strategies, and focused review of discordant findings. Without careful assessment of ascertainment methods, analyses may be subject to bias and limited in clinical impact.

Risk factors for colorectal cancer significantly vary by anatomic site

Objective

To conduct an anatomic site-specific case–control study of candidate colorectal cancer (CRC) risk factors.

Design

Case–control study of US veterans with >1 colonoscopy during 1999–2011. Cases had cancer registry-identified CRC at colonoscopy, while controls were CRC free at colonoscopy and within 3 years of colonoscopy. Primary outcome was CRC, stratified by anatomic site: proximal, distal, or rectal. Candidate risk factors included age, sex, race/ethnicity, body mass index, height, diabetes, smoking status, and aspirin exposure summarised by adjusted ORs and 95% CIs.

Results

21 744 CRC cases (n=7017 rectal; n=7039 distal; n=7688 proximal) and 612 646 controls were included. Males had significantly higher odds relative to females for rectal cancer (OR=2.84, 95% CI 2.25 to 3.58) than distal cancer (OR=1.84, 95% CI 1.50 to 2.24). Relative to whites, blacks had significantly lower rectal cancer odds (OR=0.88, 95% CI 0.82 to 0.95), but increased distal (OR=1.27, 95% CI 1.19 to 1.37) and proximal odds (OR=1.62, 95% CI 1.52 to 1.72). Diabetes prevalence was more strongly associated with proximal (OR=1.29, 95% CI 1.22 to 1.36) than distal (OR=1.15, 95% CI 1.08 to 1.22) or rectal cancer (OR=1.12, 95% CI 1.06 to 1.19). Current smoking was more strongly associated with rectal cancer (OR=1.81, 95% CI 1.68 to 1.95) than proximal cancer (OR=1.53, 95% CI 1.43 to 1.65) or distal cancer (OR=1.46, 95% CI 1.35 to 1.57) compared with never smoking. Aspirin use was significantly more strongly associated with reduced rectal cancer odds (OR=0.71, 95% CI 0.67 to 0.76) than distal (OR=0.85, 95% CI 0.81 to 0.90) or proximal (OR=0.91, 95% CI 0.86 to 0.95).

Conclusion

Candidate CRC risk factor associations vary significantly by anatomic site. Accounting for site may enable better insights into CRC pathogenesis and cancer control strategies.

A Framework for Leveraging "Big Data" to Advance Epidemiology and Improve Quality: Design of the VA Colonoscopy Collaborative

OBJECTIVE

To describe a framework for leveraging big data for research and quality improvement purposes and demonstrate implementation of the framework for design of the Department of Veterans Affairs (VA) Colonoscopy Collaborative.

METHODS

We propose that research utilizing large-scale electronic health records (EHRs) can be approached in a 4 step framework: 1) Identify data sources required to answer research question; 2) Determine whether variables are available as structured or free-text data; 3) Utilize a rigorous approach to refine variables and assess data quality; 4) Create the analytic dataset and perform analyses. We describe implementation of the framework as part of the VA Colonoscopy Collaborative, which aims to leverage big data to 1) prospectively measure and report colonoscopy quality and 2) develop and validate a risk prediction model for colorectal cancer (CRC) and high-risk polyps.

RESULTS

Examples of implementation of the 4 step framework are provided. To date, we have identified 2,337,171 Veterans who have undergone colonoscopy between 1999 and 2014. Median age was 62 years, and 4.6 percent (n = 106,860) were female. We estimated that 2.6 percent (n = 60,517) had CRC diagnosed at baseline. An additional 1 percent (n = 24,483) had a new ICD-9 code-based diagnosis of CRC on follow up.

CONCLUSION

We hope our framework may contribute to the dialogue on best practices to ensure high quality epidemiologic and quality improvement work. As a result of implementation of the framework, the VA Colonoscopy Collaborative holds great promise for 1) quantifying and providing novel understandings of colonoscopy outcomes, and 2) building a robust approach for nationwide VA colonoscopy quality reporting.

Replacing the Guaiac Fecal Occult Blood Test With the Fecal Immunochemical Test Increases Proportion of Individuals Screened in a Large Healthcare Setting

BACKGROUND & AIMS

The most commonly used noninvasive test for colorectal cancer (CRC) screening has been the guaiac fecal occult blood test (gFOBT). The fecal immunochemical test (FIT) detects CRC and colorectal polyps with higher levels of sensitivity than the gFOBT, and may be more acceptable to patients. However, the FIT has not replaced the gFOBT in many clinical settings. We analyzed data from a large healthcare system that replaced the gFOBT with the FIT to determine the effects on CRC screening.

METHODS

We conducted a retrospective observational study of 7898 patients at the Veterans' Administration San Diego Healthcare System, 50-75 years old, who were offered stool-based CRC screening as part of primary care March 2014 through January 2015. Test orders and results were extracted from electronic health records; we performed manual reviews of colonoscopy and pathology reports for Veterans with positive results from the tests. Our primary outcome was test completion within 1 year of order; secondary outcomes were positive results and detection of advanced neoplasia by diagnostic colonoscopy. The primary analysis used an intention-to-screen approach, which included all patients with test orders; as-screened analyses were also performed.

RESULTS

Among 7898 patients, 3236 had gFOBT and 4662 FIT orders. In the intention to screen analysis, a significantly higher proportion of subjects completed a FIT (42.6%) than a gFOBT (33.4%) (P < .001); advanced neoplasia was detected in a significantly higher proportion of subjects offered a FIT (0.79%) than a gFOBT (0.28%) (P = .003). The numbers needed to invite to achieve 1 additional completed test and identify 1 additional patient with advanced neoplasia were 11 and 196, respectively.

CONCLUSIONS

In a retrospective study of patients at a Veterans' administration healthcare system, replacing the gFOBT with the FIT increased the proportion of patients who completed CRC screening. Replacement of the gFOBT with the FIT should be strongly considered by all healthcare systems.

Abstract 281: Site specific risk factors for colorectal cancer

Background: Most studies of colorectal cancer (CRC) risk factors pool cases across anatomical sites, though tumor characteristics and embryologic origins differ. Our aim was to conduct a site-stratified (proximal, distal, rectal) case control study of candidate risk factors for CRC.

Methods: Our study base was US Veterans with &gt;1 colonoscopy 1999-2011. CRC cases at baseline colonoscopy were identified with the Veterans Affairs Central Cancer Registry. Controls had normal colonoscopy without biopsy, no history of CRC, and no CRC within 3 years of index colonoscopy. Age, sex, race/ethnicity, body mass index (BMI), diabetes, and smoking were considered candidate risk factors. Primary outcome was CRC, stratified by site. Site-specific odds ratios (OR) and 95% confidence intervals (CI) for each risk factor were computed with unadjusted and adjusted multinomial logistic regression models.

Results: We identified 21,739 CRC cases and 616,323 normal colonoscopy controls. For cases combined vs. controls, median age was 68 vs. 61 years, 98% vs. 95% were male, median BMI was 27.8 vs. 28.8 kg/m2, 28% vs. 24% had diabetes, and 25% vs. 29% were non-smokers; race/ethnicity was similar. Presence and strength of associations differed by risk factor and CRC site (Table). Smoking was more closely associated with rectal (OR=1.84) than proximal (OR=1.59) or distal cancer (OR=1.50). Diabetes was more closely associated with proximal than distal or rectal cancer (OR=1.28, 1.17 and 1.12, respectively). Blacks had reduced odds for rectal (OR=0.89), but increased odds for distal (OR=1.27) and particularly proximal cancer (OR=1.60) when compared to non-Hispanic whites. For males vs. females, odds of rectal was higher than distal or proximal cancer (OR=2.64, 1.95 and 1.32, respectively).

Conclusions: Presence and strength of association of cancer risk factors may differ by CRC site. Site should be a key consideration in future studies of CRC risk.

Table 1.Site specific risk factors for 21,739 CRC cases compared to 616,323 normal colonoscopy controlsAnatomic Site of CRC*Proximal (n=7,686)Distal (n=7,036)Rectal (n=7,017)Candidate Risk FactorOR (CI)OR (CI)OR (CI)Age, years†1.100 (1.096-1.103)1.065 (1.062-1.069)‡1.055 (1.051- 1.059)‡§Gender, male vs. female1.318 (1.080-1.608)1.950 (1.538-2.471)‡2.636 (2.006-3.463)‡Race/ethnicityBlack vs. non-Hispanic white1.596 (1.480-1.720)1.270 (1.167-1.381)‡0.886 (0.808-0.971)‡§Hispanic vs. non-Hispanic white1.291 (1.123-1.485)1.531 (1.337-1.753)1.219 (1.053-1.411)§Asian vs. non-Hispanic white0.872 (0.634-1.201)0.917 (0.662-1.272)0.556 (0.371-0.832)BMI, kg/m2†0.994 (0.988-1.000)1.005 (0.999-1.012)‡0.963 (0.957-0.970)‡§Diabetes, yes vs. no1.278 (1.196-1.366)1.170 (1.089-1.257)1.119 (1.038-1.207)‡SmokingCurrent vs. never1.594 (1.476-1.722)1.500 (1.383-1.627)1.837 (1.695-1.992)‡§Former vs. never0.997 (0.926-1.073)1.082 (1.001-1.171)1.085 (0.998-1.119)* Multinomial analyses adjusted for other risk factors, as well as year of colonoscopy, 1999-2011† by one unit increment‡ p&lt;0.05 when compared to proximal cancer§ p&lt;0.05 when compared to distal cancerCRC, colorectal cancer; BMI, body mass index.

Citation Format: Samir Gupta, Ranier Bustamante, Ashley Earles, Maria E. Martinez, Karen Messer, Christina D. Williams, Andrew J. Gawron, Tonya Kaltenbach, Lin Liu. Site specific risk factors for colorectal cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 281. doi:10.1158/1538-7445.AM2017-281

Tonsillectomy, adenoidectomy, and myringotomy in sickle cell disease: perioperative morbidity. Preoperative Transfusion in Sickle Cell Disease Study Group

PURPOSE

To compare the rates of perioperative morbidity of patients with sickle cell anemia who were randomly assigned to 2 preoperative transfusion regimens and to identify predisposing factors for perioperative complications.

PATIENTS AND METHODS

Investigators at 36 centers enrolled 118 patients who were scheduled to have elective surgery and agreed to randomization between 2 preoperative transfusion regimens. Forty-seven subjects were enrolled but not randomized, including 20 who were not transfused before surgery. Perioperative management was based on a prescribed care plan.

RESULTS

Tonsillectomy and/or adenoidectomy (TA) were performed on 136 persons, and 29 had myringotomy as their primary procedure. There were no differences in the frequency of complications between the randomized groups. The serious, non-transfusion complication rates for randomized patients were 32% (34 of 107) for TA and 36% (4 of 11) for myringotomy. A history of pulmonary disease was a predictor of postoperative sickle cell-related events for patients undergoing TA surgery.

CONCLUSIONS

The more intensive transfusion regimen did not result in fewer perioperative complications. The high frequency of complications emphasizes the need for anticipatory management of persons undergoing TA. A history of pulmonary disease identifies patients at increased risk for sickle cell-related events after TA surgery. Patients undergoing myringotomy have a low frequency of sickle cell-related events but a significant frequency of other serious perioperative complications.

Alloimmunization in sickle cell anemia and transfusion of racially unmatched blood

Transfusion therapy for sickle cell anemia is limited by the development of antibodies to foreign red cells. To evaluate the frequency and risk factors associated with such alloimmunization, we determined the transfusion history, red-cell phenotype, and development of alloantibodies in 107 black patients with sickle cell anemia who received transfusions. We compared the results with those from similar studies in 51 black patients with sickle cell disease who had not received transfusions and in 19 nonblack patients who received transfusions for other forms of chronic anemia. We assessed the effect that racial differences might have on the frequency of alloimmunization by comparing the red-cell phenotypes of patients and blood-bank donors (n = 200, 90 percent white). Although they received transfusions less frequently, 30 percent of the patients with sickle cell anemia became alloimmunized, in contrast to 5 percent of the comparison-group patients with other forms of anemia (P less than 0.001). Of the 32 alloimmunized patients with sickle cell anemia, 17 had multiple antibodies and 14 had delayed transfusion reactions. Antibodies against the K, E, C, and Jkb antigens accounted for 82 percent of the alloantibodies. Comparison of red-cell phenotypes in the three study groups (the patients with sickle cell anemia, the patients with other forms of anemia, and the blood donors) revealed statistically significant differences between the patients with sickle cell anemia and the donors but not between the patients with other forms of anemia and the donors. These differences are most likely racial. We conclude that alloimmunization is a common, clinically serious problem in sickle cell anemia and that it is partly due to racial differences between the blood-donor and recipient populations.

Newborn screening for sickle cell disease: effect on mortality

Newborn screening for sickle cell disease has been recommended as a method of decreasing patient mortality. However, its effectiveness in accomplishing this has not been reliably measured. To help determine the effectiveness, 10 years of experience in newborn screening have been summarized. The effects of early patient enrollment in a comprehensive treatment program on long-term morbidity and mortality are reported. From 1975 to 1985, 84,663 newborns were screened regardless of race or ethnic background. Bart's hemoglobin was present in 5%, hemoglobin AS in 2.6%, and hemoglobin AC in 0.75%. Excluding Bart's, approximately 3.6% of all newborns were carriers for hemoglobinopathy. Sickle cell disease occurred in 1:951 births (58 hemoglobin SS, 25 hemoglobin FSC, three hemoglobin S-beta +-thalassemia, and three hemoglobin S-beta O-thalassemia). In addition, one in every 4,233 newborns had a clinically significant thalassemia syndrome (eight hemoglobin FE, ten hemoglobin F only, two hemoglobin H). Compared with other newborn screening programs in California, (congenital hypothyroidism, 1:3,849; phenylketonuria 1:22,474, galactosemia 1:74,103), hemoglobinopathies are the most prevalent congenital disease. Eighty-one newborns with sickle cell disease were followed for 7.2 years. Patients experienced 513 hospitalizations, including 13 episodes of sepsis with or without meningitis and ten acute sequestration crises. The overall mortality rate for patients with sickle cell anemia diagnosed in the newborn period was 1.8%. In comparison, the clinical course of 64 patients with sickle cell anemia diagnosed after 3 months of age and followed for an average of 9.4 years was analyzed. Five of these patients died. In two of these, sickle cell anemia was diagnosed at the time of the death.(ABSTRACT TRUNCATED AT 250 WORDS)