Colonoscopy issues related to women

Magnetic endoscopic imaging in pediatric colonoscopy: A positive impact on procedure completion rate and procedure times

OBJECTIVES

To assess the impact of magnetic endoscopic imaging (MEI) on pediatric colonoscopy.

METHODS

We analyzed demographics, procedure completion, procedure times, complications, and whether or not MEI was used for all colonoscopies between April 27, 2023, and January 18, 2024. MEI was available for every case but used at the endoscopist's discretion. Attendings were surveyed on the frequency and duration of interventions during fellow-performed colonoscopies.

RESULTS

We analyzed 310 colonoscopies, 113 (36%) of which used MEI. The average patient age was 13.8 years (range 5 months to 23 years). For the aggregate sample and attending-performed cases, there were fewer males in the groups that used MEI (p < 0.01). There were no other statistically significant differences in demographics or procedure indication when MEI was used. Terminal ileum (TI) intubation rate was higher when MEI was used in the aggregate sample (p = 0.02) and for fellow-performed cases (p = 0.04). TI intubation times and total procedure times were quicker when MEI was used in the aggregate sample and in both strata of attending-performed cases and fellow-performed cases (p < 0.001). One complication was reported in an attending-performed case that did not use MEI. Of the 145 fellow-performed procedures, 98 (68%) had completed surveys, 36 (36%) of which used MEI. There was no statistically significant difference in the number (p = 0.89) or duration (p = 0.96) of attending interventions when MEI was used.

CONCLUSION

MEI use was associated with higher TI intubation rates, faster TI intubation, and shorter total procedure times. MEI may be a valuable adjunctive tool for pediatric endoscopists.

Unsedated or On-Demand Minimally Sedated Water-Aided Outpatient Colonoscopy in Colorectal Cancer Screening and Surveillance: A Step Forward or Backward? Experience from Daily Practice in a Regional (Nonacademic) Hospital

Background: By using optimal insertion techniques with water infusion and dynamic position changes, pain during colonoscopy is greatly reduced and the procedures can usually be performed without sedation. We investigated whether the excellent results with water-aided colonoscopy reported by experts are reproducible in daily practice in a regional hospital. Methods: During the year 2023, 500 consecutive outpatients 50-75 years old presenting for colorectal cancer screening and surveillance could choose between unsedated or on-demand minimally sedated colonoscopy, moderate sedation with midazolam, or deep sedation with propofol. A total of 57% opted for unsedated colonoscopy, and of those patients, 250 consecutive patients were included. The primary outcome was the feasibility of the procedure. Cecal intubation rate (CIR), pain scores, use of midazolam, and willingness to repeat future procedures in the same way were registered periprocedural. Additional outcomes were cecal intubation time (CIT), detection rate of lesions, polyp resection rate, rate of adequate bowel preparation, and volume of water aspirated during insertion. Results: 250 consecutive sedation-free or on-demand minimally sedated water-based colonoscopies were analyzed. The CIR was 98%. A total of 96.5% completed without sedation and 5% of the procedures were perceived as moderately painful, but none had severe pain. The willingness to repeat was 97%. The mean CIT was 8.2 min. Conclusions: Using water-aided insertion techniques, comfortable sedation-free, or on-demand minimally sedated colonoscopy in daily practice in a regional hospital is feasible in the vast majority of patients presenting for colorectal cancer screening and surveillance, and the willingness to repeat is very high.

Colonoscope "Looping" During Ileo-Colonoscopy in Children is Significantly Different to that Observed in Adult Practice

OBJECTIVES

Ileo-colonoscopy (IC) can be technically challenging because of unpredictable colonoscope loop formation. Aims of this study were to assess the risk of loop formation and to attempt to understand which factors were likely to predispose to which subtype of loop.

METHODS

Prospective study conducted on children referred for an IC at Sheffield Children's Hospital. Presence and type of loop was objectively assessed using the magnetic endoscope imaging tool.

RESULTS

Three hundred procedures were prospectively evaluated. Only 9% of paediatric ICs were loop-free. Alpha loops were the most common loop in children older than 5, whereas reverse alpha loops and a wider variety of complex and repetitive loops were observed in younger patients. Once a specific type of loop has formed, the risk of re-looping in a different way or in a different position of the colon is reduced. Left lateral starting position was found to increase the risk of reverse alpha loops and re-looping. Challenging loops, such as reverse alpha, were more frequent in males. Higher body mass index (BMI) was associated with an increased risk of alpha and deep transverse loops formation, while lower BMI with a higher incidence of reverse alpha and N loop. Loop formation did not prevent 100% ileal intubation.

CONCLUSIONS

This study represents the first attempt to describe loop formation according to patient characteristics in a large paediatric series. Further studies are needed in order to establish if these findings could be helpful in simplifying the execution of IC procedures in children and facilitate the learning curve during endoscopy training programs.

Efficacy and tolerability of colonoscopies in overweight and obese patients: Results from a national database on gastrointestinal endoscopic outcomes

Background and study aims  Gastroenterologists are encountering a rising number of obese patients requiring colonoscopy. Existing literature regarding colonoscopy outcomes in this population is scant and conflicting. We analyzed a nationwide cohort of patients to identify the effects of body mass index (BMI) on colonoscopy success, efficacy, and tolerability. Patients and methods  The Clinical Outcomes Research Initiative (CORI) endoscopic database was queried for all colonoscopies in adults between 2008-2014. Patients were stratified into four cohorts based on BMI classification for comparison. Multivariable analysis was performed to identify the effect of BMI on procedure outcome, efficacy and tolerability. Results  Of 41,401 procedures, 27,696 met study inclusion criteria. Of these, 49.4 % were performed for colorectal cancer screening, most commonly under anesthesia directed sedation. Patient discomfort was the reason for an incomplete colonoscopy in 18.7 % of all cases, and more frequent among the overweight and obese cohorts. An inadequate bowel preparation was most common in the class III obesity cohort. Compared to the normal BMI group, a BMI ≥ 30 and < 40 kg/m 2 was associated with an increased odds of an incomplete colonoscopy ( P  = 0.001for overweight, P  = 0.0004 for class I/II obesity), longer procedure ( P  < 0.05 for all) and poorer tolerance ( P  < 0.0001 for class I/II obesity, P  = 0.016 for class III obesity). Anesthesia-administered sedation was more commonly used than endoscopist directed sedation amongst the obese cohort compared with the normal BMI cohort ( P  < 0.0001). Conclusions  Endoscopists should consider the increased odds of incomplete colonoscopy, longer procedures, and poorer tolerance when performing colonoscopy in obese patients to improve clinical management and procedural outcome.

Cecal intubation time in screening colonoscopy

The time required to intubate the cecum varies. The aim of this study was to determine whether demographic and anthropometric factors, such as body mass index (BMI), percent body fat, muscle mass, and fat mass, affect the cecal intubation time (CIT) during complete colonoscopy.A retrospective chart review of 1229 patients (aged 40-80 years) was performed. These patients underwent average-risk screening colonoscopies performed by expert gastroenterologists at Health Check-up Center, Seoul National University Bundang Hospital, during a health check-up. We collected data on age, sex, BMI, percent body fat, muscle mass, fat mass, history of prior abdominal or pelvic surgery, CIT, and bowel preparation quality (Boston Bowel Preparation Scale [BBPS] score).Of the 1229 patients, 62% were men. The mean age was 55 years, and the mean BMI was 24 kg/m2. The median CIT was 5 min. The patients were categorized into two groups according to CIT: easy colonoscopy (CIT ≤ 10 min) and difficult colonoscopy (CIT > 10 min). In univariate analysis, CIT was prolonged by the following factors: older age, poor bowel preparation, lower BMI, lower percent body fat, and less fat mass. Multivariate analysis showed that anthropometric indices including BMI, percent body fat, muscle mass, and fat mass were not significant factors for CIT. Older age (≥ 70 years) (odds ratio [OR]: 2.272, 95% confidence interval [CI]: 1.056-4.890, P = .036) and poor bowel preparation (BBPS score ≤ 5) (OR: 3.817, 95% CI: 1.866-7.808, P = .000) were found to be correlated with difficult colonoscopy.Our study suggests that anthropometric indices including BMI, percent body fat, muscle mass, and fat mass are not associated with significantly different CIT. Furthermore, sex and prior abdominal or pelvic surgery are not useful factors for a prolonged CIT. Older age (≥ 70 years) and poor bowel preparation (BBPS score ≤ 5) are significant variables predicting the CIT of expert gastroenterologists.

A twelve-year study of the prevalence, risk factors and characteristics of interval colorectal cancers after negative colonoscopy

INTRODUCTION

The objective of our study was to describe and analyse the Post-Colonoscopy Colorectal Cancers (PCCRCs) and endoscopist performance-related risk factors in the Isère regional screening programme.

METHOD

This was a population-based retrospective cohort study between 2002-2013, where Post-Colonoscopy Colorectal Cancers (PCCRCs) were defined as colorectal adenocarcinoma diagnosed between six and sixty months post-colonoscopy following a positive gFOBT. We analysed the endoscopist performance-related risk factors of the 62 gastroenterologists who had carried out at least 30 colonoscopies during this period.

RESULTS

During the period reviewed, there were 10,557 negative colonoscopies performed. Fifteen post-colonoscopy colorectal cancers were diagnosed from 2002-2013 with an average patient age of 67.1 years. Men comprised 73% of the cases and 53% of all the cases were found in the distal colon. These 15 cases comprised 1.1% of all Colorectal Cancers (CRCs) diagnosed in the screening programme, with an incidence rate of 0.42 (0.21-0.77) per 1,000 person-years. The aetiological breakdown was as follows: 47% related to missed cancers, 27% were new cancers, 20% were failed biopsy detection, and 6% related to incomplete removal. The Adenoma Detection Rate (ADR) among gastroenterologists was an average of 30%, but large heterogeneity was present within this number, ranging from 11% to 49%.

CONCLUSION

The post-colonoscopy colorectal cancer prevalence and incident rate were low relative to the literature. However, significant heterogeneity was present in the adenoma detection rate. Decreasing this heterogeneity by establishing a national benchmark, regular performance feedback and training modules should homogenise adenoma detection rates and decrease the number of interval cancers in the region.

Index colonoscopy-related risk factors for postcolonoscopy colorectal cancers

BACKGROUND AND AIMS

Postcolonoscopy colorectal cancers (PCCRCs) are defined as those detected ≤10 years after an index colonoscopy negative for cancer, but modifiable risk factors are not well established in large, community-based populations.

METHODS

We evaluated risk factors from the index colonoscopy for PCCRCs diagnosed 1 to 10 years after an index colonoscopy using a case-control design. Odds ratios (OR) and 95% confidence intervals (CI) were adjusted for potential confounders.

RESULTS

A proximal polyp ≥10 mm (OR, 8.18; 95% CI, 4.59-14.60), distal polyp ≥10 mm (OR, 3.30; 95% CI, 1.65-6.58), adenoma with (OR, 3.23; 95% CI, 1.83-5.68) and without advanced histology (OR, 1.87; 95% CI, 1.37-2.55), and an incomplete colonoscopy (OR, 5.52; 95% CI, 2.98-10.21) were associated with PCCRC. Risk factors for early versus late cancers (12-36 months vs >36 months to 10 years after examination) included incomplete polyp excision in the colonic segment of the subsequent cancer (OR, 4.76; 95% CI, 2.35-9.65); failure to examine the segment (OR, 2.42; 95% CI, 1.27-4.60); and a polyp ≥10 mm in the segment (OR, 2.38; 95% CI, 1.53-3.70). A total of 559 of 1206 patients with PCCRC (46.4%) had 1 or more risk factors that were significant for PCCRC (incomplete examination, large polyp, or any adenoma).

CONCLUSIONS

In a large community-based study with comprehensive capture of PCCRCs, almost half of PCCRCs had potentially modifiable factors related to polyp surveillance or removal and examination completeness. These represent potential high-yield targets to further increase the effectiveness of colorectal cancer screening.

Differences between genders in colorectal morphology on CT colonography using a quantitative approach: a pilot study

PURPOSE

To explore quantitative differences between genders in morphologic colonic metrics and determine metric reproducibility.

METHODS

Quantitative colonic metrics from 20 male and 20 female CTC datasets were evaluated twice by two readers; all exams were performed after incomplete optical colonoscopy. Intra-/inter-reader reliability was measured with intraclass correlation coefficient (ICC) and concordance correlation coefficient (CCC).

RESULTS

Women had overall decreased colonic volume, increased tortuosity and compactness and lower sigmoid apex height on CTC compared to men (p<0.0001,all). Quantitative measurements in colonic metrics were highly reproducible (ICC=0.9989 and 0.9970; CCC=0.9945).

CONCLUSION

Quantitative morphologic differences between genders can be reproducibility measured.

Predictors for difficult cecal insertion in colonoscopy: The impact of obesity indices

AIM

To identify the factors influencing cecal insertion time (CIT) and to evaluate the effect of obesity indices on CIT.

METHODS

We retrospectively reviewed the data for participants who received both colonoscopy and abdominal computed tomography (CT) from February 2008 to May 2008 as part of a comprehensive health screening program. Age, gender, obesity indices [body mass index (BMI), waist-to-hip circumference ratio (WHR), waist circumference (WC), visceral adipose tissue (VAT) volume and subcutaneous adipose tissue (SAT) volume on abdominal CT], history of prior abdominal surgery, constipation, experience of the colonoscopist, quality of bowel preparation, diverticulosis and time required to reach the cecum were analyzed. CIT was categorized as longer than 10 min (prolonged CIT) and shorter than or equal to 10 min, and then the factors that required a CIT longer than 10 min were examined.

RESULTS

A total of 1678 participants were enrolled. The mean age was 50.42 ± 9.931 years and 60.3% were men. The mean BMI, WHR, WC, VAT volume and SAT volume were 23.92 ± 2.964 kg/m², 0.90 ± 0.076, 86.95 ± 8.030 cm, 905.29 ± 475.220 cm³ and 1707.72 ± 576.550 cm³, respectively. The number of patients who underwent abdominal surgery was 268 (16.0%). Colonoscopy was performed by an attending physician alone in 61.9% of cases and with the involvement of a fellow in 38.1% of cases. The median CIT was 7 min (range 2-56 min, IQR 5-10 min), and mean CIT was 8.58 ± 5.291 min. Being female, BMI, VAT volume and involvement of fellow were significantly associated with a prolonged CIT in univariable analysis. In multivariable analysis, being female (OR = 1.29, P = 0.047), lower BMI (< 23 kg/m²) (OR = 1.62, P = 0.004) or higher BMI (≥ 25 kg/m²) (OR = 1.80, P < 0.001), low VAT volume (< 500 cm³) (OR = 1.50, P = 0.013) and fellow involvement (OR = 1.73, P < 0.001) were significant predictors of prolonged CIT. In subgroup analyses for gender, lower BMI or higher BMI and fellow involvement were predictors for prolonged CIT in both genders. However, low VAT volume was associated with prolonged CIT in only women (OR = 1.54, P = 0.034).

CONCLUSION

Being female, having a lower or higher BMI than the normal range, a low VAT volume, and fellow involvement were predictors of a longer CIT.

Complete colonoscopy: impact of patients' demographics and anthropometry on caecal intubation time

Background and aim

Factors that affect caecal intubation during colonoscopy include age and sex of the patient, quality of bowel preparation, prior abdominal or pelvic surgery and pelvic inflammatory disease, among others. The aim of this prospective study was to evaluate the effects of patients' demography such as age and sex, as well as anthropometry (height, weight and body mass index (BMI)) on caecal intubation time (CIT).

Patients and methods

All consecutive patients referred for colonoscopy over a period of 6 months were recruited into the study. Prior to the procedure, patients' demographic data as well as history of prior abdominal or pelvic surgery were recorded. The height and weight of each patient were taken, and the BMI calculated. CIT was measured from the time of insertion of the colonoscope into the anal canal to the time when the base of the caecum was intubated.

Results

A total of 167 patients comprising 99 (59.3%) males and 68 (40.7%) females were studied. The mean CIT of the procedures was 912.5±477.1 s with a range of 180–3180 s. It was more prolonged in patients older than 65 years of age, in males and in those with prior abdominal/pelvic surgery, although no significant difference was observed among the groups. Multivariate logistic regression analysis showed that increased BMI and non-usage of additional manoeuvres independently reduced CIT.

Conclusions

Older age, male gender, prior abdominal/pelvic surgery, use of additional manoeuvres and lower BMI were found to prolong CIT.

Impact of hysterectomy on three-dimensional rectosigmoid morphology and endoscopy performance: a pilot study

OBJECTIVES

Assess differences in three-dimensional colonic metrics on CTC in women with or without hysterectomy following incomplete endoscopy to determine if there is a correlation between colonic morphology and incomplete colonoscopy after hysterectomy.

METHODS

Quantitative rectosigmoid metrics were derived from CTC datasets of 37 women with hysterectomy and 36 women without hysterectomy who underwent CTC for incomplete endoscopy. Evaluated metrics included colonic length, volume, tortuosity, and compactness and sigmoid apex height relative to the lumbosacral junction. Differences were measured using the Student's t test, and intra-reader reliability was assessed using ICC. The relative risk of incomplete rectosigmoid visualization was determined by reviewing the endoscopy reports.

RESULTS

Women with hysterectomy had a lower sigmoid apex height (p = 0.002), as well as increased tortuosity (p = 0.012) and compactness (p = 0.001) and decreased length (p = 0.026) and volume (p = 0.016) of the rectosigmoid. Intra-reader reliability was high for centerline length (ICC = 0.9940) and sigmoid apex height (ICC = 0.9851). The relative risk of incomplete visualization of the rectosigmoid on endoscopy in women with hysterectomy was 2.068 (p = 0.043) compared to women without hysterectomy.

CONCLUSION

Our pilot data show reproducible quantitative differences in three-dimensional metrics of the rectosigmoid in women with or without hysterectomy who underwent CTC for incomplete endoscopy and increased relative risk of incomplete endoscopic visualization of the rectosigmoid after hysterectomy. Our findings suggest that women with hysterectomy may benefit from CTC rather than endoscopy as the initial diagnostic test for evaluating the colon.

Interval Colorectal Cancer After Colonoscopy: Exploring Explanations and Solutions

There is good evidence that colorectal cancer (CRC) screening has been successful at reducing both CRC incidence and death. Colonoscopy, utilized as either a primary screening tool or a follow-up exam when other screening tests are positive, has significantly contributed to these encouraging trends. However, it is well recognized that colonoscopy is not perfectly sensitive for the detection of neoplasia and that CRC can be diagnosed within a short interval following a colonoscopy that did not detect one. The literature surrounding these cases has rapidly expanded over the last decade. Specifically, studies aimed at understanding the frequency of these events and the likely explanations for their occurrence have been performed. This review will highlight current knowledge around the epidemiology of interval post colonoscopy CRC (PCCRC). The common explanations for these cancers including missed lesions, new lesions, and incompletely resected lesions will be reviewed and their contribution to interval PCCRC estimated. Finally, the relationship of these putative explanations to potential opportunities to prevent interval PCCRC will be explored. Current approaches to prevention largely center on consistent adherence to quality colonoscopy standards. Future approaches include advances in technology to better visualize the colon and adequately resect detected neoplasia. Finally, improvement in training as well as development of a culture of continuous quality improvement will be essential to maximize the benefits of colonoscopy in daily clinical practice.

Difficult colonoscopy score identifies the difficult patients undergoing unsedated colonoscopy

Background

Many factors have been found to affect the difficulty of colonoscope insertion, such as age, gender, body mass index (BMI), history of abdominal surgery and operator etc. However, a scoring system may be more useful to predict the difficulty during colonoscopy.

Methods

The individual and procedure-related data of 616 patients undergoing colonoscopy were prospectively collected from December 2013 through February 2014 in Xijing Hospital of Digestive Diseases. Cox regression analysis was used to identify high-risk factors associated with difficulty of colonoscopy. A predicting model with the difficult colonoscopy score (DCS) was developed.

Results

Total cecum intubation rate was 98.9% (609/616). Advanced age, lower BMI, inexperienced operator and fair or poor sleep quality were identified as independent factors of prolonged insertion time (all p < 0.05), which were used to develop the DCS. Based on the score, patients could be divided into high-risk and low-risk groups with distinct incomplete rates within 10 min (42.0% vs. 16.5%, p < 0.001). Compared with those with DCS ≤ 1, patients with DCS > 1 had increased insertion time (10.6 ± 0.7 min vs. 6.9 ± 0.2 min, p < 0.001) and pain score (1.9 ± 1.5 vs. 1.4 ± 1.4, p = 0.002). More abdominal compression (36.9% vs. 16.8%, p < 0.001) and position change (51.4% vs. 22.6%, p < 0.001) were needed in this group of patients.

Conclusion

Patients with DCS > 1 had longer insertion time, higher pain score and needed more abdominal compression and position changes. DCS was useful for predicting the difficulty of colonoscope intubation.

(ClinicalTrials.gov NCT02105025 05/05/2014).

Electronic supplementary material

The online version of this article (doi:10.1186/s12876-015-0273-7) contains supplementary material, which is available to authorized users.

Pregnancy and maternal outcomes in women with prior or current gastrointestinal malignancies

OBJECTIVES

To review the fetal and maternal outcomes of women with a diagnosis of gastrointestinal (GI) cancer before or during pregnancy.

METHODS

We conducted a retrospective cohort study of pregnant women referred to a single tertiary care centre with a current or previous diagnosis of GI malignancy. Maternal, obstetric, and infant data were recorded.

RESULTS

We identified 18 pregnancies in 13 women. Nine women were found to have a GI malignancy during pregnancy (group 1). There was an indirect maternal death in this group in a woman with advanced gastric adenocarcinoma. Nine unique pregnancies occurred in eight women with diagnosis and management of GI malignancies before their pregnancies (group 2).

CONCLUSION

GI malignancies are difficult to diagnose and manage during pregnancy and are usually advanced at the time of diagnosis. Surgery can be performed during pregnancy if necessary, with chemotherapy and radiotherapy usually deferred to the postpartum period. Women who have had a prior GI malignancy have special circumstances related to the type of surgery performed and previous exposure to chemotherapy. These patients may benefit from a multidisciplinary team effort to optimize their care.

Prone positioning of obese patients for colonoscopy results in shortened cecal intubation times: a randomized trial

BACKGROUND

Obesity is a risk factor for colorectal cancer, and colonoscopy can be technically challenging in obese patients. It has been proposed (with little supporting data) that prone positioning of obese patients might facilitate a difficult colonoscopy.

AIM

The aim of this study was to determine if starting colonoscopy in the prone position for obese patients decreases cecal intubation times.

METHODS

This was a prospective, randomized study conducted at the North Texas VA Medical Center. Patients with a body mass index of ≥30 kg/m(2) undergoing elective colonoscopy were randomized 1:1 to either initial prone positioning or standard, left-lateral positioning. The outcome measurements were cecal intubation time, frequency of repositioning, sedative medications used, reports of pain, complications, and procedure tolerability.

RESULTS

Fifty patients were randomized to have colonoscopy starting in the standard, left-lateral decubitus position, and 51 to the prone position. The average cecal intubation time for the standard group was 550 vs. 424 s in the prone group (p = 0.03). Patient repositioning was used in 28 % of patients in the standard group versus 8 % in the prone group (p = 0.009). There was no difference in subjective reports of pain between groups (p = 0.95) or in average pain scores (p = 0.79). Follow-up interviews were conducted in 93 % of patients, all of whom said that they would be willing to have repeat colonoscopy in the same position.

CONCLUSIONS

Performance of colonoscopy in the prone position for obese patients results in significantly shorter cecal intubation times and decreased need for patient repositioning. Prone positioning is well accepted and does not significantly increase procedure-related discomfort.

Screening adherence for colorectal cancer among immigrant Hispanic women

PURPOSE

We sought to assess factors related to colorectal cancer (CRC) screening adherence among immigrant, Hispanic women in Harlem, New York City.

METHOD

Adherence for colonoscopy and fecal occult blood test (FQBT) screening was measured among 255 women based on self-reported screening behaviors using American Cancer Society guidelines.

RESULTS

Univariate results showed that age, language of the interview (English/Spanish), years in the United States, physician recommendation for either test, marital status (living alone/living with someone), and mammography adherence were associated with CRC screening adherence (p's < .05). In the multivariate analysis, having an age greater than 65 years, being interviewed in Spanish, having lived in the United States longer, having a regular doctor and a physician recommendation, and being currently adherent for mammography were associated with higher CRC screening adherence.

CONCLUSION

Among this sample, there proved to be differences between having ever been screened and adherence with a greater proportion of women having ever completed either colonoscopy and/or FOBT compared to women who were adherent (72.9% vs 58.8%). Therefore, it is important to determine factors associated with adherence, not just screening utilization, in order to design strategies to increase adherence among immigrant Hispanic women.

Predictors of colorectal cancer after negative colonoscopy: a population-based study

OBJECTIVES

A higher proportion of colorectal neoplasia among women occurs in the proximal colon, which might be more frequently missed by colonoscopy. There are no data on predictors of developing colorectal cancer (CRC) after a negative colonoscopy in usual clinical practice. We evaluated gender differences and predictors of CRC occurring after a negative colonoscopy.

METHODS

All individuals 40 years or older with negative colonoscopy were identified from Manitoba's provincial physicians' billing claims database. Individuals with less than 5 years of coverage by the provincial health plan, earlier CRC, inflammatory bowel disease, resective colorectal surgery, or lower gastrointestinal endoscopy were excluded. CRC risk after negative colonoscopy was compared to that in the general population by standardized incidence ratios. Cox regression analysis was performed to determine the independent predictors of CRC occurring after negative colonoscopy.

RESULTS

A total of 45,985 individuals (18,606 men; 27,379 women) were followed up for 229,090 person-years. After a negative colonoscopy, men had a 40-50% lower risk of CRC diagnosis through most of the follow-up time. Risk among women was similar to that of women in the general population in the first 3 years and then was 40-50% lower. Older subject age and performance of index colonoscopy by non-gastroenterologists were independent predictors for early/missed CRC (cancers occurring within 3 years of negative colonoscopy).

CONCLUSIONS

Women may have a higher rate of missed/early CRCs after negative colonoscopy. Predictors of missed/early CRCs after negative colonoscopy include older age and performance of index colonoscopy by a non-gastroenterologist.