Comparison of the participation rate between CT colonography and colonoscopy in screening population: a systematic review and meta-analysis of randomized controlled trials

[Colorectal cancer screening with virtual colonography]

BACKGROUND

Since 2003, a decline in the age-standardized incidence rates of colorectal cancer (CRC) has been observed in Germany. Nonetheless, one in eight cancer cases still affects the colon or rectum. The prognosis has improved, with the relative 5‑year survival rate for CRC being approximately 65%.

METHODS

This positive trend is probably a result of preventive measures introduced over the last 20 years. This could be further improved, however, as CRC can not only be detected early but in almost all cases also prevented through the identification of benign precursors. Less than half of all eligible individuals participate in screening via colonoscopy. This implies that further, possibly even imaging, screening test methods should be explored and offered. Studies have reported that virtual colonography techniques have a comparable accuracy to endoscopy of about 90% for polyp sizes larger than 5 mm. The data for computed tomography (CT) is more extensive than for magnetic resonance imaging (MRI).

CONCLUSION

Significant challenges are posed however by the fact that in Germany CT colonography (CTC) is not considered a viable screening option due to radiation protection concerns, and MRI screening is not an established screening method. Radiologists should be familiar with classification using the CT Colonography Reporting and Data System (C-RADS), which uses criteria such as CT density, morphology, size, and location for classification. C‑RADS classification follows the categories: C0 (inadequate study), C1 (normal), C2a (indeterminate), C2b (benign), C3 (suspicious), and C4 (malignant), as well as extracolonic categories E1/2 (no clinically significant findings), E3 (likely insignificant findings), and E4 (likely significant findings).

Effect of alverine citrate plus simethicone in colonoscopy: a randomized controlled trial

Colonoscopy is the standard procedure for screening, and surveillance of colorectal cancer, including the treatment for colonic lesions. Colonic spasm is an important problem from colonoscopy that affects both surgeons and patients. The spasm also might be the cause of longer cecal intubation time, difficulty of the procedure, and increased pain. Previous reports indicated that antispasmodic agents can decrease such symptoms. Therefore, we conducted this study to investigate the cecal intubation time of antispasmodic agents. A single blinded randomized controlled trial was conducted from 01/11/2020 to 31/08/2021. One hundred four patients were allocated to antispasmodic agent group and control group, in 1:1 ratio. The efficacy of median (range) cecal intubation time showed similar results of 5 (2, 14) and 5 (2, 15) minutes with no statistically significant difference. The mean scores of all domains i.e., pain, spasm, cleanliness, and difficulty were better in the antispasmodic agent group about 2.6 (1.4), 1.8 (0.8), 2.4 (0.9), and 2.0 (0.9), respectively, than control group but there were spasm and cleanliness showed statistically significant difference. Moreover, the satisfaction scores showed better efficacy in decreased spasm, decreased difficulty, and increased cleanliness than control group. Prescribing of antispasmodic drugs before colonoscopy might be the choice of treatment for the patients. The antispasmodic drugs will be beneficial to both of the patient and the doctor.

Acceptability of alternative technologies compared with faecal immunochemical test and/or colonoscopy in colorectal cancer screening: A systematic review

OBJECTIVE

Colorectal cancer (CRC) is the third most common cancer and the second largest cause of cancer-related death worldwide. Current CRC screening in various countries involves stool-based faecal immunochemical testing (FIT) and/or colonoscopy, yet public uptake remains sub-optimal. This review assessed the literature regarding acceptability of alternative CRC screening modalities compared to standard care in average-risk adults.

METHOD

Systematic searches of MEDLINE, EMBASE, CINAHL, Cochrane and Web of Science were conducted up to February 3rd, 2022. The alternative interventions examined were computed tomography colonography, flexible sigmoidoscopy, colon capsule endoscopy and blood-based biomarkers. Outcomes for acceptability were uptake, discomfort associated with bowel preparation, discomfort associated with screening procedure, screening preferences and willingness to repeat screening method. A narrative data synthesis was conducted.

RESULTS

Twenty-one studies met the inclusion criteria. Differences between intervention and comparison modalities in uptake did not reach statistical significance in most of the included studies. The findings do suggest FIT as being more acceptable as a screening modality than flexible sigmoidoscopy. There were no consistent significant differences in bowel preparation discomfort, screening procedure discomfort, screening preference and willingness to repeat screening between the standard care and alternative modalities.

CONCLUSION

Current evidence comparing standard colonoscopy and stool-based CRC screening with novel modalities does not demonstrate any clear difference in acceptability. Due to the small number of studies available and included in each screening comparison and lack of observed differences, further research is needed to explore factors influencing acceptability of alternative CRC modalities that might result in improvement in population uptake within different contexts.

Low-volume reduced bowel preparation regimen for CT colonography: a randomized noninferiority trial

PURPOSE

To determine whether the quality of a low-volume reduced bowel preparation (LV-RBP) for CT Colonography (CTC) is noninferior to full-volume reduced bowel preparation (FV-RBP) regimen.

METHODS

In this randomized controlled trial, consecutive participants referred for CTC were randomly assigned to receive LV-RBP (52.5 g of PMF104 in 500 mL of water) or FV-RBP (105 g of PMF104 in 1000 mL of water). Images were independently reviewed by five blinded readers who rated the quality of bowel preparation from 0 (best score) to 3 (worst score). The primary outcome was the noninferiority of LV-RBP to FV-RBP in the proportion of colonic segments scored 0 for cleansing quality, with noninferiority margin of 10%. Volume of residual fluids, colonic distension, lesions and polyps detection rates and patient tolerability were secondary outcomes.

RESULTS

From March 2019 to January 2020, 110 participants (mean age 65 years ± 14 [standard deviation]; 74 women) were allocated to LV-RBP (n = 55) or FV-RBP (n = 55) arms. There were 92% segment scored 0 in colon cleansing quality in LV-RBP and 94% in FV-RBP for prone scans, and 94% vs 92% for supine scans. Risk difference was - 2.1 (95% CI -5.9 to 1.7) and 1.5 (95% CI -2.4 to 5.4) for prone and supine positions, respectively. Residual fluids and colonic distension were also noninferior in LV-RBP. LV-RBP was associated with a lower number of evacuations during preparation (7 ± 5 vs 10 ± 6, p = 0.002).

CONCLUSION

The LV-RBP for CTC demonstrated noninferior quality of colon cleansing with improved gastrointestinal tolerability compared to FV-RBP regimen.

Colorectal Cancer Screening with Computed Tomography Colonography: Single Region Experience in Kazakhstan

Background/Aims

The aim of our study was to determine the efficacy of computed tomography colonography (CTC) in screening for colorectal cancer (CRC).

Methods

A total of 612 females and 588 males aged 45 to 75 years were enrolled in CTC screening. CTC was performed following standard bowel preparation and colonic insufflation with carbon dioxide. The main outcomes were the detection rate of CRC and advanced adenoma (AA), prevalence of colorectal lesions in relation to socio-demographic and health factors, and overall diagnostic performance of CTC.

Results

Overall, 56.5% of the 1,200 invited subjects underwent CTC screening. The sensitivity for CRC and AA was 0.89 and 0.97, respectively, while the specificity was 0.71 and 0.99, respectively. The prevalence of CRC and AA was 3.0% (18/593) and 7.1% (42/593), respectively, with the highest CRC prevalence in the 66-75 age group (≥12 times; odds ratio [OR], 12.11; 95% confidence interval [CI], 4.45-32.92). CRC and AA prevalence were inversely correlated with Asian descent, physical activity, and negative fecal immunochemical test results (OR=0.43; 95% CI, 0.22-0.83; OR=0.16; 95% CI, 0.04-0.68; OR=0.5; 95% CI, 0.07-3.85, respectively).

Conclusions

Our study revealed high accuracy of CTC in diagnosing colonic neoplasms, good compliance with CTC screening, and high detection rate of CRC.

What is the impact of CT colonography interpretation by advanced practitioner radiographers on delivery of the 28 day colorectal cancer target?

INTRODUCTION

CT Colonography (CTC) is an indicated test to assess the colon and rectum for evidence of polyps and neoplasms. The advanced practitioner radiographer (APR) is increasingly involved with the entirety of the radiology pathway including procedural modification, preliminary clinical evaluation (PCE) and multi-disciplinary team (MDT) meeting notification of high risk colonic pathologies.

METHODS

A retrospective audit of the Radiology Information System (RIS) was undertaken at a large secondary care centre, 12 months of data of 119 consecutive patients who had undergone CTC with summary coded reports of high risk pathology were included for analysis. Analysis of accuracy of procedural modification, PCE and impact of hypothesised earlier full radiological staging data being available for MDT discussions were measured and evaluated.

RESULTS

For high risk C4b studies, just 16.67% of colonic pathology was observed during the CTC study, rising to 79% during radiographer PCE. For likely colonic neoplasm C5a studies 86% of colonic pathology was observed during the CTC study, rising to 93% during radiographer PCE. Where subsequent CT chest staging was deemed necessary following CTC by the referring team, patients had a median wait of 34 days for completion CT chest scan staging.

CONCLUSION

This study supports the integration of the advanced practitioner radiographer into the entire radiological processes of a CTC, with time advantages apparent for both diagnostics, but also the decision to treat.

IMPLICATIONS FOR PRACTICE

Appropriately trained radiographers are able to support CTC services to ensure delivery of an effective two-week wait diagnostic service with direct MDT liaison.

Noninvasive strategies for colorectal cancer screening: opportunities and limitations

PURPOSE OF REVIEW

In the United States, only 67% of patients are up to date with colorectal cancer (CRC) screening. While colonoscopy is highly sensitive and specific for CRC and precursor lesion detection and removal, it is invasive, expensive and resource heavy. Hence, there is an unfulfilled need for multiple modality CRC screening that can improve current CRC screening rates and may be resource effective strategies when used in conjunction with a colonoscopy program. Our review highlights the complementary, often underutilized, noninvasive CRC screening methods with a focus on performance, risks, benefits, and recent updates.

RECENT FINDINGS

Studies demonstrate that fecal immunochemical testing (FIT) is superior to guaiac-based fecal occult blood tests for CRC screening. Studies show superiority of multitarget stool DNA test to FIT in sensitivity, though with concern for decreased specificity in setting of one-time tests. Technical advances continue to improve accuracy of colon capsule endoscopy. There are ongoing studies to characterize often difficult-to-detect high-risk lesions in computed tomography colonography. Septin 9 continues to have suboptimal accuracy for CRC screening, but has been shown to be associated with more advanced, invasive CRC stages.

SUMMARY

There are ongoing advances in noninvasive screening modalities for CRC; these should be considered as alternatives to colonoscopy in specific patient populations.

The choice and definition of summary measure for meta-analysis of clinical studies with binary outcomes: effect on clinical interpretation

Many systematic reviews and meta-analyses concern the effect of a healthcare intervention on a binary outcome i.e. occurrence (or not) of a particular event. Usually, the overall effect, pooled across all studies included in the meta-analysis, is summarised using the odds ratio (OR) or the relative risk (RR). Under most circumstances, it is obvious how to identify what should be considered as the event of interest-for example, death or a clinically important side-effect. However, on occasion it may not be clear in which "direction" the event should be specified-such as attendance (vs non-attendance) at cancer screening. Usually, this choice is not critical to the overall conclusion of the meta-analysis, but occasionally it can lead to differences in how the included studies are pooled, ultimately affecting the overall meta-analytic result, particularly when using RRs rather than ORs. In this commentary, we will explain this phenomenon in more detail using examples from the literature, and explore how analysts and readers can avoid some potential pitfalls.