Screening for Colorectal Cancer: Updated Evidence Report and Systematic Review for the US Preventive Services Task Force

IMPORTANCE

Colorectal cancer (CRC) remains a significant cause of morbidity and mortality in the US.

OBJECTIVE

To systematically review the effectiveness, test accuracy, and harms of screening for CRC to inform the US Preventive Services Task Force.

DATA SOURCES

MEDLINE, PubMed, and the Cochrane Central Register of Controlled Trials for relevant studies published from January 1, 2015, to December 4, 2019; surveillance through March 26, 2021.

STUDY SELECTION

English-language studies conducted in asymptomatic populations at general risk of CRC.

DATA EXTRACTION AND SYNTHESIS

Two reviewers independently appraised the articles and extracted relevant study data from fair- or good-quality studies. Random-effects meta-analyses were conducted.

MAIN OUTCOMES AND MEASURES

Colorectal cancer incidence and mortality, test accuracy in detecting cancers or adenomas, and serious adverse events.

RESULTS

The review included 33 studies (n = 10 776 276) on the effectiveness of screening, 59 (n = 3 491 045) on the test performance of screening tests, and 131 (n = 26 987 366) on the harms of screening. In randomized clinical trials (4 trials, n = 458 002), intention to screen with 1- or 2-time flexible sigmoidoscopy vs no screening was associated with a decrease in CRC-specific mortality (incidence rate ratio, 0.74 [95% CI, 0.68-0.80]). Annual or biennial guaiac fecal occult blood test (gFOBT) vs no screening (5 trials, n = 419 966) was associated with a reduction of CRC-specific mortality after 2 to 9 rounds of screening (relative risk at 19.5 years, 0.91 [95% CI, 0.84-0.98]; relative risk at 30 years, 0.78 [95% CI, 0.65-0.93]). In observational studies, receipt of screening colonoscopy (2 studies, n = 436 927) or fecal immunochemical test (FIT) (1 study, n = 5.4 million) vs no screening was associated with lower risk of CRC incidence or mortality. Nine studies (n = 6497) evaluated the test accuracy of screening computed tomography (CT) colonography, 4 of which also reported the test accuracy of colonoscopy; pooled sensitivity to detect adenomas 6 mm or larger was similar between CT colonography with bowel prep (0.86) and colonoscopy (0.89). In pooled values, commonly evaluated FITs (14 studies, n = 45 403) (sensitivity, 0.74; specificity, 0.94) and stool DNA with FIT (4 studies, n = 12 424) (sensitivity, 0.93; specificity, 0.85) performed better than high-sensitivity gFOBT (2 studies, n = 3503) (sensitivity, 0.50-0.75; specificity, 0.96-0.98) to detect cancers. Serious harms of screening colonoscopy included perforations (3.1/10 000 procedures) and major bleeding (14.6/10 000 procedures). CT colonography may have harms resulting from low-dose ionizing radiation. It is unclear if detection of extracolonic findings on CT colonography is a net benefit or harm.

CONCLUSIONS AND RELEVANCE

There are several options to screen for colorectal cancer, each with a different level of evidence demonstrating its ability to reduce cancer mortality, its ability to detect cancer or precursor lesions, and its risk of harms.

Hiatal hernia after robotic-assisted coronary artery bypass graft surgery

Background

The aim of the present study is to determine the incidence/progression of hiatal hernia (HH) after robotic-assisted coronary artery bypass grafting (RA-CABG) surgery.

Methods

We reviewed the pre- and post-operative computed tomography (CT) of 491 patients who underwent RA-CABG between 2000 and 2017. Post-operative CT was acquired prospectively in a research protocol. CT was reviewed to assess the presence and the size of HH.

Results

We found 444/491 (90.4%) had pre-operative CT, while 201/491 (40.9%) had post-operative CT. In total, 155/491 (31.6%) had both pre- and long-term post-operative CT with a mean follow-up of 6.2 (±3.5) years. HH was more prevalent on post-operative CT, 64/155 (41.3%) compared to pre-operative CT, 44/155 (28.4%), P<0.0001. The diameter of pre-existing HH 2.8 (±1.8) cm was significantly greater after surgery 3.9 (±2.5) cm, P<0.0001. As well the volume of the pre-existing HH 5.8 (4.4-9.2) mL (quartile) was significantly greater after surgery 14.1 (7.2-64.9) mL, P<0.0001. 20/155 (12.9%) had a newly developed HH after RA-CABG. A binary multivariate regression including HH risk factors showed that male gender is a predictor of developing a HH after RA-CABG with Hazard Ratio of 3.038, confidence interval (1.10-8.43), P=0.033.

Conclusions

RA-CABG is associated with an increased risk of developing HH and increases the size of pre-existing HH.

The predictive value of computed tomography in the detection of reflux esophagitis in patients undergoing upper endoscopy

BACKGROUND

Reflux esophagitis (RE) may mimic symptoms requiring cross-sectional imaging.

METHODS

From 565 patients who had CT and esophagogastroduodenoscopy within four days apart, CT scans of 72 patients with RE confirmed by esophagogastroduodenoscopy and 108 matched patients without RE were evaluated for distal esophageal wall characteristics.

RESULTS

In RE patients the distal esophageal wall thickness was greater (5.2±2.0mm) compared to patients without RE (3.5±1.2mm, p<0.0001) with AUC of 0.78 and 56% sensitivity, 88% specificity for a 5.0mm cut-off.

CONCLUSIONS

There is a moderate association between distal esophageal wall thickness on CT and RE diagnosed by esophagogastroduodenoscopy as the reference standard.

Hiatal Hernia on Chest High-Resolution Computed Tomography and Exacerbation Rates in COPD Individuals

Background: Gastroesophageal reflux disease (GERD) is associated with frequent chronic obstructive pulmonary disease (COPD) exacerbations. Hiatal hernia (HH) contributes to GERD pathogenesis and is identifiable on chest high-resolution computed tomography (HRCT). We hypothesize that the presence of an HH on HRCT identifies those at increased risk for acute exacerbation of COPD. Methods: We retrospectively reviewed a prospectively enrolled cohort of smokers with and without airflow obstruction. HHs were identified visually on inspiratory HRCT. Individuals' demographic and clinical information was compared with secondary analysis performed using a propensity score generated matched cohort. Results: There were 523 COPD individuals and 607 unobstructed smokers. COPD individuals had more HHs than unobstructed smokers, (11.6% versus 6.1%, p < 0.001). COPD individuals with hernias were older, female, overweight and GERD positive as compared to those without hernia. There was no difference in self-reported exacerbation rates or hospitalizations per year, but similar severity of obstruction, smoking rates and long-term oxygen use. Analysis with the matched cohort revealed no significant difference in exacerbation rates. Conclusions: Presence of HHs on inspiratory HRCT scan did not predict worse symptoms or exacerbation rate in COPD individuals. Those with HHs were older, more obese, and predominantly female compared to those without HHs.