β6 -integrin serves as a novel serum tumor marker for colorectal carcinoma

Colorectal cancer (CRC) is one of the leading causes of cancer-related deaths worldwide and the need for novel biomarkers and therapeutic strategies to improve diagnosis and surveillance is obvious. This study aims to identify β₆ -integrin (ITGB6) as a novel serum tumor marker for diagnosis, prognosis, and surveillance of CRC. ITGB6 serum levels were validated in retro- and prospective CRC patient cohorts. ITGB6 serum levels were analyzed by ELISA. Using an initial cohort of 60 CRC patients, we found that ITGB6 is present in the serum of CRC, but not in non-CRC control patients. A cut-off of ≥2 ng/mL ITGB6 reveals 100% specificity for the presence of metastatic CRC. In an enlarged study cohort of 269 CRC patients, ITGB6 predicted the onset of metastatic disease and was associated with poor prognosis. Those data were confirmed in an independent, prospective cohort consisting of 40 CRC patients. To investigate whether ITGB6 can also be used for tumor surveillance, serum ITGB6-levels were assessed in 26 CRC patients, pre- and post-surgery, as well as during follow-up visits. After complete tumor resection, ITGB6 serum levels declined completely. During follow-up, a new rise in ITGB6 serum levels indicated tumor recurrence or the onset of new metastasis as confirmed by CT scan. ITGB6 was more accurate for prognosis of advanced CRC and for tumor surveillance as the established marker carcinoembryonic antigen (CEA). Our findings identify ITGB6 as a novel serum marker for diagnosis, prognosis, and surveillance of advanced CRC. This might essentially contribute to an optimized patient care.

[Functional gastrointestinal disorders]

Functional gastrointestinal complaints are very common in daily clinic practice. Functional gastrointestinal disorders are characterized in disturbances of motility patterns and/or of visceral hypersensitivity. The main functional gastrointestinal disorders are functional dyspepsia and irritable bowel syndrome. There is no causative therapy, but we have many medication and also non-medication therapeutic options which all can be tried on an indivual basis.

Assessment of Obstructive Defecation by High-Resolution Anorectal Manometry Compared With Magnetic Resonance Defecography

BACKGROUND & AIMS

Patients with obstructive defecation have abnormalities of anorectal function and/or structure. Conventional anorectal manometry (ARM) can identify abnormal function and behavior (dyssynergia); however, agreement between manometry and defecography is only fair. High-resolution (HR)-ARM may improve diagnostic agreement by differentiating pressure effects caused by dyssynergia and obstruction. We compared HR-ARM findings with magnetic resonance (MR) defecography in the clinical assessment of patients with symptoms of obstructive defecation defined by Rome III criteria.

METHODS

HR-ARM (Manoscan AR 360; Given Imaging, Yoqeam, Israel) assessed anal sphincter function and pressure during simulated defecation. Abnormal manometric findings were classified according to the Rao system and compared with MR defecography as the reference standard.

RESULTS

A total of 188 consecutive patients (155 women; age, 19-93 y) with obstructive defecation underwent a full investigation. Compared with patients with dyssynergia on MR imaging (n = 66), patients with structural pathology (n = 87) had lower resting (P < .003) and squeeze pressures (P < .011), but a higher rectoanal pressure gradient (P < .0001) on HR-ARM. High intrarectal pressure with a steep, positive pressure gradient consistent with outlet obstruction on HR-ARM was present in 24 patients with intra-anal intussusception on MR imaging. This pattern was not observed in other patients. Interobserver agreement was substantial for HR-ARM diagnoses (κ = 0.67; 95% confidence interval, 0.559-0.779). Diagnostic accuracy for dyssynergia was 82% compared with MR imaging (sensitivity, 77% [51 of 66]; specificity, 85% [104 of 122]).

CONCLUSIONS

The diagnostic agreement between anorectal HR-ARM and MR defecography is high and pressure measurements accurately identify recto-anal dyssynergia and intra-anal outlet obstruction by structural pathology as causes of obstructive defecation.

Toward more accurate measurements of anorectal motor and sensory function in routine clinical practice: validation of high-resolution anorectal manometry and Rapid Barostat Bag measurements of rectal function

BACKGROUND

Measurements of anorectal function using high-resolution anorectal manometry (HR-ARM) and rectal barostat technology provide more reliable results than standard ARM with an elastic balloon; however, HR-ARM results have not been compared to ARM and standard barostat protocols are impractical in routine clinical practice. The aim of this study was to validate HR-ARM against standard ARM and standard barostat against a novel Rapid Barostat Bag (RBB) measurement and elastic balloon measurements of rectal function.

METHODS

Twenty-six healthy volunteers (15 female, 11 male, 19-52 years) were studied. Measurements of anal function and simulated defecation were compared for 12-sensor HR-ARM and 6-sensor standard ARM using line plots from the same recording. Rectal capacity, compliance, and sensation (volume threshold) were measured by elastic balloon, standard barostat, and RBB methods using stepwise inflation of a 700-mL polyethylene bag to 40 mmHg distension by electronic barostat and handheld syringe monitored by sphygmo-manometer, respectively. Results are reported as mean ± SD. Bland-Altman plots and correlation coefficients (r) for measurements were calculated.

KEY RESULTS

There was excellent agreement between HR- and standard ARM measurements (r > 0.86, <25 mmHg difference) and between standard barostat and RBB measurements of rectal capacity (r = 0.97, <25 mL difference). Correlation coefficients of threshold volumes for initial perception, urgency and discomfort were 0.37, 0.71, and 0.95, respectively. No significant correlation was present with elastic balloon measurements. Time to complete studies was shorter for HR-ARM than standard ARM and for RBB than standard barostat in historical controls.

CONCLUSIONS & INFERENCES

HR-ARM with RBB measurements of anorectal function provides quick and reasonably accurate measurements of continence function suitable for use in routine clinical practice (ClinicalTrial.gov NCT01456442).