Postoperative three-dimensional endoanal ultrasound findings and relation to anal fistula plug failure.

OBJECTIVES: To explore the utilization of three-dimensional (3D) endoanal ultrasound (EAUS) for the follow-up of the anal fistula plug (AFP), describe morphological findings in postoperative 3D EAUS, and evaluate if postoperative 3D EAUS combined with clinical symptoms can predict AFP failure. MATERIALS AND METHODS: A retrospective analysis of 3D EAUS examinations performed during a single-centre study of prospectively included consecutive patients treated with the AFP between May 2006 and October 2009. Postoperative assessment by clinical examination and 3D EAUS was performed at 2 weeks, 3 months and 6-12 months ("late control"). Long-term follow-up was carried out in 2017. The 3D EAUS examinations were blinded and analysed by two observers using a protocol with defined relevant findings for different follow-up time points. RESULTS: A total of 95 patients with a total of 151 AFP procedures were included. Long-term follow-up was completed in 90 (95%) patients. Inflammation at 3 months, gas in fistula and visible fistula at 3 months and at late control, were statistically significant 3D EAUS findings for AFP failure. The combination of gas in fistula and clinical finding of fluid discharge through the external fistula opening 3 months postoperatively was statistically significant (p < 0.001) for AFP failure with 91% sensitivity and 79% specificity. The positive predictive value was 91%, while the negative predictive value was 79%. CONCLUSIONS: 3D EAUS may be utilized for the follow-up of AFP treatment. Postoperative 3D EAUS at 3 months or later, especially if combined with clinical symptoms, can be used to predict long-term AFP failure.ClinicalTrials.gov identifier NCT03961984.

Long-term outcome of the Surgisis® (Biodesign® ) anal fistula plug for complex cryptoglandular and Crohn's fistulas.

AIM: To evaluate the long-term success rate of treatment with the Surgisis® (Biodesign® ) anal fistula plug for complex anal fistulas, assess fistula plug failure over time and compare success rates for fistula plug between a group of patients with cryptoglandular fistula and another group with Crohn's fistula. METHOD: This is a single-centre study of consecutive patients treated with the Surgisis® (Biodesign® ) anal fistula plug between May 2006 and October 2009. All patients had complex anal fistulas in need of surgical treatment. The patients were assessed preoperatively by physical examination and three-dimensional (3D) endoanal ultrasound, and treated with a loose seton. Postoperative assessment by clinical examination and 3D endoanal ultrasound was performed at 2 weeks, 3 months and 6-12 months. Long-term follow-up was carried out in 2017 using a questionnaire, and clinical examination combined with 3D endoanal ultrasound was performed if the questionnaire indicated any signs of fistula recurrence. RESULTS: A total of 95 patients were included; 30 had quiescent Crohn's disease. Overall, 151 plug procedures were performed. Long-term follow-up was undertaken in 90 (95%) patients; the results showed that after a median period of 110 months, the overall healing rate after one to five plug procedures was 38%. No statistically significant difference in success rate was found between the cryptoglandular fistula group and the Crohn's fistula group (P = 0.37). No further healing was observed after the use of three plugs. CONCLUSION: Considering its low morbidity in a complex disease with high recurrence rates over time, the anal fistula plug may still be considered as one of the first-line treatments for patients with complex anal fistulas.

High nuclear RBM3 expression is associated with an improved prognosis in colorectal cancer.

PURPOSE: In this study, we investigated the prognostic impact of human RBM3 expression in colorectal cancer using tissue microarray-based immunohistochemical analysis. EXPERIMENTAL DESIGN: One polyclonal antibody and four monoclonal anti-RBM3 antibodies were generated and epitope mapped using two different methods. Bacterial display revealed five distinct epitopes for the polyclonal antibody, while the four mouse monoclonal antibodies were found to bind to three of the five epitopes. A peptide suspension bead array assay confirmed the five epitopes of the polyclonal antibody, while only one of the monoclonal antibodies could be mapped using this approach. Antibody specificity was confirmed by Western blotting and immunohistochemistry, including siRNA-mediated knock-down. Two of the antibodies (polyclonal and monoclonal) were subsequently used to analyze RBM3 expression in tumor samples from two independent colorectal cancer cohorts, one consecutive cohort (n=270) and one prospectively collected cohort of patients with cancer of the sigmoid colon (n=305). RBM3-expression was detected, with high correlation between both antibodies (R=0.81, p<0.001). RESULTS: In both cohorts, tumors with high nuclear RBM3 staining had significantly prolonged the overall survival. This was also confirmed in multivariate analysis, adjusted for established prognostic factors. CONCLUSION AND CLINICAL RELEVANCE: These data demonstrate that high tumor-specific nuclear expression of RBM3 is an independent predictor of good prognosis in colorectal cancer.

Effects of radiation therapy on tissue and serum concentrations of tumour associated trypsin inhibitor and their prognostic significance in rectal cancer patients.

BACKGROUND: We have previously demonstrated that elevated concentrations of tumour-associated trypsin inhibitor (TATI) in both tumour tissue (t-TATI) and in serum (s-TATI) are associated with a poor prognosis in colorectal cancer patients. It was also found that s-TATI concentrations were lower in patients with rectal cancer compared to patients with colon cancer. In this study, we investigated the effects of neoadjuvant radiotherapy (RT) on concentrations of t-TATI and s-TATI in patients with rectal cancer. METHODS: TATI was analysed in serum, normal mucosa and tumour tissue collected at various time points in 53 rectal cancer patients enrolled in a case-control study where 12 patients received surgery alone, 20 patients 5 × 5 Gy (short-term) preoperative RT and 21 patients 25 × 2 Gy (long-term) preoperative RT. T-TATI was analysed by immunohistochemistry and s-TATI was determined by an immunofluorometric assay. Mann-Whitney U test and Wilcoxon Z (Z) test were used to assess t-TATI and s-TATI concentrations in relation to RT. Spearman's correlation (R) test was used to explore the associations between t-TATI, s-TATI and clinicopathological parameters. Overall survival (OS) according to high and low t-TATI and s-TATI concentrations was estimated by classification and regression tree analysis, Kaplan-Meier analysis and the log rank test. RESULTS: RT did not affect concentrations of t-TATI or s-TATI. In patients receiving short-term but not long-term RT, s-TATI concentrations were significantly higher 4 weeks post surgery than in serum drawn prior to surgery (Z = -3.366, P < 0.001). T-TATI expression correlated with male gender (R = 0.406, P = 0.008). High t-TATI expression in surgical specimens was associated with a significantly shorter OS (P = 0.045). S-TATI concentrations in serum drawn at all time points were associated with an impaired OS (P = 0.035 before RT, P = 0.001 prior to surgery, P = 0.043 post surgery). At all time points, s-TATI correlated with higher age (P < 0.001-0.021) and with increased s-creatinine concentrations assessed prior to surgery (P = 0.041). CONCLUSIONS: The results presented here further validate the utility of t-TATI and s-TATI as prognostic biomarkers in patients with rectal cancer, independent of neoadjuvant RT.

SATB2 in combination with cytokeratin 20 identifies over 95% of all colorectal carcinomas.

The special AT-rich sequence-binding protein 2 (SATB2), a nuclear matrix-associated transcription factor and epigenetic regulator, was identified as a tissue type-specific protein when screening protein expression patterns in human normal and cancer tissues using an antibody-based proteomics approach. In this respect, the SATB2 protein shows a selective pattern of expression and, within cells of epithelial lineages, SATB2 expression is restricted to glandular cells lining the lower gastrointestinal tract. The expression of SATB2 protein is primarily preserved in cancer cells of colorectal origin, indicating that SATB2 could function as a clinically useful diagnostic marker to distinguish colorectal cancer (CRC) from other types of cancer. The aim of this study was to further explore and validate the specific expression pattern of SATB2 as a clinical biomarker and to compare SATB2 with the well-known cytokeratin 20 (CK20). Immunohistochemistry was used to analyze the extent of SATB2 expression in tissue microarrays with tumors from 9 independent cohorts of patients with primary and metastatic CRCs (n=1882). Our results show that SATB2 is a sensitive and highly specific marker for CRC with distinct positivity in 85% of all CRCs, and that SATB2 and/or CK20 was positive in 97% of CRCs. In conclusion, the specific expression of SATB2 in a large majority of CRCs suggests that SATB2 can be used as an important complementary tool for the differential diagnosis of carcinoma of unknown primary origin.

Combination of pre-operative radiotherapy and surgery suppresses local accumulation of collagen and TGF-beta1 in rats.

BACKGROUND: The systemic and local tissue repair responses of radiation in combination with surgery are still unclear. We have studied the effect of fractionated pre-operative radiotherapy with or without subsequent laparotomy on collagen accumulation using a rodent model. MATERIALS AND METHODS: Thirty-two male Sprague-Dawley rats were divided into four groups (eight rats per group): 1) sham radiation and sham laparotomy (control); 2) sham radiation and laparotomy; 3) radiation and sham laparotomy; and 4) radiation followed by laparotomy. Expanded polytetrafluoroethylene (ePTFE) tubes were implanted subcutaneously in the abdominal wall in the radiotherapy field and on the back outside the radiotherapy field day 0. The abdomen (3 cm x 4 cm) was irradiated day 3 (10 Gy) and again day 7 (10 Gy). On day 10, implants were extirpated, laparotomy undertaken in groups 2 and 4 and new ePTFE tubes implanted subcutaneously. The second implants were extirpated on day 20. Implants were analyzed for hydroxyproline, total protein and transforming growth factor-beta1 (TGF-beta1) levels. RESULTS: On day 10, hydroxyproline (P < 0.05) and TGF-beta1 (P < 0.001) were lower in ePTFE tubes in irradiated compared with non-irradiated rats. On day 20, the abdominal ePTFE hydroxyproline remained low (P < 0.001) in animals subjected to laparotomy and pre-operative irradiation while hydroxyproline levels of rats subjected to irradiation only were similar to controls. The effects of radiation on hydroxyproline were confined to the irradiated abdominal area. There was a positive correlation between hydroxyproline and TGF-beta1 levels in the abdominal wall implant day 20 (r = 0.53, P < 0.005). CONCLUSION: A clinically relevant fractionated radiation scheme reduced subcutaneous collagen accumulation pre-operatively and profoundly within the radiation field post-operatively after laparotomy, possibly because of lowered TGF-beta1 levels.