Predictive factors of first-time failure on the American Board of Colorectal Surgery certifying and qualifying examinations

Objective

To discover if first-attempt failure of the American Board of Colon and Rectal Surgery (ABCRS) board examination is associated with surgical training or personal demographic characteristics.

Methods

Current colon and rectal surgery program directors in the United States were contacted via email. Deidentified records of trainees from 2011 to 2019 were requested. Analysis was performed to identify associations between individual risk factors and failure on the ABCRS board examination on the first attempt.

Results

Seven programs contributed data, totaling 67 trainees. The overall first-time pass rate was 88% (n = 59). Several variables demonstrated potential for association, including Colon and Rectal Surgery In-Training Examination (CARSITE) percentile (74.5 vs 68.0, P = 0.09), number of major cases in colorectal residency (245.0 vs 219.2, P = 0.16), >5 publications during colorectal residency (75.0% vs 25.0%, P = 0.19), and first-time passage of the American Board of Surgery certifying examination (92.5% vs 7.5%, P = 0.18).

Conclusion

The ABCRS board examination is a high-stakes test, and training program factors may be predictive of failure. Although several factors showed potential for association, none reached statistical significance. Our hope is that by increasing our data set, we will identify statistically significant associations that can potentially benefit future trainees in colon and rectal surgery.

Abstract 3481: A local tumor microenvironment acquired super-enhancer induces an oncogenic driver in colorectal carcinoma

Tumors exhibit widespread enhancer landscape reprogramming compared to normal tissue. The etiology is believed to be largely cell-intrinsic in non-hormonal cancers, attributed to such genomic alterations as focal amplification of non-coding regions, aberrant activation of transcription factors, and non-coding mutations creating de novo transcription factor binding sites. Here, using freshly resected primary CRC tumors and patient-matched adjacent normal colon epithelia, we find divergent epigenetic landscapes between primary CRC tumors and CRC cell lines. We identify a unique super-enhancer signature largely absent in cell culture. Intriguingly, this phenomenon extends to highly recurrent aberrant super-enhancers gained in CRC over patient-matched normal epithelium suggesting novel insight into the etiology of enhancer reprogramming in CRC and its downstream relevance to tumor biology. We find one such super-enhancer activated in epithelial cancer cells due to surrounding inflammation in the tumor microenvironment. CRISPR-dcas9-KRAB interference of this super-enhancer identifies PDZK1IP1 as its target gene. PDZK1IP1 is previously observed to be highly up-regulated in CRC. However, the mechanism behind its transcriptional activation is not fully understood. We restore both the super-enhancer and PDZK1IP1 levels following treatment with cytokines or xenotransplantation into nude mice, thus demonstrating its etiology via local tumor microenvironment acquisition. Deletion of inflammatory transcription factors RELA and STAT3 in human CRC cells inhibits PDZK1IP1 induction in xenografts. PDZK1IP1 appears to be critical for CRC growth in the setting of its super-enhancer induction as xenografts, but not in cell culture where the super-enhancer is absent and expression is largely silent. Building on its known role in glucose uptake via SGLT receptors, we demonstrate mechanistically that PDZK1IP1 enhances the reductive capacity CRC cancer cells via the pentose phosphate pathway using polar metabolomic profiling. We show this activation enables efficient growth under oxidative conditions both in vitro and in vivo, challenging the previous notion that PDZK1IP1 acts as a tumor suppressor in CRC. Collectively, these observations highlight the biologic significance of epigenomic profiling on patient-matched primary specimens and identify this microenvironment-acquired super-enhancer as an oncogenic driver in the setting of the inflamed tumor.

Citation Format: Royce Zhou, Jia Xu, Tiphaine Martin, Alexis Zachem, John He, Sait Ozturk, Deniz Demircioglu, Ankita Bansal, Andrew Trotta, Bruno Giotti, Berkley Gryder, Yao Shen, Saul Carcamo, Xuewei Wu, Kaitlyn Bosch, Benjamin Hopkins, Alexander Tsankov, Randolph Steinhagen, Drew Jones, John Asara, Jerry Chipuk, Rachel Brody, Steven Itzkowitz, Iok In Christine Chio, Dan Hasson, Emily Bernstein, Ramon Parsons. A local tumor microenvironment acquired super-enhancer induces an oncogenic driver in colorectal carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 3481.

A local tumor microenvironment acquired super-enhancer induces an oncogenic driver in colorectal carcinoma

Tumors exhibit enhancer reprogramming compared to normal tissue. The etiology is largely attributed to cell-intrinsic genomic alterations. Here, using freshly resected primary CRC tumors and patient-matched adjacent normal colon, we find divergent epigenetic landscapes between CRC tumors and cell lines. Intriguingly, this phenomenon extends to highly recurrent aberrant super-enhancers gained in CRC over normal. We find one such super-enhancer activated in epithelial cancer cells due to surrounding inflammation in the tumor microenvironment. We restore this super-enhancer and its expressed gene, PDZK1IP1, following treatment with cytokines or xenotransplantation into nude mice, thus demonstrating cell-extrinsic etiology. We demonstrate mechanistically that PDZK1IP1 enhances the reductive capacity CRC cancer cells via the pentose phosphate pathway. We show this activation enables efficient growth under oxidative conditions, challenging the previous notion that PDZK1IP1 acts as a tumor suppressor in CRC. Collectively, these observations highlight the significance of epigenomic profiling on primary specimens.

Endorectal Advancement Flaps for Perianal Fistulae in Crohn's Disease: Careful Patient Selection Leads to Optimal Outcomes

BACKGROUND

Anorectal fistulae resultant from Crohn's disease (CD) is a clinical challenge. The advent of immune therapy (IT) has altered the way in which fistulae have responded to treatment. Endorectal advancement flap (ERAF) is a surgical procedure that is used to treat complex fistulae. We have employed ERAF as our second stage treatment of choice in this patient population. Our aim was to determine the success of ERAF in treating perianal fistulas in patients with CD in an era of IT.

METHODS

Multicenter retrospective review from 2007 to 2017 of all patients with CD and a perianal fistulae who underwent ERAF.

RESULTS

Forty-one flaps were performed in 39 patients with perianal CD with an average follow-up of 797 days. There were no significant differences in patient demographics; however, all patients who were diverted at the time of surgery had successful healing. Of patients, 73.2% were on IT at an average of 380 days prior to surgery. The duration of single-agent therapy was associated with better healing rates (p = 0.03). The overall failure rate was 19.5% (n = 8). Six patients underwent secondary techniques for fistulae closure; five were successful. In combination with the patients who did not initially fail, the overall healing rate was 92.6%.

CONCLUSIONS

This study demonstrates several factors that may improve fistulae closure for CD patients. Patients who were diverted prior to surgery did not have a fistulae recurrence. Patients who were on IT longer prior to ERAF were more likely to achieve successful closure.

Collagen fistula plug for the treatment of anal fistulas

PURPOSE

This study was designed to evaluate the efficacy of the Surgisis (Anal Fistula Plug) in multiple patients at our institution and present early clinical results along with notable clinical observations from our experience.

METHODS

This was a prospective analysis of all patients who received the Anal Fistula Plug for treatment of anorectal fistulas between April 2006 and February 2007. All tracts were irrigated with peroxide, the plug was inserted in the tract, and buried at the internal opening with 2-0 vicryl and mucosal advancement flap. Statistical analysis was performed with Fisher's exact test.

RESULTS

Forty-five patients were treated with the Anal Fistula Plug and one patient was lost to follow-up. There were 27 males and 17 females with average age of 44.1 years treated for simple (n = 24) or complex (n = 20) fistulas. Preliminary results indicated an 84 percent healing rate by 3 to 8 weeks postoperatively, which progressively declined from 72.7 percent at 8 weeks to 62.4 percent at 12 weeks and 54.6 percent at a median follow-up of 6.5 (range, 3-13) months. Long-term Anal Fistula Plug closure rate was significantly higher in patients with simple than complex fistulas (70.8 vs. 35 percent; P < 0.02) and with non-Crohn's disease vs. Crohn's disease (66.7 vs. 26.6 percent; P < 0.02). Patients with two successive plug placements had significantly lower closure rates than patients who underwent placement of the plug once (12.5 vs. 63.9 percent; P < 0.02). No significant difference in closure rates were found between patients with one vs. multiple fistula tracts. Postoperative complications included perianal abscess in five patients (3 Crohn's disease, 2 non-Crohn's disease).

CONCLUSIONS

Anal Fistula Plug is most successful in the treatment of simple anorectal fistulas but is associated with a high failure rate in complex fistula and particularly in patients with Crohn's disease. Repeat plug placement is associated with increased failure. Given the relatively low morbidity associated with the procedure, Anal Fistula Plug should be considered as a first-line treatment for patients with simple fistulas and as an alternative in selected patients with complex fistulas.