No clinical benefit from routine histologic examination of stapler doughnuts at low anterior resection for rectal cancer

Background. The aim of this study was to evaluate the clinical utility and cost-effectiveness of routine histologic examination of the doughnuts from stapled anastomoses in patients undergoing a low anterior resection for rectal cancer. Methods. We performed a retrospective review of 486 patients who underwent a low anterior resection with stapled anastomosis for rectal cancer between 2002 and 2015 at 3 institutions. Pathologic findings in the doughnuts and their impact on patient management were recorded. Tumor characteristics that may influence how often doughnuts were included in the pathology report were analyzed. An approximate cost of histologic examination of doughnuts was also calculated. Results. A total of 412 patients (85 %) had doughnuts included in their pathology reports. Two patients had cancer cells in their doughnuts, and both patients had a positive distal margin in their primary tumor specimen; 33 patients had benign findings in their doughnuts. Pathologic examination of the doughnut did not change clinical management in any patient. Patients with rectosigmoid tumors were less likely to have their doughnuts included in the pathology report compared to patients with low tumors (P = .003). Doughnuts were not bundled with the primary tumor specimen in 374 (77 %) of our patients; in these patients, pathologic analysis of the doughnut added an additional cost of approximately $643 per specimen. Conclusion. This study demonstrates no clinical benefit in sending anastomotic doughnuts for histopathlogic evaluation after performing a low anterior resection with a stapled anastomosis for rectal cancer. Overall cost may be decreased if doughnuts are not analyzed or if they are bundled with the primary tumor specimen

Predictive Factors and Risk Model for Positive Circumferential Resection Margin Rate after Transanal Total Mesorectal Excision in 2653 Patients with Rectal Cancer

The aim of this study was to determine the incidence of, and preoperative risk factors for, positive circumferential resection margin (CRM) after transanal total mesorectal excision (TaTME). Background: TaTME has the potential to further reduce the rate of positive CRM for patients with low rectal cancer, thereby improving oncological outcome. Methods: A prospective registry-based study including all cases recorded on the international TaTME registry between July 2014 and January 2018 was performed. Endpoints were the incidence of, and predictive factors for, positive CRM. Univariate and multivariate logistic regressions were performed, and factors for positive CRM were then assessed by formulating a predictive model. Results: In total, 2653 patients undergoing TaTME for rectal cancer were included. The incidence of positive CRM was 107 (4.0%). In multivariate logistic regression analysis, a positive CRM after TaTME was significantly associated with tumors located up to 1 cm from the anorectal junction, anterior tumors, cT4 tumors, extra-mural venous invasion (EMVI), and threatened or involved CRM on baseline MRI (odds ratios 2.09, 1.66, 1.93, 1.94, and 1.72, respectively). The predictive model showed adequate discrimination (area under the receiver-operating characteristic curve >0.70), and predicted a 28% risk of positive CRM if all risk factors were present. Conclusion: Five preoperative tumor-related characteristics had an adverse effect on CRM involvement after TaTME. The predicted risk of positive CRM after TaTME for a specific patient can be calculated preoperatively with the proposed model and may help guide patient selection for optimal treatment and enhance a tailored treatment approach to further optimize oncological outcomes