Background: Mutation of the KRAS oncogene (mKRAS) in colorectal cancer has been associated with aggressive tumor biology, resistance to epidermal growth factor inhibitors, and decreased overall survival (OS). The aim of the current study was to analyze the association of mKRAS with pathologic complete response (pCR) and neoadjuvant rectal (NAR) score, and its impact on the survival of patients with locally advanced rectal cancer who were managed with multimodality therapy. Methods: The National Cancer Database was queried for stage II-III rectal cancer patients with a known KRAS status who underwent neoadjuvant chemoradiation therapy (nCRT) and proctectomy between 2004 and 2015. Results: In total, 1886 patients were identified; 12% had pCR and 36% had mKRAS. Patients with mKRAS were more likely to have advanced pathologic T stage, tumor deposits, perineural invasion, and elevated carcinoembryonic antigen levels (all p ≤ .05). After adjustment for available confounders, mKRAS status was not associated with pCR or NAR score. In multivariable analysis, patients with pCR and lower NAR score had better OS, whereas mKRAS was independently associated with a worse prognosis. Conclusion: In this cohort of locally advanced rectal cancer patients who underwent proctectomy after nCRT, mKRAS was not associated with lower pCR rates or NAR scores; however, these patients experienced worse survival.

Background: While the prognostic implications of positive circumferential resection margins (CRM) have been established for rectal cancer, its significance in colon cancer has not been well defined. The aim of the current study was to determine national rates for positive CRM in locally advanced colon cancer, associated factors, and survival impact.Methods: The National Cancer Database was queried to identify patients with stage II-III adenocarcinoma of the colon (2004)(2005)(2006)(2007)(2008)(2009)(2010)(2011)(2012)(2013)(2014)(2015).Results: Positive CRM was identified in 9% of stage II and 12% of stage III patients.Factors associated with negative CRM included surgery in a high-volume facility, adequate lymph-node harvest, and negative distal/proximal margins. No difference in CRM rates was observed between surgical approaches, although having a positive CRM was significantly associated with higher conversion rates. Positive CRM was associated with significantly lower overall survival on both univariate and multivariable analysis.Conclusions: Positive CRM rates exceeded 10% nationally and have an adverse impact on survival. While several tumor characteristics were identified as independent risk factors, oncologic resections and surgery at high-volume centers were associated with lower rates of positive CRM. These findings emphasize the need for process improvement initiatives targeting modifiable factors, including adoption of appropriate oncologic techniques, standardized pathology reporting, and potential neoadjuvant strategies. K E Y W O R D Scircumferential resection margin, colon cancer, risk factors, survival

Although uncommon, EMH should be considered in the differential diagnosis of a presacral mass. Presacral EMH is a benign condition that can be suspected on CT or MRI and confirmed with technetium scan. Patients may not necessarily need to undergo biopsy to confirm haematopoietic elements. Unlike other presacral masses, patients diagnosed with presacral EMH can be managed by observation. If symptomatic, radiotherapy or surgical excision may be offered.

BackgroundA consistent approach to cervical spine injury (CSI) clearance for patients 65 and older remains a challenge. Clinical clearance algorithms like the National Emergency X-Radiography Utilisation Study (NEXUS) criteria have variable accuracy and the Canadian C-spine rule excludes older patients. Routine CT of the cervical spine is performed to rule out CSI but at an increased cost and low yield. Herein, we aimed to identify predictive clinical variables to selectively screen older patients for CSI.MethodsThe University of Iowa’s trauma registry was interrogated to retrospectively identify all patients 65 years and older who presented with trauma from a ground-level fall from January 2012 to July 2017. The relationship between predictive variables (demographics, NEXUS criteria and distracting injuries) and presence of CSI was examined using the generalised linear modelling (GLM) framework. A training set was used to build the statistical models to identify clinical variables that can be used to predict CSI and a validation set was used to assess the reliability and consistency of the model coefficients estimated from the training set.ResultsOverall, 2312 patients ≥65 admitted for ground-level falls were identified; 253 (10.9%) patients had a CSI. Using the GLM framework, the best predictive model for CSI included midline tenderness, focal neurological deficit and signs of trauma to the head/face, with midline tenderness highly predictive of CSI (OR=22.961 (15.178–34.737); p<0.001). The negative predictive value (NPV) for this model was 95.1% (93.9%–96.3%). In the absence of midline tenderness, the best model included focal neurological deficit (OR=2.601 (1.340–5.049); p=0.005) and signs of trauma to the head/face (OR=3.024 (1.898–4.815); p<0.001). The NPV was 94.3% (93.1%–95.5%).ConclusionMidline tenderness, focal neurological deficit and signs of trauma to the head/face were significant in this older population. The absence of all three variables indicates lower likelihood of CSI for patients≥65. Future observational studies are warranted to prospectively validate this model.

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