Colibaseanu, Dorin

Abstract Background This study aimed to identify socioeconomic predictors of permanent stoma in rectal cancer treatment and examine its association with length of stay at the treatment facility.MethodsRectal cancer patients were identified from the Agency for Health Care Administration Florida Hospital Inpatient Discharge Dataset. Multivariate regression models were utilized to identify demographic, and socioeconomic factors associated with receiving a permanent stoma as well as the associated length of stay of these patients.ResultsOf 2,630 rectal cancer patients who underwent surgery for rectal cancer, 21% had a permanent stoma. The odds of receiving permanent stoma increased with higher Elixhauser score, metastatic disease, residing in Southwest Florida, and having Medicaid insurance or no insurance/self-payers (p<0.05). Patients with a permanent stoma had a significantly extended stay after surgery (p<0.001). ConclusionsPatients with a permanent stoma following cancer resection were more likely to have open surgery, had more comorbidities, and had a longer length of stay. Additionally, the payer type significantly affected the length of stay and odds of receiving a permanent stoma.

AbstractBackground and ObjectiveWhether bowel preparation utilization rates or effectiveness varies based on tumor location is unknown.MethodsThe 2012–2016 American College of Surgeons National Surgical Quality Improvement Program Colectomy Targeted participant user file was queried for patients undergoing elective colorectal resection for cancer. Bowel preparation was classified as combined, mechanical bowel preparation alone, oral antibiotic alone, or none. Cochran–Armitage tests were used for trend analysis. Multivariable analyses stratified by tumor location were performed for the outcome of anastomotic leak. An additional multivariable model including all tumor locations assessed for interaction between bowel preparation and tumor location on an anastomotic leak.ResultsA total of 29,739 operations were included and the anastomotic leak rate was 1.9% with combined preparation versus 4.0% without preparation. Combined bowel preparation utilization increased over time as tumor location became more distal (both p < .0001). However, the adjusted effect of combined bowel preparation on anastomotic leak risk reduction did not differ by individual tumor location or across all tumor locations (p = .43 for interaction).ConclusionThough the utilization rate of combined bowel preparation increased as tumor location became more distal, its risk‐reducing effect remained similar. Quality improvement initiatives should focus on increased utilization of combined bowel preparation with an emphasis on tumors in the ascending colon.

Objective: To compare short term outcomes of patients undergoing laparoscopic or robotic rectal cancer surgery. Background: Significant benefits of robotic rectal cancer surgery over laparoscopy have yet to be demonstrated. Operative time and direct institutional cost seem in favor of the laparoscopic approach. Methods: We performed a retrospective review of consecutive patients operated on for rectal cancer with a mini-invasive approach at Mayo Clinic from 2005 to 2018. The primary aim of this study was to investigate the difference in postoperative morbidity between the laparoscopic and robotic approach. Multivariable models for odds to complications and prolonged (≥6 days) length of stay were built. Results: A total of 600 patients were included in the analysis. The number of patients undergoing robotic surgery was 317 (52.8%). The 2 groups were similar in respect to age, sex, and body mass index. Laparoscopic surgery was correlated to shorter operative time (214 vs 324 minutes; P < 0.001). Patients undergoing robotic surgery had a lower overall complications rate (37.2% vs 51.2%; P < 0.001). Robotic surgery was found to be the most protective factor [odds ratio (OR) 0.485; P = 0.006] for odds to complications. The event of a complication (OR 9.33; P < 0.001) and conversion to open surgery (OR 3.095; P = 0.002) were identified as risk factors for prolonged length of stay whereas robotic surgery (OR 0.62; P = 0.027) was the only independent protective factor. Conclusions: Robotic rectal cancer surgery is strongly associated with better short-term outcomes over laparoscopic surgery.

Abstract Background The aim of this study was to review risk factors for conversion in a cohort of patients with rectal cancer undergoing minimally invasive abdominal surgery. Methods A retrospective analysis was performed of consecutive patients operated on from February 2005 to April 2018. Adult patients undergoing low anterior resection or abdominoperineal resection for primary rectal adenocarcinoma by a minimally invasive approach were included. Exclusion criteria were lack of research authorization, stage IV or recurrent rectal cancer, and emergency surgery. Risk factors for conversion were investigated using logistic regression. A subgroup analysis of obese patients (BMI 30 kg/m2 or more) was performed. Results A total of 600 patients were included in the analysis. The overall conversion rate was 9·2 per cent. Multivariable analysis showed a 72 per cent lower risk of conversion when patients had robotic surgery (odds ratio (OR) 0·28, 95 per cent c.i. 0·15 to 0·52). Obese patients experienced a threefold higher risk of conversion compared with non-obese patients (47 versus 24·4 per cent respectively; P &lt; 0·001). Robotic surgery was associated with a reduced risk of conversion in obese patients (OR 0·22, 0·07 to 0·71). Conclusion Robotic surgery was associated with a lower risk of conversion in patients undergoing minimally invasive rectal cancer surgery, in both obese and non-obese patients.

Background. Gallstone ileus (GSI) is a rare form of small bowel obstruction (SBO) in patients with cholelithiasis, which is often poorly managed. Enhanced abdominal computed tomography (CT) with contrast is considered the most helpful diagnostic tool, as it is highly sensitive, specific, and accurate. We report an interesting case of recurrent GSI that was not detected by CT but diagnosed intraoperatively. Case Presentation. A 49-year-old female with a previous history of choledocholithiasis and ERCP presented to the emergency department following episodes of sudden cramping, epigastric pain, and nausea. An abdominal CT revealed evidence of SBO with clear evidence of GSI and a cholecystoduodenal fistula. Laparoscopic exploration of the small bowel revealed a large, calcified 3.5 cm × 3 cm gallstone with evidence of pressure necrosis; segmental bowel resection with stapled anastomosis was performed and patient recovered appropriately after surgery. Cholecystectomy was not performed due to multiple co-morbidities and absence of gallbladder stones. However, she presented two months later with signs and symptoms of SBO. A repeat abdominal CT showed dilated bowel with no clear transition point. This was suspected to be due to adhesions. After an initial conservative treatment which produced mild improvement, laparotomy was performed which revealed a second large non-calcified gallstone and necrotic small bowel with a pocket of abscess. Conclusion. The most sensitive diagnostic tool for GSI is enhanced abdominal CT but dilemma arises when GSI is not detected on CT. A high index of suspicion and further exploration are required in order not to miss other vital findings.

e15067 Background: There has been a concerning rise of colorectal cancer (CRC) in young individuals (<50 years). There appears to be a preponderance of left-sided tumors and rectal cancers, however, the etiology and biology is not entirely known. Our aim was to describe the results of circulating tumor DNA based (ctDNA) testing in young-onset CRC. Methods: We studied the results of 186 patients with CRC who had ctDNA testing, of whom 41 (22%) had young-onset CRC from January 2017 to January 2019 at Mayo Clinic, Florida. They were categorized based on their age at diagnosis. Results: The age distribution and the aberrations seen are summarized in the table. 25 (61%) were left sided, 9 (22%) were right sided, 7 (17%) were rectal tumors. ctDNA testing was able to identify mutations in 4 (9.8%) patients with BRAFV600E, 8 (19.5%) with RAS and categorized 29 (70.7%) as RAS/RAF wild-type. Furthermore, amplifications were detected in MYC 6 (14.6%) , MET 3 (7.3%) and ERBB2 1 (2.4%). 3(7.3%) were MSI-High and there were 4 individuals with BRCA1/2 noted on ctDNA testing. Conclusions: ctDNA testing for young onset CRC is feasible and identifies a spectrum of clinically meaningful and actionable aberrations. These can further be of use to evaluate treatment response, progression or help in selection of clinical trials. [Table: see text]

e15066 Background: Circulating cell-free tumor-DNA (ctDNA) testing (‘liquid biopsy’) is increasingly being employed both in clinical trials as well as clinical practice. We aimed to contrast and compare the differences in the number of somatic mutations observed on ctDNA testing between mismatch repair deficient/microsatellite instability-high (dMMR/MSI-High) versus mismatch repair proficient/microsatellite stable (pMMR/MSS) colorectal cancers (CRC). Methods: We had 20 patients at Mayo Clinic Florida that were dMMR/MSI-High with testing through the commercially available platform (Guardant360) that uses a 73-gene panel. Median numbers of somatic mutations were compared between the 2 subset of CRC. Results: Patients with dMMR/MSI-High CRC had a median of 8 mutations (range: 2-15) versus a median of 4 mutations (range: 1-22) in pMMR/MSS patients, p-value of 0.001. Similarly, the mean number of somatic mutations were 7.47 (S.D. ± 4.15) versus 5.02 mutations (S.D. ± 3.83) in patients with dMMR/MSI-H and pMMR/MSS, tumors respectively. Though it is simplistic, we could still potentially identify patients who may be candidates for immunotherapy by gauging the mutational burden reported (Table). Furthermore, on serial testing, decline in mutational burden as early as few weeks into therapy was predictive of response later on imaging. Conclusions: Analysis of number of somatic mutations on ctDNA testing can be complementary to MMR/MSI-testing, especially in situations when tissue is not available or safe to obtain. This can also be of value in predicting and/or following response to immunotherapy. The utility of this may go beyond CRC in identifying patients who may benefit from immunotherapy. [Table: see text]

e15065 Background: Colorectal cancer (CRC) is a heterogeneous disease. Specifically for patients with BRAF-V600E mutations and/or mismatch repair deficiency or microsatellite instability-high (dMMR/MSI-High), there have been significant advances in terms of treatment options. Early identification of these subsets of patients has both prognostic and predictive value. We wanted to highlight an observation of utilizing 2 simple, rapid and universally available lab tests i.e. carbohydrate cancer antigen 19-9 and carcinoembryonic antigen tumor markers, the ratio (CA-19-9/CEA) of which can distinctly identify these patients. Methods: We included and analyzed the ratio of CA-19-9/CEA levels in patients with metastatic CRC at Mayo Clinic from December 2016 to February 2019, where both the results were available. Non-parametric tests were done to compare and contrast the differences in the median ratio and tumor marker levels. Results: BRAF-V600E mutant CRC patients had a discordantly profound elevation in CA-19-9 levels as opposed to the CEA levels. The median CA-19-9/CEA ratio was 20 (range: 0.3-167.3) in BRAF-V600E MSS patients as opposed to 4.40 (range: 0.003-216.2) in all other patients, p-value of 0.007 (Table). Similarly, the mean CA-19-9/CEA ratio for BRAF V600E MSS tumors was 57.15 (S.D.± 62.76) versus 10.5 (S.D.± 33.90) for all other types. Furthermore, this discordant elevation is not seen in BRAF-mutant MSI-High or any MSI-High patients (median CA-19-9/CEA ratio - 0.46). Conclusions: To date, this is the first report utilizing the ratio of tumor markers CA-19-9/CEA as predictive rather than just prognostic markers. It clearly identifies BRAF-V600E MSS and the MSI-High CRC patients from other subsets.[Table: see text]

e15063 Background: Bone metastasis from colorectal cancer is a relatively rare phenomenon. The aim of this study is to identify the risk factors and survival patterns of bone metastasis after colorectal cancer diagnosis. Methods: A total of 23,846 colorectal cancer patients who were diagnosed between 1972 and 2017 at Mayo Clinic were included in the analysis. Freedom from bone metastasis since diagnosis at 5, 10, 15, 25 and 35-years were estimated using Kaplan-Meier method. Multivariable Cox regression models were used to assess the differences in overall survival rate for patients with different cancer sides and cancer locations. All tests were two-sided with alpha level set at 0.05. Results: A total of 798 (3.3%) patients had a diagnosis of bone metastasis after colorectal cancer diagnosis over a median follow up of 3.2 years. Thirty-five year freedom from bone metastasis was 83% (95%CI: 80%-86%) for all patients, and were 87.13%, 82.29% and 77.26% for left colon, right colon and rectal cancer patients. Male gender, recent surgical years, and higher cancer stage were associated with higher risk of developing bone metastasis after colorectal cancer diagnosis. Rectal cancer patients had higher hazard of developing bone metastases compared to left and right colon cancer patients. Conclusions: We were able to identify several patient and tumor-related factors associated with the development of bone metastasis in patients with colorectal cancer. The proportion and factors identified are similar to other studies. Future directions would be to analyze other molecular determinants within this subset of patients.[Table: see text]