Can Pretreatment MRI and Planning CT Radiomics Improve Prediction of Complete Pathological Response in Locally Advanced Rectal Cancer Following Neoadjuvant Treatment?

OBJECTIVE(S): The treatment response to neoadjuvant chemoradiation (nCRT) differs largely in individuals treated for rectal cancer. In this study, we investigated the role of radiomics to predict the pathological response in locally advanced rectal cancers at different treatment time points: (1) before the start of any treatment using baseline T2-weighted MRI (T2W-MR) and (2) at the start of radiation treatment using planning CT. METHODS: Patients on nCRT followed by surgery between June 2017 to December 2019 were included in the study. Histopathological tumour response grading (TRG) was used for classification, and gross tumour volume was defined by the radiation oncologists. Following resampling, 100 and 103 pyradiomic features were extracted from T2W-MR and planning CT images, respectively. Synthetic minority oversampling technique (SMOTE) was used to address class imbalance. Four machine learning classifiers built clinical, radiomic, and merged models. Model performances were evaluated on a held-out test dataset following 3-fold cross-validation using area under the receiver operator characteristic curves (AUC) with bootstrap 95% confidence intervals. RESULTS: One hundred and fifty patients were included; 58/150 with TRG 1 were classified as complete responders, and rest were incomplete responders (IR). Clinical models performed better (AUC = 0.68) compared to radiomics models (AUC = 0.62). Overall, the clinical + T2W-MR model showed best performance (AUC = 0.72) in predicting the pathological response prior to therapy. Clinical + Planning CT-merged models could only achieve the highest AUC of 0.66. CONCLUSION: Merging clinical and baseline T2W-MR radiomics enhances predicting pathological response in rectal cancer. Validation in larger cohorts is warranted, especially for watch and wait strategies.

A Three-Year Retrospective Analysis: Do Nutritional and Immunological Indices Predict Postoperative Complications After Rectal Resection?

Background Nutritional and immunological indices, such as prognostic nutritional index (PNI), neutrophil-to-lymphocyte ratio (NLR), and platelet-to-lymphocyte ratio (PLR), have been used as predictors of outcomes and survival in a few cancers. However, the literature is unclear about their usefulness in predicting postoperative complications in rectal cancer resection operations. Additionally, the prescribed cut-off values as well as the timing of the tests for these indices vary among studies. We aimed to determine the role of PNI, NLR, and PLR in predicting postoperative complications in patients undergoing rectal resection. Methods This is a retrospective analysis from a colorectal unit of a tertiary care teaching hospital. All consecutive patients undergoing rectal resection for rectal cancer between April 2018 and March 2021 were included. PNI, NLR, and PLR were calculated from preoperative blood tests, and all morbidity and mortality within 30 days of operation were considered. Results A total of 202 patients were included. Three patients who did not have the necessary preoperative blood test reports were excluded. Of the remaining 199, 142 (71.4 %) were males. The mean age was 47.3 years. Of the patients, 13.6% (n = 27) had major morbidity (Clavien-Dindo grade 3-5), including one mortality. The mean PNI, NLR, and PLR were 49.9, 4.3, and 230.5, respectively. The mean PNI between the groups (no complication vs. complication) was 49.6 vs. 50.1 (p = 0.46) and the mean NLR between the same groups was 4.7 vs. 3.8, (p = 0.06), and both were not significant. The mean PLR between the groups (256.3 vs. 203.4, p = 0.01) was found to be significant but significance was not elicited when only major complications were considered. Hence, none of the indices were a good predictor of postoperative complications in our study. Conclusion The role of nutritional and immunological indices (PNI, NLR, and PLR) is limited in predicting postoperative morbidity in rectal resection operations.

Predicting Positive Radial Margin on Restaging MRI of Patients with Low Rectal Cancer: Can We Do Better?

Objective The aim of this study was to characterize the tissue involving the margin and study if this information will affect margin prediction on restaging magnetic resonance imaging (MRI) in low rectal adenocarcinoma (LRC) patients treated with neoadjuvant long-course chemoradiotherapy (LCCRT). Methods In this retrospective study of nonmetastatic LRC (distal margin <5 cm from the anal verge) treated with LCCRT followed by surgery, a radiologist blinded to outcome reread the restaging MRI and documented if the radial margin was involved by tumor, fibrosis, or mucin reaction using T2 high-resolution (HR) and diffusion-weighted imaging (DWI). The diagnostic performance of tumor-involving margin on restaging MRI was assessed using surgical histopathology as a reference. Interobserver agreement between three independent radiologists was assessed in a subset. Results We included 133 patients (80 males and 53 females) with a mean (range) age of 44.7 (21-86) years and 82% of them had well or moderately differentiated adenocarcinoma. Baseline MRI showed T3 ( n = 58) or T4 ( n = 60) disease in 89% of the patients. The pathological margin was positive in 21% ( n = 28) cases. In restaging MRI, the circumferential resection margin (CRM) ≤1 mm in 75.1% ( n = 100) cases and MRI predicted tumor, fibrosis, and mucin reaction at the margin in 60, 34, and 6%, respectively, and histopathology showed tumor cells in 33, 14.7, and 16.6% of them, respectively. LRC with tumor-involving margin and bad response (MR tumor regression grade [mr-TRG] 3-5) on restaging MRI had fourfold increased risk of positive pathological circumferential resection margin (pCRM). There was moderate and fair inter-reader agreement for the tissue type involving the CRM ( κ = 0.471) and mr-TRG ( κ = 0.266), p < 0.05. The use of both distance criteria and tumor-involving margins improved the diagnostic accuracy for margin prediction from 39 to 66% on restaging MRI. Conclusions Margin prediction on restaging MRI can be improved by characterizing the tissue type involving the margin in low rectal cancer patients. The inter-reader agreement was moderate for determining the tissue type.

Total Neoadjuvant Therapy (TNT) with Full Dose Concurrent Chemotherapy in Locally Advanced Rectal Adenocarcinoma Including Signet Ring and Mucinous Cancers.

PURPOSE: Total neoadjuvant therapy (TNT) with pre-operative chemotherapy and chemoradiotherapy results in improved survival and is becoming the new standard of care in locally advanced rectal cancer (LARC). We describe our experience with TNT consisting of induction chemotherapy followed by chemoradiotherapy using full dose 5FU without oxaliplatin. METHODS: Adults with biopsy-proven, newly diagnosed LARC with high-risk characteristics on pelvic MRI (T4a or T4b, extramural vascular invasion, N2, mesorectal fascia involvement, enlargement/tumor deposits on lateral lymph nodes) were included. The TNT protocol comprised of six biweekly courses of modified FOLFOX6 followed by pelvic RT with four concurrent cycles of biweekly 5-FU 2600 mg/m2 + LV 200 mg/m2 without oxaliplatin to complete 20 uninterrupted weeks of full dose 5FU. Surgery was planned 11-13 weeks after completing chemoradiotherapy. RESULTS: Eighty-four LARC patients, including 26% with signet-ring cell carcinoma, with high-risk MRI characteristics were treated with the TNT protocol with a 96% completion rate. Significant (> grade 3) toxicities included neutropenia (23.8%), diarrhea (14.2%) anemia (10.7%), and two deaths. The median DFS at 2 years was 22.5 months with better survival noted for those who underwent surgery or had cCR (with NOM) compared to those who did not undergo surgery (due to progression, inadequate regression, or patient preference despite residual disease) -mDFS 27.7 months versus 11.4 months, p = < 0.0001 and mOS 29.2 months versus 15 months p = < 0.0001. CONCLUSION: The hybrid TNT regimen was administered without significant dose delays or interruptions. Toxicity was manageable but with two treatment-related deaths. Ability to undergo surgery after TNT predicted for improved DFS and OS.

Preoperative Immuno-Nutrition and Complications After Colorectal Surgery: Results of a 2-Year Prospective Study.

INTRODUCTION: Preoperative immuno-nutrition has been associated with reductions in infectious complications and length of stay, but remains unstudied in the setting of an enhanced recovery protocol. The objective was to evaluate outcomes after elective colorectal surgery with the addition of a preoperative immuno-nutrition supplement. METHODS: In October 2017, all major colorectal surgeries were given an arginine-based supplement prior to surgery. The control group consisted of cases within the same enhanced recovery protocol from three years prior. The primary outcome was a composite of overall morbidity. Secondary outcomes were infectious complications and length of stay with subgroup analysis based on degrees of malnutrition. RESULTS: Of 826 patients, 514 were given immuno-nutrition prospectively and no differences in complication rates (21.5% versus 23.9%, P = 0.416) or surgical site infections (SSIs) (6.4% versus 6.9%, P = 0.801) were observed. Hospitalization was slightly shorter in the immuno-nutrition cohort (5.0 [3.0, 7.0], versus 5.5 days [3.6, 7.9], P = 0.002). There was a clinically insignificant difference in prognostic nutrition index scores between cohorts (35.2 ± 5.6 versus 36.1 ± 5.0, P = 0.021); however, subgroup analysis (< 33, 34-38 and > 38) failed to demonstrate an association with complications (P = 0.275) or SSIs (P = 0.640) and immuno-nutrition use. CONCLUSIONS: Complication rates and SSIs were unchanged with the addition of immuno-nutrition before elective colorectal surgery. The association with length of stay is small and without clinical significance; therefore, the routine use of immuno-nutrition in this setting is of questionable benefit.

MRI of Recurrent Fistula-in-Ano: Is it Different from Treatment-Naïve Fistula-in-Ano and How Does it Correlate with Anal Sphincter Morphology?

Objectives The main aim of this study was to compare magnetic resonance imaging (MRI) findings of recurrent and treatment-naïve fistula-in-ano and to correlate imaging findings with anal sphincter morphology in recurrent fistula-in-ano. Methods This is a retrospective study of adult patients who underwent MRI for suspected fistula-in-ano in 2018. After excluding patients with alternative diagnosis, patients were stratified into recurrent ( n = 103) and treatment-naïve ( n = 106) fistula-in-ano groups. Two blinded radiologists reread MRI scans in consensus for fistula characteristics and anal sphincter morphology. We compared imaging features of recurrent and treatment-naïve fistula-in-ano, assessed the incidence of anal sphincter scarring among patients with recurrent fistula-in-ano, and studied its association with fistula features. Results Two-hundred nine patients (187 males) with mean age of 40.6 (standard deviation: 12.2) years were included. Trans-sphincteric, inter-sphincteric, extra-sphincteric, and supra-sphincteric fistula-in-ano were seen in 63.6, 33, 2.9, and 0.5%, respectively. There were secondary tracts, supralevator extension, and secondary cause for fistula in 49.3, 12.9, and 14.8%, respectively. There was no difference between the fistula features of recurrent and treatment-naïve fistula-in-ano, except for significantly fewer external openings among recurrent fistula-in-ano ( p = 0.005). Among patients with recurrent fistula-in-ano, MRI detected anal sphincter defect/scarring was seen in 53.4% ( n = 55) and was significantly associated with posterior fistula-in-ano ( p = 0.031), collections and/or supralevator extension ( p = 0.010), and secondary tracts ( p = 0.015). Conclusion Fistula features of recurrent and treatment-naïve patients were mostly similar. There was high incidence (53.4%) of MRI-identified anal sphincter scarring/defect among recurrent fistula-in-ano, which was significantly associated with posterior fistula, collections, supra or translevator extension, and secondary tracts. Key Points MRI-identified anal sphincter scarring is very common among patients with recurrent fistula-in-ano and seen in more than half of them.There was significantly higher incidence of sphincter scarring among patients who had posterior fistula, collections, supralevator/translevator extension, and secondary tracts.

Study protocol: 'a large cohort study of postnatal events in a not-for-profit referral centre in Vellore, South India'.

INTRODUCTION: In a large developing country, with diverse population characteristics and differential access to healthcare, it is important to identify factors that influence postnatal health. This knowledge will help frame recommendations to enhance universal postnatal care. METHODS AND ANALYSIS: A prospective cohort study will be conducted by recruiting all participants who deliver in a referral centre in South India during a 1-year period after written consent is obtained from them. In addition to clinical information pertaining to their delivery and demographics, details of physical health, mental health socioeconomic status and emotional support will also be collected. Every participant will be followed up physically and/or by telephonic consultation at 3, 9 and 18 months of their postnatal period to reassess their status and that of their babies. As there are several independent and dependent variables requiring multivariate analysis, a sample size of 10 000 is considered adequate. Any unplanned visits to a health facility will be enquired into and documented for analysis.During data analysis, the effect of Caesarean section, high-risk characteristics and gestational age of the baby at delivery on various outcome measures and postnatal status will be evaluated. Interpretation of the large volume of collected data will help frame recommendations to improve postnatal care ETHICS AND DISSEMINATION: The study is approved by the Institutional Review Boards (Research and Ethics Committees) of Christian Medical College, Vellore, Tamil Nadu, India (IRB 12178 date 24 June 2020).Women are provided with a detailed information sheet and written consent is obtained. They are reassured that their care will not be compromised if they do not consent to the study. Data will be available on the clinical trial portal to assist in the dissemination of results after the project is published. TRIAL REGISTRATION NUMBER: CTRI/2022/03/041343.

Association of a Single Post-Operative Day Three C-Reactive Protein Value with Anastomotic Complications after Colorectal Surgery: A Prospective Observational Study.

Background: Early detection and treatment of a colorectal anastomotic leak reduces leak-associated morbidity. The primary objective of this study was to assess the role of C-reactive protein (CRP) as a tool to facilitate the early diagnosis of large bowel anastomotic leak. Patients and Methods: We conducted a prospective observational study at a specialized colorectal unit of a tertiary referral teaching center where we recorded CRP levels pre-operatively and on day three for 113 patients undergoing a large bowel anastomosis. The primary outcome measure was the occurrence of anastomotic leak and its association with post-operative day three CRP levels (day one considered as 24 hours after surgery). The area under the curve of the receiver operating characteristic (ROC) curve analysis for the day three CRP value with the anastomotic leak was calculated and optimal cutoffs derived. Definitions and diagnostic criteria for a leak were established before commencing the study. Demographic, operative, diagnostic, and interventional procedure data were also recorded. Results: Twenty-two patients had an anastomotic leak (19.4%), and 14 (12.3%) required re-exploration or drain placement. The cutoff value of day three CRP with the greatest area under the ROC curve in the ROC curve analysis was 166 mg/L (area under the curve [AUC], 0.853) for open and laparoscopic procedures (sensitivity and specificity of 81.81% and 82.42%, respectively) with a negative predictive value of 93.8%. There was no difference in mean day three CRP levels between open and laparoscopic surgery (116.57 mg/L vs. 108.94 mg/L) Conclusions: A CRP value of more than 166 mg/L on day three should raise suspicion of an anastomotic leak.

MDT stage migration in MRI of significant rectal polyps and early rectal cancers.

PURPOSE: To audit the diagnostic accuracy of MRI for staging early and polyp rectal cancers with the purpose of identifying scope for service improvement. METHODS: This is an IRB approved retrospective study of patients who underwent staging MRI for rectal growths followed by upfront TME type surgery or local excision without neoadjuvant therapy between 2018 and 2021. MR-T-stage was compared with surgical histopathology. The degree of stage migration in the multidisciplinary team meetings (MDT) was assessed and training needs were identified. RESULTS: 53 patients (32 males) with a mean (SD) age of 56.7 (13.6) years with 54 rectal lesions and underwent trans-anal excision (n = 18) or upfront surgery (n = 35) were included. Pathology showed < / = pT1 stage in n = 18 and > / = pT2 stage in n = 36. Radio-pathological concordance rate was 38.9% and 74.1%, respectively, for primary reports and MDT reads, respectively, and during MDT, the rates improved by 44.5% and 30.5% for < / = pT1 and > / = pT2 stages ,respectively. The overall T-stage migration rate at MDT was 44.6% (25/54) and the migration rate was higher (61.1%) for < / = pT1 stage lesions. The best sensitivity, specificity, PPV, NPV and accuracy of MRI for T-staging was 83.3%, 91.6%, 83.3%, 91.6% and 88.8%, respectively. CONCLUSION: Radio-pathological correlation for MRI T-stage is excellent for MDT reads by experienced radiologists. MDT reads lead to significant down-staging of T-stage in polyp and early rectal cancer thereby improving radio-path correlation.

Prognostic significance of MR identified EMVI, tumour deposits, mesorectal nodes and pelvic side wall disease in locally advanced rectal cancer.

AIM: To study the prognostic significance of MRI identified tumour deposits (TD), extramural vascular invasion (EMVI), lymph node metastases (LNM) and pelvic sidewall (PSW) disease in rectal cancer. METHODS: This IRB approved study was conducted on patients with stage IIA-IIIC rectal adenocarcinoma treated with neoadjuvant long course chemoradiotherapy (LCCRT) and total mesorectal excision (TME) type of surgery between 2012-2018. A radiologist blinded to outcome reviewed staging and restaging magnetic resonance imaging (MRI) for TD, EMVI, LNM and PSW. The agreement between four radiologists was studied and we obtained outcome data from a prospectively maintained database. The prognostic significance of imaging findings was assessed. RESULTS: A total of 297 (186 males) patients with a mean age of 47.3 (SD14.4) years were included in the study. The majority had T3 (n = 206) or T4 (n = 59) stage disease. The mean duration of follow-up was 49.3 ± 25 months (6.6-101 months). 5-year overall (OS) and disease-free survival (DFS) was 84% and 74%, respectively. Staging and restaging MRI had EMVI in 49.5% and 31.3%; TD in 47.5% and 31.6%; LNM in 61.1% and 38.1% and PSW in 11.4% and 6.1%. OS was adversely affected by EMVI, TD and PSW with the adjusted HR (aHR) of 3.32, 3.31, 3.27 for staging MRI and 2.99, 3.1, 2.81 for restaging MRI, respectively, p < 0.05. DFS was affected by EMVI (aHR = 1.85, 2.33) and TD (aHR = 1.83, 2.19), p < 0.05. Persistence of these findings after LCCRT led to worst outcome. Intra- and interobserver agreement for EMVI, TD and LN was 0.789, 0.734, 0.406 and 0.449, 0.354, 0.376, respectively, p < 0.001. CONCLUSIONS: MRI identified that TD, EMVI and PSW disease are independent poor prognostic indicators in rectal cancer patients. Interobserver agreement for these findings was moderate to fair.

Communicating imaging findings in peritoneal mesothelioma: the impact of 'PAUSE' on surgical decision-making.

The peritoneal cavity is the second commonest site of mesothelioma after the pleural cavity. There are five histological types of peritoneal mesothelioma with variable symptomatology, clinical presentation and prognosis. Cystic mesothelioma is a borderline malignant neoplasm with a favourable prognosis, well-differentiated papillary mesothelioma is generally a low-grade malignancy, and all other varieties such as epithelioid, sarcomatoid and biphasic mesothelioma are highly malignant types of peritoneal mesothelioma with poor prognosis. Malignant peritoneal mesothelioma was considered inevitably fatal prior to the introduction of cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) in selected cases where long-term survival and cure could be achieved. However, the survival benefits following CRS and HIPEC mainly depend on completeness of cytoreduction, which come at the cost of high morbidity and potential mortality. Using the acronym 'PAUSE', we aimed at describing the key imaging findings that impact surgical decision-making in patients with peritoneal mesothelioma. PAUSE stands for peritoneal cancer index, ascites and abdominal wall disease, unfavourable sites of involvement, small bowel and mesenteric disease and extraperitoneal disease. Reporting components of 'PAUSE' is crucial for patient selection. Despite limitations of CT in accurately depicting the volume of disease, describing findings in terms of PAUSE plays an important role in excluding patients who might not benefit from CRS and HIPEC.

Diffusion weighted imaging improves diagnostic ability of MRI for determining complete response to neoadjuvant therapy in locally advanced rectal cancer.

PURPOSE: To assess the diagnostic performance, interobserver agreement and confidence level for determining response to neoadjuvant chemoradiotherapy (NACRT) using morphology based MR-tumour regression grade (MR TRG), diffusion weighted imaging (DWI) patterns and their combination in patients with locally advanced rectal cancer. METHODS: This was a retrospective study including patients with locally advanced rectal cancer treated with NACRT and subsequent surgery. Two independent radiologists blinded to the histopathology reviewed staging and restaging MRI. Diagnostic performance of morphology based MR-TRG, DWI patterns and their combination for determining complete (CR) and incomplete (IR) response was assessed with pathological response as the reference. Likert's scale was used to assess the radiologist's level of confidence. Interobserver agreement was determined using Kappa statistics. RESULTS: The study included 251 patients (mean age of 47.9+/-14 (range 19-86) years, M:F = 164:87). Rate of pathological CR was 14.7 % (n = 37). Pattern based interpretation of DWI and combined approach (DWI + T2-HR) had superior diagnostic performance than morphology based assessment alone with area under curve (AUC) for T2HR, DWI and their combination being 0.531, 0.887, 0.874 respectively for observer 1 and 0.558, 0.653, 0.678 respectively for observer 2, p < 0.001. Interobserver agreement was substantial (k = 0.688) for combined approach, moderate (k = 0.402) for DWI patterns and fair (k = 0.265) for T2 HR MRI with both observers exhibiting highest level of confidence for determining response with the combined approach. CONCLUSION: Complete response to neoadjuvant chemoradiotherapy can be determined with excellent accuracy, substantial interobserver agreement and high level of confidence by combined interpretation of DWI and T2 high resolution MRI.

Surgical management of stomal prolapse - Is there a superior approach to repair?

BACKGROUND: Stomal prolapse is an uncommon complication related to ostomy creation without comparative studies to suggest an optimal approach. Our aim was to assess long-term recurrence rates following surgical repair, specifically local repair vs. laparotomy. METHODS: We conducted a retrospective review of patients who underwent surgical correction of a prolapsed stoma by dedicated colorectal surgeons. The primary outcome was recurrence. We evaluated perioperative risk factors for long-term recurrence, focusing on the surgical approach. RESULTS: Over 12 years, 23 patients underwent 37 surgeries (median follow-up 24 months, range 1-126). Repeat operations for recurrence were performed in 43.5% of patients, 80% within one year. Recurrence was similar regardless of the surgical approach; 43.6% local repair vs 42.9% laparotomy (p = 0.41). Age, sex, body mass index, smoking status, ASA score, type of stoma, and urgency of repair were not associated with recurrence. Re-recurrence resulting in a third operation, occurred in 50% of patients. CONCLUSION: Operative repair of stomal prolapse, regardless of approach, is associated with high recurrence rates. No identifiable factors were associated with recurrence.

Use of a robotic camera holder (FreeHand®) for laparoscopic appendicectomy.

Introduction: Use of a mechanical arm to hold the laparoscopic camera has many advantages. FreeHand® (FreeHand Ltd, Guildford, United Kingdom) is a robotic camera holder which uses head movement and infrared technology. This trial assessed the usefulness of FreeHand® in laparoscopic appendicectomy.Material and methods: This was a single center prospective cohort study on patients undergoing emergency laparoscopic appendicectomy using FreeHand®. Patient demographics, operative details, conversion to human camera holder and surgeon discomfort were recorded. Utilization of assistant time while not assisting was also recorded.Results: Twenty-two participants were included, with a mean age of 32 years and a mean BMI of 25.3. The mean set up time was nine minutes. There were five conversions to a manual camera holder (22.7%). There were 22 lens cleaning episodes with nine (40.9%) not requiring any lens cleaning and six (27.3%) requiring one clean. There were no peri-operative complications. Most surgeons reported minimal or no discomfort. Assistant's time was used for ward work (57%), clerking patients (36%) and for a break (7%).Conclusions: FreeHand® can be safely used in laparoscopic appendicectomy. It provides a stable image, puts the surgeon in control of the surgical field, causes minimal user discomfort, and frees up personnel.

Microsatellite instability in young patients with mucinous colorectal cancers - characterization using molecular testing, immunohistochemistry, and histological features.

CONTEXT: The incidence of colorectal cancers (CRCs) in young Indian patients is higher than the international average. CRCs in young patients are commonly of mucinous type and show microsatellite instability (MSI). AIMS: To ascertain the MSI status of mucinous CRCs in patients ≤40 years of age by molecular testing and to correlate this with immunohistochemical (IHC) analysis and tumor histology. SUBJECTS AND METHODS: Archived formalin-fixed paraffin embedded tissue blocks of 30 young mucinous CRC patients were retrieved. MSI testing was done using two mononucleotide markers - BAT26 and NR24. IHC analysis was done using MLH1, MSH2, and MSH6. Histological features of all cases were studied. Data were analyzed using the SPSS software and the Pearson's chi-square test and Fisher's exact test. RESULTS: Eight out of 30 cases (26.7%) showed MSI by molecular testing. IHC identified seven of these cases. Histological features showing a statistically significant association with MSI were the presence of a well-differentiated adenocarcinoma component (P = 0.003), peritumoral lymphocytes (P = 0.002) and tumor budding (P = 0.021). CONCLUSION: The detection of defective mismatch repair (MMR) proteins using IHC for MLH1, MSH2, and MSH6 and molecular testing using BAT26 and NR24 appears to be a good protocol to detect CRCs with MSI. Histology could be useful in identifying cases that require screening for presence of MMR protein defects.

Peritoneal Involvement Is More Common Than Nodal Involvement in Patients With High-Grade Appendix Tumors Who Are Undergoing Prophylactic Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy.

BACKGROUND: Right hemicolectomy is routinely recommended in patients with histologic findings of high-grade appendix tumors after appendicectomy. Undetected peritoneal disease may be encountered at surgery. In high-grade appendix tumors with disease detected radiologically, complete cytoreduction may not be possible and outcomes poor. For these reasons, we adopted a policy of prophylactic cytoreductive surgery and hyperthermic intraperitoneal chemotherapy. OBJECTIVE: The purpose of this study was to quantify the rates of peritoneal and nodal metastatic disease in patients with high-grade appendix tumors without obvious metastatic disease and to report the long-term outcomes of cytoreductive surgery and hyperthermic intraperitoneal chemotherapy in these patients. DESIGN: Data regarding peritoneal and nodal metastatic disease were extracted from surgical and histologic records. SETTINGS: The study was conducted at a high-volume tertiary referral center for peritoneal malignancy. PATIENTS: Patients referred with histologically high-grade appendix tumors at appendicectomy, without detectable metastatic spread, between January 1994 and September 2016 were included MAIN OUTCOME MEASURES:: A total of 62 patients with high-grade pathology at appendicectomy, without clinical or radiological peritoneal disease, underwent complete cytoreduction with hyperthermic intraperitoneal chemotherapy. RESULTS: Thirty-five (57%) of 62 patients had peritoneal disease (median peritoneal cancer index 5 (range, 1-28)). Eleven (31%) of 35 had microscopic peritoneal disease. Overall, 23 (37%) of 62 had peritoneal disease beyond the confines of a standard right hemicolectomy. Nine (15%) of 62 had nodal involvement. Mean overall and disease-free survival were 110.9 (95% CI, 94.8-127.0 mo) and 102.1 months (95% CI, 84.3-119.9 mo), with 5-year overall and disease-free survival of 83.2% and 76.0%. LIMITATIONS: The retrospective nature limits the interpretation of these results. CONCLUSIONS: Complete cytoreduction was achieved in all of the patients, with excellent long-term survival. The incidence of peritoneal spread (57%) compared with nodal involvement (15%) supports cytoreductive surgery and hyperthermic intraperitoneal chemotherapy as definitive treatment rather than prophylaxis in patients with high-grade appendix tumors, even without radiologically detectable disease. High-grade appendix tumors benefit from early aggressive operative management to deal with potential peritoneal and nodal spread and should be considered for cytoreductive surgery and hyperthermic intraperitoneal chemotherapy. See Video Abstract at http://links.lww.com/DCR/A360.

Pseudomyxoma peritonei: natural history and treatment.

Pseudomyxoma peritonei (PMP) is an uncommon disease characterised by mucinous ascites, classically originating from a ruptured low grade mucinous neoplasm of the appendix. The natural history of PMP revolves around the "redistribution phenomenon", whereby mucinous tumour cells accumulate at specific sites with relative sparing of the motile small bowel and to a lesser extent other parts of the gastrointestinal tract. Peritoneal tumour accumulates due to gravity and at the sites of peritoneal fluid absorption, namely, the greater and lesser omentum and the under-surface of the diaphragm, particularly on the right. The optimal treatment is complete macroscopic tumour excision termed cytoreductive surgery (CRS) combined with Hyperthermic Intra-Peritoneal Chemotherapy (HIPEC). Total operating time for complete CRS and HIPEC for extensive PMP is around 10 h and generally involves bilateral parietal and diaphragmatic peritonectomies, right hemicolectomy, radical greater omentectomy with splenectomy, cholecystectomy and liver capsulectomy, a pelvic peritonectomy with, or without, rectosigmoid resection and bilateral salpingo-oophorectomy with hysterectomy in females. A unique feature of low grade PMP, which differs from other peritoneal malignancies, includes slow disease progression, which may be asymptomatic until advanced stages. Additionally, very extensive disease with a high "PCI" (Peritoneal Carcinomatosis Index) may still be amenable to complete excision and cure. In cases where complete tumour removal is not feasible, maximum tumour debulking can still result in long-term survival in PMP. PMP is challenging, complex but nevertheless the most rewarding peritoneal malignancy amenable to cure by CRS and HIPEC.

Demographics and outcomes of surgically treated right sided colon cancer in India: a 9-year single institution experience.

Background: There is sparse Indian data on right colon cancer. Available literature suggests that it affects the young and survival is poor. Aim: This article reviews demographics and outcomes of surgically treated right sided colon cancer over a nine year period in a single colorectal unit in a tertiary care teaching hospital. Methods: A retrospective review of all patients undergoing right hemicolectomy for adenocarcinoma of the colon between January 2004 and December 2012 was undertaken. Data was collected from hospital records and telephonic interview when possible. Results: Two hundred and thirteen patients were studied. Mean age was 49 years with 57.1% being 50 years or younger. Stage 1 disease was seen in 9.9%, stage 2 in 35.2%, stage 3 in 42.3%, and stage 4 in 12.7%. Follow up was available for 81.6% with a mean follow up of 35.6 months. Five year disease free survival (DFS) and overall survival (OS) was 81% and 74%. Presence of lymphovascular invasion and age >50 years were predictors of poor survival. Poor prognostic features on histopathology were not different between the young and the old. The 5 year DFS was similar in both, but the 5 year OS was better for the young (90% vs. 73%, p=0.029). Conclusion: Patients with right colon cancer are younger in India. They have similar histopathology when compared to the older population. Operable right colon cancer has an excellent prognosis. Five year DFS is similar in the young and the old, but OS is lower in the older population.

Surgical manifestations of scrub typhus: A diagnostic dilemma.

BACKGROUND: Scrub typhus, a zoonosis caused by Orientia tsutsugamushi, is a systemic febrile illness. The disease presents with diverse clinical manifestations, ranging from subclinical disease to multiorgan failure and fatal disease. It may rarely present as an acute abdomen which may lead to a diagnostic dilemma. We describe two serologically confirmed cases of scrub typhus presenting as acute abdomen-one mimicking acute appendicitis and the other acute cholecystitis, both managed non-operatively. A high index of suspicion, along with subtle indicators in the history and clinical examination help avoid unnecessary surgery in such cases.