Choice of specimen's extraction site affects wound morbidity in laparoscopic colorectal cancer surgery.

BACKGROUND: The choice for an ideal site of specimen extraction following laparoscopic colorectal surgery remains debatable. However, midline incision (MI) is usually employed for right and left-sided colonic resections while left iliac fossa or suprapubic transverse incision (STI) were reserved for sigmoid and rectal cancer resections. OBJECTIVE: To compare the incidence of surgical site infection (SSI) and incisional hernia (IH) in elective laparoscopic colorectal surgery for cancer and specimen extraction via MI or STI. METHOD: Prospectively collected data of elective laparoscopic colorectal cancer resections between January 2017 and December 2019 were retrospectively reviewed. MI was employed for right and left-sided colonic resections while STI was used for sigmoid and rectal resections. SSI is defined according to the US CDC criteria. IH was diagnosed clinically and confirmed by CT scan at 1 year. RESULTS: A total of 168 patients underwent elective laparoscopic colorectal resections. MI was used in 90 patients while 78 patients had STI as an extraction site. Demographic and preoperative data is similar for two groups. The rate of IH was 13.3% for MI and 0% in the STI (p = 0.001). SSI was seen in 16.7% of MI vs 11.5% of STI (p = 0.34). Univariate and multivariate analysis showed that the choice of extraction site is associated with statistically significant higher incisional hernia rate. CONCLUSION: MI for specimen extraction is associated with higher incidence of both SSI and IH. The choice of incision for extraction site is an independent predicative factor for significantly higher IH and increased SSI rates.

Visceral Basidiobolomycosis Causing Bowel Ischemia.

Basidiobolomycosis is a rare fungal infection caused by saprophyte Basidiobolus ranarum. It is rarely seen in healthy adult patients; however, it usually affects children. The commonly involved sites are skin and subcutaneous tissue, mostly found in the Middle East and the southwestern United States. The diagnosis is challenging because of the lack of specific clinical presentation and the absence of predisposing factors. In our case report, we discuss a 38-year-old male patient who presented with a 2-months history of right lower quadrant pain. Initially, his pain was intermittent and gradually increased in intensity; it localized to the right lower quadrant and radiated to the right flank region. No relieving or aggravating factors were noted. In addition, the patient mentioned a history of constipation, weight loss, decreased appetite, and vomiting-however, no history of fever, night sweats, trauma, or recent travel. The diagnosis was made based on computerized tomography (CT) guided biopsy of the mass, illustrating the findings of fungal hyphae with a gradual increase in the eosinophilic count since admission. The patient was managed using a combined medical and surgical approach, including surgical debulking of the mass and a well-monitored course of anti-fungal therapy. Gastrointestinal basidiobolomycosis infection (GBI) can present in many forms, with an increasing potential to invade the colon, ultimately forming an inflamed mass. Nonetheless, the presence of a mass invading the colon, adjacent vessels, and a retroperitoneal area, along with an increase in the number of eosinophil count in the Middle East region, should raise the suspicion of basidiobolomycosis fungal infection.

Transcriptome of Tumor-Infiltrating T Cells in Colorectal Cancer Patients Uncovered a Unique Gene Signature in CD4+ T Cells Associated with Poor Disease-Specific Survival.

Colorectal cancer (CRC) is influenced by infiltration of immune cell populations in the tumor microenvironment. While elevated levels of cytotoxic T cells are associated with improved prognosis, limited studies have reported associations between CD4+ T cells and disease outcomes. We recently performed transcriptomic profiling and comparative analyses of sorted CD4+ and CD8+ tumor-infiltrating lymphocytes (TILs) from bulk tumors of CRC patients with varying disease stages. In this study, we compared the transcriptomes of CD4+ with CD8+ TILs. Functional annotation pathway analyses revealed the downregulation of inflammatory response-related genes, while T cell activation and angiogenesis-related genes were upregulated in CD4+ TILs. The top 200 deregulated genes in CD4+ TILs were aligned with the cancer genome atlas (TCGA) CRC dataset to identify a unique gene signature associated with poor prognosis. Moreover, 69 upregulated and 20 downregulated genes showed similar trends of up/downregulation in the TCGA dataset and were used to calculate "poor prognosis score" (ppScore), which was significantly associated with disease-specific survival. High ppScore patients showed lower expression of Treg-, Th1-, and Th17-related genes, and higher expression of Th2-related genes. Our data highlight the significance of T cells within the TME and identify a unique candidate prognostic gene signature for CD4+ TILs in CRC patients.

RNA-Seq Analysis of Colorectal Tumor-Infiltrating Myeloid-Derived Suppressor Cell Subsets Revealed Gene Signatures of Poor Prognosis.

Elevated levels of myeloid-derived suppressor cells (MDSCs), including polymorphonuclear MDSCs (PMN-MDSCs) and immature MDSCs (I-MDSCs), are usually associated with disease progression in cancer patients, including colorectal cancer (CRC). However, biological mechanisms and molecular pathways regulated by MDSC subpopulations in the CRC tumor microenvironment (TME) have not been fully investigated. In this study, we performed transcriptomic analysis of tumor-infiltrating I-MDSCs and PMN-MDSCs isolated from tumor tissues of six CRC patients, compared to antigen-presenting cells (APCs). We also compared the transcriptomic profiles of tumor-infiltrating PMN-MDSCs to I-MDSCs. Our results showed different molecular pathways regulated by each MDSC subset, potentially reflecting their phenotypical/molecular/functional characteristics in the CRC TME. Moreover, we identified gene signatures in PMN-MDSC and I-MDSC of poor overall survival (OS) and disease-free survival (DFS) using the Cancer Genome Atlas (TCGA) dataset from patients with colon adenocarcinoma (COAD). However, functional studies are required to validate these findings.

Heterotopic Gastric Mucosa in the Ileum: A Rare Cause for Intussusception in Adults.

Intussusception is the leading cause for intestinal obstruction in children. However, it accounts for only 5% of bowel obstructions in adults. Heterotopic gastric mucosa (HGM) can occur anywhere in the gastrointestinal tract; nevertheless, its occurrence in the small intestine is rare unless associated with remnants of vitelline duct (Meckel's diverticulum). Herein, we describe a case of a 33-year-old male who presented with symptoms and signs of intestinal obstruction caused by ileo-colic intussusception, in which polypoid HGM acted as the organic lead point for intussusception. Several cases of intussusception caused by HGM have been reported in pediatric age group; however, this event is exceedingly rare in adults.

Differential gene expression of tumor-infiltrating CD8+ T cells in advanced versus early-stage colorectal cancer and identification of a gene signature of poor prognosis.

BACKGROUND: Cytotoxic CD8+ T cell-mediated response is the most important arm of adaptive immunity, which dictates the capacity of the host immune response in eradicating tumor cells. Due to tumor intrinsic and/or extrinsic factors, the density and function of CD8+ tumor-infiltrating lymphocytes (TILs) could be compromised, leading to poor prognosis and survival. METHODS: Using RNA-Seq, transcriptomes of sorted CD3+CD8+ TILs from treatment-naïve colorectal cancer (CRC) patients at advanced stages (III and IV) were compared with those from patients with early stages (I and II). A signature referred to as 'poor prognosis CD8 gene signature (ppCD8sig)' was identified and analyzed in The Cancer Genome Atlas CRC dataset. Scores for the ppCD8sig were calculated and classified as high, intermediate and low, and its prognostic significance was assessed using multivariate analysis and Cox proportional hazard model. Densities of CD3+ and CD8+ T cell infiltration in tumors from patients with high and low ppCD8sig scores were assessed by flow cytometry and immunostaining. RESULTS: Genes related to epigenetic regulation and response to hypoxia were upregulated in CD8+ TILs from patients with advanced stages, while genes related to T cell activation, cell proliferation and cell cycle were downregulated. Patients with high ppCD8sig score had poorer disease-specific survival (DSS) and shorter progression-free interval (PFI). The ppCD8sig was an independent prognostic indicator for DSS (HR 1.83, 95% CI 1.40 to 2.38, p<0.0001) and PFI (HR 1.42, 95% CI 1.04 to 1.93, p=0.026). Additionally, patients with high ppCD8sig score were more likely to have advanced stages (χ2 p<0.0001) and residual disease after primary therapy (χ2 p=0.046). Patients with high ppCD8sig score had reduced levels of CD3+ and CD8+ TILs and low Immunoscores (IS), compared to patients with low ppCD8sig score. CONCLUSIONS: Our data provided insights into the altered regulation of biological mechanisms and signaling pathways in CD8+ TILs during CRC progression, and revealed a gene signature as an independent prognostic indicator. Patients with high ppCD8sig score had lower levels of TILs and low IS. These data further confirm the prognostic value of the identified ppCD8sig and potentially highlight its clinical relevance.

Expression of immune checkpoints and T cell exhaustion markers in early and advanced stages of colorectal cancer.

Despite recent advances in colorectal cancer (CRC) treatment, a large proportion of patients show limited responses to therapies, especially in advanced stages. There is an urgent need to identify prognostic biomarkers and/or therapeutic targets in advanced stages, aiming to improve the efficacy of current treatments. We aimed to determine prognostic biomarkers in tumor tissue and circulation of CRC patients, with a special focus on T cell exhaustion markers. We found that mRNA levels of PD-1, TIM-3, CTLA-4, TIGIT, CD160, CD244, KLRG1, TOX2, TOX3, Ki-67, and PRDM1 were elevated in CRC tumor tissues. We also investigated differences in gene expression between early and advanced disease stages. We found that TOX and potentially TIM-3, CTLA-4, VISTA, TIGIT, KLRG1, TOX2, SIRT1, Ki-67, and Helios mRNA levels in tumor tissue were elevated in advanced disease stages, suggesting their potential roles in CRC progression. In contrast, PD-1 and CD160 levels in tumor tissue were downregulated in advanced stages. In the circulation of CRC patients, mRNA levels of PD-1, VISTA and LAG-3 were higher than those of healthy individuals. Moreover, in circulation, PD-1, CTLA-4 and TIGIT mRNA levels were reduced in advanced stages. Interestingly, levels of PD-1 in both tumor tissue and circulation were reduced in advanced stages, suggesting that targeting PD-1 in patients with advanced stages could be less effective. Altogether, these findings suggest some potential T cell exhaustion markers that could be utilized as prognostic biomarkers and/or therapeutic targets for CRC. However, further investigations and validations in larger cohorts are required to confirm these findings.

Immune Checkpoints in Circulating and Tumor-Infiltrating CD4+ T Cell Subsets in Colorectal Cancer Patients.

Blockade of inhibitory immune checkpoints (ICs) is a promising therapeutic approach; however, it has shown limited success in some cancers including colorectal cancer (CRC). The tumor microenvironment (TME) is largely responsible for response to therapy, and its constituents may provide robust biomarkers for successful immunotherapeutic approaches. In this study, we performed phenotypical characterization and critical analyses of key inhibitory ICs and T regulatory cell (Treg)-related markers on CD4+ T cell subsets in CRC patients, and compared with normal colon tissues and peripheral blood from the same patients. We also investigated correlations between the levels of different CD4+ T cell subsets and the clinicopathologic features including disease stage and tumor budding. We found a significant increase in the levels of CD4+FoxP3+Helios+ T cells, which represent potentially highly immunosuppressive Tregs, in the CRC TME. Additionally, tumor-infiltrating CD4+ T cells upregulated programmed cell death protein-1 (PD-1), cytotoxic T-lymphocyte-associated protein-4 (CTLA-4), T cell immunoglobulin and mucin domain-3 (TIM-3) and lymphocyte-activation gene 3 (LAG-3). We also characterized the expression of PD-1, CTLA-4, TIM-3, and LAG-3 on different CD4+FoxP3-/+Helios-/+ T cell subsets. Interestingly, we found that CTLA-4, TIM-3, and LAG-3 were mainly co-expressed on FoxP3+Helios+ Tregs in the TME. Additionally, FoxP3high Tregs expressed higher levels of Helios, CTLA-4 and TIM-3 than FoxP3low T cells. These results highlight the significance of Tregs in the CRC TME and suggest that Tregs may hamper response to IC blockade in CRC patients, but effects of different IC inhibition regimes on Treg levels or activity warrants further investigations. We also found that CD4+CTLA-4+ T cells in circulation are increased in patients with advanced disease stage. This study simultaneously provides important insights into the differential levels of CD4+ T cell subpopulations and IC expression in CRC TME, compared to periphery and associations with clinicopathologic features, which could be used as potential biomarkers for CRC progression and response to therapy.

Frequency, characteristics and outcomes of appendicular neuroendocrine tumors: A cross-sectional study from an academic tertiary care hospital.

BACKGROUND: Appendicular neuroendocrine tumors (NET, Carcinoid tumors) of the appendix are rare and mostly diagnosed incidentally on the post-operative histopathological examination. NET are usually associated with good 5-year survival rates. We aimed to assess our experience for the diagnosis and management of NET over 11 years. METHOD: It is a retrospective chart review of all clinically suspected patients with acute appendicitis who underwent emergent appendectomy with intention to treat between January 2004-December 2014, and were clinically followed up until 2016. RESULTS: During the study period, a total of 13641 patients underwent emergency appendectomy, of which 32 were histologically confirmed NET. The mean age of the NET cases was 25.3 ± 7.9 years; 78% were males and all were clinically presented with acute appendicitis. The mean leucocyte was 15 ± 14 × 109 per Liter, and mean tumor size was 4.86 ± 3.18 (ranged 1.5-13) mm. The median length of hospital stay was 4 (2-15) days. One patient had right hemicolectomy; diagnosed with right colonic cancer with NET being an incidental finding as part of histopathological assessment. Another patient required a second stage procedure; he was diagnosed as goblet cell carcinoid with positive margin. None of the patients died 30-day postoperatively and all of them survived on clinical follow-up that ranged between 2 and 13 years. CONCLUSION: Carcinoid tumors of the appendix are rare and typically diagnosed incidentally. Detailed examination of routine appendectomy specimens is the key for diagnosis. Simple appendectomy suffices for tumors <2 cm for adequate clearance. Appendicular carcinoid tumors are associated with good long-term outcomes.

Pancreatico-enteric fistula post pancreatic duct ligation for delayed haemorrhage complicating pancreaticoduodenectomy.

INTRODUCTION: Pancreatic fistula remains the main cause for postoperative morbidity following pancreaticoduodenectomy. The coincidence of sentinel bleed prior to post pancreatectomy haemorrhage (PPH) and pancreatic fistula is associated with very high mortality. PRESENTATION OF CASE: We report a case of pancreaticoduodenectomy complicated by postoperative leak and hematemesis. Severe delayed haemorrhage from the pancreatico-jejunostomy necessitated re-laparotomy and complete disconnection of the pancreatic anastomosis. Hemodynamic instability precluded a pancreatectomy or creation of a new anastomosis. A follow up MRI done 3 weeks after the patient's discharge demonstrated a fistulous tract causing a communication between both the pancreatic and biliary systems and the enteric loop. DISCUSSION: Spontaneous development a pancreatico-enteric fistula despite ligation of the pancreatic duct and complete disconnection of the pancreatic anastomosis has never been reported in literature to date. CONCLUSION: Pancreatic duct occlusion may be considered over a completion pancreatectomy or revisional pancreatic anastomosis in hemodynamically unstable and challenging cases.