Primary small bowel adenocarcinoma: current view on clinical features, risk and prognostic factors, treatment and outcome

Immune signature of small bowel adenocarcinoma and the role of tumor microenvironment

In this editorial we comment on the article published "Clinical significance of programmed cell death-ligand expression in small bowel adenocarcinoma is determined by the tumor microenvironment". Small bowel adenocarcinoma (SBA) is a rare gastrointestinal neoplasm and despite the small intestine's significant surface area, SBA accounts for less than 3% of such tumors. Early detection is challenging and the reason arises from its asymptomatic nature, often leading to late-stage discovery and poor prognosis. Treatment involves platinum-based chemotherapy with a 5-fluorouracil combination, but the lack of effective chemotherapy contributes to a generally poor prognosis. SBAs are linked to genetic disorders and risk factors, including chronic inflammatory conditions. The unique characteristics of the small bowel, such as rapid cell renewal and an active immune system, contributes to the rarity of these tumors as well as the high intratumoral infiltration of immune cells is associated with a favorable prognosis. Programmed cell death-ligand 1 (PD-L1) expression varies across different cancers, with potential discrepancies in its prognostic value. Microsatellite instability (MSI) in SBA is associated with a high tumor mutational burden, affecting the prognosis and response to immunotherapy. The presence of PD-L1 and programmed cell death 1, along with tumor-infiltrating lymphocytes, plays a crucial role in the complex microenvironment of SBA and contributes to a more favorable prognosis, especially in the context of high MSI tumors. Stromal tumor-infiltrating lymphocytes are identified as independent prognostic indicators and the association between MSI status and a favorable prognosis, emphasizes the importance of evaluating the immune status of tumors for treatment decisions.

Characteristics and outcomes of small bowel adenocarcinoma: 14 years of experience at a single tertiary hospital in Saudi Arabia

Small bowel adenocarcinoma (SBA) is an extremely rare cancer type. In the present study, the patient characteristics and clinical outcomes of patients diagnosed and treated for SBA at a single tertiary hospital were reported. All patients diagnosed and managed between 2007 and 2020 were reviewed. Regression analysis was used to assess variables associated with the metastatic stage at diagnosis. The Kaplan-Meier method was used to estimate survival and the log-rank test was used to determine factors associated with survival outcomes. Out of 137 cases of small bowel primary tumor, 43 consecutive patients with SBA were diagnosed with a median age of 53 years and the majority (76.7%) were males. The common initial presenting symptoms were abdominal pain (58.8%) and bowel obstruction (30.2%). The most common primary site was the duodenum (60.5%) and the majority (65.1%) were diagnosed with stage III/IV disease. Patients with a high neutrophil-lymphocyte ratio (NLR) (≥0.85) were more likely to be in the metastatic stage at diagnosis (P=0.01). The 3-year overall survival (OS) rates based on stage were 100% (I), 85% (II), 53% (III) and 33.9% (IV) (P=0.001). In addition to the stage, the Eastern Cooperative Oncology Group Performance Status (P<0.001), NLR (P<0.001), hypoalbuminemia (P=0.02) and chemotherapy in a metastatic setting (P=0.02) were prognostic factors for OS. In conclusion, NLR is a potential prognostic biomarker for a metastatic stage at diagnosis. Advanced stage, lower performance status score, low albumin level and high NLR are associated with short OS.

Metastatic Small Bowel Adenocarcinoma Mimicking a Primary Ovarian Mucinous Tumour - Clinical, Radiologic, Pathologic and Molecular Correlation

We describe an interesting case of a patient who presented with a large adnexal mass, first favored to be mucinous carcinoma of the gynecologic origin. The primary tumour site was ascertained after the patient's small bowel was resected by identifying an adenomatous component evolving into an invasive adenocarcinoma identical in morphology and immunophenotype to the ovarian tumour. Notably, both tumours were found to harbor a BRAF K601E mutation, which is extremely rare for a primary of the ovary. BRAF mutations are present in a subset of large bowel and small bowel adenocarcinoma, but our case shows the first instance of a BRAF K601E mutation being present in a small bowel adenocarcinoma, to the best of our knowledge. This case serves as a great illustration of the pivotal role of molecular diagnostics in modern pathology in arriving at the correct diagnosis. Additionally, it is an excellent example of how clinical-radiologic-pathologic-molecular correlation plays into the landscape of molecular pathology to deliver optimal care for the patient.

Outcomes of Patients with Small Intestine Adenocarcinoma in a Canadian Province: A Retrospective Multi-Center Population-Based Cohort Study

Background: Small intestine adenocarcinoma is a rare cancer. The current study aims to determine the outcomes of patients with small intestine adenocarcinoma in a Canadian province. Methods: This retrospective population-based cohort study assessed patients with small intestine adenocarcinoma who were diagnosed from 2008 to 2017 in Saskatchewan. A Cox proportional multivariate regression analysis was performed to determine the correlation between survival and exploratory factors. Results: 112 eligible patients with a median age of 73 years and M:F of 47:53 were identified. Overall, 75% had a comorbid illness, and 45% had a WHO performance status >1. Of the 112 patients, 51 (46%) had early-stage disease and 61 (54%) had advanced-stage disease. The median overall survival (mOS) was as follows: stage one, 59 months; stage two, 30 months; stage three, 20 months; and stage four, 3 months (p < 0.001). The median disease-free survival of patients with stage three disease who received adjuvant chemotherapy was 26 months (95% CI:23.1−28.9) vs. 4 months (0.0−9.1) with observation (p = 0.04). Patients who received chemotherapy for advanced disease had a mOS of 10 months (3.5−16.5) vs. 2 months (0.45−3.6) without chemotherapy (p < 0.001). In the multivariate analysis, stage four disease, hazard ratio (HR), 3.20 (1.84−5.40); WHO performance status >1, HR, 2.22 (1.42−3.45); lack of surgery, HR, 2.10 (1.25−3.50); and a neutrophil:lymphocyte ratio of >4.5, HR, 1.72 (1.10−2.71) were significantly correlated with inferior survival. Conclusions: Most patients with small intestine adenocarcinoma were diagnosed with advanced-stage disease. Advanced-stage disease, poor performance status, lack of surgery and a baseline neutrophil:lymphocyte ratio >4.5 were correlated with inferior survival.

Small bowel adenocarcinoma a rare cause of upper gastrointestinal obstruction (a case report and literature review)

INTRODUCTION

Small bowel adenocarcinoma is a rare but increasing disease. It poses both a diagnostic and therapeutic challange. Small bowel adenocarcinoma is a rare cause of small bowel obstruction. We present the case of a patient admitted to our emergency department for a bowel obstruction due to a mass of the jejunum and whose anatomopathological diagnosis was adenocarcinoma.

PATIENT AND METHOD

It is a 62-year-old woman with unparticular history, admitted to the emergency of visceral surgery of Ibn Rochd University Hospital for subocclusive syndrome evolving for one year, with early postprandial vomiting becoming stenosing two months ago. The abdominal CT scan showed thickening jejunal wall of 46 mm with upstream distension. She underwent a segmental bowel resection of 50 cm of small bowel with 3 cm stenotic mass located at 40 cm from the duodenojejunal angle. The pathophysiology revealed an invasive liberkhunian adenocarcinoma. The postoperative follow-up was simple, feeding allowed at D4 with discharge allowed at D6 and functional improvement at the time of the control performed three months after the intervention.

DISCUSSION

Small bowel adenocarcinoma is rare and represents only 1-3% of all gastrointestinal cancers. The incidence of SBA is 24 to 66 times lower than that of colorectal cancer (CRC). Due to its non-specific clinical manifestation and less accessible location, SBA is diagnosed at an advanced stage, and often at specimen analysis. The treatment is resection and the overall survival is increased when diagnostic is early made.

CONCLUSION

Small bowel adenocarcinoma is a rare but increasing cause of gastrointestinal malignancy, being both a diagnostic and therapeutic challenge. In front of the occlusive syndrome of small bowel appearance, adenocarcinoma must be ruled out.

An autopsy case of primary jejunal pouch cancer which protruded from the abdominal wall 14 years after total gastrectomy for gastric cancer

Adenocarcinoma which develops in the jejunal pouch has rarely been reported, but most of such cases tend to be a recurrence of primary cancer due to the presence of residual or disseminated cancer cells. Primary jejunal pouch cancer is extremely rare. We experienced an autopsy case of primary jejunal pouch cancer which occurred 14 years after proximal gastrectomy for gastric cancer. A female in her late 60s was admitted because of hypoglycemia with liver dysfunction. She underwent total gastrectomy for fundic cancer and had been reconstructed by jejunal pouch interposition 14 years prior to this presentation. Hypoglycemia recovered by nutritional support. Computed tomography demonstrated severe fatty liver and liver biopsy proved non-alcoholic steatohepatitis, which was supposed to have been induced by malnutrition. Screening esophagogastroduodenoscopy (EGD) revealed no tumorous lesions in the jejunal pouch at this time. However, her anorexia gradually progressed and the symptom of bowel obstruction appeared. EGD performed 5 months after the previous EGD revealed adenocarcinoma which extended from the anastomosis of the interposed jejunum. Then liver metastasis developed and jejunal pouch cancer invaded the abdominal wall and protruded with ulcer formation. Finally, the patient died of malnutrition. An autopsy revealed adenocarcinoma which had developed in the interposed jejunal pouch and protruded through the abdominal wall accompanied with lung and liver metastasis. We herein describe this rare case of primary interposed jejunal pouch cancer and discuss our findings including a review of the pertinent literature.

Prognostic Value of Immune Environment Analysis in Small Bowel Adenocarcinomas with Verified Mutational Landscape and Predisposing Conditions

Background: Small bowel adenocarcinoma (SBA) is a rare yet insidious cancer with poor survival. The abundance of tumour-infiltrating lymphocytes is associated with improved survival, but the role of the programmed death-1/programmed death ligand-1 (PD-1/PD-L1) pathway in tumour escape is controversial. We evaluated immune cell infiltration, PD1/PD-L1 expression and their prognostic value in a series of SBAs with previously verified predisposing conditions and exome-wide somatic mutation characterization. Methods: Formalin-fixed paraffin-embedded tissue sections stained for CD3, CD8, PD-L1 and PD-1 were analysed from 94 SBAs. An immune cell score (ICS) was formed from the amount of the CD3 and CD8 positive lymphocytes from the tumour centre and invasive margin. The PD-L1 and PD-1 positive immune cells (ICs) and ICS were combined into a variable called Immunoprofile. Results: High ICS, PD-L1^IC and PD-1, individually and combined as Immunoprofile, were prognostic for better patient outcome. Sixty-five (69%) SBAs expressed ≥1% positive PD-L1^IC. A high tumour mutation burden was common (19%) and associated with immune markers. Immunoprofile, adjusted for TNM stage, mismatch repair status, tumour location, sex and age were independent prognostic markers for disease-specific and overall survival. Conclusions: Analysing tumoral immune contexture provides prognostic information in SBA. Combining ICS, PD-1 and PD-L1^IC as Immunoprofile enhanced the prognostic performance.

A case of small bowel adenocarcinoma wherein nivolumab conferred temporary benefit in disease control

Small bowel adenocarcinomas are rare. There is no definite consensus as to whether they should be treated in a manner similar to gastric or to colon cancer. We report the case of a young woman with a primary jejunal adenocarcinoma, bilateral ovary metastases, and peritoneal dissemination. First- and second-line chemotherapy for the gastric cancer failed. She was then treated with the immune checkpoint inhibitor nivolumab and had temporary improvement in her condition. To the best of our knowledge, this is the first case wherein nivolumab has been used to treat small bowel adenocarcinoma.

Dual loss of USP10 and p14ARF protein expression is associated with poor prognosis in patients with small intestinal adenocarcinoma

Oncogene-induced senescence occurs following oncogene activation in normal cells and is considered as a critical tumor-suppressing mechanism. Ubiquitin-specific protease 10 (USP10) has been reported to play a vital role in oncogene-induced senescence via the deubiquitination-dependent stabilization of p14ARF. However, knowledge of the clinical significance of USP10 and p14ARF expression in patients with small intestinal adenocarcinoma is limited. To study the clinical significance of USP10 and p14ARF expression, we performed immunohistochemistry for USP10 and p14ARF on 195 surgically resected small intestinal adenocarcinoma specimens. Furthermore, we performed methylation analysis on five small intestinal adenocarcinoma samples and matched adjacent normal intestinal tissue samples. UPS10 ( p = 0.023) and p14ARF ( p = 0.007) expression were significantly decreased in adenocarcinoma in comparison with normal tissue. The loss of USP10 was observed in 124/194 (63.9%) of small intestinal adenocarcinoma samples and was correlated with a higher pT stage ( p = 0.044), lymphatic invasion ( p = 0.033), and the absence of sporadic adenoma ( p = 0.024) and peritumoral dysplasia ( p = 0.019). p14ARF expression was downregulated in 75/195 (38.5%) of small intestinal adenocarcinoma samples and was associated with vascular ( p = 0.011) and lymphatic ( p = 0.013) invasions. The loss of USP10 expression was associated with the loss of p14ARF expression ( r = 0.342, p < 0.001). Multivariate survival analysis revealed that the combined loss of USP10 and p14ARF expression could be an independent prognostic factor for overall survival in small intestinal adenocarcinoma. Furthermore, the aberrant hypermethylation of the USP10 and p14ARF promoter could be a key mechanism for the downregulation of USP10 and p14ARF proteins in small intestinal adenocarcinoma. These findings suggest that the dual loss of USP10 and p14ARF could be used as a prognostic indicator of small intestinal adenocarcinoma.

Landscape of Tumor Mutation Load, Mismatch Repair Deficiency, and PD-L1 Expression in a Large Patient Cohort of Gastrointestinal Cancers

The efficacy of immunotherapy varies widely among different gastrointestinal cancers. Response to immune checkpoint inhibitors is shown to correlate with tumor mutation load (TML), mismatch repair deficiency (dMMR) status, and programmed cell death-ligand 1 (PD-L1) expression. Herein, we quantify TML, dMMR, and PD-L1 expression and determine their interrelationship in gastrointestinal cancers. Here, a total of 4,125 tumors from 14 different gastrointestinal cancer sites were studied using validated assays. Next-generation sequencing was performed on genomic DNA isolated from formalin-fixed paraffin-embedded tumor specimens using the NextSeq platform. TML was calculated using only somatic nonsynonymous missense mutations sequenced with a 592-gene panel. Microsatellite instability (MSI) was assessed using direct analysis of altered known MSI loci in the target regions of the sequenced genes. PD-L1 expression was analyzed by IHC. Interestingly, right-sided colon and small-bowel adenocarcinomas had the highest prevalence of TML-high tumors (14.6% and 10.2%, respectively). Pancreatic neuroendocrine tumors and gastrointestinal stromal tumors had the lowest rates of TML-high (1.3% and 0%, respectively). TML-high was strongly associated with MSI-H (P < 0.0001). However, all TML-high anal cancers (8.3%) were microsatellite stable (MSS). Higher PD-L1 expression was more likely to be seen in MSI compared with MSS tumors (20.6% vs. 7.8%, P < 0.0001).Implications: TML-high rate varied widely among gastrointestinal cancers. Although MSI is conceivably the main driver for TML-high, other factors may be involved. Future clinical trials are needed to evaluate whether the integration of TML, MSI, and PD-L1 could better identify potential responders to immunotherapy. Mol Cancer Res; 16(5); 805-12. ©2018 AACR.

The elusive small bowel adenocarcinoma in the terminal ileum-A case report

INTRODUCTION

Small bowel malignancies are rare and often present with non-specific symptoms. Because of this, diagnosis of small bowel malignancies is often missed.

PRESENTATION OF CASE

71-year-old male presented with a four-week history of right iliac fossa pain and loss of weight. Laboratory tests showed a raised C-reactive protein, but all other pathology results and tumour-associated antigens were normal. Computed tomography (CT) of the abdomen demonstrated an inflammatory mass extending laterally into the pelvic wall. The patient underwent an elective laparotomy and resection of the small bowel tumour. Intra-operative findings included a small bowel tumour adherent to two loops of small bowel. Histology demonstrated a 50 mm poorly differentiated mucinous adenocarcinoma of the terminal ileum.

DISCUSSION

Clinical presentation of small bowel adenocarcinoma is often non-specific, which leads to a delay in diagnosis. As a result, disease is often advanced by the time of diagnosis. Upper and lower endoscopy is useful in detecting tumours in the duodenum and terminal ileum. Video capsule endoscopy allows visualisation of the entire small bowel mucosa. Enteroscopy can also be used to obtain biopsies and perform therapeutic interventions. CT is able to detect abnormalities in 80% of patients, while CT and MR (magnetic resonance) enteroclysis give better visualisation of the mucosa and mural thickness. Surgical exploration may be indicated in patients with a strong clinical suspicion.

CONCLUSION

In conclusion, small bowel malignancies are rare and clinicians are reminded to have a high index of suspicion for small bowel malignancies in patients who present with non-specific abdominal symptoms.