Intra-abdominal Metastases Research Articles

Radiographs are of limited use and low cost-effectiveness when combined with ultrasound for abdominal restaging in dogs with solid, soft tissue tumours.

The purposes of this study were to assess the frequency of detection of clinically relevant findings by abdominal radiographs and abdominal ultrasound during restaging of solid, soft tissue tumours in dogs and to determine the cost per clinically relevant finding for both modalities. The medical records of 159 dogs which underwent a total of 223 restaging episodes following a diagnosis of a solid, soft tissue tumour within, or with potential for metastasis to, the abdomen were reviewed. Data collected from the sample dogs were reviewed for clinically relevant findings, including local recurrence, lymph node or intra-abdominal metastasis, and other changes that would influence prognosis or management. The clinically relevant findings were compared between abdominal radiographs and abdominal ultrasound. The cost per clinically relevant finding was calculated per modality based on current hospital costs. Clinically relevant findings were observed in 158 restaging episodes. Ninety-two clinically relevant findings were detected with ultrasound alone, and 65 clinically relevant findings were detected with a combination of both modalities. Only one dog had a clinically relevant finding detected with radiographs alone. Findings were identified significantly more frequently with ultrasound than radiographs. Cost per clinically relevant finding was 495 USD (approx. 373 GBP/448 EUR) for abdominal radiographs and 323 USD (approx. 242 GBP/292 EUR) for abdominal ultrasound. Abdominal radiographs were of minimal use beyond abdominal ultrasound for restaging in this study, despite a higher cost per clinically relevant finding than abdominal ultrasound. This study does not support routine use of abdominal radiographs during routine restaging of solid, soft tissue tumours.

Ascites production and prognosis after ventriculoperitoneal shunt for diffuse midline gliomas in children: A case series.

DMG is a highly invasive and lethal type of brain tumor. As these tumors progress, they often compromise the CSF circulation, leading to hydrocephalus. Ventriculoperitoneal shunt (VPS) is commonly employed to manage hydrocephalus; however, the complication of VPS-induced ascites, particularly in the presence of tumor cells, is a significant concern that merits attention. This case series details 3 pediatric patients diagnosed with brainstem DMG harboring the H3 K27M mutation. Each developed hydrocephalus underwent VPS insertion. Post-operatively, all patients developed carcinomatous ascites with tumor cells detected within the ascitic fluid. All 3 patients were diagnosed with intra-abdominal metastasis of DMG H3K27M mutant cancer cells, each presenting with distinct complications. Initially, the patients' primary head tumors responded to treatment, and their hydrocephalus resolved. However, some time after discharge, each patient developed malignant ascites and received palliative chemotherapy to control symptoms and improve quality of life. Despite the interventions, all 3 patients died within 1 month of developing malignant ascites, with central respiratory failure being the direct cause of death. These cases underscore the importance of continuous monitoring of both the CSF and ascitic fluid in patients with gliomas. Regular assessments of biochemical composition, cytology, and other diagnostic tests are crucial for early detection of disease progression. This proactive approach facilitates timely clinical judgment and intervention, potentially improving patient outcomes.

Outcomes of patients admitted with malignant small bowel obstruction: a subgroup multicentre observational cohort analysis

Introduction and purpose of the studySmall bowel obstruction (SBO) accounts for a substantial proportion of emergency surgical admissions. Malignancy is a common cause of obstruction, either due to a primary tumour or intra-abdominal metastases. However, little is known regarding the current treatment or outcomes of patients with malignant SBO. This study aimed to characterise the treatment of malignant SBO and identify areas for potential improvement and compare overall survival of patients with malignant SBO to patients with non-malignant SBO.Materials and methodsThis was a subgroup analysis of a multicentre observational study of patients admitted with SBO. Details regarding these patients’ diagnoses, treatments, and outcomes up to 1-year after admission were recorded. The primary outcome was overall survival in patients with malignant SBO.ResultsA total of 316 patients with small bowel obstruction were included, of whom 33 (10.4%) had malignant SBO. Out of the 33 patients with malignant SBO, 20 patients (60.6%) were treated with palliative intent although only 7 patients were seen by a palliative team during admission. Nutritional assessments were performed on 12 patients, and 11 of these patients received parenteral nutrition. 23 patients underwent surgery, with the most common surgical interventions being loop ileostomies (9 patients) and gastrointestinal bypasses (9 patients). 4 patients underwent right hemicolectomies, with a primary anastomosis formed and 1 patient had a right hemicolectomy with a terminal ileostomy. Median survival was 114 days, and no difference was seen in survival between patients treated with or without palliative intent.ConclusionMalignant SBO is associated with significant risks of short-term complications and a poor prognosis. Consideration should be given to the early involvement of senior decision-makers upon patient admission is essential for optimal management and setting expectation for a realistic outcome.

Effectiveness of immune checkpoint inhibitor therapy on bone metastases in non-small-cell lung cancer.

Bone metastases (BoMs) are prevalent in patients with metastatic non-small-cell lung cancer (NSCLC) however, there are limited data detailing how BoMs respond to immune checkpoint inhibitors (ICIs). The purpose of this study was to compare the imaging response to ICIs of BoMs against visceral metastases and to evaluate the effect of BoMs on survival. A retrospective, multicentre cohort study was conducted in patients with NSCLC treated with nivolumab or pembrolizumab in Alberta, Canada from 2015 to 2020. The primary endpoint was the real-world organ specific progression free survival (osPFS) of bone versus visceral metastases. Visceral metastases were categorized as adrenal, brain, liver, lung, lymph node, or other intra-abdominal lesions. The secondary outcome was overall survival (OS) amongst patients with and without BoMs. A total of 573 patients were included of which all patients had visceral metastases and 243 patients (42.4%) had BoMs. High PD-L1 expression was identified in 268 patients (46.8%). No significant difference in osPFS was observed between bone, liver, and intra-abdominal metastases (p=0.20 and p=0.76, respectively), with all showing shorter osPFS than other disease sites. There was no difference in the osPFS of extra-thoracic sites of disease in patients with high PD-L1 expression. There was significant discordance between visceral disease response and bone disease response to ICI (p=0.047). The presence of BoMs was an independent poor prognostic factor for OS (HR 1.26, 95%CI: 1.05-1.53, p=0.01). Metastatic bone, liver, and intra-abdominal lesions demonstrated inferior clinical responses to ICI relative to other sites of disease. Additionally, the presence of bone and liver metastases were independent poor prognostic factors for overall survival. This real-world data suggests that BoMs respond poorly to ICI and may require treatment adjuncts for disease control.

Hormone Receptor Expression and Activity for Different Tumour Locations in Patients with Advanced and Recurrent Endometrial Carcinoma.

Response to hormonal therapy in advanced and recurrent endometrial cancer (EC) can be predicted by oestrogen and progesterone receptor immunohistochemical (ER/PR-IHC) expression, with response rates of 60% in PR-IHC > 50% cases. ER/PR-IHC can vary by tumour location and is frequently lost with tumour progression. Therefore, we explored the relationship between ER/PR-IHC expression and tumour location in EC. Pre-treatment tumour biopsies from 6 different sites of 80 cases treated with hormonal therapy were analysed for ER/PR-IHC expression and classified into categories 0-10%, 10-50%, and >50%. The ER pathway activity score (ERPAS) was determined based on mRNA levels of ER-related target genes, reflecting the actual activity of the ER receptor. There was a trend towards lower PR-IHC (33% had PR > 50%) and ERPAS (27% had ERPAS > 15) in lymphogenic metastases compared to other locations (p = 0.074). Hematogenous and intra-abdominal metastases appeared to have high ER/PR-IHC and ERPAS (85% and 89% ER-IHC > 50%; 64% and 78% PR-IHC > 50%; 60% and 71% ERPAS > 15, not significant). Tumour grade and previous radiotherapy did not affect ER/PR-IHC or ERPAS. A trend towards lower PR-IHC and ERPAS was observed in lymphogenic sites. Verification in larger cohorts is needed to confirm these findings, which may have implications for the use of hormonal therapy in the future.

Abstract 3784: Methylated DNA markers for detection of peritoneal metastasis in pancreatic cancer

Abstract Introduction: Laparoscopy with peritoneal lavage enhances staging accuracy in patients with pancreatic ductal adenocarcinoma (PDAC). Occult intra-abdominal metastases are identified by staging laparoscopy in approximately 20% of patients with radiologically localized PDAC. Peritoneal fluid cytology has limited sensitivity in detecting occult intra-abdominal metastasis. Methylated DNA markers (MDMs) can accurately detect PDAC from tumor tissue, blood, and pancreatic secretions. This study aims to assess the feasibility of assaying MDMs in peritoneal lavage fluid obtained at the time of staging laparoscopy for patients with PDAC. Methods: Peritoneal lavage fluid (25-60 mL) obtained from patients with PDAC at the time of staging laparoscopy was centrifuged for 10 minutes at 1200 × g. The pellet was resuspended and aliquoted into 200µL tubes and frozen at -80°C. DNA extracted from one aliquot was assayed for mutant KRAS (G12A and G13D) and then bisulfite converted to measure 13 MDMs (GRIN2D, CD1D, ZNF781, FER1L4, RYR2, CLEC11A, AK055957, LRRC4, MAX.CHR5.4295, HOXA1, PRKCB, SHISA9, NTRK3) and a normalizing reference gene (B3GALT6) using quantitative methylation specific PCR. The association of KRAS and the average signal from the 13 MDMs (MDMscore) with intra-abdominal metastasis (Y/N) was assessed with the area under the receiver operator characteristic curve (AUC). Results: Among 48 PDAC patients, staging laparoscopy revealed intra-abdominal metastasis in 15 (31%). Of the 15 intra-abdominal metastases, 6 were found to have biopsy-confirmed intra-abdominal metastasis and positive peritoneal cytology, 4 were positive on peritoneal cytology alone, and 5 had biopsy-confirmed intra-abdominal metastasis alone. The sensitivity of the MDMscore for intra-abdominal metastasis was 87% (CI: 60-98%) at 90% (CI: 76-98%) specificity whereas the sensitivity for KRAS was 40% (CI: 16-68%) at 85% (CI: 68-95) specificity. The AUC for the MDMscore was 0.98 (CI: 0.94-1.00) compared to 0.62 (CI: 0.48-0.77) for that of KRAS (p<0.0001). Conclusion: MDMs assayed from peritoneal lavage fluid collected during staging laparoscopy is a novel tool for accurate molecular staging of PDAC. These early results warrant further study in a larger cohort to assess impact on peritoneal staging and its clinical utility in the neoadjuvant treatment paradigm of PDAC. Citation Format: Kalika Maheshwari, Calise K. Berger, William R. Taylor, Douglas W. Mahoney, Kelli N. Burger, Adriana M. Delgado, Karen A. Doering, Heather M. Streich, Patrick H. Foote, Sean P. Cleary, Travis E. Grotz, Micheal L. Kendrick, Rory L. Smoot, Patrick P. Starlinger, Cornelius A. Thiels, Mark J. Truty, Susanne G. Warner, John B. Kisiel, Shounak Majumder. Methylated DNA markers for detection of peritoneal metastasis in pancreatic cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3784.

Abstract 7014: Integrative DNA methylation cancer profiling reveals patterns associated with tumor progression and treatment response

Abstract DNA methylation plays a critical role in tumor progression and response to chemotherapy. Frequently dysregulated during tumor development, it is closely intertwined with mixed effects from patient epigenetic background, tissue context, and treatment pressure. Here, we leveraged methylomic and transcriptomic profiling of 400 whole-genome sequencing samples from 125 patients with ovarian high-grade serous carcinoma (HGSC), belonging to the prospective, longitudinal, multi-region DECIDER trial (NCT04846933). This cohort included 120 samples from tubo-ovarian tumors, 209 samples from intra-abdominal metastases, and 71 ascites, representing all major sites of HGSC metastases. We profiled cancer methylome across tissues, patient groups, and various anticancer treatments using decomposition method, which allows separating the effects of tumor microenvironment and treatment, tissue, and patient specific changes, thus, facilitating integration of the heterogeneous collection of samples. First, we systematically examined the tissue-specific carcinogenesis and characterized methylomes of all types of metastases and excess fluid accumulations in the abdominal cavity. In our analyses, the cancer spread from tubo-ovarian sites to metastatic deposits involved gradual loss of DNA methylation and increase in transcriptomic levels, possibly indicating stemness. Specifically, several members of the ATP-binding-cassette (ABC) family of transporters, as well as receptor tyrosine kinases were frequently hypomethylated in bowel and omentum. The methylome of ascites showed most commonality to the tubo-ovarian tumors and peritoneum. Our results confirmed that several well-known tumor-associated genes, such as PTEN, GSK3B, ESR1, FGFR2, TNC, BCL6, HIF1A, NOTCH2 are regulated epigenetically, and this dysregulation stems early from the sites of origin. Next, we built methylomic profiles of patients with various treatment responses. Direct comparisons between good and poor responders revealed pronounced methylation differences, with refractory disease being associated with severely aberrated methylome prior to chemotherapy treatment. Neoadujuvant chemotherapy resulted in very few changes to these epigenetic aberrations and no acquired mechanisms, suggesting that intrinsic methylomes of poor responders accommodate multiple drivers for EMT, hypoxia, and chronic inflammation to resist chemotherapy-induced cell death already prior to treatment. In conclusion, using a large whole-genome sequencing DNA methylation dataset we elucidated the major underlying epigenetic mechanisms of tumorigenesis and platinum resistance, which provide possible drug targets for improving platinum sensitivity. Our multi-omics analyses enabled the identification of aberrated patterns that drive transcriptional changes, shedding light on epigenetic landscape of HGSC. Citation Format: Alexandra Lahtinen, Giovanni Marchi, Daria Afenteva, Kari Lavikka, Susanna Holmström, Elsi Pöllänen, Giulia Micoli, Ilari Maarala, Yilin Li, Taru A. Muranen, Jaana Oikkonen, Sakari Hietanen, Anni Virtanen, Johanna Hynninen, Antti Häkkinen, Sampsa Hautaniemi. Integrative DNA methylation cancer profiling reveals patterns associated with tumor progression and treatment response [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 7014.

Organ-specific response with first-line atezolizumab-bevacizumab versus lenvatinib for patients with advanced hepatocellular carcinoma.

467 Background: Hepatocellular carcinoma (HCC) is the fifth most common cancer and the second leading cause of cancer-related death worldwide. Immune checkpoint inhibitor (ICI)-based treatments have become the mainstay of first-line treatment for unresectable HCC, but there has been a concern that intrahepatic HCC lesions may be less responsive to ICI monotherapy. Methods: This retrospective study included 386 patients with Child-Pugh A unresectable HCC who were treated with first-line atezolizumab-bevacizumab (n = 217) or lenvatinib (n = 169). The organ-specific response was separately evaluated according to the site of the lesions: liver, lung, lymph node (LN), and intra-abdomen based on a radiological evaluation adopted from RECIST v 1.1. Up to 2 lesions were chosen as target lesions in each organ for the organ-specific response evaluation. Results: The median age was 60 years. The majority of study patients were male in both groups (83.4% and 85.8% in the atezolizumab-bevacizumab and lenvatinib groups, respectively). The etiology of HCC was similar between the two groups: hepatitis B virus infection was the most common etiology in both groups (73.3% and 65.7% in the atezolizumab-bevacizumab and lenvatinib groups, respectively), while 21.2% and 29.0% of patients had non-viral HCC, respectively. Extrahepatic spread was identified in 76.0% and 74.6% of patients in the atezolizumab-bevacizumab and lenvatinib groups, respectively: lung, LN, and intra-abdominal metastases were present in 39.6% vs. 39.1%, 30.0% vs. 33.1% and 16.6% vs. 15.4% of patients, respectively. The proportion of patients achieving a ≥ 30% reduction in the tumor burden for each organ category was higher overall in the atezolizumab-bevacizumab group than in the lenvatinib group: 20.2% vs. 11.8%, 23.0% vs. 12.2%, 27.9% vs. 17.9%, and 33.3% vs. 15.0% for intrahepatic, lung, LN and intra-abdominal lesions, respectively. The corresponding values for the subgroup with a viral etiology were 17.3% vs. 8.1%, 18.8% vs. 13.3%, 28.9% vs. 3.6% and 36.0% vs. 12.5%, respectively. Among patients with a non-viral etiology, atezolizumab-bevacizumab was not clearly associated with a better organ-specific response for the LN and intra-abdominal lesions: 20.0% vs. 54.5% and 20.0% vs. 25.0%, respectively, for a ≥ 30% reduction in the tumor burden. Conclusions: Compared to lenvatinib, atezolizumab-bevacizumab was associated with a favorable organ-specific response regardless of the site of the tumor lesions. Unlike anti-PD-1 monotherapy, atezolizumab-bevacizumab had a comparable organ-specific response between intrahepatic and extrahepatic lesions, especially for those with viral etiology HCCs.

Ovarian Cancer with TTF-1-positive Giant Pleural Dissemination.

Thyroid transcription factor 1 (TTF-1) is primarily expressed in lung and thyroid cancers, but it has also been observed in other cancers. A 60-year-old woman presented with worsening dyspnea, pleural effusion, lung metastases, a right ovarian tumor, and para-aortic intra-abdominal lymph node metastasis. Biopsies from the pleural dissemination revealed TTF-1-positive adenocarcinomas. To confirm the presence of the primary organ, biopsies were performed on a para-aortic intra-abdominal lymph node that ascended from the ovaries. An adenocarcinoma positive for TTF-1 was identified, thus confirming the diagnosis of ovarian cancer. Our findings revealed that TTF-1 positivity does not always signify a lung cancer origin.

Extensive mutational ctDNA profiles reflect High-grade serous cancer tumors and reveal emerging mutations at recurrence

ObjectiveCirculating tumor DNA (ctDNA) offers a minimally-invasive alternative to study genomic changes in recurrent malignancies. With a high recurrence rate, the overall survival in high-grade serous ovarian carcinoma (HGSC) has remained low. Our objectives were to determine whether ctDNA from plasma adequately represents HGSC, and to find mutational changes at relapse suggesting therapy options that could alter patient outcome. MethodsWe collected 152 longitudinal plasma and 92 fresh tissue samples from 29 HGSC patients, sequencing and detecting mutations with a gene panel of more than 700 cancer-related genes. Tumor content was measured using TP53 VAF. We analyzed the concordance between the mutations in tissue and plasma samples and calculated correlations to patient outcomes. We also searched for novel mutations appearing at relapse. ResultsThe concordance rate between mutations in plasma compared to tumor tissue was 83 % at diagnosis and 90 % at relapse. CtDNA was released similarly from the tubo-ovarian tumors, intra-abdominal metastases and ascites. CtDNA release was high when CA-125 level was elevated. The TP53 VAF in ctDNA from plasma samples before the third cycle of primary chemotherapy showed a negative correlation to patient outcome. At relapse, 19 novel, pathogenic DNA mutations appeared, suggesting possible actionable alterations and biological mechanisms related to chemoresistance. ConclusionRelapse ctDNA samples reflect tissue samples well and longitudinal sampling provides a timely source for mutational profiling. The emerging genetic mutations at recurrence propose that ctDNA accurately represents the widespread disease and provides possibilities for personalized therapy options.

Morbidity, mortality, and prognostic factors in gestational trophoblastic neoplasia with liver metastasis.

Liver metastases of gestational trophoblastic neoplasia (GTN) are rare, but associated with poor prognosis. The additional concomitant presence of brain or intra-abdominal metastases, with liver metastases has been described as worsening factors, but the literature on this topic is reduced. To estimate the overall mortality, specific hepatic morbidity, and mortality, and to identify prognostic factors for patients with GTN and liver metastases. The medical records of 26 GTN patients with liver metastases registered in the French Center for Trophoblastic Diseases and treated between November 1999 and December 2019 were reviewed. Overall survival was described using Kaplan-Meier estimates. Prognostic factors were identified using univariate and multivariate Cox analyses. The 5-year overall survival rate was 60.7% for all patients with liver metastasis. The survival rate was higher in patients who achieved complete remission after first-line chemotherapy than in those who did not (100% vs 20%, p=0.001). The only factor independently associated with prognosis was the presence of 6 or more liver metastases (5-year survival, 16.7% vs. 82.4% otherwise; HR =11.1, 95%CI, 2.3-53.1; p=0.003). None of the five patients with a single liver metastasis died. GTN with liver metastasis is very rare (1.6%). The prognosis of patients seems to be improving. The results of this study are also reassuring for patients with complete remission after first-line combination chemotherapy, as well as for those with a single liver metastasis.

A Cost-Effective, Machine Learning-Based New Unified Risk-Classification Score (NU-CATS) for Patients with Endometrial Cancer

Treatment for endometrial cancer (EC) with radiotherapy is increasingly guided by molecular risk classifications. Derived from genomic profiling of The Cancer Genome Atlas (TCGA) project, several EC risk classification systems, including ProMisE and Leiden/TransPORTEC, have been developed. However, the current systems were developed on a relatively homogeneous population. Black or African American (BOAA) patients have consistently been demonstrated to have worse stage-adjusted prognosis than Caucasians. Given this, we intended to develop a new unified risk classification system (NU-CATS) for EC patients using machine learning (ML) utilizing datasets with demographically diverse populations. TCGA-Uterine Corpus Endometrial Carcinoma (n = 596), Memorial Sloan Kettering-Metastatic Events and Tropisms (MSK-MET, n = 1,315) and the American Association for Cancer Research Project Genomics Evidence Neoplasia Information Exchange (AACR-GENIE, n = 4,561) were used to identify genetic alterations and clinicopathological features, including age, race, stage, histologic grade and features, and distribution of metastatic disease. Software packages including Keras, Pytorch, and Scikit Learn were tested to build artificial neural networks (ANNs) with a binary output as either intra-abdominal metastatic lesions vs. non-metastatic. A 5-layered ANN (5-6-4-2-1) using 5 inputs ('age at surgery', 'histology', 'race', 'mismatch repair status' and 'TP53'). The optimal performing ANN was selected and cross validated. The weights and biases of the trained ANN were used to reconstruct the algorithm. BOAA patients with EC have worse prognosis than Caucasians, adjusting for TP53 or POLE mutation status. TP53 is the most common gene differentially altered by race in EC. Over 75% of BOAA patients carry TP53 mutations as compared to approximately 40% of Caucasians. Older age is associated with an increasing likelihood of TP53 mutations, high risk histology, and distant metastasis. For patients above age 70, 91% of BOAA and 60% of Caucasian EC patients carry TP53 mutations. The NU-CATS that incorporates age, race, histology, mismatch repair (MMR) status, and TP53 mutation status showed 75% accuracy in prognosticating intra-abdominal metastasis. A higher NU-CATS (>50) is associated with about 2-fold increased risk of having positive pelvic or para-aortic lymph nodes (LNs) and distant. NU-CATS was shown to outperformed TransPORTEC model for estimating risk of FIGO Stage I/II disease progression and survival in BOAA EC patients. Despite adjusting for molecular classification, race and age retain prognostic importance in EC. NU-CATS, a ML-based, cost-effective algorithm, incorporates diverse clinicopathologic and molecular variables of EC, and yields superior prognostication of the risk of nodal involvement, distant metastasis, disease progression, and overall survival as compared to other classification systems.

Prognostic Value of Tumor Markers in Gastric Cancer: A Tertiary Cancer Centre Experience.

Gastric cancer is a heterogeneous malignancy in terms of stage-wise prognosis. This study aimed at finding any prognostic significance of preoperative carcinoembryonic antigen (CEA) and cancer antigen (CA) 19-9 in resectable gastric cancer. A total of 57 patients at Kidwai Memorial Institute of Oncology, Bengaluru, India from January 2022 to March 2023 were included in this observational prospective study. Included patients had a resectable tumor at clinical staging. Patients were divided into two categories (raised and non-raised) based on serum tumor marker (CEA and CA 19-9) levels. Their relationship with clinicopathological features was studied. The association was studied using chi-square test, and p-value <0.05 was considered significant. The mean age of the study group was 55.47 years with male predominance (63.2%, n=36). Raised CEA and CA 19-9 were seen in 15.8% (n=9) and 10.5% (n=6) patients, respectively, while both markers were raised in 5.3% (n=3). Raised CEA was found significantly associated with grade 3 adenocarcinoma stomach (OR 7.825, 95%CI: 1.374-44.562; p= 0.020) and intraoperative finding of inoperability due to occult intra-abdominal disease (p<0.05). CA 19-9 (pre- and post-operative levels) had no statistically significant association (p>0.05) with the grade of adenocarcinoma. This study indicates a benefit in estimating CEAfor the prediction of prognosis in gastric cancer. CEA levels have been found to predict chances of finding occult intra-abdominal metastasis in gastric cancer.

O149 The utility of chest computed tomography in the staging of pancreatic cancer: a retrospective observational study

Abstract Background Almost 50% of patients with pancreatic cancer initially present with metastatic disease. Current NICE guidelines recommend chest, abdomen and pelvis computed tomography (CT) for all patients with a diagnosis of pancreatic cancer. This study aimed to determine the incidence of lung metastases and the clinical utility of completion chest CT in this group. Methods Electronic healthcare records were retrospective reviewed at a regional hepatopancreaticobiliary centre to identify patients diagnosed with pancreatic cancer between 2010-2019 inclusive. Patient demographics, tumour characteristics, metastatic pattern and management outcomes such as surgery and chemotherapy were assessed for all patients. Kaplan Meier survival analysis were used to assess survival outcomes stratified by pattern of metastatic disease and treatment strategy. Results Of the 1293 patients who met the inclusion criteria 69.1%(n=863) had metastatic disease at diagnosis. Only 2.6% (32/1293) of the entire cohort presented with lung-only metastasis, with the liver being the commonest site of metastases (17.7%, 221/1293). Detection of lung metastases in the absence of intra-abdominal metastatic disease precluded surgery. However, lung metastases synchronous with intra-abdominal metastases did not alter management – chemotherapy or best supportive care. Patients with isolated lung metastasis had marginally improved median (IQR) survival [134 (48-347 days] compared with isolated liver [88 (36-221) days] and synchronous lung and liver metastases [88 (29-185) days, p&amp;lt;0.0001]. Conclusion For potential surgical candidates, a chest CT would be recommended as detection of lung metastasis would alter management. However, for patients with unresectable disease, a chest CT confers no additional benefit as management strategy would remain unchanged.

O147 The incidence and impact of pattern of metastases on treatment strategy and outcomes for patients with pancreatic cancer

Abstract Background Pancreatic cancer is a major cause of cancer mortality with dismal survival outcomes. At the time of diagnosis, 15% of patients with pancreatic cancer have resectable disease, 35% present with locally advanced pancreatic cancer and 50% of patients present with metastatic disease. This study aimed to determine the pattern of metastatic disease in patients with pancreatic cancer and evaluate their influence on survival outcomes. Methods Electronic healthcare records were retrospectively reviewed at a regional hepatopancreaticobiliary centre to identify patients diagnosed with pancreatic cancer between 2010-2019 inclusive. Patient demographics, tumour characteristics, metastatic pattern and management were recorded and compared. Kaplan Meier survival analysis were used to assess survival outcomes stratified by sex, metastatic pattern, and treatment strategy. Results Of the 1293 patients who met the inclusion criteria, metastatic disease was present in 863 (69.1%) at diagnosis. The commonest site of metastases was liver only [25.6% (221/863], followed by disseminated metastases [24.1% (208/863)] and regional lymph nodes [22.9% (198/863)]. Only 3.7% (32/863) of patients with metastases had lung-only metastases. Detection of lung metastases synchronous with intra-abdominal metastases did not alter management. The surgical resection rate was only 15% and the 5-year survival for those who underwent surgery was 9.8% compared with 0.8% for those with unresectable disease (p&amp;lt;0.0001). Conclusion A large proportion of patients with pancreatic cancer were diagnosed with metastatic disease with the liver being the commonest site. Metastases reduce resectability rates and consequently lead to poor 5-year survival outcomes.

Feasibility study on the use of single-port laparoscopic surgery for diagnosis and tumor sampling in advanced epithelial ovarian cancer — Case series of three cases

IntroductionIn advanced epithelial ovarian cancer (AEOC), it is often difficult to achieve optimal surgery at primary debulking surgery (PDS) due to intra-abdominal dissemination and/or metastasis. When it is determined that optimal surgery is not possible, neoadjuvant chemotherapy (NAC) is performed prior to subsequent debulking surgery. Also, a histological diagnosis of the tumor is very important before initiation of NAC. Laparoscopic surgery is thus useful to objectively diagnose whether an optimal primary debulking surgery is feasible and to obtain tumor biopsy samples. In order to minimize the invasive procedures at initial surgery, we performed laparoscopic surgery using a single-port method. Case presentationThree patients were diagnosed as stage IV ovarian cancer based on imaging and physical examination. Single-port laparoscopic surgery was performed. The intraabdominal findings were evaluated in all patients by predictive index scoring and objectively diagnosed as not ideal candidates for optimal surgery at PDS. Our use of single-port laparoscopic surgery (SPLS) allowed for safe surgical outcomes and sufficient tissue sampling for histological diagnosis. Clinical discussionLaparoscopic surgery is not appropriate for tumor reduction surgery in AEOC; however, its use as an alternative method to laparotomy is recommended for tumor tissue biopsy and/or intraperitoneal observation. Previous studies have reported on the use of conventional multi-port laparoscopic surgery. The single-port method, when compared to conventional laparoscopic surgery, is less invasive with only one abdominal wound at the umbilicus. ConclusionSPLS is feasible and clinically useful for diagnosis and tumor sampling in AEOC.

E030 Rheumatologists beware! Digital ischaemia as a presenting feature in metastatic ovarian cancer

Abstract Background/Aims Digital ischaemia is an umbrella term to describe the spectrum of acral vascular phenomena irrespective of aetiology, ranging from temporary (as in Raynaud’s phenomenon) to permanent (necrosis). It can be the presenting feature in multiple cancer types, and can be present with or without other features of connective tissue disease. Methods A 54-year-old woman was referred to Rheumatology with a four-day history of acute pain and ischaemic discolouration of all her fingertips bilaterally. There was no history of Raynaud’s phenomenon and no other clinical features of connective tissue disease. She had never smoked. There was a family history of breast cancer in her maternal aunt. She was admitted under vascular surgery for urgent review. All ten fingertips were ischaemic, with a capillary refill time of greater than five seconds. The history was otherwise significant for abdominal bloating, altered bowel habit and fatigue. Examination revealed normal peripheral pulses with no bruits, normal heart sounds and chest sounds. Her abdomen was soft with a mildly enlarged liver. Results FBC, U&amp;E, and LFTs showed no abnormalities. CRP, ESR, ANA, serum protein electrophoresis and complement levels were all normal. Blood tests for ANCA, rheumatoid factor and anti-CCP were also negative. Lupus anticoagulant, anti-cardiolipin and anti-B2-glycoprotein were all negative. The tumour marker CA125 was markedly elevated at 837kU/L (0.0-35.0kU/L). A CT abdomen &amp; pelvis showed a large right-sided adnexal mass with multiple enhancing peritoneal and omental nodules and moderate ascites. Biopsy of a metastatic deposit in the omentum revealed high grade serous ovarian adenocarcinoma. Partial improvement in digital ischaemia was achieved with iloprost and maintenance apixaban and sildenafil. Four cycles of carboplatin and paclitaxel chemotherapy produced near-complete resolution of digital ischaemia symptoms, corresponding to a fall in her CA125 level and reduction in the size of the ovarian mass and intra-abdominal metastases on CT. Ten cases of digital ischaemia associated with ovarian cancer have been described prior to this. The age of onset ranged from 45 to 71, with a median age of 56. Most patients had digital ischaemia without features of connective tissue disease. Four had no blood test abnormalities other than a raised tumour marker CA125. The time from onset of digital ischaemia to diagnosis of ovarian cancer ranged from less than one week to 2 years, with a median time of four months. Conclusion This case study supports previous findings that patients with digital ischaemia associated with ovarian cancer may have normal markers of inflammatory or rheumatological disease. Marked therapeutic responses can be achieved with systemic anti-cancer therapies. Therefore, underlying cancer should be suspected in patients with new-onset or worsening digital ischaemia over the age of 45. A high index of suspicion is required - rheumatologists beware! Disclosure J.H. Miller: None. P. Merry: None.

Palliative and Supportive Care Consultation for Patients With Malignant Gastrointestinal Obstruction is Associated With Broad Interdisciplinary Management.

The aim of this study was to assess rates of palliative care (PC) involvement in the care of patients with malignant gastrointestinal obstruction (GIO) and its influence on interdisciplinary team involvement. Malignant GIO is an advanced oncologic diagnosis with associated poor prognosis. Data regarding PC and interdisciplinary team involvement in these patients is lacking. We identified consecutive surgical consultations for GIO in cancer patients at a single institution from August 2017 to July 2019. Clinical characteristics were collected. Rates of PC consultation, ACP discussion, code status change to do not resuscitate, and interdisciplinary service consultation were evaluated. We identified 200 patients with consultations for GIO, of whom 114 (57%) had malignant GIO and were included in our study. Of these patients, 95 (83%) had stage IV disease; 68 (60%) had peritoneal metastasis, and 70 (61%) had other intra-abdominal recurrence or metastasis. PC consultation was obtained in 69 patients (61%). PC consultation was associated with higher rates of ACP discussion (64% vs 29%; P < 0.001), code status change to do not resuscitate (30% vs 2%; P < 0.001), nonsurgical procedure (46% vs 11%; P < 0.001), discharge to hospice (30% vs 7%; P < 0.001), and involvement of spiritual care (48% vs 22%; P = 0.01), social work (77% vs 42%, P < 0.001), psychology/psychiatry (42% vs 4%, P < 0.001), nutrition (86% vs 62%, P = 0.006), physical therapy (54% vs 31%, P = 0.02), and occupational therapy (42% vs 16%, P = 0.004). PC consultation benefits patients with malignant GIO by facilitating comprehensive interdisciplinary care, ACP discussions, and transition to hospice care, where appropriate. Diagnosis of malignant GIO should be a trigger for PC consultation or, in facilities with limited PC resources, consideration of deliberately broad interdisciplinary consultation.

HPB P60 Pancreatic Carcinosarcoma as a rare cause of upper gastrointestinal bleeding requiring resection

Abstract Background Pancreatic carcinosarcoma is a rare malignant neoplasm and has a very poor prognosis. Diagnosis is mainly by pathological examination including immunohistochemistry (IHC) of the biopsy or resected specimen. Due to the rarity of the cancer, information regarding clinical presentation, pathology and management is limit to a few case reports. Methods We report a 61-year-old fit and healthy male, who presented to the emergency department with melaena and syncope. Initial CT scan showed a pancreatic body/tail tumour, likely pancreatic cancer without nodal or intra-abdominal metastasis. Upper GI endoscopy revealed a lesion in the second part of the duodenum, with a visible vessel, and evidence of recent bleeding . Two clips were applied, and a biopsy of the lesion showed ulcer slough only. Tumour markers and IgG4 levels were normal. An MRI pancreas showed no definite pancreatic mass, features of chronic pancreatitis and irregular bile ducts. HPB MDT consensus was to proceed for EUS, which confirmed a hypoechoic, vascular, 3cm mass lesion in D1-D2. Biopsies again, showed ulcer slough. A PET CT scan showed avidity in the second part of the duodenum and pancreatic head, neck and distal body. The patient presented to the surgical emergency unit twice during this time with symptoms of anaemia requiring IV iron and blood transfusions, and with early signs of obstruction, which settled with conservative management. Interval MRI showed increase in size of the duodenal mass, and stable appearance of the lesion in the head of the pancreas. Eventually, semi-emergency total pancreaticoduodenectomy and splenectomy was undertaken. Results Intraoperatively, a large D2 tumour was found extending into the pancreatic head posteriorly, compressing but not infiltrating the IVC. The rest of the pancreas was hard in consistency and nodular. Soft lymph nodes were found at the aorto-caval, common hepatic and around the SMA. There was no obvious intra-abdominal metastasis. The final histopathology showed a malignant, biphasic tumour favouring pancreatic carcinosarcoma staged pT3 N0 (0/29) L1 V1 R1 (posterior and SMV). On molecular cytogenetic analysis there was no evidence of rearrangement associated with synovial sarcoma in the cells examined. He recovered well post operatively and has commenced adjuvant chemotherapy of modified Folfirinox. Conclusions Pancreatic carcinosarcoma is a rare entity, which due to its unusual presentation, can be challenging to manage. Prompt MDT discussion is instrumental in such cases. The assessment of different radiological modalities, showing progressive increase in the size of the lesion within a short time period, raised the suspicion of an aggressive mitotic lesion, with the repeat biopsies unlikely to yield diagnosis in an otherwise operable lesion. Ultimately, the patient underwent a semi-emergency, total pancreaticoduodenectomy and splenectomy due to ongoing bleeding and the rapidly growing tumour size. In this case, surgery followed by adjuvant chemotherapy has been adopted as the optimum management strategy, for both bleeding control, and oncological benefit.

Mesenteric desmoid fibromatosis entrapping metastatic urothelial carcinoma: a unique collision tumor or fibromatosis-like variant?

A collision tumor is a neoplastic lesion comprised of two or more distinct cell populations with distinct borders. Desmoid fibromatosis (DF) is a rare musculoaponeurotic tissue tumor that grows deep in the connective tissue and shows locally aggressive behavior. Only two cases of collision tumors with desmoid fibromatosis are reported in the English literature, albeit papillary thyroid carcinoma with desmoid fibromatosis-like stroma is regarded as a variant rather than a collision tumor. We present a unique case of collision tumor with desmoid fibromatosis surrounding intra-abdominal metastasis from urothelial carcinoma. A 65-year-old white male with history of bladder and left renal pelvis high-grade papillary urothelial carcinoma status post-nephrectomy was found to have a small bowel obstruction due to a soft tissue mass. Histology of the mass showed multiple matted lymph nodes with metastatic urothelial carcinoma admixed with a proliferation of spindle cells positive for nuclear beta-catenin, consistent with desmoid fibromatosis. While the prior surgical site likely acted as a nidus for development of desmoid fibromatosis, we also hypothesize that a dysregulation of beta-catenin signaling pathways within the cancer cells might have attributed to the spindle cell proliferation in the stroma surrounding the tumor. Our case emphasized the importance of clinical suspicion of desmoid fibromatosis in patients with metastatic cancer, requiring a prompt diagnosis and treatment to decrease the risk of complications and local recurrence.