P-L04 Temporal changes in prevalence and associated risk factors for gallbladder dysplasia and adenocarcinoma in patients undergoing cholecystectomy. A UK hospital-based observational study Stephen Lam 1,2 , Wing Chou 1 , Giles Toogood 3 , Simon Wemyss-Holden 2 , Alexia Tsigka 2 , Bhaskar Kumar 1,2 1 Norwich Medical School, University of East Anglia, Norwich, United Kingdom, 2 Norfolk and Norwich University Hospital NHS Trust, Norwich, United Kingdom, 3 St. James’s University Hospital, Leeds, United Kingdom Background: A metaplasia-dysplasia–carcinoma sequence is the most plausible carcinogenic pathway for gallbladder cancer. Although the in- cidence of gallbladder carcinoma is increasing, little is known about its precancerous lesions. The aim of this study was to determine temporal changes in the prevalence of low-grade dysplasia (LGD), high-grade dysplasia (HGD) and gallbladder adenocarcinoma and associated risk factors. Methods: We retrospectively identified consecutive patients who underwent cholecystectomy between January 2011 and March 2020. Patients were grouped according to histology: no dysplasia; LGD; HGD; and adenocarcinoma. Fitted linear models estimated temporal trends in prevalence and mean age for all histological outcomes. Logistic re- gression estimated associated risk factors. Results: A total of 5 835 patients were included in the analysis. The prevalence of LGD was 1.47%, HGD 0.17% and adenocarcinoma 0.19%. Prevalence for all diseases increased over time, and mean age at diag- noses decreased over time. In a multivariate logistic regression model, with no dysplasia as the reference group, female sex increased the odds of LGD (OR 4.57, 95% CI 3.07-10.10, p ¼ <0.0001). BMI was not asso- ciated with disease risk. Conclusions: Our data suggests the prevalence of precancerous gall- bladder lesions are increasing in younger patients. Although a risk fac- tor for cholelithiasis, BMI was not associated with disease progression. If occurring in a dysplasia-carcinoma sequence, mean age of diagnoses suggests a progression period of 20 years. Further research is required to explain both the significant sex disparity and potential environmen- tal risk factors for gallbladder dysplasia. P-L05 Enterohepatic migration of ingested fishbone resulting in hepatic abscess- Case report and review of literature Niamh Grayson, Hiba Shanti, Ameet G. Patel King’s College Hospital, London, United Kingdom Background: Ingestion of foreign bodies is common, particularly in children. In adults, most foreign body ingestions are related to food bo- lus or bone. The majority present with pharyngeal symptoms. Most for- eign bodies exit the gastrointestinal tract without complication. However, around 1% result in perforation. Patients may have a delayed presentation with nonspecific symptoms and pose a diagnostic di- lemma. We report a rare case of silent migration of a fishbone into the liver and a review of the literature. Methods: We present the case of a 56 year old man who presented with a liver abscess second to an ingested fishbone. We conducted a PUBMED search and reviewed the published data over a period of thirty years. We identified 52 similar cases and compared the presentation, site of perforation and location of the fish bone. We observed the differ- ent approaches in presentation and management of such patients. Results: A 56-year-old man presented to his local hospital with dull epigastric pain and raised inflammatory markers. CT scan revealed a 4 cm abscess in the left lobe of the liver, with a linear radio-dense body within. The patient was given antibiotics and the abscess was aspi- rated. The patient was transferred to our Hepatopancreaticobiliary unit for further management. Laparoscopy was performed. The left lateral segment of the liver was adherent to the gastric antrum. The hepato- gastric fistula was disconnected. The fishbone was retrieved from the liver. The abscess was drained and wash out performed. The patient was discharged the following day. Conclusions: Left lobe liver abscess should raise suspicion of foreign body. Although antibiotic treatment may be effective in the short term, there is no long-term data regarding recurrence. We believe that lapa- roscopic drainage of the abscess and extraction of the foreign body of- fer control of the source of sepsis and reduces the risk of recurrence. P-L06 Establishing minimum datasets and disease specific forms for cancer patients in multidisciplinary team meetings Simrita Agrawal 1 , Gobeka Ponniah 1 , Keith Roberts 2 1 University of Birmingham, Birmingham, United Kingdom, 2 University Hospital Birmingham, Birmingham, United Kingdom Background: Multidisciplinary team (MDT) meetings aim to ensure standardised access to cancer pathways and treatment. It is thus im- portant that minimum datasets are established and provided to the MDT clinicians to facilitate thorough discussion and encourage shared decision making. To determine the effectiveness of pre-established minimum dataset proformas for periampullary tumours, hepatocellu- lar carcinoma (HCC), colorectal cancer with liver metastases (CRLM) and hilar cholangiocarcinoma in cancer MDT meetings. Methods: Cancer specific minimum dataset forms were developed by consultants to be implemented in MDTs for the four types of hepato- biliary pancreatic cancers: HCC, periampullary cancer, hilar cholangio- carcinoma and CRLM. 189 MDT reports and 184 referral letters were analysed from three weekly MDT meetings to determine the outcomes reported against those outlined in the proformas. The proformas were then implemented by consultants leading the weekly MDT meetings for three consecutive weeks. 128 MDT reports and 126 referral letters were re-audited from these MDT meetings to determine if there was a change in the outcomes reported. Results: In this quality improvement project, 21.25% (11/52) of out- comes in MDT and 19.23% (10/52) of outcomes in the referral letters had a statistically significant difference in the reporting of outcomes from Cycle 1 to Cycle 2 across all four cancers. Greater changes in reporting were observed for outcomes that may carry higher prognostic value, such as tumour size and vascular invasion. Despite the notable difference in reporting seen for datasets consisting of smaller cohorts, the change was not statistically significant due to the insufficient sta- tistical power proving the need for trialling such proformas in a wider population. Conclusions: The minimum dataset proformas were associated with a limited gain in compliance with data reporting. Further work, with par- ticular focus on user acceptability and attitudes is required to improve use of minimum dataset proformas in MDT. P-L07 Nematode infection mimicking Liver metastasis from previous Melanoma Luke Bennett, Claire Stevens, Arjun Takhar University Hospital Southampton, Southampton, United Kingdom Background: Malignant melanoma is known to metastasise to the liver. In the absence of any other disease spread it is prudent to resect these lesions. This case highlights how certain pathology can masquer- ade as liver metastases. Here we present a case of a gentleman previ- ously diagnosed with malignant melanoma in 2016. He had previous liver resection for metastatic disease in 2017. Surveillance MRI picked up what was assumed to be a further metastatic deposit in the right lobe of the liver. Patient underwent resection, and subsequent histolog- ical analysis has shown this to be a worm cast from a parasitic infec- tion. Methods: Review of the current literature reveals just one previous case of nematode infection masquerading as liver metastasis making this a very unusual and rare finding at operation. We have undertaken review of patients imaging and histopathological specimens as well as seeking expert opinion from the infectious diseases centre in London Abstracts | ix53 Downloaded from https://academic.oup.com/bjs/article/108/Supplement_9/znab430.099/6462681 by guest on 14 March 2022