Presence Of Malignant Cells Research Articles

Malignant Pleural Effusion: Diagnosis and Treatment-Up-to-Date Perspective.

Malignant pleural effusion is the presence of malignant cells within the pleural fluid, representing the second most common cause of pleural exudate. Although diagnostic methods and management techniques for malignant pleural effusion have dramatically improved over the decades, the current treatment is still palliative, aiming to remove pleural fluid, possibly prevent its recurrence, and alleviate symptoms through a wide range of available procedures. Treatment should be tailored to the individual patient, considering comorbidities, size of the effusion, rate of fluid accumulation, underlying cardiac or respiratory conditions, rate of recurrence, presence of loculations or trapped lung, tumor characteristics, cancer type, and patient preferences. This manuscript aims to review the available literature and to present the latest evidence on malignant pleural effusion management in order to provide an updated perspective on its diagnosis and treatment.

041. A Case of Cholangiocarcinoma in A Young Adolescent

Background: Cholangiocarcinoma usually occurs in 50-70 years age group. Recent study showed an increased incidence in younger age group. We describe a case of Cholangiocarcinoma in an adolescent girl in order to understand its natural history. Case: A 16 year old girl presented with 2 months history of jaundice, itchyness, right upper quadrant abdominal pain, pale stool and dark urine. Initial investigation showed : Total Bilirubin 8.87, (Direct 3.53, Indirect 12.40), SGOT 75, SGPT 56, ALP 240, GGT 59, Hepatitis B and C negative, AFP 1.96, CA19-9 3.1, and CEA 5.1. Imaging showed dilated hepatic duct with 1.5cm mass in mid-Common Bile Duct (CBD). Due to unforeseen personal circumstances, surgery was done 16 months from onset of complaints. Tumor was found at junction of cystic duct + CBD. The CBD and Gallbladder was resected (with frozen section), lymph node dissected along hepatic artery, Roux-en-Y hepaticojejunostomy anastomosis and Jejuno-Jejunostomy anastomosis was performed. Histopathology showed Cholangiocarcinoma grade 2 with perineural + lymphovascular invasion, and malignant cells’ perineural invasion at proximal margin. She underwent adjuvant chemotherapy (Gemcitabine + Cisplatin). CT scan 6 months post Chemotherapy showed 3cm lesion in CBD. After a further 2 months of chemotherapy, CT evaluation showed no residual mass left. Conclusion: This highlight that despite significant time lapse from onset of symptoms, surgery with curative intent may still be considered. Secondly, chemotherapy is an extremely important part of the treatment, especially in presence of malignant cells at resection margin.

Histological Features, Risk Factors, and Classification of Breast Cancer: A Rapid Review

Breast cancer (BC) is developing from cells of breast tissue and is caused by the presence of malignant cells, which are characterized by uncontrolled cell division, leading to abnormal growth (in situ carcinoma), and their ability to invade normal tissue locally. BC's diagnosis and treatment strategies have recently improved, but the incidence rates continue to increase. Worldwide, BC is the most common cancer in women. The aim of this study is to combine histological, classification, and risk factors in a small review for easy searching by clinical researchers. Currently, there are many studies on BC in Iraq or in other regions of the world. Therefore, combining these studies in one work may give an advantage in the clinical trials of BC. In conclusion, BC is the first of the ten top cancers in Iraqi women up to 2018.

Role of cytoblock on pleural effusion for diagnosis of malignant disease.

Thoracocentesis of pleural effusion is a simple technique for pleural fluid examination through cytology. In addition to cytological examination to assess the nature of pleural fluid content, we can also perform more detailed examinations through cytoblocks of residual fluid. These paraffin-embedded cytoblock samples are important because we can perform examinations as in other bioptic samples. In these samples, immunohistochemical and molecular analyses can be performed. Two hundred fifty-five cytological samples from patients with pleural effusion were examined. In cases in which the presence of malignant cells was identified in the cytological examination, as well as cases that were suspicious but not definitive for the presence of a malignant effusion, a cytoblock was prepared. Histological examination and immunohistochemical analysis were performed. Among 255 cases with pleural effusion, 152 had the presence of malignant cells and 6 cases were suspicious, but uncertain for the presence of malignant cells, while 86 cases had inflammatory pleural effusion or other pathologies but were not malignant. After histological analysis of the cytoblock and immunohistochemical analysis, we identified 82 malignant tumors of the lung, 8 malignant tumors of the gastrointestinal tract, 15 malignant tumors of the breast, and 6 malignant tumors of the female genital tract, as well as 24 tumors of undetermined origin. Cytoblocks are important for the diagnosis of the primary nature of malignant pleural effusions. The highest importance is primary lung tumors, as well as those tumors in which the primary site of the tumor cannot be determined clinically.

Performance Analysis of an Aperture-Coupled THz Antenna for Diagnosing Breast Cancer.

The most important technique for exposing early-stage breast cancer is terahertz imaging. It aids in lowering the number of breast cancer-related fatalities and enhancing the quality of life. An essential component of developing the THz imaging system for high-quality photos is choosing the right sensor. In this article, a wideband antenna for microwave imaging of breast tissue with an operating frequency of 30 GHz (107 GHz to 137 GHz) is constructed and analyzed. An aperture-coupled antenna with an optimized ground aperture is proposed and analyzed, which made it possible to obtain better and consistent impedance matching in the wideband spectrum. The variation of backscattered signal energy in body tissue is assessed with healthy breast tissue and in the presence of malignant cells. A significant difference in energy scattering is observed for both situations. The suggested antenna's linear and stable time domain characteristics make it an appropriate component for THz imaging technology.

Factors associated with overall survival in patients with melanoma leptomeningeal disease (M-LMD): A single institution retrospective review.

e21548 Background: Leptomeningeal disease (LMD) is characterized by tumor metastasis to the membranes and cerebrospinal fluid (CSF) surrounding the brain and spinal cord. This devastating complication confers a poor overall survival (OS) measured in weeks for untreated patients. Melanoma has one of the highest rates of dissemination to the leptomeninges. The advances in targeted and immune therapies have revolutionized OS for patients with melanoma systemic metastases and there is a growing number of individual case reports showing clinical responses to these agents in patients with melanoma-LMD (M-LMD) . However, few studies have examined the association between these and other therapies with the OS of a large cohort of melanoma-LMD (M-LMD) patients. Methods: M-LMD patients treated at Moffitt Cancer Center between 2011 and 2020 were retrospectively identified. M-LMD diagnosis was confirmed radiographically via magnetic resonance imaging (MRI) and/or positive CSF cytology indicating the presence of malignant cells. Demographic data and pre/post LMD diagnosis treatment data were collected and analyzed using the Kaplan-Meier method to determine factors that improve OS. Results: 86 M-LMD patients were identified. 50 were male and 36 were female, but patient gender did not have an impact on OS. 53 patients were diagnosed via MRI only and 33 patients had positive CSF cytology confirming M-LMD diagnosis. 34 patients did not receive any treatment post-LMD diagnosis and had a median OS of 3.72 weeks, while 52 patients receiving treatment (i.e. systemic, intrathecal [IT], and/or whole brain radiation therapy [WBRT]) had a median OS of 10.80 weeks (p < 0.0001). More specifically, 30 patients receiving targeted BRAF/MEKi treatment had an 18.8 week median OS compared to 6.68 weeks for the 56 patients who did not receive such treatments (p = 0.0015). Furthermore, 44 patients received immune therapy and had a median OS of 12.00 weeks compared to 5.88 weeks for those who did not (p = 0.002). The 16 Patients that received IT chemotherapy had a prolonged median OS when compared to the 70 patients who did not (9.72 weeks vs 4.72 weeks, p = 0.009). Furthermore, WBRT also improved median OS in the 22 patients that received the therapy (15.72 weeks vs 7.88 weeks, p = 0.0007). The 36 patients that received BRAF/MEKi treatment prior to their LMD diagnosis had a slightly shorter OS (7.00 weeks) compared to the 46 patients that did not receive such treatment beforehand (10.80 weeks, p = 0.005). Conclusions: The current data supports the use of systemic, IT, and radiation therapies to prolong OS for M-LMD patients; however, the OS for these patients remains grim despite advances in such therapies. Further research is necessary to understand the pathophysiology of LMD, and new clinical trials are urgently needed to identify novel therapies that improve M-LMD prognosis.

When to cryopreserve ovarian tissue: Determining the effects of chemotherapy on the ovarian reserve by studying follicular density and apoptosis.

Patients scheduled to receive chemotherapy should be counselled on fertility preservation. Known gonadotoxic chemotherapies such as alkylating agents have a high risk of altering ovarian reserve. In some cases, the urgency of treatment requires the use of chemotherapy before fertility preservation, which will be carried out at a later stage. Usually the ovarian tissue is cryopreserved. The aim of our study is to investigate the impact of chemotherapies on follicular density and the apoptosis of reserve follicles. We included 140 patients: 63 patients, mean age 18.8 years, were included in the group "no chemotherapy" (group A) and 77 patients, mean age 17.1 years, in the group "received chemotherapy before ovarian conservation" (group B). None of the patients had had pelvic radiotherapy prior to ovarian cryopreservation. The histological parameters studied were follicular density and the presence of malignant cells. We selected 12 patients from group A and 15 patients from group B, comparable in age and pathology, for whom we evaluated follicle apoptosis by immunostaining cleaved caspase-3. We demonstrated an inverse relationship between follicular density and age (p < 0.0001), as well as a lack of effect of chemotherapy on follicular density (p=0.87). We showed the impact of various chemotherapies, especially with alkylating agents, on the apoptosis of ovarian follicles (p < 0.0001). Three patients had ovarian tissue infiltration, two of which were malignant. This work underlines the fact that conservation of ovarian tissue after chemotherapy remains possible.

Frequency of Urological Carcinomas in Patients with Gross Haematuria

Objective: The aim of this study is to determine the frequency of urological carcinomas in patients with gross haematuria. Study Design: Prospective study Place and Duration : Department of Urology, PIMS Islamabad, from December, 2021 to May, 2022. Methods: There were one hundred and forty five patients with ages 20-55 years were presented in this study. All the included patients had blood in urine. After receiving informed written permission, detailed demographic information about the recruited patients, including age, gender, body mass index, and causes of haematuria, was compiled. Urine cytology and microscopy were used to rule out the presence of malignant cells in haematuria. Every time a cystoscopy or computed tomography (CT) scan was needed to monitor the health of our patients, we sent them for an ultrasound. Frequency of urological carcinomas was calculated. SPSS 22.0 was used to analyze all of the data in the study. Results: There were 90 (62.1%) males and 55 (37.9%) females in our study. Mean age of the patients was 41.8±5.54 years with mean BMI 24.5±4.76 kg/m2. 80 (55.2%) patients were literate. Most common cause was urinary tract infection found in 50 (34.5%) cases, trauma in 45 (31.03%), urolithiasis in 30 (20.7%) cases and smoking in 20 (13.8%) patients. Prevalence of urological carcinoma was found in 27 (18.6%) cases. Conclusion: We found a significant incidence of urological carcinomas in our research. Gross haematuria was most often caused by urinary tract infection or trauma. Keywords: Urological carcinomas, Gross haematuria, Urinary tract infection

Abstract 2121: Gene expression and functional characterization of obesity-induced MDSC to uncover the link between obesity and cancer risk

Abstract Strong epidemiologic evidence suggests that excess body weight gain is a major risk of at least 13 different types of cancers. One of the mechanisms explaining the increased cancer incidence in obese patients is associated with the chronic low-grade inflammatory condition. Myeloid cells including macrophages and Myeloid-derived suppressor cells (MDSC) are increased in advanced adiposity. Previous studies in mouse models have shown that obesity-induced MDSC play a protective role on metabolic control; however, in the presence of malignant cells, MDSC facilitates tumor growth and metastasis. Our data show that compared to non-obese individuals, patients with severe obesity (body mass index [BMI] &amp;gt; 40) have a significant increase of circulating granulocytic cells displaying a gene signature resembling tumor-MDSC. Intriguingly, obesity-induced MDSC lacked the potent immunosuppressive function; and therefore, we called them obesity-induced G-MDSC-like cells (Ob-MDSC). The mechanisms underlying the regulation of MDSC phenotype in obesity and obesity-related cancer are unclear. We found that LDL, one altered obesity-related factor, and LPS differentially impact the expression of several genes including the immunosuppressive MDSC markers, arginase-1 and iNOS, when comparing mouse bone marrow-derived MDSC from high-fat fed mice with low-fat fed mice. This finding indicates that the responsiveness of MDSC may be regulated by their long-lasting exposure to the obese microenvironment. Therefore, we propose that long-term adaptation of MDSC is induced by dysfunctional metabolic factors in obesity that modulate their response to subsequent triggers, such as signals derived by the tumor microenvironment (TMA) in the context of obesity-associated cancer. Our data from obese mice with Diethylnitrosamine (DEN)-induced hepatocellular carcinoma and genetically altered hepatic lipid and lipoprotein metabolism show an increased infiltration of G-MDSC associated with enhanced tissue chemokine signaling pathway, ECM remodeling/metastasis, inflammation, and epigenetic and transcriptional regulation. Together our data suggest that chronic exposure to an obesity-related environment establishes a phenotype prone to become pro-tumor MDSC. The identification of key regulators of the gene expression driving the immunosuppressive phenotype of MDSC in obesity is critical for the discovery of therapeutical targets to reduce the risk of obesity-associated cancers. Citation Format: Maria D. Sanchez-Pino, Ramesh Thylur Puttalingaiah, Jone Garai, Jovanny Zabaleta, Randall L. Mynatt, William Richardson, Augusto Ochoa. Gene expression and functional characterization of obesity-induced MDSC to uncover the link between obesity and cancer risk [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 2121.

Would the Addition of Immunotherapy Impact the Prognosis of Patients With Malignant Pericardial Effusion?

Pericardial effusion is a common finding in advanced-stage lung cancer. The presence of malignant cells or drainage of exudate effusion in the pericardial space may cause symptoms of dyspnea, pleuritic chest pain, and syncope. In addition to the difficulty physicians face in the detection and diagnosis of malignant pericardial effusion, treatment may be challenging considering the cancer prognosis and cardiovascular stability of the patient. Despite the availability of several treatment modalities for malignant pericardial effusion, including chemotherapy and surgery, patients with lung cancer historically present with poor prognoses. In addition to lung adenocarcinoma with malignant pericardial effusion, this case was complicated by COVID-19 and malignancy-associated obstructive pneumonia. We present a case of a 64-year-old woman with advanced non-small cell lung carcinoma (NSCLC) with malignant pericardial effusion who, despite testing positive for COVID-19 and having obstructive pneumonia, had favorable outcomes following systemic therapy with combined chemo-immunotherapy.

Frequency of Urological Carcinomas in Patients with Gross Haematuria

Objective: The aim of this study is to determine the frequency of urological carcinomas in patients with gross haematuria. Study Design: Prospective study Place and Duration: Swat Urology Ward Saidu Group of Teaching Hospital, Swat for the duration of six months from 1st April 2021 to 31st September 2021. Material and Methods: There were one hundred and forty five patients with ages 20-55 years were presented in this study. All the included patients had blood in urine.After receiving informed written permission, detailed demographic information about the recruited patients, including age, gender, body mass index, and causes of haematuria, was compiled.Urine cytology and microscopy were used to rule out the presence of malignant cells in haematuria. Every time a cystoscopy or computed tomography (CT) scan was needed to monitor the health of our patients, we sent them for an ultrasound.Frequency of urological carcinomas was calculated. SPSS 22.0 was used to analyze all of the data in the study. Results:There were 90 (62.1%) males and 55 (37.9%) females in our study. Mean age of the patients was 41.8±5.54 years with mean BMI 24.5±4.76 kg/m2. 80 (55.2%) patients were literate. Most common cause was urinary tract infection found in 50 (34.5%) cases, trauma in 45 (31.03%), urolithiasis in 30 (20.7%) cases and smoking in 20 (13.8%) patients. Prevalence of urological carcinoma was found in 27 (18.6%) cases. Conclusion:We found a significant incidence of urological carcinomas in our research. Gross haematuria was most often caused by urinary tract infection or trauma. Keywords: Urological carcinomas, Gross haematuria, Urinary tract infection

Recurrent intraductal papillary neoplasm of the bile duct due to intraductal dissemination: a case report and literature review

BackgroundIntraductal papillary neoplasm of the bile duct (IPNB) is a subtype of biliary tumor. The 5-year survival rate of patients with IPNB who underwent curative resection is 81%. However, IPNB is known to often recur in other parts of the bile duct. Nevertheless, its mechanism remains poorly understood. Herein, we report the case of a patient with recurrent IPNB, which was considered to be attributed to intraductal dissemination in the common bile duct at 12 months after curative resection. We also made a review of the existing literature.Case presentationA 69-year-old man was referred to our hospital for the evaluation and dilation of an intrahepatic bile duct (IHBD) mass. Computed tomography (CT) findings confirmed a mass in the left hepatic duct. Left trisectionectomy, extrahepatic bile duct resection with biliary reconstruction, and regional lymph node dissection were performed. Intraoperative examination of the resection margin at the common bile duct and posterior segmental branch of the hepatic duct was negative for the presence of malignant cells. Histologically, the tumor showed intraductal papillary growth of the mucinous epithelium and was diagnosed as non-invasive IPNB. It had a papillary structure with atypical epithelial cells lined up along the neoplastic fibrovascular stalks. Immunohistochemically, this was as a gastric-type lesion. At 12 postoperative months, CT revealed a 1.5-cm mass in the lower remnant common bile duct. We performed subtotal stomach-preserving pancreaticoduodenectomy. The tumor exhibited papillary growth and was microscopically and immunohistochemically similar to the first tumor. At approximately 16 months after the patient’s second discharge, CT showed an abdominal mass at the superior mesenteric plexus, which was diagnosed as recurrent IPNB. Chemotherapy is ongoing, and the patient is still alive. In this case, as described in many previous reports, IPNB recurred below the primary lesion in the bile duct.ConclusionBased on our review of previous reports on IPNB recurrence, intraductal dissemination was considered one of the mechanisms underlying recurrence after multicentric development. Considering the high frequency and oncological conversion of recurrence in IPNB, regular follow-up examination is essential to achieve better prognosis in patients with recurrent IPNB.

Management of Medulloblastoma Metastases: Algerian Experience

This work is based on the study of patients treated for medulloblastoma metastasis at diagnosis between January 2006 and December 2015 in the neurosurgery department of the Ait IDDIR Health Hospital Establishment. Our series consisted of 16 patients, 11 men and 5 women; the median age was 16.9 years. The baseline, presentation of symptoms and signs, imaging results (MRI), surgical results and clinical results were recorded. The clinical manifestation was revealed by intracranial hypertension syndrome (100%), associated with cerebellar syndrome (80%). The localization was in Intra-nevraxics: (81.25%) and in Extra-nevraxics (18.75%). 68.75% of patients underwent total surgical excision and 31.25% underwent subtotal surgical excision. The presence of malignant cells in the CSF is marked in 56.25%. The pathological study revealed that 62.5% of cases had a classic variant and 37.5% a desmoplastic variant. 30% of the cases were classified as “standard risk” and 70% as “high risk”. The surgery was supplemented by radiotherapy of the entire neuraxis using the “movable junctions” technique in all cases. The average delay was 70 days. Adjuvant chemotherapy was performed in 9 cases. The long-term survival rate after metastasis varies between 06 months to 24 months, only 04 cases (25%) are still alive. The management of medulloblastoma must be multidisciplinary involving neurosurgeons and radiotherapist oncologists. This collaboration is the only guarantee of an improvement in his prognosis

Clinical Management of Pancreatic Premalignant Lesions

Clinical Management of Pancreatic Premalignant Lesions

The Ommaya catheter as a treatment for pain and chemotherapy in meningeal carcinomatosis patient

Meningeal carcinomatosis consists of focal or multiple malignant metastases of extra neural solid tumors in the leptomeninges and subarachnoid space. It’s a rare complication and neurological symptoms include headache and nonspecific nerve palsy. The standard diagnosis is obtained by the presence of malignant cells in the cerebrospinal fluid cytology. The prognosis is poor, the treatment is limited and aims at palliating symptoms and stabilizing or partial improvement in neurological status.

O-179 Safety of ovarian tissue cryopreservation and transplantation in patients with central nervous system cancers

Abstract Study question Is cryopreserved ovarian tissue transplantation safe in patients with central nervous system (CNS) tumors? Summary answer Cancer cell contamination was not detected in any ovarian samples from patients with CNS tumors by histological analysis, immunohistochemistry, molecular biology or long-term xenotransplantation. What is known already Frequently encountered CNS cancers in childhood include astrocytoma, medulloblastoma, ependymoma, glioblastoma and germinoma. CNS tumors have the capacity for extraneural metastases in 0.5-18% of cases. There are two publications reporting metastases to patients’ ovaries from medulloblastoma. Study design, size, duration Prospective experimental study conducted in an academic gynecology research laboratory using frozen-thawed ovarian tissue from 20 patients suffering from 6 types of CNS tumors, including the most common forms mentioned above and primitive neuroectodermal tumors (PNET). Five-month xenotransplantation was performed to severe combined immunodeficient (SCID) mice. Participants/materials, setting, methods Cryopreserved ovarian tissue from 20 patients with CNS cancers was thawed and analyzed for minimal disseminated disease and long-term xenografting to immunodeficient mice. The presence of malignant cells was assessed in both cryopreserved and xenografted ovarian tissue using histological analysis, immunohistochemistry for disease-­specific markers (neuron-specific enolase [NSE] and glial fibrillary acidic protein [GFAP]) and reverse transcription droplet digital polymerase chain reaction (RT-ddPCR) for quantification of GFAP gene amplification. Main results and the role of chance No malignant cells were detected in frozen-thawed ovarian tissue from any of the patients by histology, immunolabeling for NSE and GFAP, RT-ddPCR for detection of GFAP gene amplification or xenotransplantation to SCID mice. One patient successfully underwent frozen-thawed ovarian tissue transplantation, resulting in the birth of 3 healthy children, but suffered a recurrence of her PNET 6 years after reimplantation and sadly died. Scrupulous analysis of her remaining frozen tissue showed no infiltration by malignant cells, neither after thawing nor long-term xenotransplantation. No relationship was ever established between the patient’s relapsed cancer and reintroduction of her cryopreserved ovarian tissue. The risk of reseeding cancer cells when transplanting ovarian tissue in patients with CNS cancers can therefore be considered low. Limitations, reasons for caution The risk of ovarian metastases cannot be completely ruled out for any type of tumor because we cannot analyze the actual fragments that will be reimplanted. Wider implications of the findings Our results indicate that the risk of disseminated disease in ovarian tissue from CNS patients is minimal. This is useful information for doctors when counseling women looking to undergo ovarian tissue transplantation. Trial registration number Not applicable

Malignant invasion of the cerebrospinal fluid in adult and paediatric patients with haematological and solid malignancies: a monocentric retrospective study

ABSTRACT Objectives In this study, we describe the clinical presentation, the cerebrospinal fluid (CSF) characteristics and outcome of children and adults with leptomeningeal invasion due to haematological and solid malignancies. Methods Routine CSF samples analyzed from 2008 to 2018 at our institution were retrospectively reviewed for the presence of malignant cells based on cytomorphological analysis. Results Leptomeningeal invasion was identified in 212 patients: 45 children versus 167 adults, and 92 haematological versus 120 solid malignancies. Leukaemic invasion in childhood was mainly due to ALL, and lymphoma invasion was often due to a high-grade B-cell lymphoma in adults. Metastatic invasion by solid tumours was almost exclusively seen in adults. Patients suffered most frequently from cranial neuropathy and headache (both 32%), while asymptomatic presentations were seen mainly in children (33%) and haematological malignancies (17%). Laboratory CSF parameters often showed an elevated WBC count (87%), total protein (74%) and lactate (76%) and a decreased glucose (77%). These deviations were especially found in solid malignancies (>84%) and adults (>82%). Brain and/or spinal cord imaging was more often suggestive for the leptomeningeal invasion in solid than in haematological malignancies (86% vs. 46%). The 5-year overall survival (OS) rates for patients with haematological and solid malignancies were 21.5% and 5.9%, respectively. The 5-year OS rate for children (55.6%) was significantly better than for adults (3.5%). Conclusion Leptomeningeal invasion is more often asymptomatic, and CSF parameters and imaging are more often normal in children and haematological malignancies than in adults and solid malignancies, possibly leading to underdiagnosis.

Abstract PO-010: Feature pyramid network for revealing tumour infiltrating lymphocyte presence and distribution in a whole slide image

Abstract Ductal Carcinoma in Situ (DCIS) is a subtype of non-invasive breast cancer contained in the ducts of the breast. DCIS is not a life-threatening condition however a small number of cases will progress to or reoccur as invasive breast cancer. Clinical workflows lack a robust biomarker to determine which patients will reoccur. Recently pathologists have turned towards investigating the tumour microenvironment to predict cancer recurrence. Machine learning models present an opportunity to analyze these features on large amounts of data with minimal requirement of pathologist time. One feature of recent interest are Tumour infiltrating lymphocytes or TILs, lymphocytes within a small region around a cancerous duct. Through a method of bootstrapping a U-Net on top of a fully convolutional network we have designed a network that is able to segment lymphocyte and malignant cells in H&amp;E Images of Ductal Carcinoma In Situ. The original network was trained on a private set of cellularity data in breast cancer, manually annotated by pathologists to mark the centre and type of each cell in a patch. Probabilistic output from this model was used to generate segmentation maps on a much larger dataset of DCIS images from the Ontario DCIS Cohort. These segmentation maps were used as training data for a feature pyramid network. The results of this bootstrapping method was a significant increase to speed of the model in addition to much larger flexibility in the input size and shape for the model, which came at a small cost to overall model accuracy. In addition to the original segmentation target, the use of this model to generate lower resolution WSI heat-maps has been investigated for this work. This model can generate low resolution heat-maps for a 20X magnification whole slide image showing the presence of malignant cells in addition to the location and distribution of TILs around ducts. This can provide a visual overview of differences between slides and we will be examining the potential for this output to serve as information for analytical methods to process to predict recurrence free survival. Citation Format: Jonathan Mazurski, Sharon Nofech-Mozes, Dina Bassiouny, Anne L. Martel. Feature pyramid network for revealing tumour infiltrating lymphocyte presence and distribution in a whole slide image [abstract]. In: Proceedings of the AACR Virtual Special Conference on Artificial Intelligence, Diagnosis, and Imaging; 2021 Jan 13-14. Philadelphia (PA): AACR; Clin Cancer Res 2021;27(5_Suppl):Abstract nr PO-010.

Relationship between Streptococcus gallolyticus Infective Endocarditis and Pre-Neoplastic Colorectal Lesions

Colorectal cancer is associated with Infective Endocarditis (IE) due to specific gut pathogens, such as Streptococcus gallolyticus subspecies, that use tumor presence as a point of blood entry. However, the association between Streptococcus gallolyticus related IE and pre-cancerous colorectal lesions like dysplastic adenomas is unclear. Seventy-one patients diagnosed with IE who underwent colonoscopy in the extension study during admission were included in a clinical, microbiological and imaging follow-up, between January 2008 and December 2020. Pre-cancerous lesions were divided as high and low-grade dysplasia based on World Health Organization criteria. Colorectal cancer was defined as the presence of malignant cell beyond the muscularis mucosa. Twenty-two IE patients (31%) presented colorectal lesions: 8 (36%) colorectal cancer and 14 (64%) pre-cancerous lesions [14% high degree (n = 2); 86% low degree (n = 12)]. Both, colorectal cancer (25% Vs 2%; p = 0.007) and pre-neoplastic lesions (50% Vs 2%; p<0.001) were related with higher prevalence of IE caused by Streptococcus gallolyticus. Additionally, the subgroup of low grade pre-cancerous lesions also showed this association (50% Vs 2%; p<0.001). Pre-cancerous colorectal lesions are associated with Streptococcus gallolyticus IE. These results suggest that high and low degree colorectal lesions may also act as a gateway for gut pathogens.

Ovarian tissue cryopreservation and transplantation in patients with central nervous system tumours.

Is there a possibility of reseeding cancer cells potentially present in frozen ovarian tissue from patients with central nervous system (CNS) tumours? Malignancy reseeding in cryopreserved ovarian tissue from 20 patients with CNS tumours was not detected by histology, immunohistochemistry (IHC), molecular biology or xenotransplantation. Ovarian metastasis potential has been documented in patients with leukaemia, borderline ovarian tumours, advanced breast cancer and Ewing sarcoma. However, data on the safety of transplanting frozen-thawed ovarian tissue from cancer patients with CNS tumours are still lacking. This prospective experimental study was conducted in an academic gynaecology research laboratory using cryopreserved ovarian cortex from 20 patients suffering from CNS tumours. Long-term (5 months) xenografting was performed in immunodeficient mice. Subjects enrolled in the study were suffering from one of six types of CNS tumours including medulloblastoma, ependymoma, primitive neuroectodermal tumours, astrocytoma, glioblastoma and germinoma. The presence of malignant cells was investigated with disease-specific markers for each patient in cryopreserved and xenografted ovarian tissue by histology, IHC via expression of neuron-specific enolase (NSE) and glial fibrillary acidic protein (GFAP), and reverse transcription droplet digital polymerase chain reaction (RT-ddPCR) for quantification of GFAP and ENO2 gene amplification. Serial sections of cryopreserved and xenografted ovarian tissue from 20 patients showed no malignant cells by histology. All samples were negative for NSE and GFAP, although these neural markers were expressed extensively in the patients' primary tumours. Analysis by RT-ddPCR revealed no cancer cells detected in cryopreserved and xenografted ovarian fragments from subjects with astrocytoma, ependymoma, glioblastoma or medulloblastoma. Taken together, the study found no evidence of malignancy seeding in frozen-thawed and xenotransplanted ovarian tissue from patients affected by CNS cancers. This analysis cannot guarantee complete elimination of disseminated disease from all cryopreserved ovarian cortex, since we are unable to examine the fragments used for transplantation. This is the first study to be conducted in patients with CNS cancers undergoing ovarian tissue cryopreservation and transplantation, and clearly demonstrates no tumour seeding in their frozen-thawed and xenografted tissue. This information is vital for doctors to provide patients with meaningful and accurate advice on the possibilities and risks of ovarian tissue reimplantation. This study was supported by grants from the Fonds National de la Recherche Scientifique de Belgique-the Excellence of Science (FNRS-EOS), number 30443682 awarded to M.-M.D. and T.Y.T.N., FNRS grant number 5/4/150/5 and FNRS-PDR Convention grant number T.0077.14 awarded to M.-M.D., grant 2018-042 from the Foundation Against Cancer awarded to A.C., and private donations (Ferrero, de Spoelberch). The authors declare no competing financial interests. N/A.