Post-treatment Biopsies Research Articles

Gastric Perforation Due to Yellow Oleander Poisoning: First Case Report in Humans

Yellow oleander (Thevetia peruviana) is a commonly found shrub in India which produces multiple alkaloidswhich are cardiotoxic. Numerous cases of yellow oleander poisoning have been reported in humans. The spectrumof toxicity due to this plant ranges from nausea, vomiting, diarrhoea, electrolyte abnormalities and arrhythmiasin humans. No case of bowel necrosis due to yellow oleander has been reported in humans to the best of ourknowledge.We present a case of 45-year-old female with suicidal consumption of crushed yellow oleander seeds. The patientwas admitted and observed for arrhythmias. On day 2 of admission, she developed bloody stools, hematemesisand abdominal pain. Abdominal examination showed rigidity and per rectal examination showed blood-stainedmucoid stools. A CECT was done which showed findings suggestive of gastric necrosis with perforation. Thepatient was taken up for surgery and stomach was found to be gangrenous with a perforation at the greatercurvature. Total gastrectomy was performed. The post operative biopsy showed extensive transmural coagulativenecrosis of the stomach and lymphoplasmacytic infiltration of the submucosa.Necrosis of bowel has been reported in experimental settings in animals and in cattle poisoning but no reportedcase of stomach necrosis and perforation due to yellow oleander has been reported in humans. As yellow oleanderis a commonly used suicidal poison in Southern Asia, an eye needs to be kept out for gastrointestinal symptoms.We conclude with recommendations on management of yellow oleander poisoning in the light of these newmanifestations.

Laryngeal Cancers at the Pathological Anatomical Laboratory (ACP) in Dakar about 215 Cases

Introduction: Laryngeal cancer is the first cancer of upper aerodigestive tract. Dysphonia, dyspnea and dysphagia are evocative signs. Diagnosis is histological and squamous cell carcinoma is the most common type. The objective of our study was to discuss epidemiological and anatomo-pathological characteristics of laryngeal cancers diagnosed in different pathological anatomy and cytology (ACP) laboratories of Dakar hospitals. Material and method: This was a retrospective study spanning from January 2013 to December 2018 at the pathological anatomy laboratories of Fann, Aristide Le Dantec and Idrissa Pouye hospitals. All patients with laryngeal cancer confirmed at histology were included. Data collection was based on clinical records of the patients and archives of histological reports of the pathological laboratories. Data analysis was performed under the Excel software. Results: We collected 215 cases of laryngeal cancer. The average age was 58.01 years with extremes of 07 and 94 years. The male sex was predominant with 183 patients (85.12%) against 32 women (14.88%). The most noted risk factor was tobacco which affected 14 patients, or 60.87%. Three patients (13.04%) did not present any alcohol-smoking impregnation. Clinically, dysphonia was noted in 22 patients (26.51%). It was associated with dyspnea in 0.48% of cases and dysphagia in 3.61%. Laryngoscopy was performed in 62 patients or 28.83% of cases, nasofibroscopy in 6.45% of cases. Cord arythenoid fixity was noted in two patients (3.23%) and hypo-mobility in 1 patient (1.61%). The most frequent local extension was involvement of the piriform sinus with 11.29% of cases. Palpable lymphadenopathy reported in 17 patients (20.48%). Pathological examination was performed in all patients after post endoscopic biopsy in 92 patients (42.79%), and after obtaining the operative specimen in 123 cases (57.21%). The three floors affected 76 patients (35.35%). The ulcerative budding aspect most noted concerned 108 patients (60.97%). Histologically, it was a squamous cell carcinoma in 205 patients (95.34%). The most site invaded by the tumor was cricoid cartilage.T4 type was most found (45 patients or 40.90%) followed by the T3 type with 34.55%. There was no lymphadenopathy invasion (Type N0) in 74 patients (67.27%), capsular rupture was reported in five patients (6.77%), no evaluable metastasis in 110 patients (97.27%), and stage IVA predominated in 66 patients (60%). Conclusion: laryngeal cancer is a reality in our contexts, however, its incidence is poorly understood in Senegal. The main risk factors remain tobacco and alcohol. Histology confirms the diagnosis. Its management is multidisciplinary and must be early.

Research Letter-Outcomes of Outpatient Native Kidney Biopsies at the McGill University Health Center: A Quality Assurance Audit.

Percutaneous kidney biopsies are essential for diagnosis and management of kidney diseases. However, post-procedural bleeding is a significant risk associated with biopsies. At the McGill University Health Center, the 2 main hospitals, the Royal Victoria Hospital and the Montreal General Hospital, have different observation protocols for outpatient native kidney biopsies. Currently, patients are admitted for a 24-hour inpatient observation at the Montreal General Hospital, whereas patients biopsied at the Royal Victoria Hospital are discharged after 6 to 8 hours of observation at the end of the day. Most Canadian centers do not admit patients for an overnight observation, and it was unclear why this practice continued at the Montreal General Hospital. Our objective was to determine the incidence of complications post-renal biopsy over the past 5 years at both hospital sites, and compare them to each other, as well as to established rates in the available literature. This assessment was designed as a quality assurance audit. This audit was conducted from a local registry of renal biopsies performed at the McGill University Health Center between January 2015 to January 2020. We included all adult patients (between the ages 18 and 80) with outpatient native kidney biopsies performed at the McGill University Health Center between 2015 and 2020. We collected the included patients' baseline demographics and risk factors at the time of biopsy, including age, BMI, creatinine, estimated glomerular filtration rate, pre- and post-biopsy hemoglobin, platelet, urea, coagulation profile, blood pressure, kidney side/size as well as needle size, and number of passes made. We compared the incidence of both minor and major bleeding complications at the Montreal General and the Royal Victoria Hospital. Variables that were measured included hemoglobin before and after biopsy, incidence of minor bleeding complications (defined by hematomas and gross hematuria), and incidence of major complications (defined by post-biopsy bleeding requiring either transfusions or another procedure to stop the bleeding), as well as the incidence of admissions post-biopsy. The incidence of major complications was 2.87% over 5 years (5/174 patients), which is comparable with that reported in the literature. Our transfusion incidence was 1.72% (3/174 patients) and our embolization incidence was 2.3% (4/174 patients) over the 5 study years. Our total number of major events was low and the patients who had major events had significant risk factors for bleeding. All events occurred within 6 hours of observation. This was a retrospective study with a low event number. Additionally, since the events included only those recorded at the McGill University Health Center, it is possible that the events of interest may have occurred at other hospital sites without the author's knowledge. Based on the results of this audit, all major bleeding events occurred within 6 hours of a percutaneous kidney biopsy, suggesting that patients should be monitored for 6 to 8 hours following biopsy. The next step after this quality assurance audit is a quality improvement project and a cost-effectiveness analysis to assess whether post-biopsy practices should be amended at the McGill University Health Center.

Tumor Microenvironment before and after Chemoradiation in Locally Advanced Rectal Cancer: Beyond PD-L1.

In locally advanced rectal cancer treatment, neoadjuvant concurrent chemoradiation therapy (cCRT) is the standard of care. The tumor microenvironment (TME) is a complex entity comprising of tumor cells, immune cells and surrounding stroma and is closely associated with tumor growth and survival, response to antitumor therapies and also resistance to treatment. We aimed to assess the change in biomarkers associated with TME following standard neoadjuvant cCRT in rectal cancer. We accessed archival tissue from rectal cancer patients treated with neoadjuvant cCRT at Allegheny Health Network (AHN) facilities over the past 14 years. Pre-treatment and post-treatment biopsies were assayed for PD-L1, CD8+ T-cells, CXCL9, TIM-3, IDO-1, IFN-G, IL17RE, LAG-3, and OX40 in 41 patients. We found statistically significant upregulation in multiple biomarkers namely CD8, IL17RE, LAG3 and OX40 post neoadjuvant cCRT and a trend towards upregulation, although not statistically significant, in biomarkers PD-L1, CXCL9, TIM-3, IDO-1 and IFN-G expression. This provides a glimpse into the TME before and after neoadjuvant cCRT. We suggest that the biomarkers noted to be upregulated could be used for designing appropriate clinical trials and development of therapeutic targeted drug therapy in an effort to achieve better response to neoadjuvant therapy, increasing clinical and pathological complete response rates and improved overall outcomes.

Off-label use of intrabronchial valves for persistent air leak is safe and effective: a retrospective case analysis.

Persistent air leak (PAL) is a challenging clinical problem associated with prolonged hospital stay and increased morbidity. Historically, treatment options were limited to thoracostomy tube drainage, pleurodesis, and surgical repair. The development of one-way airway valves has represented a paradigm shift in PAL management. We present our experience using intrabronchial valves (IBVs) for PAL management looking at both on-label (post-thoracic surgery) and off-label (all other) indications. We performed a retrospective review of our single-center experience. Data collected included demographics, primary pathology leading to PAL, comorbidities, time to chest tube removal, complications, mortality, need for any additional procedure, and time to IBV removal. During the study period, 15 patients underwent IBV insertion for PAL. The on-label cohort contained three patients (post lobectomy or segmentectomy). The off-label cohort had 12 patients (6 empyema, 4 secondary spontaneous pneumothorax, 1 penetrating trauma, and 1 post percutaneous lung nodule biopsy). In the on-label cohort, chest tube was removed after a mean duration of 4.0±1.0 days for all patients. In the off-label cohort, 83.3% (10/12) had chest tube removal 16.2±5.7 days (P=0.396) after IBV placement. One patient developed hypoxic respiratory failure shortly after IBV insertion, necessitating removal of 2 out of 5 valves. IBVs are a minimally invasive, well tolerated treatment modality for patients with PAL and a viable alternative to invasive surgical interventions. Procedure or valve-related complications are uncommon. Valves can be removed and do not preclude surgical intervention. Updated guidelines are necessary to formalize PAL management.

Abstract B005: Intralesional injections with checkpoint inhibitors and cytokines can modify DCIS lesions with infiltrating T cells

Abstract Background: Ductal carcinoma in situ (DCIS) is a risk factor for the development of invasive ductal carcinoma. Previous work has shown that an increased presence of T cells corresponds to high-risk DCIS features: age <45 years, size >5 cm, high-grade, palpable mass, hormone receptor negativity, and HER2 positivity. The presence of T cells colocalized with tumor is emerging as a predictor of response to checkpoint inhibition in invasive cancer. We previously have demonstrated that intratumoral injections of a checkpoint inhibitor (pembrolizumab) in DCIS resulted in an increased number of T cells, but without tumor cell killing. We hypothesized that the addition of an agent that could potentiate both innate and adaptive immune responses might increase the efficacy of checkpoint inhibition. Methods/Materials: We administered intralesional injections of immunotherapy (4-8 mg pembrolizumab + 2-4mg mRNA 2752) to patients with “high-risk” DCIS in an attempt to modulate the immune system and protect from disease progression and recurrence. Two patients have been enrolled and completed therapy and 4 more are being treated. Immune infiltrates were characterized by multiplex immunofluorescence (mIF) staining of pre- and post-treatment tissue samples using two 6-plex panels. Staining was performed on a Leica Bond autostainer and images were acquired on a Vectra Polaris imaging system. Image analysis was performed utilizing inForm and QuPath software packages, as well as R scripts. Results: The first patient treated, a 41-year-old woman with ER+/PR+, HER2- disease, with low T cells in her pre-treatment biopsy, received one dose of pembrolizumab (8mg) with mRNA 2752 (4mg). While she experienced fatigue, sustained fever, and muscle aches for 3-5 days, draining node enlargement and redness and swelling at the breast a week after treatment, there was no change on her post-treatment MRI, and no significant change in the number of T cells in her post-treatment tissue. The second patient, a 74-year-old woman with ER-/PR-, HER2+ disease had high numbers of T cells in the pre-treatment biopsy. She received one injection of pembrolizumab (4mg) with mRNA 2752 (2mg), followed 3 weeks later by an injection of pembrolizumab (4mg) alone. She declined the second dose of mRNA 2752 due to side effects from the first injection. Her post-treatment MRI showed some reduction in tumor volume and her post-treatment biopsy showed no evidence of DCIS, as well as an increase in T cells. Conclusions: The presence of T cells prior to therapy is likely to be important for eliciting a strong anti-tumor response. The addition of an agent that enhances both innate and adaptive immune responses may increase the efficacy of immune checkpoint blockade. Four additional patients will have completed their therapy by the end of August and we await results. It will be important to understand if pre-existing T cells within the DCIS lesion are a predictor for response to therapy as we continue to screen and enroll patients. Citation Format: Nicole F. Schindler, Alexa Glencer, Phoebe Miller, Christopher Schwartz, Gillian Hirst, Alexander Borowsky, Michael Campbell, Laura Esserman. Intralesional injections with checkpoint inhibitors and cytokines can modify DCIS lesions with infiltrating T cells [abstract]. In: Proceedings of the AACR Special Conference on Rethinking DCIS: An Opportunity for Prevention?; 2022 Sep 8-11; Philadelphia, PA. Philadelphia (PA): AACR; Can Prev Res 2022;15(12 Suppl_1): Abstract nr B005.

This Month in Adult Urology.

This Month in Adult Urology.

Safety and technical success of diphenhydramine as an alternative local anaesthetic agent for radiology procedures

To evaluate retrospectively the safety and technical success of subcutaneous diphenhydramine as an alternative local anaesthetic for radiology procedures. Between January 2000 and April 2021, 84 image-guided procedures were performed in 81 adult patients (mean age 61 years, 86% female) using 1% injectable diphenhydramine as a local anaesthetic. Indications were history of severe allergy to "-caine" local anaesthetics in 76 (90%) patients and recent administration of bupivacaine liposomal injectable suspension in eight (10%) patients. Twelve of the 84 (14%) procedures were performed with concomitant moderate sedation. Patient characteristics, procedural techniques, and clinical outcomes were reviewed. Early and delayed (30-day) complications were classified as either related to local diphenhydramine injection or to the procedure itself. Procedure-related complications were gradated using the Clavien-Dindo system. Percutaneous biopsy was the most frequently performed procedure (57/84, 67%). Fifty-nine (70%) of the 84 procedures were ultrasound guided. The most common procedural site was the breast (34/84, 40%). All procedures were technically successful. There were two minor injection-related complications related to post-procedural pain. A single minor procedure-related complication involved a patient requiring hospital admission for post-renal biopsy related haematuria. Injectable diphenhydramine appears to be a safe and effective local anaesthetic alternative in patients with "-caine" class contraindications undergoing radiology procedures. A future prospective trial would be useful to assess the safety profile in an large cohort of patients.

Resistance to MET inhibition in MET-dependent NSCLC and therapeutic activity after switching from type I to type II MET inhibitors

ObjectivesResistance to MET inhibition occurs inevitably in MET-dependent non-small cell lung cancer and the underlying mechanisms are insufficiently understood. We describe resistance mechanisms in patients with MET exon 14 skipping mutation (METΔex14), MET amplification, and MET fusion and report treatment outcomes after switching therapy from type I to type II MET inhibitors. Materials and methodsPre- and post-treatment biopsies were analysed by NGS (next generation sequencing), digital droplet PCR (polymerase chain reaction), and FISH (fluorescense in situ hybridization). A patient-derived xenograft model was generated in one case. ResultsOf 26 patients with MET tyrosine kinase inhibitor treatment, eight had paired pre- and post-treatment biopsies (Three with MET amplification, three with METΔex14, two with MET fusions (KIF5B-MET and PRKAR2B-MET).) In six patients, mechanisms of resistance were detected, whereas in two cases, the cause of resistance remained unclear. We found off-target resistance mechanisms in four cases with KRAS mutations and HER2 amplifications appearing. Two patients exhibited second-site MET mutations (p.D1246N and p. Y1248H). Three patients received type I and type II MET tyrosine kinase inhibitors sequentially. In two cases, further progressive disease was seen hereafter. The patient with KIF5B-MET fusion received three different MET inhibitors and showed long-lasting stable disease and a repeated response after switching therapy, respectively. ConclusionResistance to MET inhibition is heterogeneous with on- and off-target mechanisms occurring regardless of the initial MET aberration. Switching therapy between different types of kinase inhibitors can lead to repeated responses in cases with second-site mutations. Controlled clinical trials in this setting with larger patient numbers are needed, as evidence to date is limited to preclinical data and case series.

Transient Responses and Significant Toxicities Due to Cytopenias and Rashes with Anti-CD30 CAR T Cells for CD30-Expressing Lymphomas: Results of a Phase I Clinical Trial

Although several effective therapies are available for Hodgkin lymphoma (HL), new treatments are needed, especially for chemotherapy-refractory HL. We developed a novel anti-CD30 CAR, designated 5F11-28Z, with a human antibody-derived binding domain, CD28 hinge, transmembrane, and costimulatory domains, and a CD3-ζ domain (Choi et al., Hum Gene Ther 2021; 32(13-4): 730-43). T cells expressing 5F11-28Z are designated 5F11-28Z-T; 5F11-28Z-T exhibited a full range of T-cell functions in vitro and eradicated tumors from mice. Safety and feasibility of 5F11-28Z-T were evaluated in a phase I clinical trial for patients (Pts) with CD30-expressing lymphomas (NCT03049449). Pts were divided into 2 cohorts with separate dose escalations based on prior allogeneic stem cell transplant status and received 5F11-28Z-T on one of 4 dose levels (Table). The treatment protocol was 300 mg/m2 or 500 mg/m2 of cyclophosphamide and 30 mg/m2 of fludarabine on days -5 to -3 followed by infusion of 5F11-28Z-T on day 0. Normal organ function and absence of baseline Grade (Gr) 3-4 cytopenias were required for eligibility. Twenty-one Pts received 5F11-28Z-T infusions, 20 with HL and 1 Pt with anaplastic large cell lymphoma (Table). The median prior lines of therapy was 7 (4-15). Forty-three percent of Pts (9 of 21) obtained a response of partial remission or better with one (4.8%) obtaining a complete remission. The median event-free survival was 13 (4-22) weeks. Eleven Pts (52%) had cytokine release syndrome (CRS): 4 (19%) with Gr 1, 6 (29%) with Gr 2, 1 (4.8%) with Gr 3, and no Pts had grade 4-5. Two Pts (9.5%) received tocilizumab; no Pts received corticosteroids for CRS. Neurologic toxicity possibly related to CAR T cells (graded by CTCAE v 5) occurred at Gr 2 in 5 (24%) Pts, with no Gr 3-4 events. There were no treatment related deaths. Nine Pts (43%) had new onset maculopapular or pustular rashes after 5F11-28Z-T infusion (Figure). Rashes occurred a median of 11 (7-55) days after 5F11-28Z-T infusion and lasted at Gr of 2 or higher for a median of 7 (3-39) days. Six Pts had Gr 2 rashes; 3 Pts had Gr 3 rashes. Two Pts with Gr 3 rashes lasting 29 and 39 days received systemic corticosteroids for management of rash. One Pt received phototherapy. Nineteen Pts (90%) had Gr 3-4 neutropenia; 5 (24%) had Gr 3-4 thrombocytopenia; and 6 (29%) had Gr 3-4 anemia. Three Pts (14%) had Gr 3-4 cytopenias lasting more than 30 days. Two Pts had prolonged pancytopenia, lasting 77 and > 82 days; both Pts had infections requiring intensive care while neutropenic. Three Pts received eltrombopag; 2 Pts received corticosteroids for management of prolonged cytopenias. Eleven bone marrow (BM) biopsies were performed for 5 Pts to evaluate cytopenias. All biopsies showed hypocellularity; 10/11 (4 Pts) showed trilineage or myeloid hypoplasia, 4/11 (2 Pts) showed fibrosis, 1 showed stromal gelatinous changes, and none showed HL or dysplasia. Blood 5F11-28-T were detected in all 15 patients assessed so far. A median of 2.2% (range 0.1-29.4%) of peripheral blood mononuclear cells contained the CAR gene. An immunohistochemical stain for CAR+ cells was performed with an antibody against the CAR linker. Seven Pts had technically adequate tumor biopsies within 30 days following 5F11-28Z-T; infiltrating CAR+ cells were not detected in any of these biopsies. For comparison, post-treatment tumor biopsy specimens from Pts with B-cell lymphoma were collected within 30 days after infusion of anti-CD19 CAR T-cells (Brudno et al., Nat Med 2020; 26: 270-80). These specimens were stained for CAR+ cells with the same antibody used to stain for 5F11-28Z-T. Two of 5 Pts (40%) had one or more tumor biopsy samples with detectable CAR+ cells. Four Pts with rashes after 5F11-28Z-T had skin biopsies, which showed a spongiotic dermatitis. CD30 was detected on mononuclear cells in 2 biopsies (2 Pts). Of 3 evaluable skin biopsies, 1 performed at Day 7 had detectable CAR+ cells in the dermis; none from later time points had CAR+ cells. Three Pts with Gr 4 cytopenias had 5 evaluable BM biopsies after 5F11-28Z-T. The earliest biopsy, performed at Day 16, had CAR+ cells. In conclusion, 5F11-28Z-T cells have limited anti-malignancy efficacy. Severe toxicities from rashes and myelosuppression may be due to CD30 expression on dermal mononuclear cells and on hematopoietic stem cells (Hombach et al., Mol Ther 2016; 24(8):1423-34). These toxicities along with limited anti-lymphoma activity prompted us to end this clinical trial. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

TAIL GUT CYST- A RARE FINDING- CASE REPORT AND REVIEW OF LITERATURE

Introduction: Tailgut cysts are rare congenital entity that arises from the embryological hindgut and usually located in presacral space. Here we report a case of tail gut cyst which is an infrequent condition. Case report: Here, we report a nineteen year old male with lower abdominal pain. The relevant investigations were performed. The CT abdomen revealed a well-dened cystic lesion in the pelvis in lower presacral region and posterior to rectum with small calcied foci suggestive of tail gut cyst with scalloping of sacrum. MRI pelvis suggested large well dened unilocular cystic lesion in the retro-rectal and pre-sacral region extending from S2 to mid coccygeal level showing thin imperceptible walls few tiny projections and small rounded non enhancing nodule along its posterior wall with thin focal calcication seen in its wall with no evidence of malignancy and no signs of osseous destruction. The patient was explored and intraoperatively ndings revealed a cyst of size 8 cm * 5 cm behind the rectum and in front of sacrum which was densely adhered to the posterior wall of rectum but free from sacrum. The mass was resected as a whole and sent for histopathological exam which was suggestive of tailgut cyst. Tailgut cysts is infrequent condition which manifests as chronic lower abdominal pai Conclusion: n. It is crucial that such entity be diagnosed and surgically excised early in its presentation. It is important to rule out malignancy in the post operative biopsy

118. Single-cell RNA sequencing and co-occurring cellular state analysis of high-grade serous ovarian cancer

High-grade serous carcinoma (HGSC) is the most lethal subtype of ovarian cancer, and a majority of patients are diagnosed at advanced stages. One standard-of-care is neoadjuvant chemotherapy followed by cytoreductive surgery, however up to 80% of HGSC patients develop recurrent disease. There exists a critical need to better understand the features of this tumor microenvironment that may highlight potential therapeutic targets, help stratify chemotherapy responders from non-responders, and uncover novel cell states that may serve as prognostic or predictive biomarkers. We obtained multiple biopsies from five patients with advanced-stage HGSC, both pre- and post-treatment, and analyzed these samples using single-cell RNAseq. We identified 20 distinct transcriptional clusters of cells, including a well-defined tumor subset enriched for EPCAM and KRT8. We annotated each cluster using known marker genes, and additionally validated these data through genome-wide copy number and developmental maturity analyses. We then performed transcriptome deconvolution to identify co-occurring transcriptional states using EcoTyper. We then performed bulk RNAseq on paired pre- and post-treatment tumor biopsies from 23 HGSC patients. Applying our fingerprints of ecotypes from the scRNA-seq data, we identified multiple distinct transcriptional states within the pre- and post-treatment HGSC tumor microenvironment, which were enriched for distinct co-occurring states comprised of multiple immunologic lineages, including CD4 T and NK cell states. We plan to validate these ecotypes using spatial transcriptomics and compare clinical outcomes across transcriptional states to determine the potential prognostic or predictive implications of our discoveries.

Calretinin Staining in Anorectal Line Biopsies Accurately Distinguished Hirschsprung Disease in a Retrospective Study.

The absence of submucosal ganglion cells does not reliably distinguish Hirschsprung disease from non Hirschsprung disease in anorectal line biopsies. Calretinin staining might be helpful in these biopsies. To determine its value, we analyzed calretinin positive mucosal neurites in anorectal line biopsies. Two pediatric pathologists, without access to patient data, evaluated calretinin positive mucosal neurites in anorectal line junctional mucosa in archival rectal biopsies contributed by 17 institutions. A separate investigator compiled patient information and sent data for statistical analysis. Biopsies with anorectal junctional mucosa from 115 patients were evaluated for calretinin positive mucosal neurites. 20/20 Hirschsprung disease biopsies were negative. 87/88 non Hirschsprung disease biopsies and 7/7 post pullthrough Hirschsprung disease neorectal biopsies were positive. Statistical analysis of the 108 non pullthrough biopsies yielded an accuracy of 99.1% (sensitivity 100%, specificity 98.9%). Age range was preterm to 16 years. Biopsy size was less than 1 mm to over 1 cm. Absence of calretinin positive mucosal neurites at the anorectal line was highly accurate in distinguishing Hirschsprung disease from non Hirschsprung disease cases in this blinded retrospective study. Calretinin staining is useful for interpreting biopsies from the physiologic hypoganglionic zone up to the anorectal line.

Superior Post-Treatment Biopsy Outcomes with High Dose SBRT Compared to High-Dose Conventionally Fractionated IMRT for Clinically Localized Prostate Cancer

<h3>Purpose/Objective(s)</h3> To compare post-treatment biopsy outcomes for clinically localized prostate cancer patients treated with high-dose conventionally fractionated intensity modulated radiotherapy (CF- IMRT) versus high-dose stereotactic body radiotherapy (SBRT). <h3>Materials/Methods</h3> 451 patients with low and intermediate risk prostate cancer treated with high dose external beam radiotherapy underwent a post-treatment biopsy which was routinely performed at our institution to assess local control status. Biopsies were performed 2-3 years after completion of radiotherapy. 221 patients were treated with CF-IMRT to a median dose of 75.6 Gy (range: 64.8-86.4) and 230 patients were treated with SBRT to a median dose of 40 Gy in 5 fractions (range: 32.5-42.0). A 6-month course of androgen deprivation therapy (ADT) was used in conjunction CF-IMRT and SBRT in 38% and 17% of patients. The percentage comprising low, favorable intermediate and unfavorable intermediate risk group were similar (CF-IMRT: 23%, 36% and 41%; SBRT: 18%, 49%, 33%). The histological outcome of the prostate biopsy was classified as positive (prostatic adenocarcinoma without typical radiation–induced changes), negative (no evidence of carcinoma) or severe treatment effect. <h3>Results</h3> The incidence of a positive post treatment among the IMRT and SBRT cohorts were 49% and 17%, respectively (p< 0.001). The incidence of a positive biopsy for low risk, favorable- intermediate risk and unfavorable- intermediate risk patients treated with IMRT and SBRT were: IMRT: 40%, 52%, and 52%; SBRT: 7.1%, 17%, and 21%, respectively. Multivariable analysis evaluating co-variates associated with a positive post-treatment biopsy was IMRT (P< 0.001 CI:0.12, 0.33) with 5-fold higher odds of a positive biopsy compared to SBRT. Other variables including the use of ADT and the risk group did not significantly impact on the biopsy outcome. <h3>Conclusion</h3> The use of SBRT in the treatment of low and intermediate risk prostate was associated with improved post-treatment biopsy outcomes compared to conventionally fractionated IMRT. These findings were observed even in the setting of high-dose IMRT to prescribed doses of ≥75.6 Gy. We hypothesize that these findings may be related to the greater ablative potential of high dose SBRT compared to IMRT.

Trial in Progress: 2019-1001 A Phase I Study of NBTXR3 Activated by Radiotherapy for Locally Advanced or Borderline Resectable Pancreatic Ductal Adenocarcinoma (LAPC or BRPC)

<h3>Purpose/Objective(s)</h3> Patients with pancreatic ductal adenocarcinoma (PDAC), who are not eligible for surgery after induction chemotherapy often receive radiation. Although radiation therapy (RT) improves local disease control, the placement of the pancreas proves to be difficult when safely delivering therapeutic doses. NBTXR3 is a novel, potentially first-in-class radio enhancer, composed of functionalized hafnium oxide nanoparticles that is administered via one-time intratumoral injection and activated by RT. Pre-clinical testing suggests up to a 9-fold enhancement of the RT dose delivered within tumor cells. In this phase 1 trial-in-progress, the primary objective is to determine the recommended phase II dose (RP2D) of NBTXR3 for LAPC and BRPC patients undergoing RT. The secondary objectives are to evaluate the safety, feasibility, and anti-tumor response of NBTXR3 intratumoral injection on PDAC patients as well as time-to-event outcomes of subjects. <h3>Materials/Methods</h3> For the dose-finding part 1 of the study, patients with LAPC and no metastatic disease after at least 2-6 months of chemotherapy will be eligible. For part 2, the expansion at RP2D, patients with BRPC or LAPC and no metastatic disease after chemotherapy will be eligible. The statistical design of the trial uses a Bayesian optimal interval (BOIN) design. A maximum of 24 patients will be enrolled. For baseline and follow-up, imaging and blood biomarkers will be collected. Patients enrolled will receive NBTXR3, once, through intratumoral injection via endoscopic ultrasound (Day 1). Pre-treatment biopsy will be collected. Post NBTXR3 injection, blood samples will be collected at 4 time points (0,5,30, and 120 minutes). Two urine voids will be collected post injection for hafnium quantification as well. At least three days later, patients will undergo imaging for RT dosimetry and planning where NBTXR3 can be visualized. Patients will then receive 45 Gy in 15 fractions with IMRT, with regional nodal basins receiving 37.5 Gy. Follow-up period will begin 4 weeks after end of treatment and continue every 3 months for a year. Patients will be evaluated for surgery 4-12 weeks post RT. At 11-13 weeks after end of RT, if the patient is not eligible for surgery, an endoscopic ultrasound procedure will be performed. In both events, a post-treatment biopsy will be obtained. The imaging collected of pancreatic target lesion will be used to determine tumor response as per RECIST v1.1 criteria. <h3>Results</h3> Trial is open and accruing, with 8 patients enrolled so far. <h3>Conclusion</h3> We expect to determine the RP2D, safety, and preliminary efficacy of NBTXR3 in pancreatic cancer with this study with blood, tissue, and imaging correlates in 2022.

Molecular Biomarker Expression in Window of Opportunity Studies for Oestrogen Receptor Positive Breast Cancer-A Systematic Review of the Literature.

Simple SummaryWindow of opportunity (WoO) trials allow the opportunity to assess the use of drugs in breast cancer research before treatment has commenced. The aim of this review of the literature is to review WoO trials in patients with oestrogen receptor-positive (ER+) breast cancer to help guide treatment. This will be useful for patients who receive drug treatment before surgery, or as an alternative to surgery in older, more frail adults.Window of opportunity (WoO) trials create the opportunity to demonstrate pharmacodynamic parameters of a drug in vivo and have increasing use in breast cancer research. Most breast cancer tumours are oestrogen receptor-positive (ER+), leading to the development of multiple treatment options tailored towards this particular tumour subtype. The aim of this literature review is to review WoO trials pertaining to the pharmacodynamic activity of drugs available for use in ER+ breast cancer in order to help guide treatment for patients receiving neoadjuvant and primary endocrine therapy. Five databases (EMBASE, Cochrane, MEDLINE, PubMed, Web of Science) were searched for eligible studies. Studies performed in treatment-naïve patients with histologically confirmed ER+ breast cancer were included if they acquired pre- and post-treatment biopsies, compared measurement of a proteomic biomarker between these two biopsies and delivered treatment for a maximum mean duration of 31 days. Fifteen studies were eligible for inclusion and covered six different drug classes: three endocrine therapies (ETs) including aromatase inhibitors (AIs), selective oestrogen receptor modulators (SERMs), selective oestrogen receptor degraders (SERDs) and three non-ETs including mTOR inhibitors, AKT inhibitors and synthetic oestrogens. Ki67 was the most frequently measured marker, appearing in all studies. Progesterone receptor (PR) and ER were the next most frequently measured markers, appearing five and four studies, respectively. All three of these markers were significantly downregulated in both AIs and SERDs; Ki67 alone was downregulated in SERMs. Less commonly assessed markers including pS6, pGSH3B, FSH and IGF1 were downregulated while CD34, pAKT and SHBG were significantly upregulated. There were no significant changes in the other biomarkers measured such as phosphate and tensin homolog (PTEN), Bax and Bcl-2.WoO studies have been widely utilised within the ER+ breast cancer subtype, demonstrating their worth in pharmacodynamic research. However, research remains focused upon routinely measured biomarkers such ER PR and Ki67, with an array of less common markers sporadically used.

Tumour-stroma ratio to predict pathological response to neo-adjuvant treatment in rectal cancer

IntroductionManagement of rectal cancer has advanced, with an increasing use of neoadjuvant chemoradiotherapy (nCRT). This opens options for organ preserving treatment for those with a major response to nCRT. However, the degree of clinical response, based on MRI and post-treatment biopsies, only poorly matches the degree of actual pathological response. In order to select patients with major pathological response without surgical resection, it is of importance to define tumour markers predicting the degree of pathological response to nCRT. The intra-tumoural tumour-stroma ratio (TSR) might be this marker. MethodsTSR in pre-treatment biopsies was estimated according to the method described by van Pelt et al. The degree of pathological response was assessed on the tumour resection according to tumour regression grading (TRG) by Mandard. The primary endpoint of this study was the difference in pathological response to nCRT between TSR-high and TSR-low groups. ResultsWe found that 26.2% of patients with major response was classified as TSR-high, while 73.8% of patients were classified as TSR-low. A high TSR in pre-treatment biopsies was associated with a lower chance of major-response to nCRT (OR = 0.37, 95%CI; 0.19–0.73), p = 0.004), independent of tumour stage and time between nCRT and surgery. ConclusionIn rectal cancer, TSR in pre-treatment biopsies predicts pathologic response to nCRT, with a high TSR bringing twice the risk of poor to no response compared to low TSR. In future, assessment of TSR may fulfil a role in a therapeutic algorithm identifying patients who will or will not respond to nCRT prior to treatment initiation.

S161 Cold Snare Endoscopic Mucosal Resection for Colon Polyps: A Systematic Review and Meta-Analysis

Introduction: Cold snare endoscopic mucosal resection (CS-EMR) has become increasingly popular for the removal of colon polyps > 10 mm. CS-EMR can potentially avert some of the risks associated with the use of electrocautery during polyp resection without compromising clinical efficacy. Therefore, we conducted a systematic review and meta-analysis to evaluate the efficacy and safety of CS-EMR in removing colon polyps. Methods: We conducted a comprehensive literature search of MEDLINE, EMBASE, Cochrane, ClinicalTrials.gov, and Scopus databases for studies published in the English language addressing outcomes of CS-EMR for colon polyps from database inceptions through April 2022. The weighted pooled estimates with the 95% confidence interval (CI) were calculated. Cochran Q test and I2 statistics were used to evaluate heterogeneity. Results: We identified 3599 articles on the initial search, and 32 full-text studies were assessed for eligibility. Fifteen studies met inclusion criteria. There were three randomized controlled trials, six prospective, and six retrospective studies. Six studies were from the United States, two each from Australia, China, and Japan, one from the United Kingdom, and one from Greece. A total of 2382 polyps were removed from 1756 patients. 45% were females. Polyps ranged from 6-80 mm in size, and 72.4% were proximal to the splenic flexure. In addition, 50.4% of the polyps were NICE I or serrated lesions and 48.5% were NICE II, and 0.1% were NICE III. Polyp recurrence rate after CS-EMR was 9.4 % (95% CI: 3.3-15.6%, I2= 95.8%), piecemeal resection rate 59.4% (95% CI: 46.3-72.4%, I2= 99.9%), and complete histological resection rate (defined by post polypectomy biopsies) was 93.1% (95% CI: 88.7-97.6%, I2=90.8%). For adverse events, delayed post-polypectomy bleeding rate was 0.8% (95% CI: 0.3-1.3%, I2= 21.4%), perforation and the post-polypectomy syndrome rate was 0.3% (95% CI: 0-0.5%, I2= 0%) (Figure). Given significant heterogeneity in recurrence rate, subgroup analyses were performed. Recurrence rate in serrated lesions (n=484) was 3.8% (95% CI: 0.2-7.4%, I2= 76.7%), in polyps < 20 mm (n= 137) 0.8% (95% CI: -0.7-2.3%, I2= 0%), and in polyps ≥ 20 mm (n=617) 15.7% (95% CI: 2.6-28.7%, I2= 95.2%). Conclusion: CS-EMR has an excellent safety profile and acceptable recurrence rate for resection of colon polyps, especially for polyps < 20 mm and serrated lesions. However, large prospective studies to validate safety and efficacy are needed.Figure 1.: Forest plots of A) recurrence rate, B) complete histological resection, C) delayed post polypectomy bleeding, and D) perforation of cold snare endoscopic mucosal resection in colon polyps

Vulvar High-Grade Squamous Intraepithelial Lesions Treated with Imiquimod: Can Persistence of Human Papillomavirus Predict Recurrence?

Simple SummaryVulvar high-grade intraepithelial lesion (vulvar HSIL) is a premalignant vulvar condition that requires intervention, usually surgery. It recurs frequently, and its treatment involves repeated disfiguring surgeries. Vulvar HSIL is associated with human papillomavirus. Imiquimod is a medical treatment option currently attracting attention because vulvar high-grade intraepithelial neoplasia is frequent in young women with multiple vulvar lesions. Few studies have evaluated the long-term effects of the response to imiquimod and the association of human papillomavirus with response and recurrence. We describe a retrospective (with cases already treated) study designed to determine the long-term response to imiquimod in patients with vulvar HSIL, and also to analyze the role of human papillomavirus (HPV), and different HPV types, in the persistence or recurrence of vulvar HSIL after imiquimod treatment.Objectives: Vulvar high-grade squamous intraepithelial lesion (vulvar HSIL) or vulvar intraepithelial neoplasia (VIN) is a premalignant condition that can progress to carcinoma. Imiquimod is a topical drug with high effectiveness and low morbidity. We aimed (1) to assess the long-term response to imiquimod in a cohort of patients with vulvar HSIL and (2) and to analyze the role of HPV determined in pre- and post-imiquimod treatment biopsies in the persistence or recurrence of vulvar HSIL. Design: Retrospective study between 2011 and 2022. Setting: Referrals from the primary care area of Baix Llobregat treated in the gynecology department of a university hospital in Barcelona, Spain. Population: 20 women with vulvar HSIL treated with imiquimod. Methods: The inclusion criteria were vulvar HSIL, vulvar HPV determination by pre- and post-treatment biopsy, acceptance of medical treatment, at least one follow-up and 4 weeks of treatment. Main outcome measures: Histological diagnosis of vulvar HSIL with pre- and post-imiquimod HPV determination. Response to treatment (complete, partial, no response, recurrence). Results: After imiquimod, 10 (50%) and 6 (30%) cases had complete and partial responses, respectively. Another 4 cases (20%) did not respond. Before treatment, 19 (95%) cases were positive for vulvar HPV (16 cases had HPV type 16). After treatment, 10 cases (50%) were positive for HPV (8 cases with HPV type 16): 2 cases (20%) with a complete response, 5 cases (83.3%) with a partial response and 3 cases (75%) with no response. Eight of the 10 HPV-negative cases (80%) post-treatment showed a complete response. HPV type 16 was present in 16 cases (84.2%) pre-treatment and in 8 cases (80%) post-treatment. Ten patients underwent additional treatments following a partial response, no response or recurrence. The 2 HIV and 3 immunosuppressed patients treated with imiquimod showed a partial response and required additional treatment. All these patients were HPV-positive pre- and post-treatment (100%). Response to imiquimod was associated with post-treatment vulvar HPV positivity (p = 0.03). The median time to a complete response in HPV-negative cases was 4.7 months versus 11.5 months in HPV-positive cases post-imiquimod treatment. Recurrence of vulvar HSIL was observed in 7 patients (35%), with a median time to recurrence of 19.7 months (range 3.2–32.7). Recurrence was experienced in 10% of cases with a complete response, in 4/6 (66.6%) cases with a partial response, and in 2/4 (50%) women with no response. Four of the 7 recurrent cases (57%) were infected with HIV or immunosuppressed. Six (85%) of the recurrent cases were HPV-positive post-treatment (all were HPV type 16). Four (30.7%) of the non-recurrent cases were HPV-positive post-treatment with imiquimod (p = 0.05), two of which were HPV type 16 (50%). Conclusions: Imiquimod effectively treats vulvar HSIL. Cases with a complete response showed less HPV positivity post-treatment than partial or non-response cases. Recurrences were more frequent in those with a partial or no response to imiquimod, and in immunosuppressed patients. In recurrent cases, 85% were HPV-positive post-treatment, while 30.7% of non-recurrent cases were HPV-positive. HPV positivity in the post-treatment biopsy suggests the need for stricter follow-up of patients.

Longitudinal Changes and Predictive Value of Multiparametric MRI Features for Prostate Cancer Patients Treated with MRI-Guided Lattice Extreme Ablative Dose (LEAD) Boost Radiotherapy.

Simple SummaryIn this study, we investigated the longitudinal changes and predictive value of multiparametric MRI (mpMRI) features of prostate cancer patients receiving Lattice Extreme Ablative Dose (LEAD) boost radiotherapy (RT). Ninety-five mpMRI from 25 patients, acquired pre-RT and at 3 time points following RT were analyzed. Five regions of interest were analyzed, related to tumor, peritumoral, and normally-appearing tissues. We identified significant changes in the imaging parameters following RT in all regions. By using selected features at the four scan points and their differences (Δ radiomics), we were able to build viable predictive models for endpoint biopsy positivity. Our study demonstrates that RT causes significant changes to quantitative imaging features in both tumorous and normally-appearing tissues. Because of the noninvasive nature of the mpMRI, acquiring multiple exams post-RT is feasible to monitor treatment response. Several quantitative imaging features are promising predictors of treatment failure based on post-treatment positive biopsy, a strong marker for clinically relevant endpoints.We investigated the longitudinal changes in multiparametric MRI (mpMRI) (T2-weighted, Apparent Diffusion Coefficient (ADC), and Dynamic Contrast Enhanced (DCE-)MRI) of prostate cancer patients receiving Lattice Extreme Ablative Dose (LEAD) radiotherapy (RT) and the capability of their imaging features to predict RT outcome based on endpoint biopsies. Ninety-five mpMRI exams from 25 patients, acquired pre-RT and at 3-, 9-, and 24-months post-RT were analyzed. MRI/Ultrasound-fused biopsies were acquired pre- and at two-years post-RT (endpoint). Five regions of interest (ROIs) were analyzed: Gross tumor volume (GTV), normally-appearing tissue (NAT) and peritumoral volume in both peripheral (PZ) and transition (TZ) zones. Diffusion and perfusion radiomics features were extracted from mpMRI and compared before and after RT using two-tailed Student t-tests. Selected features at the four scan points and their differences (Δ radiomics) were used in multivariate logistic regression models to predict the endpoint biopsy positivity. Baseline ADC values were significantly different between GTV, NAT-PZ, and NAT-TZ (p-values < 0.005). Pharmaco-kinetic features changed significantly in the GTV at 3-month post-RT compared to baseline. Several radiomics features at baseline and three-months post-RT were significantly associated with endpoint biopsy positivity and were used to build models with high predictive power of this endpoint (AUC = 0.98 and 0.89, respectively). Our study characterized the RT-induced changes in perfusion and diffusion. Quantitative imaging features from mpMRI show promise as being predictive of endpoint biopsy positivity.