DNA mismatch repair proficient (pMMR) metastatic colorectal cancer (mCRC) is not responsive to pembrolizumab monotherapy. DNA methyltransferase inhibitors can promote antitumor immune responses. This clinical trial investigated whether concurrent treatment with azacitidine enhances the antitumor activity of pembrolizumab in mCRC. We conducted a phase 2 single-arm trial evaluating activity and tolerability of pembrolizumab plus azacitidine in patients with chemotherapy-refractory mCRC (NCT02260440). Patients received pembrolizumab 200 mg IV on day 1 and azacitidine 100 mg SQ on days 1–5, every 3 weeks. A low fixed dose of azacitidine was chosen in order to reduce the possibility of a direct cytotoxic effect of the drug, since the main focus of this study was to investigate its potential immunomodulatory effect. The primary endpoint of this study was overall response rate (ORR) using RECIST v1.1., and secondary endpoints were progression-free survival (PFS) and overall survival (OS). Tumor tissue was collected pre- and on-treatment for correlative studies. Thirty chemotherapy-refractory patients received a median of three cycles of therapy. One patient achieved partial response (PR), and one patient had stable disease (SD) as best confirmed response. The ORR was 3%, median PFS was 1.9 months, and median OS was 6.3 months. The combination regimen was well-tolerated, and 96% of treatment-related adverse events (TRAEs) were grade 1/2. This trial was terminated prior to the accrual target of 40 patients due to lack of clinical efficacy. DNA methylation on-treatment as compared to pre-treatment decreased genome wide in 10 of 15 patients with paired biopsies and was significantly lower in gene promoter regions after treatment. These promoter demethylated genes represented a higher proportion of upregulated genes, including several immune gene sets, endogenous retroviral elements, and cancer-testis antigens. CD8+ TIL density trended higher on-treatment compared to pre-treatment. Higher CD8+ TIL density at baseline was associated with greater likelihood of benefit from treatment. On-treatment tumor demethylation correlated with the increases in tumor CD8+ TIL density. The combination of pembrolizumab and azacitidine is safe and tolerable with modest clinical activity in the treatment for chemotherapy-refractory mCRC. Correlative studies suggest that tumor DNA demethylation and immunomodulation occurs. An association between tumor DNA demethylation and tumor-immune modulation suggests immune modulation and may result from treatment with azacitidine. Trial registration ClinicalTrials.gov, NCT02260440. Registered 9 October 2014, https://clinicaltrials.gov/ct2/show/NCT02260440 .

Calyceal diverticula (CD) are relatively uncommon urologic conditions that generally follow an asymptomatic course and rarely require medical intervention. CD are thought to have a congenital origin due to abnormalities during the process of ureteral bud formation. Clinically and radiologically, they can mimic multiple neoplastic and non-neoplastic renal processes, with potentially relevant differences in the management of these patients. Symptoms are usually associated with the presence of stones, obstruction to the drainage of the diverticulum, large size, or secondary infection. In chronic cases, surgery might become necessary, creating an opportunity to examine the histopathological characteristics of this condition. Although these are benign in the majority of patients, some rare instances of malignancy arising from the CD have been reported. In this series, we addressed the clinical, radiological, and histopathological findings of CD.

173 Background: DNA mismatch repair (MMR) proficient colorectal cancer (CRC) is resistant to immune checkpoint therapy compared to MMR deficient CRC. DNA hypomethylating agents may promote anti-tumor immune response by re-expression of cancer-testis antigen and reactivating immune genes suppressed by DNA methylation. This trial tested whether epigenetic modulation by concurrent treatment with azacitidine could enhance the anti-tumor activity of pembrolizumab in mCRC. Methods: Phase II trial was conducted to evaluate activity, safety, and tolerability of pembrolizumab in combination with azacitidine in patients with previously treated pMMR metastatic CRC. Patients received pembrolizumab 200 mg IV on day 1 and azacitidine 100 mg daily SQ injection on days 1-5 every 3 weeks. The primary endpoint of the study was ORR. Tumors were biopsied pre-treatment and on-treatment for biomarker studies. Results: 30 patients received at least one dose of therapy. One patient experienced a confirmed partial response, one experienced stable disease. ORR was 3% (1/30; 95% CI, 0.1-17%). Median PFS was 1.9 months, median OS was 6.3 months. Treatment was well tolerated with only one patient (3%) experiencing grade 3 adverse event. The patient with a PR had positive pre-treatment TILs, but no evaluable tumor from on-treatment biopsy. 2 of 6 patients who continued therapy despite PD on first restaging experienced temporary stabilization of disease later. 5 of 16 evaluable biopsy pairs demonstrated increased TILs on treatment compared to baseline; however, all of these patients experienced PD. 10 of 15 paired samples demonstrated decreased methylation of hypermethylated loci on-treatment. Clustering analysis demonstrated a correlation between pre-treatment methylation of immune activation genes with overall survival of the patients. Conclusions: Combining azacitidine and pembrolizumab is safe and tolerable for pMMR mCRC with only limited activity. DNA methylation and TIL changes are detectable after 3 cycles of therapy. DNA methylation of immune activation genes correlate with overall survival. RNA sequencing and peripheral immune cell flow cytometry are ongoing. Clinical trial information: NCT02260440.

e14016 Background: Small biopsies and cytology specimens are becoming increasingly important for clinical trials and biomarker testing. Thus, institutions must ensure that there is adequate lesional material meeting specifications for a multitude of different protocols, which can involve rapid on-site evaluation (ROSE). The aim of this study is to look at the recent clinical trial biopsy characteristics and feedback on these collections at our institution. Methods: Clinical trial biopsies performed at our institution and trial feedback (so called “queries”) were analyzed from the past two years (2017-2019). The query data was reviewed in detail, in addition to protocol modifications related to biopsy requirements and study protocol changes. Results: A total of 698 biopsy collections were performed for clinical trial purposes for 95 trials, with the majority of these requiring biopsies at more than 1 time point (63.2%), for phase 1 or 2 trials (92.6%), and for specific tumor types (67.4%). Only 18 (18.9%) of the 95 trials requiring fresh tissue biopsies provided feedback. This included 90 (12.9%) cases, of which 27 (30.0%) had queries regarding insufficient (10, 37.0%) or borderline (17, 63.0%) tumor, and only 1 (3.7%) of these had ROSE by cytology. ROSE was performed due to institutional guidelines (45.3%), requirement by study (1.1%), or trial modification (5.3%).(Table). Conclusions: This investigation shows the high volume of clinical trial biopsies managed at our academic cancer center. Feedback from trials is low at 18.9%, and frequently involves suboptimal cases without ROSE at acquisition, which has led to more widespread adoption of ROSE to mitigate insufficient biopsies and repeat procedures. The high volume of clinical trial biopsies and variability in trial needs necessitates a collaborative multi-disciplinary network to facilitate these important biopsies for cancer patients. [Table: see text]

•This investigation shows the recent high volume of clinical trial biopsies managed at an academic cancer center.•Although feedback from trials was limited, the communication frequently involved suboptimal cases without rapid on-site evaluation (ROSE) by cytopathology at acquisition, which has led to more widespread adoption of ROSE to mitigate insufficient biopsies and repeat procedures.•The high volume of clinical trial biopsies and variability in trial needs necessitates a collaborative multi-disciplinary network, including cytology services, to facilitate these important biopsies for cancer patients.

BACKGROUNDGiven the tolerability of nPG in first-line therapy, we desired to evaluate the response and toxicity profiles of second-line gemcitabine with nab-paclitaxel (nPG) following FOLFIRINOX. Methods: We retrospectively identified 30 patients who received first-line FOLFIRINOX for unresectable or metastatic pancreatic adenocarcinoma followed by second-line nPG. Response was evaluated by RECIST criteria and carbohydrate antigen 19-9 (CA19-9) change.RESULTSMedian age was 63 years with 77% percent having metastatic disease. Nineteen patients (63%) achieved PR based on CA19-9. Median overall survival (OS) with nPG was 12.4 months (mo) and median progression-free survival (PFS) was 3.7 mo. Median PFS and OS for patients with at least stable CA19-9 were 4.7 and 13.9 mo since initiation of nPG. Patients with an increased CA19-9 level during nPG had a shorter median PFS (1.4 mo) and OS (5.3 mo). A significant PFS difference was demonstrated in patients with at least stable disease as the best RECIST response versus in those with progressive disease (5.4 vs. 1.9 mo, P<0.001). Grade 3/4 adverse events include thrombocytopenia (33%), anemia (23%), nausea (17%), lymphopenia (7%), infectious complications (6%), diarrhea (3%), and neuropathy (3%).CONCLUSIONSThis study demonstrates a clinical benefit of second-line nPG. The study also suggests a possible use of CA19-9 to predict response to therapy.

3054 Background: Microsatellite stable (MSS) metastatic colorectal cancer (mCRC) has relatively poor tumoral infiltration of CD8+ T cells and is resistant to pembrolizumab (Pembro) when compared to MSI-H mCRC. DNA hypomethylating agent induces epigenetic expression of multiple genes including cancer-testis antigens in CRC, which are recognized by cytotoxic CD8+ T cells in vitro and in vivo. This trial tested whether concurrent treatment with azacitidine (Aza) could enhance the anti-tumor activity of Pembro. Methods: This is a phase 2 trial to evaluate anti-tumor activity and safety of Pembro plus Aza in patients (pts) with previously treated mCRC without any further standard chemotherapy option. Pts received Pembro 200 mg IV on day 1 of each cycle Q3W and Aza 100 mg daily SQ injection on days 1-5 of each cycle Q3W. Primary endpoint was response rate (ORR) using RECIST v1.1. Secondary endpoints included progression-free survival (PFS) and overall survival (OS). Tumor tissues were collected for correlative studies. Results: Thirty-one pts were enrolled [median age, 61 years (range, 30-79); 17 M/14 F; ECOG PS 0/1 (58%/42%); 30 pts with MSS mCRC]. Pts received at least 2 lines of prior systemic chemotherapy for mCRC (median, 3; range, 1-5). Thirty pts received at least one dose of study therapy (median, 3 cycles; range, 1-8). Ten pts could not complete the first 3 cycles due to rapid symptomatic tumor progression. One pt with MSS mCRC achieved PR and 3 pts had SD as best response. The ORR was 3% (1/30; 95% CI, 0.1-17%). Seven pts with PD at the end of cycle 3 continued on study therapy, and 2 pts had stabilization of tumor progression. Median PFS was 2.1 months (95% CI, 1.8-2.8), and median OS was 6.2 months (95% CI, 3.5-8.7). While treatment-related adverse events (TRAEs) were reported in 63% of pts, most of the TRAEs were Gr 1/2 (96%). Frequent TRAEs possibly related to Aza were anemia (n = 5), constipation (n = 5), and leukopenia (n = 4); and possibly related to both Aza and Pembro were nausea (n = 5) and fatigue (n = 5). Gr 3 TRAEs included anemia (n = 1), ALT elevation (n = 1), and alkaline phosphatase elevation (n = 1). Conclusions: Pembro plus Aza is feasible with a tolerable safety profile but appears to have minimal anti-tumor effect for MSS mCRC. Clinical trial information: NCT02260440.

An 88 year-old male with significant CAD, prior CABG, atrial fibrillation and CHF, presented to our hospital with worsening right upper quadrant (RUQ) abdominal pain of a 24-hour duration. He has been on aspirin, clopidogrel and apixaban, amongst many other meds. Two weeks prior to presentation, the pt had coronary artery stent placement. Following this procedure, he developed RUQ abdominal pain with radiation to the rest of his abdomen. He had poor appetite but no nausea or emesis. CT A/P showed nonspecific gallbladder (GB) wall thickening and GB distention, moderate bilateral pleural effusions, and pelvic ascites. RUQ US showed mild GB wall thickening and sludge but no gallstones. There was no GB dilatation. The pt was thought to have cholecystitis and was started on IV ampicillin/sulbactam. He also underwent thoracentesis which showed a transudative effusion and thought to be from fluid overload state. Pt improved and was discharged home. His RUQ abdominal pain worsened 24 hours prior to presentation and became constant. It was deep, aching and without radiation. He denied fevers or chills. On exam, he was afebrile, BP 125/67mmHg and HR 92bpm. Abdomen was diffusely tender to palpation, particularly in RUQ with positive Murphy sign. No rebound tenderness. Labs showed WBC 11.3, Hgb 12.7, platelets 368, Na 130, K 3.9, Cl 94, Cr 0.9, TBili 1.0, ALT 68, AST 88, alk phos 429, lactate 1.5, lipase 44. Blood cultures were negative. CT A/P showed hemorrhagic cholecystitis with perforation of GB wall at the fundus (Images), reactive bowel wall thickening of the cecum and hepatic flexure, hemorrhagic ascites and a moderate right sided pleural effusion. Given his cardiac comorbidities, recent coronary artery stenting, current triple antiplatelet/anticoagulation therapy, surgery was delayed. He was treated with IV piperacillin/tazobactam, holding antiplatelet/anticoagulation therapy, and blood transfusion as needed. He underwent laparoscopic subtotal cholecystectomy and drainage of perihepatic hematoma 7 days later and was discharged 4 days postoperatively in stable condition on his antiplatelet meds. Perforated hemorrhagic GB is a very rare complication of acute cholecystitis and is associated with high mortality. Management entails emergent surgery. In this case, our pt likely developed hemorrhagic cholecystitis due to antiplt/anticoagulant use. Because of hemodynamic stability and pt comorbidities, conservative management was preferred initially.Figure 1Figure 2Figure 3

BACKGROUNDAfter increased requests for biopsies for clinical trials and biomarker research, the University of Pittsburgh Medical Center created a clinical trial research service that partnered pathology, radiology, and medicine to facilitate rapid on-site evaluation (ROSE) of fine-needle aspiration (FNA) and/or core needle biopsy (CNB) samples to confirm the presence of tumor in these studies. METHODSClinical trial coordinators organized biopsies for patients needing tumor samples for trials, and informed the cytopathology and radiology team. ROSE was performed to confirm the presence of sufficient tumor in FNA specimens and/or touch preparations of CNB. RESULTSA total of 79 cases from a total of 14 clinical trials were evaluated with ROSE, 77 of which (97%) were for research only. There were 53 cases (67%) from breast/ovarian cancer studies that were initiated between 2008 and 2009, whereas 26 cases (33%) included a variety of other tumors for studies that were started between 2011 and 2014. The majority required CNB samples (60 cases; 76%), 20% of which used an FNA for needle placement before obtaining CNB material and 56% of which had touch preparations of the CNB evaluated without a preceding FNA. The concordance rate for ROSE with final adequacy of the sample was 96% to 100%. CONCLUSIONSThe study institution has experienced an increase in the number of clinical trial studies requesting ROSE to confirm the presence of tumor in a variety of malignancies. Cytology laboratories can help with patient care by offering ROSE to determine the adequacy of clinical trial material to minimize the submission of unsatisfactory or nonrepresentative material. Developing a clinical research service enhances communication and the processing of novel research specimens for cancer patients. Cancer Cytopathol 2018;126:481-89. (c) 2018 American Cancer Society. Due to increased requests for biopsies for clinical trials and research, the authors' institution has created a clinical trial research service, partnering pathology, radiology, and medicine to facilitate rapid on-site evaluation of fine-needle aspiration and/or core needle biopsy samples to confirm the presence of tumor in these studies. Cytology laboratories can help with the care of patients with cancer by offering rapid on-site evaluation to determine the adequacy of clinical trial material to minimize the submission of unsatisfactory or nonrepresentative material.

Stuart S. Sagel: Master Radiologist and EducatorH. Scott BeasleyAudio Available | Share

Erdheim-Chester disease (ECD) is a rare, multisystem disorder of macrophages. Patients manifest with histiocytic infiltrates that lead to xanthogranulomatous lesions in multiple organ systems. The cytologic features of this disorder are not well characterized. As a result, the cytologic diagnosis of ECD can be very challenging. The aim of this report is to describe the cytomorphology of ECD in a patient presenting with a retroperitoneal soft tissue lesion. A 54-year-old woman with proptosis and diabetes insipidus was found on imaging studies to have multiple intracranial lesions, sclerosis of both femurs and a retroperitoneal soft tissue mass. Fine needle aspiration (FNA) and a concomitant core biopsy of this abnormal retroperitoneal soft tissue revealed foamy, epithelioid and multinucleated histiocytes associated with fibrosis. The histiocytes were immunoreactive for CD68, CD163, Factor XIIIa and fascin, and negative for S100, confirming the diagnosis of ECD. ECD requires a morphologic diagnosis that fits with the appropriate clinical context. This case describes the cytomorphologic features of ECD and highlights the role of cytology in helping reach a diagnosis of this rare disorder.

BACKGROUND:The bypassed portion of the stomach is difficult to access and evaluate after Roux-en-Y gastric bypass. Access to the excluded stomach may be needed for nutritional support or decompression owing to acute distension and obstruction. We report our experience with percutaneous, computed tomography (CT)-guided gastrostomy tube placement into the gastric remnant after laparoscopic Roux-en-Y gastric bypass (LRYGB). METHODS:Of 569 consecutive LRYGB procedures performed, 9 patients underwent successful percutaneous, CT-guided gastrostomy placement. One additional patient was referred from another facility. We reviewed the indications, interval from surgery to the intervention, interval to removal, complications, and success or outcome of the procedure in our patient population. RESULTS:Ten patients underwent percutaneous, CT-guided gastric remnant gastrostomy tube placement. The indications included distended gastric remnant in 6, nutritional access in 4, and remnant drainage after leak in 1. Of the 10 patients, 2 had undergone previous gastric operations. The attempt at percutaneous gastrostomy was unsuccessful in 1 additional patient, who subsequently required laparoscopic gastrostomy (success rate 91%). CONCLUSION:In selected patients after LRYGB, CT-guided gastrostomy tube placement is safe and efficient. It may be used to manage complications of LRYGB, serve as a bridge to definitive surgery, or offer a convenient route for enteral nutritional support.

POEMS syndrome is a rare disorder in which patients present with the hallmark signs of polyneuropathy, organomegaly, endocrinopathy, M protein and skin changes. Many other clinical findings are also often present, most notably osseous lesions. The MRI appearance of the bony lesions in POEMS syndrome has been described in five cases, four of which are in the non-English literature. We report the MRI appearance of the osseous lesions in a patient with POEMS syndrome who presented with sciatic neuropathy.

MRI Diagnosis of Subpubic Cartilaginous CystConnie E. Kim1 and H. Scott BeasleyAudio Available | Share

Purpose: The patients in this study have proven to be refractory to medications for gastroparesis (GP), thus requiring the surgical implantation of a gastric electrical stimulator. Goals: 1) To determine if pre-surgery hope level predicts levels of depressive symptoms and anxiety at 3 and 6 months post surgery; 2) To compare levels of hope, depressive symptoms, and anxiety across three different subgroups of GP patients: diabetic, idiopathic, and post-surgical patients. Methods: Twenty-four participants (mean age 35. 5, 88.2% female) have been recruited to date. Patients were asked to fill out the Beck Depression Inventory-II, the State Anxiety Inventory (SAI), and the State Hope Scale (SHS). The study consists of two baseline assessments (the first approximately two weeks prior to surgery, the second while in the hospital awaiting surgery) and 3 and 6 month follow-ups. First baseline data was gathered to show that depressive symptoms and anxiety levels were not merely the result of being in a hospital awaiting surgery. Results: (See Table)