TET1 and TDG Suppress Inflammatory Response in Intestinal Tumorigenesis: Implications for Colorectal Tumors With the CpG Island Methylator Phenotype.

BACKGROUND & AIMS: Aberrant DNA methylation is frequent in colorectal cancer (CRC), but underlying mechanisms and pathologic consequences are poorly understood. METHODS: We disrupted active DNA demethylation genes Tet1 and/or Tdg from ApcMin mice and characterized the methylome and transcriptome of colonic adenomas. Data were compared to human colonic adenocarcinomas (COAD) in The Cancer Genome Atlas. RESULTS: There were increased numbers of small intestinal adenomas in ApcMin mice expressing the TdgN151A allele, whereas Tet1-deficient and Tet1/TdgN151A-double heterozygous ApcMin colonic adenomas were larger with features of erosion and invasion. We detected reduction in global DNA hypomethylation in colonic adenomas from Tet1- and Tdg-mutant ApcMin mice and hypermethylation of CpG islands in Tet1-mutant ApcMin adenomas. Up-regulation of inflammatory, immune, and interferon response genes was present in Tet1- and Tdg-mutant colonic adenomas compared to control ApcMin adenomas. This up-regulation was also seen in murine colonic organoids and human CRC lines infected with lentiviruses expressing TET1 or TDG short hairpin RNA. A 127-gene inflammatory signature separated colonic adenocarcinomas into 4 groups, closely aligned with their microsatellite or chromosomal instability and characterized by different levels of DNA methylation and DNMT1 expression that anticorrelated with TET1 expression. Tumors with the CpG island methylator phenotype (CIMP) had concerted high DNMT1/low TET1 expression. TET1 or TDG knockdown in CRC lines enhanced killing by natural killer cells. CONCLUSIONS: Our findings reveal a novel epigenetic regulation, linked to the type of genomic instability, by which TET1/TDG-mediated DNA demethylation decreases methylation levels and inflammatory/interferon/immune responses. CIMP in CRC is triggered by an imbalance of methylating activities over demethylating activities. These mice represent a model of CIMP CRC.

Imaging of soft tissue sarcomas of the extremities with radiologic-pathologic correlation.

Soft tissue sarcomas are a rare diverse group of mesenchymal malignancies that can arise in any location in the body and have extremely variable presentations. Liposarcoma, pleomorphic undifferentiated sarcoma, leiomyosarcoma, myxofibrosarcoma, and synovial sarcoma constitute 75% of all soft tissue sarcomas. These along with more uncommon sarcomas will be reviewed with emphasis on the 2013 World Health Organization (WHO) classification. Imaging plays a crucial role in the initial staging, monitoring response to chemotherapy and radiation therapy, and surveillance to detect local or distant recurrence. In this review, the imaging, as well as histopathologic findings of various soft tissue sarcomas will be demonstrated with biomarker correlation. Given the rarity and heterogeneous nature of these tumors, they are generally managed in tertiary care hospitals by a sarcoma tumor board comprised of an oncologist, surgical oncologist, pathologist, radiation oncologist, and radiologist. Overall clinical outcomes are improving due to rapid advances in the understanding of soft tissue sarcomas. We also review imaging features of treatment response and recurrence of these tumors including imaging follow-up guidelines.

Prospective randomized trial to compare the safety, diagnostic yield and utility of 22-gauge and 19-gauge endobronchial ultrasound transbronchial needle aspirates and processing technique by cytology and histopathology.

INTRODUCTION: Endobronchial ultrasound (EBUS)-guided transbronchial needle aspirate (TBNA) is a widely used method of minimally invasive lymph node sampling. The benefit of processing samples by cytologic methods versus "core biopsy" is unclear. It is unknown if safety or diagnostic yield varies by needle gauge. MATERIALS AND METHODS: Between June 2018 and July 2019, 40 patients (56 lesions) undergoing EBUS TBNA lymph node evaluation were enrolled in this single-center prospective trial. Patients were chosen by permuted block randomization to undergo EBUS TBNA starting with 22-gauge (22g) or 19-gauge (19g) needles. Separate samples were sent for processing by cytologic methods and histopathology. Surgical pathologists and cytopathologists were blinded to needle size. The primary endpoint was diagnostic yield. Secondary endpoints compared specimen adequacy by rapid onsite evaluation (ROSE), sample adequacy for molecular testing, sample quality, and safety. RESULTS: Diagnostic yield for histopathologic examination was 87.5% and 83.9% for 19g and 22g respectively (P = 0.625). There was no significant difference in diagnostic yield by cytologic examination based on needle size. There was no significant difference in slide quality. Molecular adequacy for core-biopsy was 77% and 80% for 22g and 19g needles, respectively. Molecular adequacy for cytology cell block was 77% and 80% for 22g and 19g needles, respectively. There were no significant procedural complications. CONCLUSION: Both the 22g and 19g EBUS TBNA needles provided a similar diagnostic yield and clinical utility for ancillary testing. Processing techniques by cytologic methods or "core biopsy" showed no significant impact in diagnostic yield or utility of molecular testing.

Genetic Variants and Tumor Immune Microenvironment: Clues for Targeted Therapies in Inflammatory Breast Cancer (IBC).

To better understand the etiology of inflammatory breast cancer (IBC) and identify potential therapies, we studied genomic alterations in IBC patients. Targeted, next-generation sequencing (NGS) was performed on cell-free DNA (cfDNA) (n = 33) and paired DNA from tumor tissues (n = 29) from 32 IBC patients. We confirmed complementarity between cfDNA and tumor tissue genetic profiles. We found a high incidence of germline variants in IBC patients that could be associated with an increased risk of developing the disease. Furthermore, 31% of IBC patients showed deficiencies in the homologous recombination repair (HRR) pathway (BRCA1, BRCA2, PALB2, RAD51C, ATM, BARD1) making them sensitive to poly (ADP-ribose) polymerase (PARP) inhibitors. We also characterized the tumor-infiltrating lymphocytes (TILs) in tumor tissue biopsies by studying several markers (CD4, CD8, FoxP3, CD20, PD-1, and PD-L1) through immunohistochemistry (IHC) staining. In 7 of 24 (29%) patients, tumor biopsies were positive for PD-L1 and PD-1 expression on TILs, making them sensitive to PD-1/PD-L1 blocking therapies. Our results provide a rationale for considering PARP inhibitors and PD-1/PDL1 blocking immunotherapy in qualifying IBC patients.

The Utility of Preoperative Vascular Grading in Patients Undergoing Surgery First for Pancreatic Cancer: Does Radiologic Arterial or Venous Involvement Predict Pathologic Margin Status?

Controversy exists on accurately grading vascular involvement on preoperative imaging for pancreatic ductal adenocarcinoma. We reviewed the association between preoperative imaging and margin status in 137 patients. Radiologists graded venous involvement based on the Ishikawa classification system and arterial involvement based on preoperative imaging. For patients with both classifications recorded, we categorized vascular involvement as "None," "Arterial only," "Venous only," or "Both" and examined the association of vascular involvement and pathologic margin status. Of 134 patients with Ishikawa classifications, 63%, 17%, 11%, and 9% were graded as I, II, III, and IV, respectively. Of 96 patients with arterial staging, 74%, 16%, and 10% were categorized as stages i, ii, and iii, respectively. Of 93 patients with both stagings, 61% had no vascular involvement, 7% had arterial only, 14% had venous only, and 17% had both involved. Ishikawa classification was strongly associated with a positive SMA and SMV margin (p<0.001). However, for arterial staging, there was no association with SMA or SMV margin. Overall, Ishikawa grading was more predicative of arterial involvement and remained significant on multivariate analysis. The use of diagnostic imaging in predicting positive margins is more accurate when using a venous grading system.

Mismatch repair deficient metastatic colon cancer and urothelial cancer: A case report of sequential immune checkpoint therapy.

A major recent advance in cancer therapy involves the use of immune checkpoint therapy for tumors with mismatch repair deficiency, as they have a high tumor mutation load and neoantigen burden. Approximately 4% of advanced colorectal cancer harbors a mismatch repair deficiency. When mismatch repair deficiency exists in the germline, there is increased susceptibility to a variety of cancers including colorectal cancer, uterine cancer, urothelial carcinoma, and skin cancer. Herein we report the case of a 62-year-old man with mismatch repair deficient metastatic colorectal adenocarcinoma, urothelial carcinoma and a history of sebaceous carcinomas. As the patient in 2016 was ineligible for clinical trials he received immune checkpoint anti-PD-1 therapy with pembrolizumab (200 mg every 3 weeks), on compassionate use basis, after the failure of second-line treatment. The patient's CEA initially responded to pembrolizumab for 4 months and then kept rising for 5 months before mildly declining again. His treatment was then switched to anti-PD-L1 therapy with atezolizumab as it was approved for urothelial carcinoma at that time, and his CEA declined again. This case raises interesting questions about caring for patients with mismatch repair deficient colorectal cancer, including the role of PD-L1 therapy, sequencing of immunotherapy, relying on CEA trends and determining future therapies after progression on pembrolizumab.

Androgen-producing steroid cell ovarian tumor in a young woman and subsequent spontaneous pregnancy.

PURPOSE: To describe the presentation and fertility sparing treatment of a young woman found to have a steroid cell tumor not otherwise specified (NOS) and her spontaneous pregnancy and delivery shortly after surgery. METHODS: A 20-year-old Hispanic female presented with hirsuitism, virilization, and elevated androgen levels (testosterone 328 ng/dL) and was wrongly diagnosed with polycystic ovarian syndrome. Four months later she sought a second opinion. Her androgens were as follows: testosterone level 485 ng/dL, androstenedione 1,738 ng/dL and DHEA 1,459 ng/dL. She had normal levels of progesterone, estradiol, and DHEA-SO4. On transvaginal ultrasound she had a solid-appearing right ovarian mass. She underwent fertility sparing surgery with a laparoscopic right oophorectomy. RESULTS: Gross and histological pathology confirmed a benign steroid cell tumor NOS. She had rapid normalization of all androgens 13 days after surgery. She had spontaneous resumption of menses 4 months later. She conceived despite using emergency contraception approximately 9 months following surgery and delivered a healthy boy at term without complication. CONCLUSION: Prompt evaluation for an androgen producing tumor should be performed when testosterone levels are greater than 200 ng/dL. Pregnancy following removal of this rare tumor has not previously been reported.