Graham, Rondell P.

AbstractFusion genes have been identified in a wide array of human neoplasms including hematologic and solid tumors, including gastrointestinal tract neoplasia. A fusion gene is the product of parts of two genes that are joined together following a deletion, translocation, or chromosomal inversion. Together with single nucleotide variants, insertions, deletions, and amplification, fusion genes represent one of the key genomic mechanisms for tumor development. Detecting fusions in the clinic is accomplished by a variety of techniques including break‐apart fluorescence in situ hybridization, reverse transcription‐polymerase chain reaction, and next‐generation sequencing. Some recurrent gene fusions have been successfully targeted by small molecule or monoclonal antibody therapies (ie targeted therapies), while others are used as biomarkers for diagnostic and prognostic purposes. The purpose of this review article is to discuss the clinical utility of detection of gene fusions in carcinomas and neoplasms arising primarily in the digestive system.

AbstractBackgroundNodular regenerative hyperplasia (NRH) is a rare condition characterized clinically by the development of non‐cirrhotic portal hypertension. NRH is the histopathological result in the liver of various systemic disease processes including autoimmune disorders, haematological malignancies and medications. However, natural history of this condition has been limited to small case series while patient outcomes pertaining to different aetiologies of NRH are largely unknown.MethodsA retrospective cohort of consecutive patients diagnosed with pathology‐confirmed NRH at Mayo Clinic between 2002 and 2017 was identified. The histological diagnosis of NRH was determined by expert liver pathologists. Patients with metastatic liver disease, history of liver transplantation or younger than 18 were excluded. Potential aetiologies of NRH were classified as haematological, rheumatological, drug‐associated, miscellaneous or idiopathic. Long‐term mortality was analysed using Kaplan‐Meier estimation and Cox regression models.ResultsOne hundred and sixty‐seven consecutive patients with pathology‐confirmed NRH were analysed over a 15‐year period and followed for a median time of 50 months (1–306 months). The mean age at diagnosis was 53 years. No aetiology or risk factor for NRH was identified in the majority of patients (94, 56.3%), whereas an associated, possibly causal, condition was found in 73 patients (secondary NRH). The most common presenting feature was elevated liver tests (80%), but no significant differences in laboratory tests were seen based on aetiology of NRH. Compared to idiopathic NRH, those with an identified cause had a higher rate of splenomegaly at presentation (54% vs. 27%, p = 0.002). Portal hypertension‐related complications at diagnosis were common, with ascites present in one‐third of patients. Overall transplant‐free survival was 63% at 5 years. Median survival in idiopathic NRH was 9.4 years compared to 7.3 years in secondary NRH. Age, renal function and volume status at presentation were significantly associated with survival; however, MELD score was not.ConclusionsThe rates of liver‐related complications and mortality in NRH are low, and only a small number of patients ultimately require liver transplantation. Most patients do not have an identified risk factor or aetiology for NRH, and liver‐related outcomes do not appear to differ based on associated, possibly causal, conditions.

192 Background: Rectal cancer treatment paradigm has been evolving over time. Historically, for locally advanced rectal cancer, standard therapy (ST) consisted of neoadjuvant chemoradiation followed by surgery and adjuvant chemotherapy. Recently, total neoadjuvant treatment (TNT) approach that delivers both neoadjuvant chemotherapy (CAPOX or FOLFOX) and chemoradiation (or radiation only) prior to surgery is increasingly being utilized. The prognostic and predictive values of mismatch repair deficient (dMMR) in rectal cancer is not well characterized. Most dMMR patients receive the same treatment as MMR proficient (pMMR) patients although there is limited data that dMMR rectal cancer patients may not have the same level of benefits from neoadjuvant treatment. This retrospective study aims to evaluate the clinicopathological/molecular characteristics, disease response, and clinical outcomes in dMMR localized rectal cancer patients. Methods: A retrospective analysis was conducted on consecutive adult patients with a diagnosis of dMMR rectal cancer who were treated at Mayo Clinic between January 2000 to September 2021. Patients who presented with concurrent primary non-colorectal malignancies were excluded. The distributions of demographics, clinicopathological features, biomarkers, and outcome data were collected. Survival was assessed using Kaplan-Meier curves and Cox models were stratified by treatment arms to determine significance of treatment strategies. Results: Forty-one patients were identified with a median age of 45.3 years. Thirty (73.2%) pts were male. The most common MMR were loss of MSH2 and MSH6 (12/42; 29.3%) followed by loss of MLH1 and PMS2 (10/42; 24.4%) and solitary loss of MSH2 (4/42; 9.8%). The treatment, pathological response, and clinical outcomes are listed in table. With a median follow up of 101 months, only 6 patients (14.3%) died and median overall survival was not reached. Conclusions: Our findings showed dMMR localized rectal cancer responded to both ST and TNT with good clinical outcomes.[Table: see text]

BACKGROUND: Intraoperative frozen-section analysis provides real-time margin resection status that can guide intraoperative decisions made by the surgeon and radiation oncologist. For patients with locally recurrent rectal cancer undergoing surgery and intraoperative radiation therapy, intraoperative re-resection of positive margins to achieve negative margins is common practice. OBJECTIVE: This study aimed to assess whether re-resection of positive margins found on intraoperative frozen-section analysis improves oncologic outcomes. DESIGN: This is a retrospective cohort study. SETTINGS: This study was an analysis of a prospectively maintained multicenter database. PATIENTS: All patients who underwent surgical resection of locally recurrent rectal cancer with intraoperative radiation therapy between 2000 and 2015 were included and followed for 5 years. Three groups were compared: initial R0 resection, initial R1 converted to R0 after re-resection, and initial R1 that remained R1 after re-resection. Grossly positive margin resections (R2) were excluded. MAIN OUTCOME MEASURES: The primary outcome measures were 5-year overall survival, recurrence-free survival, and local re-recurrence. RESULTS: A total of 267 patients were analyzed (initial R0 resection, n = 94; initial R1 converted to R0 after re-resection, n = 95; initial R1 that remained R1 after re-resection, n = 78). Overall survival was 4.4 years for initial R0 resection, 2.7 years for initial R1 converted to R0 after re-resection, and 2.9 years for initial R1 that remained R1 after re-resection (p = 0.01). Recurrence-free survival was 3.0 years for initial R0 resection and 1.8 years for both initial R1 converted to R0 after re-resection and initial R1 that remained R1 after re-resection (p ≤ 0.01). Overall survival did not differ for patients with R1 and re-resection R1 or R0 (p = 0.62). Recurrence-free survival and freedom from local re-recurrence did not differ between groups. LIMITATIONS: This study was limited by the heterogeneous patient population restricted to those receiving intraoperative radiation therapy. CONCLUSIONS: Re-resection of microscopically positive margins to obtain R0 status does not appear to provide a significant survival advantage or prevent local re-recurrence in patients undergoing surgery and intraoperative radiation therapy for locally recurrent rectal cancer. See Video Abstract at http://links.lww.com/DCR/B886. LA RE-RESECCIÓN DE LOS MÁRGENES MICROSCÓPICAMENTE POSITIVOS ENCONTRADOS DE MANERA INTRAOPERATORIA MEDIANTE LA TÉCNICA DE CRIOSECCIÓN, NO DA COMO RESULTADO UN BENEFICIO DE SUPERVIVENCIA EN PACIENTES SOMETIDOS A CIRUGÍA Y RADIOTERAPIA INTRAOPERATORIA PARA EL CÁNCER RECTAL LOCALMENTE RECIDIVANTE ANTECEDENTES: El análisis de la ténica de criosección para los margenes positivos encontrados de manera intraoperatoria proporciona el estado de la resección del margen en tiempo real que puede guiar las decisiones intraoperatorias tomadas por el cirujano y el oncólogo radioterapeuta. Para los pacientes con cáncer de recto localmente recurrente que se someten a cirugía y radioterapia intraoperatoria, la re-resección intraoperatoria de los márgenes positivos para lograr márgenes negativos es una práctica común. OBJETIVO: Evaluar si la re-resección de los márgenes positivos encontrados en el análisis de la ténica por criosecciónde manera intraoperatorios mejora los resultados oncológicos. DISEÑO: Estudio de cohorte retrospectivo. AJUSTES: Análisis de una base de datos multicéntrica mantenida de forma prospectiva. POBLACIÓN: Todos los pacientes que se sometieron a resección quirúrgica de cáncer de recto localmente recurrente con radioterapia intraoperatoria entre 2000 y 2015 fueron incluidos y seguidos durante 5 años. Se compararon tres grupos: resección inicial R0, R1 inicial convertido en R0 después de la re-resección y R1 inicial que permaneció como R1 después de la re-resección. Se excluyeron las resecciones de márgenes macroscópicamente positivos (R2). PRINCIPALES MEDIDAS DE RESULTADO: Supervivencia global a cinco años, supervivencia sin recidiva y recidiva local. RESULTADOS: Se analizaron un total de 267 pacientes (resección inicial R0 n = 94, R1 inicial convertido en R0 después de la re-resección n = 95, R1 inicial que permaneció como R1 después de la re-resección n = 78). La supervivencia global fue de 4,4 años para la resección inicial R0, 2,7 años para la R1 inicial convertida en R0 después de la re-resección y 2,9 años para la R1 inicial que permaneció como R1 después de la re-resección (p = 0,01). La supervivencia libre de recurrencia fue de 3,0 años para la resección inicial R0 y de 1,8 años para el R1 inicial convertido en R0 después de la re-resección y el R1 inicial que permaneció como R1 después de la re-resección (p ≤ 0,01). La supervivencia global no difirió para los pacientes con R1 y re-resección R1 o R0 (p = 0,62). La supervivencia libre de recurrencia y la ausencia de recurrencia local no difirieron entre los grupos. LIMITACIONES: Población de pacientes heterogénea, restringida a aquellos que reciben radioterapia intraoperatoria. CONCLUSIONES: La re-resección de los márgenes microscópicamente positivos para obtener el estado R0 no parece proporcionar una ventaja de supervivencia significativa o prevenir la recurrencia local en pacientes sometidos a cirugía y radioterapia intraoperatoria para el cáncer de recto localmente recurrente. Consulte Video Resumen en http://links.lww.com/DCR/B886. (Traducción—Dr. Daniel Guerra)

BACKGROUND: Basal cell carcinoma of the perianal region is a rare anorectal disease. This condition is not related to exposure to ultraviolet radiation. Because of the low prevalence and poor detection, there is a paucity of data relating to this condition in the literature. Perianal basal cell carcinoma presents surgical challenges different from other anatomic locations and may not share the same prevalence or natural history. Here, we describe the largest series to date on the surgical management of perianal basal cell carcinoma. OBJECTIVE: We aimed to present our 35-year experience in managing perianal basal cell carcinoma in this study. DESIGN: This was a retrospective single-center analysis. SETTING: The study was conducted at a large tertiary referral academic health care system. PATIENTS: All patients undergoing surgical management of pathology confirmed perianal basal cell carcinoma. INTERVENTIONS: All patients underwent surgical management of their disease. MAIN OUTCOME MEASURES: The primary outcomes were disease recurrence, mortality, and wound complications. RESULTS: A total of 29 patients were identified with an average follow-up of 5.5 years. At index presentation, 27.6% of patients had multiple basal cell carcinoma in other anatomic locations. Ninety-three percent of patients were adequately treated with local excision, but 60% had wound dehiscence at the time of their first follow-up visit. Ultimately, there were no recurrences or disease-related mortality during the follow-up period. LIMITATIONS: Limitations to our study include its nonrandomized retrospective nature, single-institution experience, and small patient sample size. CONCLUSIONS: Perianal basal cell carcinoma carries a high rate of synchronous presentation in other locations and should prompt a thorough evaluation. Perianal basal cell carcinomas can and should be successfully treated with local excision despite the high rate of wound complications. See Video Abstract at http://links.lww.com/DCR/B883. Carcinoma perianal de células basales: 35 años de experiencia ANTECEDENTES: El carcinoma de células basales de la región perianal es una enfermedad anorrectal rara. Esta condición no está relacionada con la exposición a la radiación ultravioleta. Debido a la baja prevalencia y detección pobre, hay escasez de datos relacionados con esta condición en la literatura. El carcinoma de células basales perianal presenta diferentes desafíos quirúrgicos en otras ubicaciones anatómicas y puede no compartir la misma prevalencia o historia natural. A continuación, describimos la serie más grande hasta la fecha sobre el tratamiento quirúrgico del carcinoma de células basales perianal. OBJETIVO: Presentar nuestra experiencia de 35 años en el manejo del carcinoma de células basales perianal. DISEÑO: Este fue un análisis retrospectivo de un solo centro. ENTORNO CLINICO: El estudio se llevó a cabo en un gran centro de salud académico de referencia terciaria. PACIENTES: Todos los pacientes sometidos a tratamiento quirúrgico con patología confirmatoria de carcinoma basocelular perianal. INTERVENCIONES: Todos los pacientes fueron sometidos a tratamiento quirúrgico de su enfermedad. PRINCIPALES MEDIDAS DE RESULTADO: Los resultados primarios fueron la recurrencia de la enfermedad, mortalidad, y complicaciones de la herida. RESULTADOS: Se identificaron un total de 29 pacientes con un seguimiento promedio de 5.5 años. El 27,6% de los pacientes tenían carcinoma basocelular múltiple en otras localizaciones anatómicas en la presentación inicial. El 93% de los pacientes fueron tratados adecuadamente con escisión local, pero el 60% tuvo dehiscencia de la herida en el momento de la primera visita de seguimiento. En última instancia, no hubo recurrencias ni mortalidad relacionada con la enfermedad durante el período de seguimiento. LIMITACIONES: Las limitaciones de nuestro estudio incluyen su naturaleza retrospectiva no aleatorizada, la experiencia de una sola institución y el tamaño pequeño de la muestra de pacientes. CONCLUSIONES: El carcinoma de células basales perianal tiene una alta tasa de presentación sincrónica en otras localizaciones y debe dar lugar a una evaluación exhaustiva. Los CBC perianales pueden y deben ser tratados exitosamente con escisión local a pesar de la alta tasa de complicaciones de herida. Consulte Video Resumen en http://links.lww.com/DCR/B883. (Tradducción—Dr. Francisco M. Abarca-Rendon)

Currently, there are no internationally accepted consensus guidelines for pathologic evaluation of posttherapy pancreatectomy specimens. The Neoadjuvant Therapy Working Group of Pancreatobiliary Pathology Society was formed in 2018 to review grossing protocols, literature, and major issues and to develop recommendations for pathologic evaluation of posttherapy pancreatectomy specimens. The working group generated the following recommendations: (1) Systematic and standardized grossing and sampling protocols should be adopted for pancreatectomy specimens for treated pancreatic ductal adenocarcinoma (PDAC). (2) Consecutive mapping sections along the largest gross tumor dimension are recommended to validate tumor size by histology as required by the College of American Pathologists (CAP) cancer protocol. (3) Tumor size of treated PDACs should be measured microscopically as the largest dimension of tumor outer limits that is bound by viable tumor cells, including intervening stroma. (4) The MD Anderson grading system for tumor response has a better correlation with prognosis and better interobserver concordance among pathologists than does the CAP system. (5) A case should not be classified as a complete response unless the entire pancreas, peripancreatic tissues, ampulla of Vater, common bile duct, and duodenum adjacent to the pancreas are submitted for microscopic examination. (6) Future studies on tumor response of lymph node metastases, molecular and/or immunohistochemical markers, as well as application of artificial intelligence in grading tumor response of treated PDAC are needed. In summary, systematic, standardized pathologic evaluation, accurate tumor size measurement, and reproducible tumor response grading to neoadjuvant therapy are needed for optimal patient care. The criteria and discussions provided here may provide guidance towards these goals.

Abstract The mismatch repair system is a major pathway that functions in the maintenance of genomic integrity. It is involved in mitotic and meiotic recombination, apoptosis, immunoglobulin gene rearrangement, somatic hypermutation, and other processes. Deficiencies in mismatch repair give rise to hypermutability and the phenomenon called microsatellite instability. Detection of deficient mismatch repair function or microsatellite instability is used diagnostically, predictively, and prognostically. Specifically, deficient mismatch repair function is used for screening of Lynch syndrome, determining patients who are likely to respond to immune checkpoint inhibition, and to contributes to an understanding of which cancer patients may pursue a more aggressive clinical course. Microsatellite instability can be evaluated directly by polymerase chain reaction (PCR) or indirectly by assessment of mismatch repair protein expression using immunohistochemistry (IHC), and mismatch repair function using next‐generation sequencing assays which evaluates homopolymer indels. In this article, we provide a concise practical review on mismatch repair deficiency (MMR‐d)/microsatellite instability (MSI), focusing on clinical testing, different testing methods, interpretation of findings, the predictive, and prognostic utility of MSI.

Context.— Comprehensive genomic profiling has demonstrated that approximately 20% of pancreatic carcinomas with acinar differentiation harbor potentially targetable BRAF fusions that activate the MAPK pathway. Objectives.— To validate the above finding by BRAF break-apart fluorescence in situ hybridization (FISH) in a large series of pure acinar cell carcinomas (ACCs), evaluate tumors for the presence of BRAF V600E mutations, and compare clinicopathologic features of tumors with BRAF rearrangements with those without. Design.— Thirty cases of pure ACC and 6 cases of mixed acinar-neuroendocrine carcinoma (ACC-NEC) were retrieved. A break-apart FISH probe was used to detect BRAF rearrangements. Immunohistochemistry for BRAF V600E was performed. Results.— BRAF rearrangements by FISH were found in 6 of 36 cases (17%), 5 of which were pure ACC and 1 was a mixed ACC-NEC. Follow-up was available in 29 of 36 cases (81%). The median survival was 22 months for BRAF-rearranged cases and 16 months for BRAF-intact cases; the 2-year overall survival was 50% for BRAF-rearranged cases and 35% for BRAF-intact cases. No significant clinicopathologic differences were identified in cases with BRAF rearrangement compared with those without BRAF rearrangement. BRAF V600E mutation was identified in 2 of 34 cases (6%), both of which were pure ACC and were BRAF-intact by FISH. Conclusions.— This study supports the finding that BRAF rearrangements are present in approximately 20% of cases and identified BRAF V600E mutations in approximately 5% of cases. These cases may benefit from targeted therapy.