Rebamipide for the Improvement of Gastric Atrophy and Intestinal Metaplasia: A Prospective, Randomized, Pilot Study

BACKGROUND

The presence of atrophic gastritis (AG) and intestinal metaplasia (IM) is associated with an increased risk of gastric cancer (GC). Thus, the development of new strategies to improve AG/IM is essential for reducing the incidence of GC.

AIMS

We aimed to evaluate the efficacy of rebamipide for improving AG/IM.

METHODS

This was a prospective, randomized, pilot study from a single tertiary referral center. Fifty-three (rebamipide, n = 34 vs. placebo, n = 19) patients, who underwent endoscopic resection for gastric dysplasia or early GC, were analyzed. We obtained tissue samples from the antrum and corpus of the stomach, at the time of screening and 1-year later. The histologic grading of inflammation was performed by histopathologists RESULTS: The AG grade in the antrum improved significantly after rebamipide treatment (pre-administration, 1.870 ± 0.932 vs. post-administration, 1.430 ± 0.986; P = 0.013). Additionally, the severity of IM in the antrum was significantly improved (pre-administration, 1.750 ± 0.963 vs. post-administration, 1.370 ± 1.032; P = 0.038). The rebamipide subgroup analysis revealed that patients with no Helicobacter pylori (HP) infection showed significant improvements in AG in the antrum (pre-administration, 1.880 ± 1.040 vs. post-administration, 1.250 ± 0.894; P = 0.028) and IM in antrum (pre-administration, 1.840 ± 1.012 vs. post-administration, 1.180 ± 0.912; P = 0.020).

CONCLUSIONS

This study demonstrated that the administration of rebamipide improves AG and IM in the antrum, especially in patients with HP non-infection (KCT0001915).

Genomic Profiling of Aggressive Thyroid Cancer in Association With its Clinicopathological Characteristics

BACKGROUND/AIM

Poorly differentiated thyroid carcinoma (PDTC), anaplastic thyroid carcinoma (ATC), and advanced DTC have poor outcomes.

MATERIALS AND METHODS

We performed next-generation sequencing in nine selected aggressive thyroid cancers.

RESULTS

Among the nine patients, the driver gene mutations BRAF V600E (3/9) and NRAS Q61K (1/9) were detected. Other oncogenic mutations included ERBB2 (1/9) and CDK4 (1/9). Telomerase reverse transcriptase (TERT) promoter mutation was found in five cases. Among tumor suppressor genes, mutations in TP53 (3/9), ARID1A (1/9), APC (1/9), MEN1 (1/9), DICER1 (1/9), and MED12 (1/9) were identified. RET fusions were found in two cases, one with PTDC and the other with ATC. The ATC with RET fusion also harbored TP53 and TERT promoter mutations. None of the PDTC cases had BRAF or RAS gene alterations.

CONCLUSION

Since genetic alterations with therapeutic and prognostic implications were detected using next-generation sequencing, this technique is recommended to be performed for patients with aggressive thyroid cancer.

Impact of the distal resection margin on local recurrence after neoadjuvant chemoradiation and rectal excision for locally advanced rectal cancer

We aimed to evaluate whether a short distal resection margin (< 1 cm) was associated with local recurrence in patients with locally advanced rectal cancer who underwent preoperative chemoradiotherapy. Patients with rectal cancer who underwent preoperative chemoradiotherapy followed by curative surgery were divided into two groups based on the distal resection margin (≥ 1 cm and < 1 cm). In total, 507 patients were analyzed. The median follow-up duration was 48.9 months. The 3-year local recurrence rates were 2% and 8% in the ≥ 1 cm and < 1 cm groups, respectively (P < 0.001). Multivariable analysis revealed that a distal resection margin of < 1 cm was a significant risk factor for local recurrence (P = 0.008). Subgroup analysis revealed that a distal resection margin of < 1 cm was not an independent risk factor for local recurrence in the ypT0-1 group. However, among patients with tumor stages ypT2-4, the cumulative 3-year incidences of local recurrence were 2.3% and 9.8% in the ≥ 1 cm and < 1 cm groups, respectively (P = 0.01). A distal resection margin of < 1 cm might influence local recurrence rates in patients with locally advanced rectal cancer undergoing preoperative chemoradiotherapy, especially in patients with tumor stages ypT2-4.

Prognostic Value of Venous Invasion Detected by Elastin Stain May Surpass Lymph Node Status in Colon Cancer

BACKGROUND

Venous invasion is a poor prognostic factor in colon cancer but is often underreported with significant variability.

OBJECTIVES

We aimed to determine the impact of an elastin stain on venous invasion detection in colon cancer and evaluate the value of venous invasion in predicting disease recurrence in combination with lymph node status and other prognostic factors.

DESIGN

This is a retrospective analysis of a prospectively collected database.

SETTING

This study was conducted at a tertiary cancer center.

PATIENTS

A total of 418 patients who underwent curative resection for stage I to III colon cancer and routinely adopted an elastin stain were evaluated.

MAIN OUTCOME MEASURES

Venous invasion detection rate after adopting elastin stain, prognostic factors influencing disease recurrences by multivariate Cox regression models, and survival were measured. The zones of lymph node metastasis were defined as LNZ1, LNZ2, and LNZ3, corresponding to metastases in the pericolic, intermediate, and apical nodes.

RESULTS

Venous invasion detection rate increased from 11.3% to 35.4% compared with the previous period in which only hematoxylin and eosin stain was performed. Cox regression analysis showed venous invasion (HR, 3.856; 95% CI, 1.249-11.910; p = 0.019) and lymph node metastases (HR, 3.156; 95% CI, 1.094-9.108; p = 0.034) in all stages and LNZ 2, 3 (HR, 2.649; 95% CI, 1.244-5.640; p = 0.012) in stage III to be significantly associated with poor disease-free survival. When stratifying all patients by these 3 factors, patients with stage III [LNZ1/venous invasion (-)] had disease-free survival comparable with stage I, but significantly better disease-free survival than those with stage II [venous invasion (+)] (p = 0.018). Patients with stage II [venous invasion (+)] had better disease-free survival by using adjuvant chemotherapy (p < 0.001).

LIMITATIONS

This study was limited by its retrospective design.

CONCLUSION

Elastin stain contributed to a considerable increase in venous invasion detection. Venous invasion can be a powerful predictor of poor disease-free survival beyond lymph node metastases when limited to the pericolic area and is useful for deciding the use of adjuvant chemotherapy in stage II colon cancer. See Video Abstract at http://links.lww.com/DCR/B573.

EL VALOR PRONSTICO DE LA INVASIN VENOSA DETECTADA POR LA TINCIN DE ELASTINA PUEDE SUPERAR EL ESTADO DE LOS GANGLIOS LINFTICOS EN EL CNCER DE COLON

ANTECEDENTES:Invasión venosa (IV) es un factor de mal pronóstico en el cáncer de colon, que frecuentemente no se informa con una variabilidad significativa.OBJETIVOS:Nuestro objetivo fue determinar el impacto de tinción de elastina en la detección de IV en el cáncer de colon y evaluar el valor de IV en la predicción de la recurrencia de la enfermedad en combinación con el estado de los ganglios linfáticos y otros factores pronósticos.DISEÑO:Este es un análisis retrospectivo de una base de datos recopilada prospectivamente.ENTORNO CLINICO:Este estudio se realizó en un centro oncológico de referencia de tercer nivel.PACIENTES:Se valoraron un total de 418 pacientes sometidos a resección curativa por cáncer de colon en estadio I-III utilizando de manera rutinaria una tinción de elastina.PRINCIPALES MEDIDAS DE VALORACION:Se midieron la tasa de detección de IV después de adoptar la tinción de elastina, los factores de pronóstico que influyen en las recurrencias de la enfermedad mediante modelos de regresión de Cox multivariados y la supervivencia. La zona de metástasis ganglionares se definió como, LNZ1, LNZ2 y LNZ3, correspondientes a las metástasis en los ganglios pericólicos, intermedios y apicales, respectivamente.RESULTADOS:La tasa de detección de IV aumentó de 11,3% a 35,4% en comparación con el período anterior en el que solo se realizó tinción con hematoxilina y eosina. El análisis de regresión de Cox mostró VI (razón de riesgo, 3.856; intervalo de confianza [IC] del 95%, 1.249-11.910, p = 0.019) y metástasis en los ganglios linfáticos (razón de riesgo, 3.156; IC del 95%, 1.094-9.108, p = 0.034) en todos los estadios y LNZ 2, 3 (cociente de riesgo, 2.649; IC del 95%, 1.244-5.640, p = 0.012) en el estadio III se asociaron significativamente con una pobre supervivencia libre de enfermedad. Al estratificar a todos los pacientes según estos tres factores, los pacientes con estadio III [LNZ1 / VI (-)] tuvieron una sobrevivencia sin enfermedad (SSE) comparable con el estadio I, pero una supervivencia libre de enfermedad significativamente mejor que aquellos con estadio II [VI (+)] (p = 0,018). Pacientes en estadío II [VI (+)] tuvieron una mejor supervivencia sin enfermedad mediante el uso de quimioterapia adyuvante (p <0,001).LIMITACIONES:Estudio limitado por su diseño retrospectivo.CONCLUSIÓN:La tinción de elastina contribuyó a un aumento considerable en la detección de IV. IV puede ser un poderoso predictor de supervivencia sin enfermedad deficiente más allá de las metástasis de los ganglios linfáticos cuando se limita al área pericólica y es útil para decidir el uso de quimioterapia adyuvante en el cáncer de colon en estadío II. Consulte Video Resumen en http://links.lww.com/DCR/B573. (Traducción-Dr. Adrian Ortega).

Expression of the immune checkpoint receptors PD-1, LAG3, and TIM3 in the immune context of stage II and III gastric cancer by using single and chromogenic multiplex immunohistochemistry

We sought to determine the clinicopathological significance of PD-1, LAG3, and TIM3 in gastric cancer (GC) by examining their expression and immune context. Immunohistochemistry (IHC) for PD-1, TIM3, LAG3, and tumor-infiltrating immune cell (TIIC) markers was performed in 385 stage II/III GCs. Epstein-Barr virus (EBV) and microsatellite stability (MSI) testing were performed for molecular classification. Chromogenic multiplex IHC (mIHC) for PD1, TIM3, LAG3, CD3, CD8, FOXP3, CD68, and cytokeratin was performed in 58 of the total samples. PD-1, LAG3, and TIM3 expression in TIICs was observed in 91 (23.6%), 193 (50.1%), and 257 (66.8%) GCs by single IHC, respectively. The expression was associated with EBV⁺ and MSI-H molecular subtypes (p ≤ 0.001). A positive expression of LAG3 in the invasive margin of the tumor was associated with better prognosis in univariate (p = .020) and multivariate (p = .026) survival analyses. The expression of different immune checkpoint receptors (ICRs) was significantly positively correlated. Dual or triple ICR expression was more frequent in high PD-1 and TIM3 density groups than in low-density groups by mIHC (all p ≤ 0.05). ICRs were mainly expressed in CD3⁺CD8⁺ and CD3⁺CD8⁻ T cells. Fifty-eight GCs were classified into three groups by clustering analysis based on mIHC, and the group with the highest ICR expression in TIICs showed significantly better outcomes in progression-free survival (p = .020). In GC, PD-1, LAG3, and TIM3 expression is positively correlated and associated with better prognosis. Our study provides information for the application of effective immune checkpoint inhibitors against GC.

Initial experience of preoperative short-course radiotherapy followed by oxaliplatin-based consolidation chemotherapy for locally advanced rectal cancer

PURPOSE

We analyzed the safety and feasibility of preoperative short-course radiotherapy (SCRT) followed by consolidation chemotherapy for patients with locally advanced rectal cancer (LARC).

METHODS

From April 2018 to May 2019, 19 patients with LARC were treated with SCRT followed by three cycles of consolidation chemotherapy with leucovorin, fluorouracil, and oxaliplatin (FOLFOX6) before surgery. Adjuvant chemotherapy relied on oxaliplatin. Tumor response, patient compliance, and toxicities were analyzed.

RESULTS

The median age was 60 years (range 44-71), and 16 of the patients were male. The median tumor height was 5 cm (range 0-9) from anal verge. All patients received a total dose of 25 Gy in five fractions. The number of cycles of FOLFOX6 before surgery was three in 17, four in one, five in one. Five patients required dose reductions in consolidation chemotherapy. The median interval between initiation of SCRT and surgery was 10.6 weeks (range 8.6-16.4). A pathologic complete response was seen in two patients (11%). Grade III toxicities to the preoperative treatment were seen in five patients (26%): diarrhea in two, a decreased white blood cell count in one, and anemia in two. Postoperative complications arising within 30 days developed in five patients (26%). During the median follow-up period of 20.4 months, there was no tumor recurrence.

CONCLUSION

Preoperative SCRT followed by oxaliplatin-based consolidation chemotherapy showed acceptable toxicity and feasibility in patients with LARC. Prospective randomized trials are warranted to verify the efficacy and safety of this treatment strategy compared with conventional long-course concurrent chemoradiotherapy.

Forward-Looking Multimodal Endoscopic System Based on Optical Multispectral and High-Frequency Ultrasound Imaging Techniques for Tumor Detection

We developed a forward-looking (FL) multimodal endoscopic system that offers color, spectral classified, high-frequency ultrasound (HFUS) B-mode, and integrated backscattering coefficient (IBC) images for tumor detection in situ. Examination of tumor distributions from the surface of the colon to deeper inside is essential for determining a treatment plan of cancer. For example, the submucosal invasion depth of tumors in addition to the tumor distributions on the colon surface is used as an indicator of whether the endoscopic dissection would be operated. Thus, we devised the FL multimodal endoscopic system to offer information on the tumor distribution from the surface to deep tissue with high accuracy. This system was evaluated with bilayer gelatin phantoms which have different properties at each layer of the phantom in a lateral direction. After evaluating the system with phantoms, it was employed to characterize forty human colon tissues excised from cancer patients. The proposed system could allow us to obtain highly resolved chemical, anatomical, and macro-molecular information on excised colon tissues including tumors, thus enhancing the detection of tumor distributions from the surface to deep tissue. These results suggest that the FL multimodal endoscopic system could be an innovative screening instrument for quantitative tumor characterization.

Dual Clarithromycin and Metronidazole Resistance Is the Main Cause of Failure in Ultimate Helicobacter pylori Eradication

BACKGROUND/AIM

Antimicrobial resistance significantly affects the cure rate of Helicobacter pylori (H. pylori) eradication. We evaluated the risk factor of failure in ultimate H. pylori eradication and assessed the efficacy of current regimens to overcome antibiotic resistance.

METHODS

Patients with H. pylori infection were prospectively enrolled in a single center. They were classified into 3 groups according to the previous history of H. pylori eradication, and antibiotic susceptibility was evaluated by culture and minimum inhibitory concentrations (MICs).

RESULTS

Ninety-seven patients were successfully cultured for H. pylori and 81 (83.5%), 7 (7.2%), and 9 (9.3%) were classified into primary resistance, 1st eradication failure, and 2nd or more eradication failure groups; the resistance to clarithromycin (CLA), metronidazole (MET), and levofloxacin increased in the 1st eradication failure (85.7, 57.1, and 42.9%) and 2nd or more eradication failure (88.9, 88.9, and 55.6%) groups. The prevalence of MDR was 21.0% (17/81), 57.1% (4/7), and 88.9% (8/9) in the primary, 1st eradication failure, and 2nd or more eradication failure groups, respectively. In multivariate analysis, dual CLA/MET resistance (CLA/MET-R) (OR = 31.432, 95% CI: 3.094-319.266, p = 0.004) was an independent risk factor for ultimate H. pylori eradication failure. In patients with dual CLA/MET-R, the eradication ratio of concomitant therapy was 57.1% (4/7), whereas that of bismuth-containing quadruple therapy was 27.3% (3/11) (p = 0.350).

CONCLUSIONS

Dual CLA/MET-R was the main cause of failure in ultimate H. pylori eradication, and 7-day bismuth quadruple or concomitant regimen would not be suitable for H. pylori eradication in the dual CLA/MET-R group.

Case Report: Development of Type 1 Autoimmune Pancreatitis in an Adolescent With Ulcerative Colitis Mimicking Pancreatic Cancer

Introduction: Autoimmune pancreatitis (AIP) is a rare extraintestinal manifestation of inflammatory bowel disease (IBD) which is typically responsive to corticosteroid treatment. Case Presentation: We report a case of a 17-year-old male diagnosed with ulcerative colitis who subsequently developed acute pancreatitis. Blood tests demonstrated elevated pancreatic enzyme levels of amylase (1319 U/L) and lipase (809 U/L). Abdominal computed tomography revealed peripancreatic fat stranding and the presence of a perisplenic pseudocyst. Azathioprine and mesalazine were stopped as possible causes of drug-induced pancreatitis. However, pancreatic enzymes remained elevated and corticosteroid treatment was started. Despite corticosteroid therapy, amylase and lipase levels continued to increase. Infliximab was started due to a flare in gastrointestinal symptoms of ulcerative colitis. Follow-up abdominal ultrasonography revealed a pancreatic tail mass. Tumor markers, including CA 19-9, were elevated and atypical cells were seen on histological examination of an endoscopic ultrasonography-guided fine needle aspiration biopsy. Surgical pancreaticosplenectomy was performed for suspected pancreatic neoplasm. Surprisingly, histology revealed chronic pancreatitis with storiform fibrosis and infiltration of IgG4-positive cells, compatible with AIP type 1. Thereafter, pancreatic enzymes gradually decreased to normal levels and the patient has been in remission for 9 months on infliximab monotherapy. Conclusion: Pediatric gastroenterologists should keep in mind that AIP may develop during the natural course of pediatric IBD. Moreover, the development of pancreatic fibrosis may be non-responsive to corticosteroid treatment and mimic pancreatic neoplasia.

Cytological, histological, and molecular characteristics of pure invasive micropapillary carcinoma of pancreas: A case report

INTRODUCTION

Pure invasive micropapillary carcinoma (IMPC) is a rare histologic subtype of pancreatic cancer which has a high propensity for lymph node metastasis and poor prognosis.

PATIENT CONCERNS

An 81-year-old woman was admitted to our institution with a 3-month history of back pain. Computed tomography of the abdomen and pelvis confirmed the presence of a low-density mass in the tail of the pancreas.

DIAGNOSIS

Endoscopic ultrasound-guided fine needle aspiration cytology (FNAC) from the pancreatic mass showed small tumor cell clusters with three-dimensional aggregates and morula-like structures. The tumor was diagnosed as adenocarcinoma with micropapillary features.

INTERVENTIONS

The patient underwent radical antegrade modular pancreatosplenectomy and regional lymph node dissection. Histological examination showed small clusters of tumor cells that were closely adhered to one another. The cells were located in empty stromal spaces mimicking lymphovascular channels. All tumor cells showed reverse polarity, resulting in an "inside-out" pattern. An extensive search was performed, and no typical ductal adenocarcinoma component was found. The tumor measured 1.5 × 1.3 cm and invaded into the peripancreatic fat tissue without adjacent organ invasion. One of the 12 regional lymph nodes showed metastasis. Ion Torrent next-generation sequencing identified missense mutations in KRAS, TP53, and SMAD4 using the Oncomine Comprehensive Panel version 1.

OUTCOMES

Twelve months following surgical resection the patient remained healthy with no evidence of recurrence at clinical follow-up.

LESSONS

This report highlights the diagnostic features and molecular characteristics of pure pancreatic IMPC and the challenges with diagnosis by FNAC. A centralized and collaborative accumulation of additional cases of pure IMPC could further elucidate its pathogenesis.

Changes and prognostic values of tumor-infiltrating lymphocyte subsets after primary systemic therapy in breast cancer

Tumor-infiltrating lymphocyte (TIL) levels have prognostic and predictive values in treatment-naïve breast cancers. However, there have been controversies regarding TIL subset changes and their clinical implications in post-treatment breast cancers. This study aimed to explore change and prognostic significance of TIL subset infiltration after primary systemic therapy (PST) in breast cancer. One-hundred-fifty-five patients who had residual disease after anthracycline- or anthracycline plus taxane-based PST were included. The quantities of intratumoral and stromal TIL subsets (CD8+, CD4+, and FOXP3+ TILs) in pre- and post-PST breast cancer samples, as well as changes between them, were analyzed along with their correlations with clinicopathologic features and outcome of patients. As a whole, intratumoral CD8+ and CD4+ TILs increased after PST while stromal TILs decreased. Both intratumoral and stromal FOXP3+ TILs decreased after PST. The chemo-sensitive group [residual cancer burden (RCB) class I and II] showed the same pattern of change in intratumoral CD8+ TILs as the whole group, whereas the chemo-resistant group (RCB class III) showed no significant change in intratumoral CD8+ TIL infiltration after PST. Survival analyses for each TIL subset as well as their ratios revealed that high levels of intratumoral, stromal, and total CD8+ TIL infiltration after PST were independent predictors of longer patient survival. In subgroup analyses, CD8+ TIL infiltration after PST revealed prognostic significance in the chemo-resistant group but not in the chemo-sensitive group. In conclusion, infiltration of CD8+, CD4+, and FOXP3+ TIL changed after PST in the intratumoral and stromal compartments. Especially, increase of intratumoral CD8+ TILs was associated with chemo-responsiveness. Moreover, CD8+ TIL status in residual tumors after PST may be used as a potential prognostic marker in breast cancer patients who receive PST and provide additional prognostic information to chemo-resistant group.

Comparison of the Diagnostic Performances of Same-session Endoscopic Ultrasound- and Endoscopic Retrograde Cholangiopancreatography-guided Tissue Sampling for Suspected Biliary Strictures at Different Primary Tumor Sites

Background/Aims

Determining the cause of suspected biliary stricture is often challenging in clinical practice. We aimed to compare the diagnostic yields of endoscopic ultrasound-guided tissue sampling (EUS-TS) and endoscopic retrograde cholangiopancreatography-guided tissue sampling (ERCP-TS) in patients with suspected biliary stricture at different primary lesions.

Methods

We enrolled patients who underwent same-session EUS- and ERCP-TS for the evaluation of suspected biliary stricture. Forceps biopsy and/or brush cytology of intraductal lesions and fine-needle aspiration for solid mass lesions were performed during ERCP and EUS, respectively.

Results

One hundred and twenty-five patients treated at our institution between January 2011 and September 2016, were initially considered for the study. However, 32 patients were excluded due to loss of follow-up (n=8) and ERCP-TS on the pancreatic duct (n=20) or periampullary lesions (n=4). Of the 93 patients included, 86 had a malignant tumor including cholangiocarcinoma (n=39), pancreatic cancer (n=37), and other malignancies (n=10). Seven patients had benign lesions. EUS-TS had higher rate of overall diagnostic accuracy than ERCP-TS (82.8% vs. 60.2%, p=0.001), and this was especially true for patients with a pancreatic lesion (84.4% vs. 51.1%, p=0.003).

Conclusions

EUS-TS was found to be superior to ERCP-TS for evaluating suspected biliary strictures, especially those caused by pancreatic lesions.

Standardized Pathology Report for Colorectal Cancer, 2nd Edition

The first edition of the 'Standardized Pathology Report for Colorectal Cancer,' which was developed by the Gastrointestinal Pathology Study Group (GIP) of the Korean Society of Pathologists, was published 13 years ago. Meanwhile, there have been many changes in the pathologic diagnosis of colorectal cancer (CRC), pathologic findings included in the pathology report, and immunohistochemical and molecular pathology required for the diagnosis and treatment of colorectal cancer. In order to reflect these changes, we (GIP) decided to make the second edition of the report. The purpose of this standardized pathology report is to provide a practical protocol for Korean pathologists, which could help diagnose and treat CRC patients. This report consists of "standard data elements" and "conditional data elements." Basic pathologic findings and parts necessary for prognostication of CRC patients are classified as "standard data elements," while other prognostic factors and factors related to adjuvant therapy are classified as "conditional data elements" so that each institution could select the contents according to the characteristics of the institution. The Korean version is also provided separately so that Korean pathologists can easily understand and use this report. We hope that this report will be helpful in the daily practice of CRC diagnosis.

Tumor immune response and immunotherapy in gastric cancer

Remarkable developments in immuno-oncology have changed the landscape of gastric cancer (GC) treatment. Because immunotherapy intervenes with tumor immune response rather than directly targeting tumor cells, it is important to develop a greater understanding of tumor immunity. This review paper summarizes the tumor immune reaction and immune escape mechanisms while focusing on the role of T cells and their co-inhibitory signals, such as the immune checkpoint molecules programmed death-1 and programmed deathligand 1 (PD-L1). This paper also describes past clinical trials of immunotherapy for patients with GC and details their clinical implications. Strong predictive markers are essential to improve response to immunotherapy. Microsatellite instability, Epstein-Barr virus, PD-L1 expression, and tumor mutational burden are now regarded as potent predictive markers for immunotherapy in patients with GC. Novel immunotherapy and combination therapy targeting new immune checkpoint molecules such as lymphocyte-activation gene 3, T cell immunoglobulin, and mucin domain containing-3, and indoleamine 2,3-dioxygenase have been suggested, and trials are ongoing to evaluate their safety and efficacy. Immunotherapy is an important treatment option for patients with GC and has great potential for improving patient outcome, and further research in immuno-oncology should be carried out.

Clinical significance and prognostic role of hypoxia-induced microRNA 382 in gastric adenocarcinoma

Hypoxia and angiogenesis are critical components in the progression of solid cancer, including gastric cancers (GCs). miR-382 has been identified as a hypoxia-induced miR (hypoxamiR), but the clinical significance in GCs has not been identified yet. To explore the clinical and prognostic importance of miR-382 in GCs, the surgical specimens of 398 patients with GCs in KNU hospital in Korea, the total of 183 patients was randomly selected using simple sampling methods and big data with 446 GCs and 45 normal tissues from the data portal (https://portal.gdc.cancer.gov/) were analysed. Expression of miR-382 as well as miR-210, as a positive control hypoxamiR by qRT-PCR in histologically malignant region of GCs showed significantly positive correlation (R = 0.516, p<0.001). High miR-210 and miR-382 expression was significantly correlated with unfavorable prognosis including advanced GCs (AGC), higher T category, N category, pathologic TNM stage, lymphovascular invasion, venous invasion, and perinueral invasion, respectively (all p<0.05). In univariate analysis, high miR-210 expression was significantly associated with worse overall survival (OS) (p = 0.036) but not high miR-382. In paired 60 gastric normal and cancer tissues, miR-382 expression in cancer tissues was significantly higher than normal counterpart (p = 0.003), but not miR-210 expression. However, by increasing the patient number from the big data analysis, miR-210 as well as miR-382 expression in tumor tissues was significantly higher than the normal tissues. Our results suggest that miR-382, as novel hypoxamiR, can be a prognostic marker for advanced GCs and might be correlated with metastatic potential. miR-382 might play important roles in the aggressiveness, progression and prognosis of GCs. In addition, miR-382 give a predictive marker for progression of GCs compared to the normal or preneoplastic lesion.

Development and Validation of an Easy-to-Implement, Practical Algorithm for the Identification of Molecular Subtypes of Gastric Cancer: Prognostic and Therapeutic Implications

BACKGROUND

Gastric cancer (GC) is a heterogeneous disease, and substantial efforts have been made to develop a molecular biology-based classification system for GC. Analysis of the genomic signature is not always feasible, and thus, we aimed to (i) develop and validate a practical immunohistochemistry (IHC)- and polymerase chain reaction (PCR)-based molecular classification of GC and (ii) to assess HER2 status according to this classification.

MATERIALS AND METHODS

A total of 894 consecutive patients with GC from two individual cohorts (training, n = 507; validation, n = 387) were classified using Epstein-Barr virus (EBV) in situ hybridization, microsatellite instability (MSI) testing, and IHC for E-cadherin and p53.

RESULTS

We were able to classify patients into five groups in the training cohort: group 1 (MSI⁺), group 2 (EBV^-, MSI^-, non-epithelial-mesenchymal transition [non-EMT]-like, p53^-), group 3 (EBV⁺), group 4 (EBV^-, MSI^-, non-EMT-like, p53⁺), and group 5 (EBV^-, MSI^-, EMT-like). In the training cohort, each group showed different overall survival (OS) after gastrectomy (p < .001); group 1 had the best prognosis, and group 5 showed the worst survival outcome. The significant impact of the classification system on OS was also verified in the validation cohort (p = .004). HER2 positivity was observed in 6.5% of total population, and most of HER2-positive cases (93.1%) were included in groups 2 and 4.

CONCLUSION

We developed and validated a modified IHC- and PCR-based molecular classification system in GC, which showed significant impact on survival, irrespective of stage or other clinical variables. We also found close association between HER2 status and non-EMT phenotype in our classification system.

IMPLICATIONS FOR PRACTICE

Molecular classification of gastric cancer suggested by previous studies mostly relies on extensive genomic data analysis, which is not always available in daily practice. The authors developed a simplified immunohistochemistry- and polymerase chain reaction-based molecular classification of gastric cancer and proved the prognostic significance of this classification, as well as the close association between HER2 status and certain groups of the classification, in the largest consecutive cohort of gastric cancer. Results of this study suggest that this scheme is a cost-effective, easy-to-implement, and feasible way of classifying gastric cancer in daily clinical practice, also serving as a practical tool for aiding therapeutic decisions and predicting prognosis.

ARID3A Positivity Correlated With Favorable Prognosis in Patients With Residual Rectal Cancer After Neoadjuvant Chemoradiotherapy

BACKGROUND/AIM

Recent studies have shown a marked increase of AT-rich interactive domain 3A (ARID3A) in colon cancer tissue compared to normal colon mucosa. However, the role of ARID3A has not yet been determined in rectal cancer. We, therefore, investigated the clinical relevance of ARID3A expression in patients with residual rectal cancer after neoadjuvant chemoradiotherapy (NACRT).

MATERIALS AND METHODS

One hundred thirty-four patients who underwent surgical resection for residual rectal cancer after NACRT were analyzed. ARID3A expression was evaluated using immunohistochemistry on whole-tissue sections. KRAS exon 2 (codons 12 and 13) and BRAF V600E mutation status were determined using polymerase chain reaction.

RESULTS

ARID3A positivity was found in 91 cases (64.5%), and it correlated with absence of perineural invasion (p=0.031), longer disease-free survival (DFS) (p=0.048) and cancer-specific survival (CSS) (p=0.006). However, ARID3A positivity was not correlated with KRAS (p=0.231) or BRAF mutation status (p=0.577). In multivariate analysis, ARID3A positivity was independently associated with a favorable CSS (p=0.035), but not DFS (p=0.051).

CONCLUSION

ARID3A positivity can predict favorable prognosis in patients with residual rectal cancer after NACRT.

S122: impact of fluorescence and 3D images to completeness of lateral pelvic node dissection

BACKGROUND

Lateral pelvic lymph node dissection (LPND) is a technically demanding procedure. Consequently, there is a possibility of incomplete dissection of lateral pelvic lymph nodes (LPNs). We aimed to identify metastatic LPNs intraoperatively in real-time under dual guidance of fluorescence imaging and 3D lymphovascular reconstruction, and then to remove them completely.

METHODS

Rectal cancer patients who were scheduled to undergo LPND after preoperative chemoradiotherapy (CRT) were prospectively enrolled. We traced changes in suspected metastatic LPNs during preoperative CRT and defined them as index LPNs on post-CRT imaging studies. For fluorescence imaging, indocyanine green (ICG) at a dose of 2.5 mg was injected transanally around the tumor before the operation. For 3D reconstruction images, each patient underwent preoperative axial CT scan with contrast (0.6 mm slice thickness). These images were then manipulated with OsiriX. Index LPNs and essential structures in the pelvic sidewall, such as the obturator nerve, were reconstructed with abdominal arteries from 3D volume rendering. All surgical procedures were performed via laparoscopic or robotic approach.

RESULTS

From March to July 2017, ten rectal cancer patients underwent total mesorectal excision with LPND after preoperative CRT under dual image guidance. Bilateral LPND was performed in five patients. All index LPNs among ICG-bearing lymph nodes were clearly identified intraoperatively by matching with their corresponding 3D images. Pathologic LPN metastasis was confirmed in four patients (40.0%) and in five of the 15 dissected pelvic sidewalls (33.0%). All metastatic LPNs were identified among index LPNs. Four (80.0%) of the five metastatic LPNs were located in the internal iliac area.

CONCLUSION

Index LPNs among ICG-bearing lymph nodes in pelvic sidewall were clearly identified and completely removed by matching with their corresponding 3D reconstruction images. Further studies and long-term oncologic outcomes are required to determine the real impact of dual image guidance in LPND.

TFE3-expressing primary perivascular epithelioid cell tumor of the Lymph node mimicking nodal relapse of rectal cancer: A case report

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TFE3-expressing PEComa has unique morphological and immunohistochemical features.

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PEComa can mimic lymph node relapse of rectal cancer.

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Surgical excision can aid a proper diagnosis of suspicious lesions in rectal cancer.

Introduction

Perivascular epithelioid cell tumor (PEComa) is a rare mesenchymal neoplasm.

Presentation of case

We treated a 50-year-old woman who underwent neoadjuvant chemoradiotherapy followed by low anterior resection and adjuvant chemotherapy for ystage IIIB rectal adenocarcinoma. The patient was diagnosed with metastatic rectal adenocarcinoma in the right lower lobe of the lung after 14 months of follow-up. Later, after 3 years of follow-up, a mass in the gastrosplenic area was revealed by computed tomography, which was considered indicative of metachronous mass relapse. The patient underwent partial omentectomy, and an enlarged mass measuring 2.2 × 1.3 cm was found. Microscopic findings revealed an alveolar-like collection of epithelioid cells surrounded by a thin-wall vascular channel within a lymph node (LN). These epithelioid cells were positive for HMB45 and TFE3 but negative for Melan-A, CK, and S100. The patient was finally diagnosed with TFE3-expressing primary PEComa of LN.

Discussion

We report a rare case of TFE3-expressing primary LN PEComa that mimicked nodal recurrence of rectal cancer. Thus, imaging results in patients affected by neoplasm present a clinical diagnostic dilemma, as the presence of newly onset PEComa of LN may lead to the erroneous diagnosis of tumor recurrence or progression.

Conclusion

Suspicious isolated recurrences of rectal cancer in unusual locations may require surgical excision to confirm definitive diagnosis.

Exon 9 Mutation of PIK3CA Associated With Poor Survival in Patients With Epstein-Barr Virus-associated Gastric Cancer

BACKGROUND

Epstein-Barr virus (EBV)-associated gastric cancer (GC) is known to harbor a significant enrichment of of phosphatidylinositol 4, 5-biphosphate 3- kinase catalytic subunit alpha isoform (PIK3CA). Therefore, this study investigated the clinical relevance and prognostic role of PIK3CA mutations in patients with EBV-GC.

MATERIALS AND METHODS

After reviewing 1,318 consecutive cases of surgically resected GC, 120 patients were identified as EBV-positive using EBV-encoded RNA in situ hybridization. PIK3CA mutations were identified in formalin-fixed and paraffin-embedded surgical specimens from 112 patients with EBV-GC with available tumor tissue samples. Real-time polymerase chain reaction was used to evaluate hot-spot mutations of exons 1, 4, 7, 9, and 20 of PIK3CA.

RESULTS

Among the 112 patients, the frequency of PIK3CA mutations was 25.0% (n=28), and among the 28 patients harboring a PIK3CA mutation, most mutations were identified in exon 9 (n=21, 18.8%). The presence of PIK3CA mutation was also correlated with a higher T category (p<0.001) and N category (p<0.001), as well as the presence of perinueral invasion (p<0.001) and venous invasion (p<0.001). In a univariate analysis, PIK3CA mutation showed no association with overall survival (OS) (p=0.184) or disease-free survival (DFS) (p=0.150). Patients harboring exon 9 PIK3CA mutations exhibited a significantly shorter OS (p=0.023) and DFS (p=0.013) than the patients lacking an exon 9 PIK3CA mutation, yet without statistical significance in the multivariate analysis. Notably, exon 9 E542K mutation of PIK3CA was associated with the worst DFS (p=0.011).

CONCLUSION

The current data show that PIK3CA mutations appear to play an important role in carcinogenesis and tumor aggressiveness in EBV-GC, and also support the concept that exon 9 mutation of PIK3CA is a prognostic indicator for predicting patient outcomes and a rationale for therapeutic targeting in EBV-GC.

Rectal Invasion by Prostatic Adenocarcinoma That Was Initially Diagnosed in a Rectal Polyp on Colonoscopy

Despite anatomical proximity, prostatic adenocarcinoma with rectal invasion is extremely rare. We present a case of rectal invasion by prostatic adenocarcinoma that was initially diagnosed from a rectal polyp biopsied on colonoscopy in a 69-year-old Korean man. He presented with dull anal pain and voiding discomfort for several days. Computed tomography revealed either prostatic adenocarcinoma with rectal invasion or rectal adenocarcinoma with prostatic invasion. His tumor marker profile showed normal prostate specific antigen (PSA) level and significantly elevated carcinoembryonic antigen level. Colonoscopy was performed, and a specimen was obtained from a round, 1.5 cm, sessile polyp that was 1.5 cm above the anal verge. Microscopically, glandular tumor structures infiltrated into the rectal mucosa and submucosa. Immunohistochemically, the tumor cells showed alpha-methylacyl-CoA-racemase positivity, PSA positivity, and caudal-related homeobox 2 negativity. The final diagnosis of the rectal polyp was consistent with prostatic adenocarcinoma. Here, we present a rare case that could have been misdiagnosed as rectal adenocarcinoma.

Early Gastric Adenosquamous Carcinoma Resected Using Endoscopic Submucosal Dissection

Adenosquamous carcinoma (ASC) is characterized as a mixed neoplasia (adenocarcinoma with glandular architecture and squamous cell carcinoma [SqCC]). Because most ASCs are found in the advanced stage at the time of diagnosis, early gastric ASC is an extremely rare tumor. Here, we present the case of an incidental finding of early gastric ASC in a 61-year-old Korean man during a health screening. Histological biopsy through esophagogastroduodenoscopy revealed a moderately differentiated adenocarcinoma in the distal body. The patient underwent endoscopic submucosal dissection and was diagnosed with ASC. The SqCC components of this tumor were located adjacent to the adenocarcinoma components and occupied 40% of the tumor. Two individual tumor components had invaded into the submucosal layer with lymphovascular invasion. An abdominal computed tomography scan indicated no definite mass or wall thickening of the stomach and revealed neither lymph node enlargement nor distant metastasis. To the best of our knowledge, this is the 14th reported case of early gastric ASC, and all cases were reported in East Asians.

What are the most important prognostic factors in patients with residual rectal cancer after preoperative chemoradiotherapy?

Background

We aimed to establish robust histoprognostic predictors on residual rectal cancer after preoperative chemoradiotherapy (CRT).

Methods

Analyzing known histoprognostic factors in 146 patients with residual disease allows associations with patient outcome to be evaluated.

Results

The median follow-up time was 77.8 months, during which 59 patients (40.4%) experienced recurrence and 41 (28.1%) died of rectal cancer. On univariate analysis, residual tumor size, ypT category, ypN category, ypTNM stage, downstage, tumor regression grade, lymphatic invasion, perineural invasion, venous invasion, and circumferential resection margin (CRM) were significantly associated with recurrence free survival (RFS) or/and cancer-specific survival (CSS) (all p<0.005). On multivariate analysis, higher ypTNM stage and CRM positivity were identified as independent prognostic factors for RFS (ypTNM stage, p=0.024; CRM positivity, p<0.001) and CSS (p=0.022, p=0.017, respectively). Furthermore, CRM positivity was an independent predictor of reduced RFS and CSS, irrespective of subgrouping according to downstage (non-downstage, p<0.001 and p<0.001; downstage, p=0.002 and p=0.002) or lymph node metastasis (non-metastasis, p<0.001 and p=0.001; metastasis, p<0.001 and p<0.001).

Conclusion

CRM status may be as powerful as ypTNM stage as a prognostic indicator for patient outcome in patients with residual rectal cancer after preoperative CRT.

Aquaporin 5 expression correlates with tumor multiplicity and vascular invasion in hepatocellular carcinoma

Aquaporins (AQPs) are a family of water channel transmembrane proteins that play a key role in transcellular water movement and transport. Recent studies have reported that AQPs are involved in cancer biology and can be a novel biomarker for predicting prognosis. The aim of this study was to identify clinical significance and prognostic impact of AQP5 in surgically resected hepatocellular carcinomas (HCCs). We analyzed the association between the expression of AQP5, Ki-67, and E-cadherin. Immunohistochemical stains for AQP5, KI-67, and E-cadherin were performed on 72 surgically resected HCCs. As a result, 46 patients (63.9%) showed AQP5 expression, 46 patients (63.9%) revealed high expression of Ki-67, and E-cadherin loss was identified in 8 patients (11.1%). No significant relationship among the three markers was found (all P > 0.05). AQP5 expression was associated with tumor multiplicity (P = 0.039), microvascular invasion (P = 0.040), and major vessel invasion (P = 0.044). High expression of Ki-67 was related to high serum AFP level (P = 0.006), tumor grade (P = 0.002), and microvascular invasion (P = 0.040). AQP5 expression tended to be associated with worse overall survival (OS) (P = 0.093) in the univariate analysis, but no significance was found in the multivariate survival analysis. High expression of Ki-67 was associated with shorter recurrence-free survival (RFS) in both univariate (P = 0.012) and multivariate analysis (P = 0.020). In conclusion, AQP5 might be a prognostic marker in HCC based on its association with tumor multiplicity, microvascular invasion, and major vessel invasion; and Ki-67 is an independent prognostic factor in HCC.

An Extragastrointestinal Stromal Tumor Originating from the Pancreas

Gastrointestinal stromal tumor (GIST) is the most common mesenchymal neoplasm of the gastrointestinal tract (GIT). In fewer than 5% of cases, GIST originates primarily from outside the GIT. The occurrence of GIST originating from the pancreas is rare. Sometimes, neuroendocrine tumors should be differentiated from GISTs because of their hyperenhancing nature in radiologic images. We report a case of GIST arising in the pancreas that was confirmed by surgical resection.