Clinical usefulness of F-18 FDG PET in lymphoepithelioma-like gastric carcinoma

Estimating the Global Burden of Epstein-Barr Virus-Associated Gastric Cancer: A Systematic Review and Meta-Analysis

BACKGROUND & AIMS

Evidence suggests that a fraction of new gastric cancer cases may be etiologically associated with Epstein-Barr virus (EBV), a known carcinogenic agent. We aimed to systematically explore the proportion of EBV-positive gastric cancer.

METHODS

We did a systematic review (PROSPERO CRD42020164473) from January 1990 to August 2021. For each country and geographical region with available data, pooled prevalence and corresponding 95% confidence intervals (CIs) of EBV in gastric tumors were calculated for 3 subtypes of gastric adenocarcinoma (conventional adenocarcinoma, lymphoepithelioma-like gastric carcinoma, and remnant/stump carcinoma). For conventional adenocarcinoma, prevalence ratios (PRs) were presented for sex, Lauren's classification, gastric cancer stage, and anatomical location of the stomach.

RESULTS

In 220 eligible studies including over 68,000 cases of conventional gastric adenocarcinoma, EBV prevalence in tumor cells was 7.5% (95% CI, 6.9%-8.1%) and was higher in men compared with women (PR, 2.1; 95% CI, 1.9-2.4), in diffuse type compared with intestinal type (PR, 1.3; 95% CI, 1.1-1.5), and in the proximal region compared with the distal region (PR, 2.5; 95% CI, 2.0-3.1). There was no difference in EBV prevalence by gastric cancer stage. EBV prevalence was 75.9% (95% CI, 62.8%-85.5%) among lymphoepithelioma-like gastric carcinoma and 26.3% (95% CI, 22.2%-32.0%) among remnant or stump carcinoma.

CONCLUSIONS

Assuming a causal association between EBV and gastric cancer, our findings, when applied to the GLOBOCAN 2020 gastric cancer incidence, suggest that primary prevention such as the development of an effective EBV vaccine might prevent 81,000 EBV-associated gastric cancer cases worldwide annually.

TCGA-TCIA-Based CT Radiomics Study for Noninvasively Predicting Epstein-Barr Virus Status in Gastric Cancer

OBJECTIVE. The purpose of this study was to investigate the value of TCGA-TCIA (The Cancer Genome Atlas and The Cancer Imaging Archive)-based CT radiomics for noninvasive prediction of Epstein-Barr virus (EBV) status in gastric cancer (GC). MATERIALS AND METHODS. A total of 133 patients with pathologically confirmed GC (94 in the training cohort and 39 in the validation cohort) who were identified from the TCGA-TCIA public data repository and two hospitals were retrospectively enrolled in the study. Two-dimensional and 3D radiomics features were extracted to construct corresponding radiomics signatures. Then, 2D and 3D nomograms were built by combining radiomics signatures and clinical information on the basis of multivariable analysis. Their performance and clinical practicability were determined, validated, and compared with respect to discrimination, calibration, reclassification, and time spent on tumor segmentation. RESULTS. Both 2D and 3D nomograms were robust and showed good calibration. The AUCs of the 2D and 3D nomograms showed no significant difference in the training cohort (0.919 vs 0.945, respectively; p = .41) or validation cohort (0.939 vs 0.955, respectively; p = .71). The net reclassification index showed that the 3D nomogram revealed no significant improvement in risk reclassification when compared with the 2D nomogram in the training cohort (net reclassification index, 0.68%; p = .14) and the validation cohort (net reclassification index, 6.06%; p = .08). Of note, the time spent on 3D segmentation (median, 907 seconds) was higher than that spent on 2D segmentation (median, 129 seconds). CONCLUSION. The 2D and 3D radiomics nomograms might have the potential to be used as effective tools for prediction of EBV in GC. When time spent on segmentation is considered, the 2D nomogram is more highly recommended for clinical application.

Surgical treatment of Epstein-Barr virus-associated lymphoepithelioma-like carcinoma occurring in both the posterior mediastinum and liver: Case report

RATIONALE

Lymphoepithelioma-like carcinoma (LELC) is a rare malignant tumor that can occur in many areas of the body. The pathogenesis of LELC remains unknown, but Epstein-Barr virus (EBV) has been shown to be strongly correlated with LELC at several anatomic sites, including the lungs and thymus. To the best of our knowledge, EBV-associated LELC has never been reported in both the posterior mediastinum and liver. Herein, we report the case of a 41-year-old female diagnosed with LELC in both the posterior mediastinum and liver and discuss whether it is beneficial to perform surgery on advanced LELC when resectable metastases are found.

PATIENT CONCERNS

The patient was a 41-year-old woman who had been suffering from intermittent pain in the upper right quadrant for 3 months without obvious cause and was admitted to our hospital with occasional nausea without vomiting.

DIAGNOSIS

Her cancer antigen 125 and cytokeratin 19 fragment levels were elevated, whereas alpha-fetoprotein and alanine aminotransferase were normal. Computed tomography (CT) and magnetic resonance imaging revealed a mass in the S6 segment of the liver. Whole-body positron emission tomography/computed tomography (PET/CT) revealed a 3.2-cm mass in the posterior mediastinum and a 6.7-cm mass on the right side of the liver. We made a diagnosis of LELC based on the histological and immunohistochemical findings of specimens obtained by operation. However, it was difficult to determine the primary origin of the tumor.

INTERVENTIONS

The patient underwent mediastinal tumor resection, hepatectomy, and diaphragmatic repair. Thereafter, she was administered paclitaxel and cisplatin as adjuvant chemotherapy.

OUTCOMES

The postoperative course was uneventful, and the patient was discharged 10 days later. Although she was administered paclitaxel and cisplatin as adjuvant chemotherapy, we noted recurrence during the 4-month follow-up examination. Then, the patient passed away 5 months after surgery.

LESSONS

We present the first case of LELC found in both the posterior mediastinum and liver and describe the functionality of PET/CT for finding occult carcinomas and identifying their primary tumor origin. Additional studies are urgently needed to discover whether it is beneficial to perform surgery on advanced LELC when resectable metastases are revealed by PET/CT.

Tracheal Lymphoepithelioma-Like Carcinoma on FDG PET/CT

Lymphoepithelioma-like carcinoma (LELC) in the trachea is an extremely rare disease. We present a case of a 64-year-old man with FDG-avid tracheal LELC on F-FDG PET/CT. Despite its rarity, LELC in the trachea should be considered as one of the possibilities in patients with a hypermetabolic mass in the trachea. If LELC in the trachea is suspected, F-FDG PET/CT is a useful tool for initial staging.

Prognostic Value and Clinical Impact of Pretreatment FDG PET in Pulmonary Lymphoepithelioma-Like Carcinoma

PURPOSE

Compared with other forms of non-small cell lung cancer, pulmonary lymphoepithelioma-like carcinoma (LELC) is rarer and portends better outcomes. We sought to investigate the prognostic role and clinical impact of pretreatment F-FDG PET in pulmonary LELC.

METHODS

A total of 71 patients with pulmonary LELC were identified through a retrospective review of clinical records. Of them, 41 underwent F-FDG PET for primary staging. Outcomes were assessed using the Kaplan-Meier method and Cox regression models with a forward stepwise selection procedure. Staging changes served as the main outcome measure for assessing the impact of F-FDG PET. For the purpose of analyses, all patients were restaged according the American Joint Committee on Cancer Staging Manual eighth edition.

RESULTS

Stage and pretreatment F-FDG PET were significantly independent predictors of overall survival (OS) on multivariate analysis. Five-year OS rates for patients with stages I-II, III-IVA, and IVB were 92.3%, 70.4%, and 20.0%, respectively. The use of F-FDG PET for staging purposes was associated with a better OS (P = 0.003). Specifically, the 5-year OS rates for patients who were staged with and without F-FDG PET were 85.4% and 49.7%, respectively (P = 0.012). F-FDG PET resulted in a disease upstage in 28.6% of patients with CT-defined stages III-IVA; of them, 14.3% were upstaged to IVB disease.

CONCLUSIONS

The American Joint Committee on Cancer eighth edition stage and pretreatment F-FDG PET were independent prognostic factors for OS in patients with pulmonary LELC. F-FDG PET imaging resulted in a better disease staging with a corresponding optimization of therapeutic interventions, which ultimately improved survival outcomes.

Surgical treatment for metastasis from lymphoepithelioma-like cholangiocarcinoma in the liver: A case report

RATIONALE

Lymphoepithelioma-like cholangiocarcinoma (LEL-CC) is a rare variant of intrahepatic cholangiocarcinoma (ICC), which is characterized by the better outcome than normal ICC. There is no report about the treatment for the metastasis of the LEL-CC. Here, we describe a rare case of LEL-CC of the liver and report the treatment for metastasis of it.

PATIENT CONCERNS

A 38-year-old woman with a chronic hepatitis B infection was referred to the department of liver surgery in our hospital with a mass in the liver.

DIAGNOSES

A past ultrasound examination had revealed a 28 mm × 16 mm nodular lesion in the right posterior lobe of the liver in May 2013. She had undergone partial resection of the thyroid gland for papillary carcinoma 1 year earlier.

INTERVENTION

Suspicious of the metastasis from thyroid cancer, she underwent surgery with liver segmentectomy. The pathologic diagnosis of the lesion was LEL-CC. After surgery, she regularly got checked in our hospital, and in the 6 months after surgery, there was enlargement of lymph node before the inferior vena cava in CT. The doctor did not detect the enlargement of the lymph node until June 2017. The PET-CT was done in June of 2017, which showed the lymph node was hypermetabolic.

OUTCOMES

The patient got her second surgery for lymph node three years after the first surgery, which was proved that the lymph node was metastasis from LEL-CC. The patient was free from recurrence 9 months after surgery.

LESSONS

We report the first case of surgery for metastasis from LEL-CC in the liver that was diagnosed 3 years after hepatectomy. Our findings suggest that surgery could be an effective way of treating lymph node metastasis of LEL-CC and early PET-CT can help to identify metastasis.