RESUMEN
Hepatocellular carcinoma (HCC) is an aggressive tumor that usually occurs in patients with chronic liver disease and cirrhosis. Surgical resection is an optimal treatment for HCC, but the 5-year recurrence rates are significantly high. The majority of recurrent HCCs occur through intrahepatic metastasis with local tumor progression, and less than 20% of recurrences are extrahepatic metastases. HCC with gastric metastasis is extremely rare, and it is easily misdiagnosed as primary gastric cancer with liver metastasis. An 80-year-old male chronic hepatitis B virus carrier had received lamivudine and entecavir for years and was regularly followed up in the clinic. He had a 3.5 cm solitary HCC with microvascular invasion and received curative surgical resection in 2009. In 2013, he developed a 1.3 cm solitary HCC again and was treated with combination therapy with radiofrequency ablation and pure ethanol injection. Afterwards, he was followed every 3-6 months and was HCC-free. Three years later, in 2016, endoscopy for intermittent epigastralgia showed a solitary 4 cm intraluminal gastric subepithelial tumor without mucosal ulcers or erosions over the gastric fundus. All imaging studies, including computed tomography, favored the diagnosis of gastrointestinal stromal tumor (GIST), but the pathology of the tumor proved to be HCC. The patient did not receive any systemic anticancer therapy but only wedge resection of the stomach and remained tumor- and HCC-free until his latest clinic visit in 2023. The current case is unique and indicates the possibility of HCC with late solitary gastric metastasis mimicking GIST. Complete gastric tumor resection ensured an extremely good outcome for the patient, which is different from the devastating prognosis of most cases of HCC with gastric metastasis.
RESUMEN
BACKGROUND: Cancer-related genes show racial differences. Therefore, identification and characterization of DNA copy number alteration regions in different racial groups helps to dissect the mechanism of tumorigenesis. METHODS: Array-comparative genomic hybridization (array-CGH) was analyzed for DNA copy number profile in 40 Asian and 20 Caucasian lung cancer patients. Three methods including MetaCore analysis for disease and pathway correlations, concordance analysis between array-CGH database and the expression array database, and literature search for copy number variation genes were performed to select novel lung cancer candidate genes. Four candidate oncogenes were validated for DNA copy number and mRNA and protein expression by quantitative polymerase chain reaction (qPCR), chromogenic in situ hybridization (CISH), reverse transcriptase-qPCR (RT-qPCR), and immunohistochemistry (IHC) in more patients. RESULTS: We identified 20 chromosomal imbalance regions harboring 459 genes for Caucasian and 17 regions containing 476 genes for Asian lung cancer patients. Seven common chromosomal imbalance regions harboring 117 genes, included gain on 3p13-14, 6p22.1, 9q21.13, 13q14.1, and 17p13.3; and loss on 3p22.2-22.3 and 13q13.3 were found both in Asian and Caucasian patients. Gene validation for four genes including ARHGAP19 (10q24.1) functioning in Rho activity control, FRAT2 (10q24.1) involved in Wnt signaling, PAFAH1B1 (17p13.3) functioning in motility control, and ZNF322A (6p22.1) involved in MAPK signaling was performed using qPCR and RT-qPCR. Mean gene dosage and mRNA expression level of the four candidate genes in tumor tissues were significantly higher than the corresponding normal tissues (P<0.001~P=0.06). In addition, CISH analysis of patients indicated that copy number amplification indeed occurred for ARHGAP19 and ZNF322A genes in lung cancer patients. IHC analysis of paraffin blocks from Asian Caucasian patients demonstrated that the frequency of PAFAH1B1 protein overexpression was 68% in Asian and 70% in Caucasian. CONCLUSIONS: Our study provides an invaluable database revealing common and differential imbalance regions at specific chromosomes among Asian and Caucasian lung cancer patients. Four validation methods confirmed our database, which would help in further studies on the mechanism of lung tumorigenesis.