SUMMARY Intrahepatic cholangiocarcinoma (ICC) and hepatocellular carcinoma (HCC) are clinically disparate primary liver cancers with etiological and biological heterogeneity. We identified common molecular subtypes linked to similar prognosis among 199 Thai ICC and HCC patients through systems integration of genomics, transcriptomics, and metabolomics. While ICC and HCC share recurrently mutated genes, including TP53, ARID1A, and ARID2, mitotic checkpoint anomalies distinguish the C1 subtype with key drivers PLK1 and ECT2, whereas the C2 subtype is linked to obesity, T-cell infiltration and bile acid metabolism. These molecular subtypes are found in 582 Asian, but less so in 265 Caucasian patients. Thus, Asian ICC and HCC, while clinically treated as separate entities, share common molecular subtypes with similar actionable drivers to improve precision therapy.

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BackgroundIsocitrate dehydrogenase 1 and 2 (IDH1 and IDH2) metabolic genes encode cytosolic and mitochondrial enzymes that catalyze the conversion of isocitrate to α-ketoglutarate. Acquired somatic mutations of IDH1 and IDH2 have recently been reported in some types of brain tumors and a small proportion of acute myeloid leukemia (AML) cases.MethodsTwo-hundred and thirty newly diagnosed AML patients were analyzed for the presence of IDH1 and IDH2 heterozygous mutations by polymerase chain reaction-denaturing high performance liquid chromatography (PCR-DHPLC) followed by direct sequencing. Clinical and biological characteristics were analyzed and correlated to the IDH mutational status. Coexisting mutations such as FLT3, PML-RARA, RAS, AML1, and NPM1 mutations were additionally explored.ResultsThe prevalence of IDH1 and IDH2 mutations was 8.7% (20/230) and 10.4% (24/230), respectively. Six missense mutations were identified among IDH1-mutated cases; p.R132H (n = 8), p.R132C (n = 6), p.R132S (n = 2), p.R132G (n = 2), p.R132L (n = 1), and p.I99M (n = 1). Two missense mutations were found in IDH2-mutated cases; p.R140Q (n = 20) and p.R172K (n = 4). No patients had dual IDH1 and IDH2 mutations. About 18% of AML with normal cytogenetics and 31% of acute promyelocytic leukemia had IDH mutations. Half of the IDH-mutated cohort had normal karyotype and the major FAB subtype was AML-M2. Interestingly, IDH1- and IDH2-mutated cases predominantly had NPM1 mutations (60-74%) as compared to the wild type (P < 0.001). Very few IDH-mutated cases had FLT3 and/or RAS abnormalities and none of them had AML1 mutations. Older age and higher median platelet counts were significantly associated with IDH2 mutations although the clinical impact of either IDH1 or IDH2 mutations on patients' overall survival could not be observed.ConclusionOverall, 19% of newly diagnosed AML patients had alterations of IDH genes. No patients concurrently carried both IDH1 and IDH2 mutations suggesting that these mutations were mutually exclusive. NPM1 mutation appears as a major coexisting genetic mutation in IDH-mutated patients. Our present data failed to support the prognostic relevance of IDH mutations although alterations of these metabolic genes potentially have an important role in leukemia development.

Bone marrow is an important extranodal site in diffuse large B-cell lymphoma (DLBCL), and marrow histology has been incorporated into the new National Comprehensive Cancer Network international prognostic index. Marrow involvement demonstrated histologically confers poor prognosis but is identified by staging PET in more cases. How information from staging PET and biopsy should be combined to optimize outcome prediction remains unclear. Methods: The International Atomic Energy Agency sponsored a prospective international cohort study to better define the use of PET in DLBCL. As a planned subsidiary analysis, we examined the interplay of marrow involvement identified by PET and biopsy on clinical outcomes. Results: Eight countries contributed 327 cases with a median follow-up of 35 mo. The 2-y outcomes of cases with no evidence of marrow involvement (n 5 231) were 81% (95% confidence interval [CI], 76%-86%) for event-free survival (EFS) and 88% (83%-91%) for overall survival (OS); cases identified only on PET (n 5 61), 81% (69%-89%) for EFS and 88% (77%-94%) for OS; cases indentified only on biopsy (n 5 10), 80% (41%-95%) for EFS and 100% for OS; or cases identified by both PET and biopsy (n 5 25), 45% (25%-64%) for EFS and 55% (32%-73%) for OS. The hazard ratios for PET-negative/biopsy-negative cases versus PET-positive/ biopsy-positive cases were 2.67 (95% CI, 1.48-4.79) for ) for OS. Conclusion: This large study demonstrates that positive iliac crest biopsy histology only confers poor prognosis for patients who also have abnormal marrow 18 F-FDG uptake identified on the staging PET scan. Abnormal 18 F-FDG uptake in marrow, when iliac crest biopsy histology is normal, has no adverse effect on outcomes.