The Clinical Significance of Microsatellite Instability in Patients with Right-sided Colorectal Cancer.

BACKGROUND/AIMS: Colorectal cancer (CRC) with microsatellite instability (MSI) has a better prognosis than CRC with microsatellite stable (MSS). Recent studies have reported biological differences according to tumor location in CRC. In this study, we investigated the clinical significance of MSI in patients with right-sided CRC. METHODS: The medical records of 1,009 CRC patients diagnosed at our institute between October 2004 and December 2016 with MSI test results were retrospectively reviewed. The long-term outcomes of CRC patients with MSI were assessed with respect to tumor location using Kaplan-Meier curves and Cox regression models. RESULTS: The median follow-up duration for all 1,009 study subjects was 25 months (interquartile range, 15-38). One hundred twenty-four of the study subjects had MSI (12.3%) and 250 had right-sided CRC (24.8%). The patients with MSI and right-sided CRC had better disease-free survival (DFS) than those with MSS as determined by the log-rank test (p=0.013), and this result was significant in females (p=0.035) but not in males with right-sided CRC. Multivariate Cox regression analysis showed MSS significantly predicted poor DFS in patients with right-sided CRC (hazard ratio 3.97, 95% CI 1.30-12.15, p=0.016) and in female patients (hazard ratio 4.69, 95% CI 1.03-21.36, p=0.045). CONCLUSIONS: The study shows MSI is a useful predictor of DFS in patients with right-sided CRC, especially in female patients.

Outcomes of allogeneic hematopoietic cell transplantation in acute myeloid leukemia patients with monosomal karyotypes.

This study investigated the outcomes of allogeneic hematopoietic cell transplantation (allo-HCT) in acute myeloid leukemia (AML) patients with monosomal karyotypes (MK). A total of 114 AML patients who received allo-HCT were retrospectively analyzed. At the time of diagnosis, 13 patients were categorized with a favorable cytogenetic risk, 78 with an intermediate risk, and 23 with an adverse risk. MK was found in 12 patients among 23 with adverse cytogenetic risk. Pretransplant disease status was active disease in 5 cases (45.5%) in the adverse-risk without MK group, and 8 cases (66.7%) in the corresponding group with MK, 15 (19.2%) in the intermediate group and 4 (30.8%) in the favorable group. In multivariate analysis, active disease before transplant (hazard ratio, HR 3.913, p < 0.001), acute graft-versus-host disease (GVHD) ≥grade 2 (HR 1.908, p = 0.048) and chronic GVHD (HR 0.364, p = 0.001) affected overall survival (OS). The initial cytogenetic risk groups were not a significant risk factor for OS in allogeneic settings. The 2-year OS rate was 44.0 ± 15.9% without MK and 20.7 ± 17.9% with MK (p = 0.246). However, the OS rate was better for patients with chronic GVHD (p = 0.025). In conclusion, a survival benefit was observed for MK-positive patients with chronic GVHD in an allogeneic setting. However, the prognosis still remained poor for patients with MK.

Two CML patients who subsequently developed features of essential thrombocythemia with JAK2-V617F mutation while in complete cytogenetic remission after treatment with imatinib mesylate.

The present report describes two chronic myelogenous leukemia (CML) patients with the JAK2-V617F mutation who were in complete hematologic and cytogenetic remission and subsequently developed clinical features of essential thrombocythemia under treatment with tyrosine kinase inhibitors. In light of the findings from previous reports, screening for the JAK2-V617F mutation should be considered for any Ph(+) CML patients with thrombocytosis, leukocytosis, or erythrocytosis at diagnosis and for patients who subsequently develop thrombocytosis, leukocytosis, or erythrocytosis during follow-up, even for CML patients in complete cytogenetic response and major molecular response.