Although recent studies have suggested that cessation of imatinib (IM) in chronic myeloid leukemia patients can be associated with sustained response, further validation is needed to explore predictive factors. In a prospective, multicenter study, chronic phase patients were eligible for cessation of IM therapy after more than 3 years if they had no detectable BCR-ABL1 transcript for at least 2 years. A total of 48 patients with a median age of 47 years (19-74 years) were enrolled. Twenty patients received IM for post-transplant relapse. After a median follow-up of 15.8 months (1.4-28.2 months) after IM discontinuation, nine of the non-transplant group lost undetectable molecular residual disease (UMRD) and major molecular response (MMR), whereas none of the 20 patients in the transplant group experienced UMRD loss. Probabilities for sustained MMR and UMRD were 64.4% and 66.3% in the non-transplant group, respectively. Of nine patients re-treated with IM, eight patients re-achieved MMR at a median of 1.7 months (0.9-2.8 months). Seven of these patients re-achieved UMRD at a median of 5.6 months (2.8-12.1 months). Previous transplantation, IM duration, and UMRD duration were significantly associated with sustained molecular responses. Our data strongly suggest that immunological control contributes to sustained suppression of residual leukemia cell expansion and that IM can be safely discontinued in patients with post-transplant relapse. Am. J.

Rising BCR-ABL1 transcripts indicate potential loss of imatinib response in CML. We determined whether the BCR-ABL1 doubling time could distinguish nonadherence from resistance as the cause of lost response. Distinct groups were examined: (1) acquired clinical resistance because of blast crisis and/or BCR-ABL1 mutations; and (2) documented imatinib discontinuation/interruption. Short doubling times occurred with blast crisis (median, 9.0 days; range, 6.1-17.6 days; n ‫؍‬ 12 patients), relapse after imatinib discontinuation in complete molecular response (median, 9.0 days; range, 6.9-26.5 days; n ‫؍‬ 17), and imatinib interruption during an entire measurement interval (median, 9.4 days; range, 4.2-17.6 days; n ‫؍‬ 12; P ‫؍‬ .72). Whereas these doubling times were consistently short and indicated rapid leukemic expansion, fold rises were highly variable: 71-, 9.5-, and 10.5-fold, respectively. The fold rise depended on the measurement interval, whereas the doubling time was independent of the interval. Longer doubling times occurred for patients with mutations who maintained chronic phase (CP: median, 48 days; range, 17.3-143 days; n ‫؍‬ 29; P < .0001). Predicted short and long doubling times were validated on an independent cohort monitored elsewhere. IntroductionThe primary genetic abnormality of chronic myeloid leukemia (CML) is the BCR-ABL1 gene, and transcripts are measured to assess response to the kinase inhibitor imatinib. 1 An appropriate frequency of molecular monitoring potentially provides early warning of pending relapse for timely therapeutic intervention before overt relapse. The recommended monitoring frequency is every 3 months until a major molecular response (MMR) is confirmed, and then at least every 6 months. 1 The molecular warning for potential resistance or nonadherence is a BCR-ABL1 transcript rise. [2][3][4][5][6] However, there is no consensus or clarity on the lower limit of a fold rise that should prompt BCR-ABL1 kinase domain mutation analysis or an evaluation of compliance. 1,7 A 10-fold rise is considered clinically significant by the National Comprehensive Cancer Network, 7 whereas Press et al found that a 2.6-fold rise was optimal for predicting mutations and concluded that a 10-fold rise is set too high and lacks diagnostic sensitivity. 8 A rise is undoubtedly a useful trigger to screen for causes of treatment resistance, but the fold rise is itself a product of 2 factors: the velocity of the rise (a property of the leukemic clone) and the measurement interval (which is arbitrary). Both factors will influence the fold rise; however, they are not considered in current monitoring guidelines.The velocity of a BCR-ABL1 rise has significance for disease phase at relapse. 2,9 A more rapid rise, assessed by the number of days over which BCR-ABL1 doubled (doubling time), occurred with relapse into accelerated phase (AP) or blast crisis (BC) after transplantation, 9 and with loss of imatinib response, 2 compared with chronic phase (CP) relapse. The doubling time provides an evaluation of...

Background The neutrophil-lymphocyte ratio (NLR) is associated with a poor prognosis in many cancers but the biological mechanisms involved are unknown. Since cytokines and angiogenic factors (CAFs) are reflected by various immune responses, we analyzed the association between the NLR and CAFs and their prognostic implications in gastric cancer (GC). Methods Of 745 GC patients who were enrolled in NLR analysis, 70 underwent NLR and CAF association analyses. Pretreatment serum levels of 52 CAFs were measured by means of multiplex bead immunoassays and enzymelinked immunosorbent assays. Linear regression analysis and survival analysis of the NLR with each CAF were performed. Results Metastatic organ numbers and carbohydrate antigen 19-9 levels were significantly higher in patients with a high NLR [greater than 2.42 (median): P = 0.047 and P \ 0.001 respectively]. The overall survival was significantly worse in the high NLR group (17.8 months vs 11.2 months, P \ 0.001). In CAF analysis, osteopontin (R 2 = 0.337, P \ 0.001) and interleukin-6 (R 2 = 0.141, P = 0.001) were significantly associated with the NLR. Stromal-cell-derived factor 1 (SDF-1) was a significant poor prognostic factor independently of the NLR. Consideration of both the NLR and SDF-1 divided patient groups with different overall survival (both low, 21.0 months; either high, 15.8 months; both high, 8.2 months). Conclusion The NLR is a significant poor prognostic factor in advanced GC. The NLR is mainly associated with osteopontin and interleukin-6. Besides the NLR, SDF-1 is an independent poor prognostic factor in GC. Consideration of both the NLR and SDF-1 might give insights into antitumor immunity in GC.

Trastuzumab in combination with chemotherapy is the standard of care for patients with human epidermal growth factor receptor 2 (HER2)-positive breast and gastric cancers. Several resistance mechanisms against anti-HER2 therapy have been proposed. Src activation has been suggested to be responsible for the resistance of HER2-positive breast cancer. In our study, we generated four trastuzumab-resistant (HR) cancer cell lines from HER2-amplified gastric and biliary tract cancer cell lines (SNU-216, NCI-N87, SNU-2670, and SNU-2773). Elevated Src phosphorylation was detected in SNU2670HR and NCI-N87HR cell lines, but not in SNU216HR or SNU2773HR cell lines. In SNU216HR and SNU2773HR cell lines, phospho-FAK (focal adhesion kinase) was elevated. Bosutinib as a Src inhibitor suppressed growth, cell-cycle progression, and migration in both parental and HR cell lines. Specifically, Src interacted with FAK to affect downstream molecules such as AKT, ERK, and STAT3. Bosutinib showed more potent antitumor effects in Src-activated HR cell lines than parental cell lines. Taken together, this study suggests that Src inhibition may be an effective measure to overcome trastuzumab resistance in HER2-positive cancer. .

Purpose The DNA damage response (DDR) is a multi-complex network of signaling pathways involved in DNA damage repair, cell cycle checkpoints, and apoptosis. In the case of biliary tract cancer (BTC), the strategy of DDR targeting has not been evaluated, even though many patients have DNA repair pathway alterations. The purpose of this study was to test the DDR-targeting strategy in BTC using an ataxia-telangiectasia and Rad3-related (ATR) inhibitor. Materials and Methods A total of nine human BTC cell lines were used for evaluating anti-tumor effect of AZD6738 (ATR inhibitor) alone or combination with cytotoxic chemotherapeutic agents through MTT assay, colony-forming assays, cell cycle analyses, and comet assays. We established SNU478-mouse model for in vivo experiments to confirm our findings. Results Among nine human BTC cell lines, SNU478 and SNU869 were the most sensitive to AZD6738, and showed low expression of both ataxia-telangiectasia mutated (ATM) and p53. AZD6738 blocked p-Chk1 and p-glycoprotein and increased γH2AX, a marker of DNA damage, in sensitive cells. AZD6738 significantly increased apoptosis, G2/M arrest and p21, and decreased CDC2. Combinations of AZD6738 and cytotoxic chemotherapeutic agents exerted synergistic effects in colony-forming assays, cell cycle analyses, and comet assays. In our mouse models, AZD6738 monotherapy decreased tumor growth and the combination with cisplatin showed more potent effects on growth inhibition, decreased Ki-67, and increased terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling than monotherapy with each drug. Conclusion In BTC, DDR targeting strategy using ATR inhibitor demonstrated promising antitumor activity alone or in combination with cytotoxic chemotherapeutic agents. This supports further clinical development of DDR targeting strategy in BTC.