Epigenetic scars in regulatory T cells are retained after successful treatment of chronic hepatitis C with direct-acting antivirals.

BACKGROUND & AIMS: Chronic hepatitis C virus (HCV) infection results in abnormal immunological alterations, which are not fully normalized after viral elimination by direct-acting antiviral (DAA) treatment. Here we longitudinally examined phenotypic, transcriptomic, and epigenetic alterations in peripheral blood regulatory T (TREG) cells from patients with chronic HCV infection according to DAA treatment. METHODS: Patients with chronic genotype 1b HCV infection who achieved sustained virologic response (SVR) by DAA treatment and age-matched healthy donors were recruited. Phenotypic characteristics of TREG cells were investigated through flow cytometry analysis. Moreover, transcriptomic and epigenetic landscape of TREG cells were analyzed using RNA-seq and ATAC-seq analysis. RESULTS: The TREG cell population-especially the activated TREG cell subpopulation-was expanded in peripheral blood during chronic HCV infection, and this expansion was sustained even after viral clearance. RNA-seq analysis revealed that viral clearance did not abrogate the inflammatory features of these TREG cells, such as TREG activation and TNF signal. Moreover, ATAC-seq analysis showed inflammatory imprinting in the epigenetic landscape of TREG cells from patients, which remained after treatment. These findings were further confirmed by intracellular cytokine staining, demonstrating that TREG cells exhibited inflammatory features and TNF production in chronic HCV infection that were maintained after viral clearance. CONCLUSIONS: Overall, our results showed that during chronic HCV infection, the expanded TREG cell population acquired inflammatory features at phenotypic, transcriptomic, and epigenetic levels, which were maintained even after successful viral elimination by DAA treatment. Further studies are warranted to examine the clinical significance of sustained inflammatory features in the TREG cell population after recovery from chronic HCV infection. IMPACT AND IMPLICATIONS: During chronic HCV infection, several immune components are altered both quantitatively and qualitatively. The recent introduction of DAAs led to a high cure rate of chronic HCV infection. Nevertheless, we have demonstrated that inflammatory features of TREG cells are maintained at phenotypic, transcriptomic, and epigenetic levels even after successful DAA treatment. Further in-depth studies are required to investigate the long-term clinical outcomes of patients who have recovered from chronic HCV infection.

Adjuvant treatment for locally advanced gastric cancer: an Asian perspective.

Standard adjuvant treatment for locally advanced gastric cancer (LAGC) is regionally different. Whereas perioperative chemotherapy is the standard in Western populations, D2 gastrectomy followed by adjuvant chemotherapy has been the standard in East Asia. Recently, the pivotal phase 3 PRODIGY and RESOLVE studies have demonstrated survival benefits of adding neoadjuvant chemotherapy to surgery followed by adjuvant chemotherapy over up-front surgery followed by adjuvant chemotherapy in Asian patients. Based on these results, neoadjuvant chemotherapy is considered one of the viable options for patients with LAGC. In this review, various aspects of neoadjuvant chemotherapy will be discussed for its optimal application in Asia. Candidates for neoadjuvant chemotherapy should be carefully chosen in consideration of the inaccurate aspects of radiological clinical staging and its potential benefit over up-front surgery followed by a decision on adjuvant chemotherapy according to the pathological stage. Efforts should continuously be made to optimally apply neoadjuvant chemotherapy to patients with LAGC, considering various factors, including a more accurate radiological assessment of the tumor burden and the optimization of post-operative chemotherapy. Future neoadjuvant trials involving novel agents for Asian patients should be designed based on proven Asian regimens rather than adopting Western regimens.

Factors associated with the efficacy of first-line nivolumab plus chemotherapy in advanced gastric cancer patients with deficient mismatch repair.

BACKGROUND: We aimed to investigate clinicopathologic factors leading to different clinical outcomes in patients with deficient mismatch repair protein (d-MMR) gastric cancer (GC) treated with nivolumab plus chemotherapy (nivolumab chemotherapy). METHODS: This retrospective study included 28 patients with d-MMR advanced GC treated with first-line nivolumab chemotherapy. As a control group, 68 treated with first-line chemotherapy alone were included. Clinicopathological factors, including the neutrophil-to-lymphocyte ratio (NLR) and PD-L1 combined positive score (CPS), were analyzed with regards to the efficacy outcomes. RESULTS: Progression-free survival (PFS) was longer (median PFS; not reached [NR] vs. 5.2 months, hazard ratio [HR] 0.28, P < 0.001), and overall survival (OS) tended to be longer (median OS; NR vs. 17.9 months, HR 0.43, P = 0.057) in patients treated with nivolumab chemotherapy than those treated with chemotherapy. The PFS benefit of nivolumab chemotherapy over chemotherapy was pronounced in the subgroup with a lower NLR (< 3.80 [median NLR]) (HR 0.10), whereas it was less prominent in patients with a high NLR (≥ 3.80) (HR 0.58). Among patients treated with nivolumab chemotherapy, PFS was worse in patients with a higher NLR (≥ 3.80) than in those with a lower NLR (< 3.80), and survival outcomes were similar between those with PD-L1 CPS ≥ 5 and < 5. CONCLUSION: Nivolumab chemotherapy was associated with better efficacy outcomes than chemotherapy alone among patients with d-MMR GC, but survival outcomes were poor even with nivolumab chemotherapy for those with a high NLR. Survival outcomes were not different according to PD-L1 CPS among d-MMR patients treated with nivolumab chemotherapy.

SMARCA4-deficient undifferentiated gastric carcinoma: a case series and literature review.

Undifferentiated gastric carcinoma, characterized by anaplastic cells lacking distinct features of cytological or architectural differentiation, poses diagnostic and therapeutic challenges. Recent studies have suggested an association between this carcinoma and deficiencies in the SWI/SNF complex, particularly mutations in subunits such as SMARCA4. We herein report six cases of SMARCA4-deficient undifferentiated gastric carcinoma with molecular findings, highlighting the rarity and diagnostic pitfalls of this malignancy. Predominantly occurring in males over 50 years, these cases presented with nonspecific symptoms and were often diagnosed at an advanced stage. Histologically, the tumors exhibited a sheet-like growth pattern, reduced or absent epithelial markers, and loss of BRG-1 expression, with molecular analysis confirming SMARCA4 gene mutations. The response to conventional chemotherapy was poor, underscoring the importance of complete surgical resection and the development of alternative treatment modalities.

DNA mismatch repair deficiency and outcomes of patients with locally advanced gastric cancer treated with preoperative docetaxel, oxaliplatin, and S-1 plus surgery and postoperative S-1 or surgery plus postoperative S-1: a sub-analysis of the phase 3 PRODIGY trial.

BACKGROUND: The benefit of adjuvant chemotherapy for locally advanced gastric cancer (LAGC) patients with DNA mismatch repair (MMR) deficiency (D-MMR) is controversial due to concerns about its potential detrimental effect. The PRODIGY trial showed the survival benefit of adding preoperative docetaxel, oxaliplatin, and S-1 (DOS) to surgery plus postoperative S-1 for LAGC patients. In this sub-analysis, we evaluated the benefit of preoperative DOS according to MMR status. METHODS: Among patients enrolled in the PRODIGY trial treated with either preoperative DOS followed by surgery and postoperative S-1 (CSC arm), or surgery and postoperative S-1 (SC arm) at Asan Medical Center (n = 249), those in the full analysis set with available tissue to assess MMR status were included in the present analysis. RESULTS: A total of 231 patients (CSC arm, n = 108; SC arm, n = 123) were included (median age, 58 years [range, 27-75]), and 21 patients (CSC arm, n = 8 [7.4%]; SC arm, n = 13 [10.6%]) had D-MMR tumors. Progression-free survival and overall survival tended to be superior in the CSC arm than in the SC arm among D-MMR patients (HR 0.48 [95% CI 0.09-2.50]; log-rank P = 0.37 and HR 0.55 [95% CI 0.11-2.86]; log-rank P = 0.46, respectively), as well as among proficient MMR (P-MMR) patients (HR 0.68 [95% CI 0.46-1.03]; log-rank P = 0.07 and HR 0.75 [95% CI 0.49-1.14]; log-rank P = 0.17, respectively). CONCLUSION: Preoperative DOS followed by surgery and postoperative S-1 may be considered a treatment option for LAGC patients regardless of MMR status.

Discordant PD-L1 results between 28-8 and 22C3 assays are associated with outcomes of gastric cancer patients treated with nivolumab plus chemotherapy.

BACKGROUND: We evaluated the concordance/discordance of PD-L1 staining results between the 28-8 and 22C3 assays and its impact on the efficacy outcomes of advanced gastric cancer patients treated with nivolumab plus chemotherapy. METHODS: This retrospective study involved 143 gastric cancer patients treated with first-line nivolumab plus chemotherapy whose PD-L1 results with both 28-8 and 22C3 assays were available. The concordance/discordance between these assays and the inter-observer variability were evaluated for PD-L1 combined positive score (CPS) positivity. Discordant PD-L1 results were analyzed regarding survival outcomes. RESULTS: The agreement rates and Cohen's kappa values between the 28-8 and 22C3 assays were 78.3% and 0.56 (for CPS ≥ 1), 81.8% and 0.60 (for CPS ≥ 5), and 88.8% and 0.66 (for CPS ≥ 10), respectively. Inter-observer variability, as represented by the intra-class correlation coefficient, was 0.89 and 0.88 for the 28-8 and 22C3 assays, respectively. With PD-L1 CPS ≥ 5 defined as positive, 35 (24.5%) and 82 (57.3%) had concordantly positive and negative results, respectively, between the 28-8 and 22C3 assays, whereas 26 (18.2%) had discordant results. Progression-free survival was shorter for those who exhibited negatively concordant PD-L1 results and discordant PD-L1 positivity between the 28-8 and 22C3 assays relative to those with positively concordant PD-L1 results (P = 0.013). CONCLUSION: PD-L1 assays by 28-8 and 22C3 showed suboptimal concordance, while inter-observer variability was not critical in advanced gastric cancer. Discordant PD-L1 results between 28-8 and 22C3 assays may be associated with unfavorable efficacy outcomes in patients treated with nivolumab plus chemotherapy.

Clinical outcomes of Epstein-Barr virus (EBV)-associated metastatic and locally advanced unresectable gastric cancers (GCs) in patients receiving first-line fluoropyrimidine and platinum (FP) doublet chemotherapy.

BACKGROUND: Epstein-Barr virus-associated gastric cancer (EBVaGC) is a distinct molecular subgroup showing excellent outcomes after surgery for localized disease. Prominent immune cell infiltration in EBVaGC reflects the immunogenicity of Epstein-Barr virus (EBV) and, as suggested by some investigators, responsiveness to immune checkpoint inhibitors in the palliative setting. However, few data are available on the prevalence, clinical characteristics, and prognosis of EBVaGC patients receiving palliative cytotoxic chemotherapy. METHODS: In this retrospective study, we identified 1061 patients with metastatic, recurrent, or locally advanced unresectable gastric cancer (GC) who started first-line fluoropyrimidine/platinum (FP) doublet chemotherapy with or without trastuzumab from January 2015 to August 2018. For 766 patients with available tumor tissue, the presence of EBV in cancer cells was evaluated by EBV-encoded RNA in situ hybridization and correlated with clinical characteristics and treatment outcomes. RESULTS: Among the patients evaluated (n = 766), 40 (5.0%) were EBV-positive. EBVaGC was associated with male sex (p = 0.009) and lower neutrophil-lymphocyte ratio (NLR < 2.46, p = 0.03). Efficacy of first-line FP chemotherapy, in terms of response rate ad progression-free survival (PFS), did not differ between EBVaGC and EBV-negative GC (overall response rate: 53.8% vs. 51.8%, p = 0.99; median PFS: 6.4 vs. 6.7 months, p = 0.90). However, overall survival tended to be better with EBVaGC than EBV-negative GC (16.4 vs. 14.0 months, p = 0.07). CONCLUSIONS: EBVaGC accounted for 5% of metastatic/unresectable GCs. While EBVaGC was not associated with better response to or PFS following first-line cytotoxic chemotherapy, it showed a trend toward better overall survival.

Prognostic value of mismatch repair deficiency in patients receiving first-line fluoropyrimidine plus platinum for metastatic, recurrent, or unresectable gastric cancer.

BACKGROUND: We examined the impact of mismatch repair (MMR) status on efficacy of first-line fluoropyrimidine plus platinum (FP) chemotherapy in patients with HER2-negative metastatic, recurrent, or unresectable gastric cancer (mGC). METHODS: Patients with mGC receiving first-line FP between 2015 and 2018 at Asan Medical Center, Korea, were reviewed. We evaluated the clinical characteristics and the efficacy of chemotherapy according to MMR status in patients with available immunohistochemistry results. RESULTS: Of 895 patients, we analyzed 543 with available MMR protein expression results, and deficient MMR (dMMR) was detected in 4.4% (n = 24). Patients with dMMR exhibited a significantly higher median age than those with proficient MMR (pMMR) (64 vs. 58 years, p = 0.044). No signet ring cell carcinoma (SRCC) was detected among dMMR tumors, whereas SRCC was found in 17.5% of pMMR. Objective response rate was 27.3% in dMMR and 34.3% in pMMR (p = 0.556). No difference in progression-free survival was noted between patients with dMMR and pMMR (median, 5.6 vs. 5.8 months, p = 0.266). Patients with dMMR tended to have better overall survival than those with pMMR although this difference was not statistically significant (median, 17.9 vs. 12.2 months, p = 0.183). CONCLUSIONS: Efficacy of first-line FP was not different by MMR status in mGC patients.

A randomised phase 2 study of continuous or intermittent dosing schedule of imatinib re-challenge in patients with tyrosine kinase inhibitor-refractory gastrointestinal stromal tumours.

BACKGROUND: Imatinib re-challenge is one of the available therapeutic options for patients with treatment-refractory gastrointestinal stromal tumours (GIST). Intermittent dosing of imatinib was suggested to delay outgrow of the imatinib-resistant clones in a preclinical study, and it could potentially reduce the adverse events. METHODS: A randomised phase 2 study was performed to evaluate the efficacy and safety of a continuous or intermittent imatinib schedule in GIST patients whose disease had progressed to at least imatinib and sunitinib. RESULTS: Fifty patients were included in the full analysis set. The disease control rate at 12 weeks was 34.8% and 43.5%, and median progression-free survival was 1.68 and 1.57 months in the continuous and intermittent groups, respectively. The frequency of diarrhoea, anorexia, decreased neutrophil, or dysphagia was lower in the intermittent group. The scores for global health status/quality of life was not significantly deteriorated over the 8 weeks in both groups. CONCLUSIONS: The intermittent dosage did not improve the efficacy outcomes as compared to the continuous dosage, but showed slightly better safety profiles. Given the limited efficacy of imatinib re-challenge, intermittent dosage may also be considered in clinical circumstances where standard fourth-line agent is unavailable or all other viable treatments failed.

Dynamic changes in peripheral blood monocytes early after anti-PD-1 therapy predict clinical outcomes in hepatocellular carcinoma.

Immune checkpoint inhibitors are effective for advanced hepatocellular carcinoma (HCC), but there remains a need for peripheral blood biomarkers to predict the clinical response. Here, we analyzed the peripheral blood of 45 patients with advanced HCC who underwent nivolumab. During treatment, frequency of classical monocytes (CD14+CD16-) was increased on day 7, and the fold increase in the frequency on day 7 over day 0 (cMonocyteD7/D0) was significantly higher in patients with durable clinical benefit (DCB) than in patients with non-DCB (NDB). When we analyzed transcriptomes of classical monocytes, CD274, gene encoding PD-L1, was upregulated in NDB patients compared to DCB patients at day 7. Notably, gene signature of suppressive tumor-associated macrophages, or IL4l1+PD-L1+IDO1+ macrophages, was enriched after treatment in NDB patients, but not in DCB patients. Accordingly, the fold increase in the frequency of PD-L1+ classical monocytes at day 7 over day 0 (cMonocyte-PDL1D7/D0) was higher in NDB patients than DCB patients. The combined biomarker cMonocyteD7/D0/cMonocyte-PDL1D7/D0 was termed the "monocyte index", which was significantly higher in DCB patients than NDB patients. Moreover, the monocyte index was an independent prognostic factor for survival. Overall, our results suggest that early changes of circulating classical monocytes, represented as a monocyte index, could predict clinical outcomes of advanced HCC patients undergoing anti-PD-1 therapy.

Interruption of imatinib in advanced gastrointestinal stromal tumor after prolonged imatinib maintenance in the absence of gross tumor lesions.

BACKGROUND: Current guidelines recommend indefinite imatinib treatment for advanced gastrointestinal stromal tumor (GIST) patients. Imatinib-refractory progression-free survival (PFS) and overall survival were previously reported not to differ between GIST patients who interrupted imatinib and those who did not. METHODS: Clinical outcomes of 77 consecutive patients with recurrent or metastatic GIST who interrupted imatinib treatment after maintaining years of imatinib treatment in the absence of gross tumor lesions were retrospectively analyzed. Associations between clinical factors and progression-free survival (PFS) following imatinib interruption were analyzed. RESULTS: The median time from the absence of gross tumor lesions to imatinib interruption was 61.5 months. Since imatinib interruption, the median PFS was 19.6 months, and 4 patients (26.3%) remained progression-free for longer than 5 years. Among the patients who had progressive disease following the interruption, imatinib re-introduction led to an 88.6% objective response rate and a 100% disease control rate. Complete removal of the initial gross tumor lesion(s) and complete removal of the residual gross tumor lesion(s) by local treatment (vs. no local treatment or residual lesions after local treatment) were independently associated with favorable PFS. CONCLUSION: Interruption of imatinib following prolonged maintenance in the absence of gross tumor lesions led to disease progression in the majority of cases. However, re-introduction of imatinib resulted in effective tumor control. Unmaintained remission seems to be possible in some patients with metastatic or recurrent GIST after a prolonged remission with imatinib if there is complete removal of any gross tumor lesions.

Heat Treatment Enhances the Neuroprotective Effects of Crude Ginseng Saponin by Increasing Minor Ginsenosides.

Ginsenoside is the primary active substance of ginseng and has many pharmacological effects, such as anti-cancer, immune, regulating sugar and lipid metabolism, and antioxidant effects. It also protects the nervous and cardiovascular systems. This study analyzes the effects of thermal processing on the bioactivities of crude ginseng saponin. Heat treatment increased the contents of minor ginsenosides in crude saponins, such as Rg3, and heat-treated crude ginseng saponin (HGS) had better neuroprotective effects than non-treated crude saponin (NGS). HGS reduced glutamate-induced apoptosis and reactive oxygen species generation in pheochromocytoma 12 (PC12) cells, significantly more than NGS. HGS protected PC12 cells against glutamate-induced oxidative stress by upregulating Nrf2-mediated antioxidant signaling and downregulating MAPK-mediated apoptotic signaling. HGS has the potential for the prevention and treatment of neurodegenerative disorders, such as Alzheimer's and Parkinson's disease.

Clinical outcomes and prognostic factors for patients with high-risk gastrointestinal stromal tumors treated with 3-year adjuvant imatinib.

Three years of adjuvant imatinib is the current standard for patients with high-risk gastrointestinal stromal tumors (GIST). We aimed to investigate the safety and efficacy profiles of 3-year imatinib, focusing on the prognostic value of various factors. In this registry-based study, 222 patients with high-risk GIST who underwent surgical resection followed by 3 years of adjuvant imatinib between 2010 and 2018 were included. The imatinib dose was reduced in 39 (17.6%), and 13 (5.9%) discontinued imatinib due to toxicity. With a median follow-up duration of 65.7 months, 5-year recurrence-free survival (RFS) and overall survival (OS) were 73.2% and 93.9%, respectively. Tumor rupture, tumor size of >10 cm, mitotic index of >10/50 high power fields (HPF) were independent factors for short RFS. Patient subgroups stratified by the risk factors showed distinct RFS (P < .001): patients without the above risk factors or those with only a tumor size of >10 cm showed favorable RFS (5-year RFS 83.8% and 92.3%, respectively), whereas those with tumor rupture or those with tumor size of >10 cm and mitotic index of >10/50 HPF showed prominently poor RFS (5-year RFS of 54.8% and 47.9%, respectively). Three years of adjuvant imatinib treatment was generally tolerable and effective, which were consistent with the clinical outcomes of previous reports. The presence of tumor rupture, large tumor and high mitotic count was independently associated with poor RFS. Based on these risk factors, different management strategies, such as different durations of adjuvant imatinib, deserve further investigation.

Uncoupling immune trajectories of response and adverse events from anti-PD-1 immunotherapy in hepatocellular carcinoma.

BACKGROUND & AIMS: While immune checkpoint blockade (ICB) has shown promise in patients with hepatocellular carcinoma (HCC), it is associated with modest response rates and immune-related adverse events (irAEs) are common. In this study, we aimed to decipher immune trajectories and mechanisms of response and/or irAEs in patients with HCC receiving anti-programmed cell death 1 (anti-PD-1) therapy. METHODS: Pre- and on-treatment peripheral blood samples (n = 60) obtained from 32 patients with HCC (Singapore cohort) were analysed by cytometry by time-of-flight and single-cell RNA sequencing, with flow cytometric validation in an independent Korean cohort (n = 29). Mechanistic validation was conducted by bulk RNA sequencing of 20 pre- and on-treatment tumour biopsies and using a murine HCC model treated with different immunotherapeutic combinations. RESULTS: Single-cell analyses identified CXCR3+CD8+ effector memory T (TEM) cells and CD11c+ antigen-presenting cells (APC) as associated with response (p = 0.0004 and 0.0255, respectively), progression-free survival (p = 0.00079 and 0.0015, respectively), and irAEs (p = 0.0034 and 0.0125, respectively) in anti-PD-1-treated patients with HCC. Type-1 conventional dendritic cells were identified as the specific APC associated with response, while 2 immunosuppressive CD14+ myeloid clusters were linked to reduced irAEs. Further analyses of CXCR3+CD8+ TEM cells showed cell-cell interactions specific to response vs. irAEs, from which the anti-PD-1 and anti-TNFR2 combination was harnessed to uncouple these effects, resulting in enhanced response without increased irAEs in a murine HCC model. CONCLUSIONS: This study identifies early predictors of clinical response to anti-PD-1 ICB in patients with HCC and offers mechanistic insights into the immune trajectories of these immune subsets at the interface between response and toxicity. We also propose a new combination immunotherapy for HCC to enhance response without exacerbating irAEs. CLINICAL TRIAL NUMBER: NCT03695952. LAY SUMMARY: Response rates to immune checkpoint blockade (ICB) treatment in hepatocellular carcinoma (HCC) remain modest and adverse events are common. Herein, we identified early predictors of response and gained an in-depth understanding of the immunological mechanisms behind response and adverse events in patients with HCC treated with ICB. We also proposed a new combination immunotherapy for HCC that enhances response without exacerbating adverse events.

Prognostic value of natural killer cell activity for patients with HER2 + advanced gastric cancer treated with first-line fluoropyrimidine-platinum doublet plus trastuzumab.

BACKGROUND: We aimed to evaluate the prognostic value of natural killer (NK) cell activity for patients with HER2 + advanced gastric cancer (AGC) treated with first-line fluoropyrimidine-platinum doublet plus trastuzumab. METHODS: Forty-one patients with HER2 + AGC who received fluoropyrimidine-platinum doublet plus trastuzumab as first-line treatment were prospectively enrolled. NK cell activity was evaluated using the NK Vue®. RESULTS: The median age was 63.5 years, and 31 patients (75.6%) were male. Patients with low baseline NK cell activity (≤ median, n = 21) were associated worse progression-free survival (PFS) and overall survival (OS) compared with patients with high baseline NK cell activity (> median, n = 20) with a median PFS of 4.21 vs. 9.53 months (P < 0.001), and median OS of 8.15 months vs. 17.82 months (P = 0.025), respectively. In the multivariate analysis, low baseline NK cell activity was independently associated with poor PFS (HR 4.35, P = 0.007). NK cell activity recovered to a normal range in nine patients (47.4%) with a low baseline NK cell activity (n = 19) after two cycles of treatment. The median PFS and OS among patients with recovered NK cell activity were significantly better than that among patients with persistently low NK cell activity (PFS, P = 0.038; OS, P = 0.003). CONCLUSION: Our results demonstrated the prognostic value of baseline NK cell activity for patients with HER2 + AGC treated with fluoropyrimidine-platinum doublet plus trastuzumab. The association between treatment outcomes and dynamic changes in NK cell activity suggests that NK cell treatment may improve treatment outcomes, especially for patients with low baseline NK cell activity.

Insertion-deletion rate is a qualitative aspect of the tumor mutation burden associated with the clinical outcomes of gastric cancer patients treated with nivolumab.

BACKGROUND: We aimed to investigate the clinical implications of the tumor mutation burden (TMB) and insertion-deletion (indel) rate in gastric cancer patients treated with nivolumab. METHODS: A total of 105 patients with advanced gastric cancer who were treated with nivolumab as third or later line of therapy were included as the study population. The indel rate was defined as the proportion of indels making up the TMB. RESULTS: The median age was 58 (32-78 years), and 65 (61.9%) were men. Patients with TMB > 18.03/Mb showed superior progression-free survival (PFS) and overall survival (OS) compared to those with TMB ≤ 18.03/Mb. Patients with a high indel rate (> 40%) had a favorable PFS and OS compared to those with a lower indel rate (≤ 40%) (P = 0.009 and P = 0.007, respectively). The association between a high indel rate and favorable PFS and OS was prominent in a subgroup with TMB > 18.03/Mb (P < 0.001 and P = 0.007 for PFS and OS, respectively), but not in that with TMB ≤ 18.03/Mb. All five patients with deficient-MMR fell into the category of 'TMB > 18.03/Mb with an indel rate of > 40%. TMB ≥ 18.03/Mb with an indel rate of > 40% was independently associated with a favorable PFS (hazard ratio [HR] 0.07, P = 0.012) and OS (HR 0.09, P = 0.023). CONCLUSION: TMB and indel rate should be jointly considered to better predict survival outcomes of gastric cancer patients treated with nivolumab. Our findings deserve further investigation and validation in future studies.

Association between HER2 heterogeneity and clinical outcomes of HER2-positive gastric cancer patients treated with trastuzumab.

BACKGROUND: The GASTHER1 study showed that re-evaluation of HER2 status rescued 8% of HER2-positive gastric cancer (GC) patients with initially HER2-negative GC. Since rescued HER2 positivity represents HER2 heterogeneity, we aimed to investigate this in a larger cohort with longer follow-up duration. METHODS: Data of 153 HER2-positive advanced GC patients who received first-line trastuzumab-based chemotherapy were analyzed. Repeat endoscopic biopsy was performed in patients with initially HER2-negative GC. Survival outcomes were analyzed according to the immunohistochemistry (IHC) score (IHC 2+ /in situ hybridization [ISH] + vs IHC 3+), HER2 status (initially vs rescued HER2 positive), and H-score. RESULTS: IHC 2+ /ISH + patients showed worse progression-free survival (PFS) and overall survival (OS) than those with IHC 3+ (p < 0.05). Rescued HER2-positive patients showed worse PFS and OS than initially HER2-positive patients (p < 0.05). Although survival outcomes were comparable according to HER2 status in IHC 2+ /ISH + patients, initially HER2-positive patients showed more favorable PFS and OS than rescued HER2-positive patients (p < 0.05) among those with IHC 3+ . Among the subgroups determined by HER2 status and IHC score, the initially IHC 3+ subgroup had the highest H-score. The low H-score group (H-score ≤ 210) had significantly worse survival outcomes than the high H-score group (H-score > 210) (p < 0.05). An H-score of ≤ 210 was independently associated with shorter OS (HR = 1.54, 95% CI 1.02-2.31, p = 0.04). CONCLUSIONS: Rescued HER2-positive patients showed worse clinical outcomes than initially HER2-positive patients, especially those with IHC 3+ . This finding highlights the impact of HER2 heterogeneity, which can be quantified indirectly as an H-score.

Radiological criteria for selecting candidates for neoadjuvant chemotherapy for gastric cancer: an exploratory analysis from the PRODIGY study.

BACKGROUND: In this exploratory analysis from the PRODIGY study, we aimed to define the radiological criteria to identify patients with gastric cancer who may derive maximal clinical benefit from neoadjuvant chemotherapy. PATIENTS AND METHODS: There were 246 patients allocated to receive surgery followed by adjuvant S-1 (SC group) and 238 allocated to receive neoadjuvant chemotherapy (CSC group). As the PRODIGY's radiological method of lymph node (LN) evaluation considers short diameter and morphology (the size and morphology method), a method considering only short diameter was also employed. In the SC group, the correlation between radiologic and pathologic findings was analyzed. The hazard ratio (HR) for the progression-free survival (PFS) of the CSC group was analyzed in subgroups with different cT/N stages. RESULTS: cT4 disease showed a sensitivity of 85.6% for detecting pT4 and had a low proportion of pathologic stage (pStage) I disease (4.5%). Among the criteria determined by different cT/N stages by each method of LN positivity, those involving cT4Nany or cT4N + by both methods had a minimal proportion of pStage I disease (≤ 5%), while cT4Nany by both methods and cT4N + by the size and morphology method exhibited ≥ 75.9% sensitivity for detecting pStage III disease. The relative risk reduction in PFS of the CSC group was greatest in patients meeting the cT4Nany criterion defined by both methods (HR 0.67, 95% confidence interval 0.48-0.93). CONCLUSIONS: The cT4Nany criterion, regardless of the radiological method used for LN evaluation, may help select patients with resectable gastric cancer for neoadjuvant chemotherapy.

Determinants of clinical outcomes of gastric cancer patients treated with neoadjuvant chemotherapy: a sub-analysis of the PRODIGY study.

BACKGROUND: In this post hoc analysis of the PRODIGY study, we aimed to investigate factors associated with survival outcomes and provide evidence for designing optimal perioperative treatment strategies for gastric cancer patients receiving neoadjuvant chemotherapy. PATIENTS AND METHODS: A total of 212 patients in the neoadjuvant chemotherapy group of the PRODIGY study were included as the study population. The prognostic impact of clinicopathologic factors, including the initial radiological clinical stage (cStage) and post-neoadjuvant chemotherapy pathological stage (ypStage), was analyzed. RESULTS: The median age was 58 years. The majority of patients (77.4%) had cStage III disease, and about 10% and 25% had ypStage 0 and I disease, respectively. According to the initial cStage, progression-free survival (PFS) and overall survival (OS) were significantly different (P < 0.01). PFS and OS were also different according to the ypStage (P < 0.01). In multivariate analyses, cStage IIIC disease (vs. cStage II) and ypStage II and III disease (vs. ypStage 0/I) were independent factors for poor survival outcomes. Based on the patterns of PFS and OS according to both cStage and ypStage, three patient groups were defined. These groups showed distinct PFS and OS (P < 0.01) with 5-year PFS rates of 95.7%, 77.9%, and 31.3% and 5-year OS rates of 95.7%, 82.4%, and 42.5%, respectively. CONCLUSIONS: Both initial cStage and ypStage were independent factors for survival outcomes of gastric cancer patients treated with neoadjuvant chemotherapy. Efforts should be made to develop optimal peri-operative treatment strategies for patients at different risks according to cStage and ypStage.

Antioxidant and Anti-Melanogenic Activities of Heat-Treated Licorice (Wongam, Glycyrrhiza glabra × G. uralensis) Extract.

Melanin is a brown or black pigment that protects skin from ultraviolet radiation and reactive oxygen species (ROS). However, overproduction of melanin is associated with lentigines, melasma, freckles and skin cancer. Licorice has shown antioxidant, anti-tumor, anti-platelet, anti-inflammatory and immunomodulatory activities and is used as a natural treatment for skin whitening. We aimed to confirm the potential of Wongam, a new cultivar of licorice developed by the Rural Development Administration (RDA), as a whitening agent in cosmetics. In addition, we verified the effect of heat treatment on the bioactivity of licorice by comparing antioxidant and anti-melanogenic activities of licorice extract before and after heating (130 °C). The heat-treated licorice extract (WH-130) showed higher radical-scavenging activities in the ABTS+ (2,2'-azino-bis-(3-ethylbenzothiazolin-6-sulfonic acid) diammonium salt) and DPPH (2,2-diphenyl-1-picrylhydrazyl) assays. In addition, WH-130 inhibited melanogenesis more effectively due to downregulation of tyrosinase in B16F10 melanoma cells than non-heated licorice extract. Moreover, heat treatment increased total phenolic content. In particular, isoliquiritigenin, an antioxidant and anti-melanogenic compound of licorice, was produced by heat treatment. In conclusion, WH-130, with increased levels of bioactive phenolics such as isoliquiritigenin, has potential for development into a novel skin whitening material with applications in cosmetics.