Efficacy and Safety of Avapritinib in Treating Unresectable or Metastatic Gastrointestinal Stromal Tumors: A Phase I/II, Open-Label, Multicenter Study.

BACKGROUND: Avapritinib is a type 1 kinase inhibitor designed to potently and selectively inhibit oncogenic KIT/PDGFRA mutants by targeting the kinase active conformation. This multicenter, single-arm, open-label, phase I/II bridging study of NAVIGATOR in Chinese patients evaluated the safety and the antineoplastic activity of avapritinib in Chinese patients with unresectable/metastatic gastrointestinal stromal tumors (GIST). METHODS: Phase I comprised dose escalation for safety and phase II dose determination. Phase II comprised dose expansion for safety/efficacy evaluations in patients with PDGFRA D842V mutations or patients having received at least 3 lines of therapy without PDGFRA D842V mutations. The primary endpoints were recommended phase II dose, safety, and Independent Radiology Review Committee (IRRC)-assessed objective response rate (ORR). RESULTS: No dose-limiting toxicities occurred (n = 10); the recommended phase II dose was avapritinib 300 mg once daily orally. Fifty-nine patients initially received avapritinib 300 mg. Common grade ≥3 treatment-related adverse events were anemia, decreased white blood cell count, increased blood bilirubin levels, and decreased neutrophil count. In patients with PDGFRA D842V mutations, IRRC- and investigator-assessed ORRs were 75% and 79%, respectively; clinical benefit rates were both 86%. Median duration of response/progression-free survival were not reached. IRCC- and investigator-assessed ORRs in patients in the fourth- or later-line setting were 22% and 35%, respectively. Median progression-free survivals were 5.6 months for both. Overall survival data were immature and not calculated. CONCLUSION: Avapritinib was generally well tolerated and showed marked anti-tumor activity in Chinese patients with GIST bearing PDGFRA D842V mutations and notable efficacy as fourth- or later-line monotherapy (ClinicalTrials.gov Identifier: NCT04254939).

Does resection after neoadjuvant chemotherapy of docetaxel, oxaliplatin, and S-1 (DOS regimen) benefit for gastric cancer patients with single non-curable factor? a multicenter, prospective cohort study (Neo-REGATTA).

BACKGROUND: The Neo-REGATTA study evaluated the effectiveness and safety of Docetaxel, oxaliplatin, and S-1 (DOS regimen) followed by radical resection vs. chemotherapy in advanced gastric adenocarcinoma patients with single non-curable factor. METHODS: This cohort study prospectively enrolled advanced gastric adenocarcinoma patients with single non-curable factor between November 2017 and June 2021. Patients without progression after four cycles of DOS were divided into resection group and chemotherapy group. The outcomes included overall survival (OS), progression-free survival (PFS) and safety. Effectiveness analysis was also performed by propensity score matching (PSM). RESULTS: A total of 73 patients were enrolled and 13 patients were withdrawn due to disease progression after 4 cycles of DOS. Afterwards, 35 and 25 participants were in the resection and chemotherapy groups, respectively. After a median follow-up time of 30.0 months, the median PFS and OS were 9.0 months, and 18.0 months for the chemotherapy group, but not reached in the resection group. After PSM, 19 matched participants were in each group, and the median PFS and OS were longer in resection group than that in chemotherapy group. The most common grade 3 or 4 adverse events both in the resection group and chemotherapy groups were neutropenia (5.7%, 8.0%) and leukopenia (5.7%, 8.0%). CONCLUSIONS: Radical resection might provide survival benefit compared with continuous chemotherapy alone in advanced gastric adenocarcinoma patients who had a disease control after DOS, with a good safety profile. TRIAL REGISTRATION: The study protocol was registered on ClinicalTrial.gov (NCT03001726, 23/12/2016).

Current applications and future perspective of CRISPR/Cas9 gene editing in cancer.

Clustered regularly interspaced short palindromic repeats (CRISPR) system provides adaptive immunity against plasmids and phages in prokaryotes. This system inspires the development of a powerful genome engineering tool, the CRISPR/CRISPR-associated nuclease 9 (CRISPR/Cas9) genome editing system. Due to its high efficiency and precision, the CRISPR/Cas9 technique has been employed to explore the functions of cancer-related genes, establish tumor-bearing animal models and probe drug targets, vastly increasing our understanding of cancer genomics. Here, we review current status of CRISPR/Cas9 gene editing technology in oncological research. We first explain the basic principles of CRISPR/Cas9 gene editing and introduce several new CRISPR-based gene editing modes. We next detail the rapid progress of CRISPR screening in revealing tumorigenesis, metastasis, and drug resistance mechanisms. In addition, we introduce CRISPR/Cas9 system delivery vectors and finally demonstrate the potential of CRISPR/Cas9 engineering to enhance the effect of adoptive T cell therapy (ACT) and reduce adverse reactions.

Neoadjuvant apatinib combined with oxaliplatin and capecitabine in patients with locally advanced adenocarcinoma of stomach or gastroesophageal junction: a single-arm, open-label, phase 2 trial.

BACKGROUND: Adding anti-angiogenics to neoadjuvant chemotherapy for localized gastric cancer is recognized as a promising strategy, but its clinical value remains to be defined. METHODS: This single-center, single-arm, phase 2 trial included patients with locally advanced (cT3/4aN+M0) adenocarcinoma of the stomach or gastroesophageal junction (GEJ) who received three cycles of intravenous oxaliplatin (135 mg/m2 on day 1), oral capecitabine (1000 mg/m2 twice daily on days 1 to 14), and oral apatinib for 21 days (250 mg once daily in the first two cycles, and further increased to 500 mg daily in the third cycle based on whether any adverse event of grade 3 or worse occurred), and an additional cycle of oxaliplatin plus capecitabine, followed by gastrectomy with D2 lymphadenectomy. The primary endpoint was the proportion of patients who achieved an objective response according to RECIST version 1.1. RESULTS: Between April 28, 2017, and October 23, 2019, 37 patients were screened and 35 participants were included. Of the 32 patients assessable for efficacy and safety, objective responses were achieved in 25 (78.1%; 95% confidence interval [CI], 60.0% to 90.7%) patients. Thirty-one (96.9%) patients received R0 resection, two (6.3%) patients achieved pathological complete response, and 11 (34.4%) patients achieved pathological response. At the data cutoff date (September 30, 2021), the median event-free survival was 42.6 (95% CI, 16.2 to not reached) months, and the median overall survival was not reached. The most common grade 3 or 4 treatment-emergent adverse events were hypertension (9/32, 28.1%), thrombocytopenia (7/32, 21.9%), and neutropenia (5/32, 15.6%). Seven (21.9%) patients developed surgical complications, and the most common one was intra-abdominal abscess (4/32, 12.5%). CONCLUSIONS: The concomitant use of apatinib, oxaliplatin, and capecitabine as neoadjuvant therapy showed promising efficacy and manageable safety profile in patients with locally advanced adenocarcinoma of the stomach or GEJ, and further phase 3 study is warranted. TRIAL REGISTRATION: This study was registered with ClinicalTrial.gov ( NCT03229096 ).

Efficacy of AS versus SOX regimen as first-line chemotherapy for gastric cancer patients with peritoneal metastasis: a real-world study.

BACKGROUND: To compare the prognosis of first-line systemic chemotherapy of AS (Albumin-bound paclitaxel and S-1) versus SOX (S-1 and oxaliplatin) regimen in Chinese gastric cancer patients with peritoneal metastasis. METHODS: This was a real-world study of gastric cancer patients with peritoneal metastasis who have been treated with AS or SOX regimen as first-line chemotherapy. Patients were matched by the method of propensity score matching (PSM). The primary and secondary endpoints were overall survival (OS) and progress-free survival (PFS). RESULTS: A total of 108 gastric cancer patients with peritoneal metastasis were enrolled after PSM analysis. There was no significant difference between AS and SOX regimen based on gender, age, ascites, treatment cycles, gastric cancer resection, received checkpoint inhibitors, and HER-2 expression after PSM analysis. The median OS (14.13 vs. 11.17 months, p = 0.0356) and median PFS (10.30 vs. 6.70 months, p = 0.0003) of patients who received AS regimen were longer than those treated by SOX regimen as first-line systemic chemotherapy. In sub-group analysis, the median OS and median PFS were longer for patients in AS regimen than SOX regimen in Lauren diffuse type. The occurrence of toxicity between the two groups was shown no significant difference. CONCLUSIONS: The results verified that AS regimen was more effective than SOX chemotherapy in gastric cancer patients with peritoneal metastasis, especially in Lauren diffuse type.

Tumor-derived LIF promotes chemoresistance via activating tumor-associated macrophages in gastric cancers.

Chemotherapy is the preferred clinical treatment for advanced stage gastric cancer (GC) patients, of which efficacy could be markedly impaired due to the development of chemoresistance. Alternatively activated or M2-type tumor associated macrophages (TAMs) are recruited under chemotherapy and are highly implicated in the chemoresistance development, but underlying molecular mechanism for TAM activation is largely unknown. Here, we present that tumor-derived Leukemia inhibitory factor (LIF) induced by chemo drugs represses the chemo sensitivity of gastric tumor cells in a TAM-dependent manner. Mechanistically, cisplatin-induced HIF1α signaling activation directly drive the transcription of LIF, which promotes the resistance of gastric tumors to chemo drug. Further study revealed that tumor cell-derived LIF stimulates macrophages into tumor-supporting M2-type phenotype via activating STAT3 signaling pathway. Therapeutically, blocking LIF efficiently elevates chemo sensitivity of tumor cells and further represses the growth rates of tumors under chemotherapy. Therefore, our study reveals a novel insight in understanding the cross talking between tumor cells and immune cells and provides new therapeutic targets for gastric cancer.

Identification of key genes involved in tumor immune cell infiltration and cetuximab resistance in colorectal cancer.

BACKGROUND: The anti-epidermal growth factor receptor (EGFR) antibody introduces adaptable variations to the transcriptome and triggers tumor immune infiltration, resulting in colorectal cancer (CRC) treatment resistance. We intended to identify genes that play essential roles in cetuximab resistance and tumor immune cell infiltration. METHODS: A cetuximab-resistant CACO2 cellular model was established, and its transcriptome variations were detected by microarray. Meanwhile, public data from the Gene Expression Omnibus and The Cancer Genome Atlas (TCGA) database were downloaded. Integrated bioinformatics analysis was applied to detect differentially expressed genes (DEGs) between the cetuximab-resistant and the cetuximab-sensitive groups. Then, we investigated correlations between DEGs and immune cell infiltration. The DEGs from bioinformatics analysis were further validated in vitro and in clinical samples. RESULTS: We identified 732 upregulated and 1259 downregulated DEGs in the induced cellular model. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analyses, along with Gene Set Enrichment Analysis and Gene Set Variation Analysis, indicated the functions of the DEGs. Together with GSE59857 and GSE5841, 12 common DEGs (SATB-2, AKR1B10, ADH1A, ADH1C, MYB, ATP10B, CDX-2, FAR2, EPHB2, SLC26A3, ORP-1, VAV3) were identified and their predictive values of cetuximab treatment were validated in GSE56386. In online Genomics of Drug Sensitivity in Cancer (GDSC) database, nine of twelve DEGs were recognized in the protein-protein (PPI) network. Based on the transcriptome profiles of CRC samples in TCGA and using Tumor Immune Estimation Resource Version 2.0, we bioinformatically determined that SATB-2, ORP-1, MYB, and CDX-2 expressions were associated with intensive infiltration of B cell, CD4+ T cell, CD8+ T cell and macrophage, which was then validated the correlation in clinical samples by immunohistochemistry. We found that SATB-2, ORP-1, MYB, and CDX-2 were downregulated in vitro with cetuximab treatment. Clinically, patients with advanced CRC and high ORP-1 expression exhibited a longer progression-free survival time when they were treated with anti-EGFR therapy than those with low ORP-1 expression. CONCLUSIONS: SATB-2, ORP-1, MYB, and CDX-2 were related to cetuximab sensitivity as well as enhanced tumor immune cell infiltration in patients with CRC.

Reevaluation of lymphovascular invasion in gastric cancer using endothelial markers D2-40 and EVG: Enhanced detection, better predictor of lymph node metastasis and biological aggressiveness.

BACKGROUND AND OBJECTIVES: The diagnosis of lymphovascular invasion (LVI) is often inaccurate with routine histology. This study aimed to evaluate the use of immunohistochemistry (IHC) in detecting LVI and reevaluate the clinical implications of LVI in gastric cancer. METHODS: This prospective unrandomized cohort study analyzed the rates of LVI positivity and its relevance with other clinicopathologic features. RESULTS: Between November 2017 and April 2018, 558 patients undergoing curative gastrectomy were enrolled and assigned to the IHC group (n = 285) and hematoxylin-eosin group (n = 273). The use of IHC increased the rates of LVI positivity (60.8% vs. 43.3%, p < .001) and decreased the rates of undetermined LVI subtype (7.7% vs. 27.1%, p < .001). The LVI-negative patients identified by IHC had fewer lymph node metastases (16.8% vs. 34.6%, p = .002) and earlier pathological stage (p = .004) than those identified by routine histology. The LVI-positive patients identified by IHC had a higher percentage of perineural invasion (p = .019). CONCLUSIONS: The use of endothelial markers significantly enhanced the detection of LVI. The LVI detected by IHC could be a better predictor of lymph node metastasis and biological aggressiveness in gastric cancer.

A 16-mRNA signature optimizes recurrence-free survival prediction of Stages II and III gastric cancer.

High-throughput messenger RNA (mRNA) analysis has become a powerful tool for exploring tumor recurrence or metastasis mechanisms. Here, we constructed a signature to predict the recurrence risk of Stages II and III gastric cancer (GC) patients. A least absolute shrinkage and selection operator method Cox regression model was utilized to construct the signature. Using this method, a 16-mRNA signature was identified to be associated with the relapse-free survival of Stages II and III GCs in training dataset GSE62254 (n = 194). Then this signature was validated in an independent Gene Expression Omnibus cohort GSE26253 (n = 297) and a dataset of The Cancer Genome Atlas (TCGA; n = 235). This classifier could successfully screen out the high-risk Stages II and III GCs in the training cohort (hazard ratio [HR] = 40.91; 95% confidence interval [CI] = 5.58-299.7; p < .0001). Analysis in two independent validation cohorts yielded consistent results (GSE26253: HR = 1.69, 95% CI = 1.17-2.43,; p = .0045; TCGA: HR = 2.01, 95% CI = 1.13-3.56, p = .0146). Cox regression analyses revealed that the risk score derived from this signature was an independent risk factor in Stages II and III GCs. Besides, a nomogram was constructed to serve clinical practice. Through gene set variation analysis, we found several gene sets associated with chemotherapeutic drug resistance and tumor metastasis significantly enriched in high-risk patients. In summary, this 16-mRNA signature can be used as a powerful tool for prognostic evaluation and help clinicians identify high-risk patients.

Activated HIF1α of tumor cells promotes chemoresistance development via recruiting GDF15-producing tumor-associated macrophages in gastric cancer.

Chemotherapy is the preferred treatment for advanced stage gastric cancer (GC) patients, and developing chemoresistance is a tremendous challenge to efficacy of GC treatment. The treatments of anti-tumor chemo-agents recruit more tumor-associated macrophages (TAMs) which are highly implicated in the chemoresistance development, but the underlying molecular mechanism is unclear. Here, we demonstrate that hypoxia-inducible factor 1α (HIF1α) in GC cells is activated upon 5-fluorouracil (5-FU) treatment and results in much more accumulation of M2-type TAMs which protect tumor cells from chemo-agents. Mechanistically, in the GC cells under the 5-FU treatment, reactive oxygen species is accumulated and then induces the activation of HIF1α signaling to drive the expression of high-mobility group box 1, which leads to more macrophage's infiltration into GC tumor. In turn, the recruited TAMs exhibit tumor-protected M2-type phenotype and promote the chemoresistance of GC cells via producing growth differentiation factor 15 (GDF15) to exacerbate the fatty acid ß-oxidation in tumor cells. Blocking GDF15 using antibody or inhibiting FAO of tumor cells by etomoxir efficiently gave rise to the tumor cell sensitivity to 5-FU. Therefore, our study demonstrates a novel insight in understanding the cross talking between tumor cells and immune microenvironment and provides new therapeutic targets for clinic treatments of gastric cancer.

5-Hydroxymethylcytosine profiling from genomic and cell-free DNA for colorectal cancers patients.

5-Hydroxymethylcytosine (5hmC) is a DNA modification that is generated by the oxidation of 5-methylcytosine (5mC) in a reaction catalyzed by the ten-eleven translocation (TET) family enzymes. It tends to mark gene activation and affects a spectrum of developmental and disease-related biological processes. In this manuscript, we present a 5hmC selective chemical labelling technology (hmC-Seal) to capture and sequence 5hmC-containing DNA fragments with low input. We tested 10 tumour/adjacent colon cancer tissues and 10 tumour/healthy plasma samples. Furthermore, we tested if this methodology could generate the 5hmC differential genes among cancer patients, healthy controls and precancerous adenoma patients from plasma. Robust cancer-specific epigenetic signatures were identified for colon cancers. The results show that 5hmC is mainly distributed in gene active regions. The results also indicate the potential application of 5hmC change signals in early stage of colon cancer, even show potential in the diagnosis of precancerous adenoma. We demonstrated the robustness of the 5hmC-Seal method in tissue and cell-free DNA (cfDNA) as potential biomarkers. Moreover, this study provides the potential value and feasibility of 5hmC-Seal approach on colorectal cancer (CRC) early detection. We believe this strategy could be an effective liquid biopsy-based diagnosis and a potential prognosis method for colon cancer using cfDNA.

Oxaliplatin plus Capecitabine in the Perioperative Treatment of Locally Advanced Gastric Adenocarcinoma in Combination with D2 Gastrectomy: NEO-CLASSIC Study.

LESSONS LEARNED: The NEO-CLASSIC study provided valuable insight for the clinical efficacy and tolerability profiles of perioperative chemotherapy with oxaliplatin and capecitabine, plus gastrectomy, in patients with localized resectable gastric cancer.The study was designed to explore the potential survival benefits of an eight-cycle, perioperative oxaliplatin and capecitabine (XELOX) schedule in the above-mentioned setting and to explore the feasibility of prolonging the cycles of preoperative chemotherapy. The projected endpoint was not met. BACKGROUND: This multicenter, open-label study (NEO-CLASSIC) evaluated the efficacy and safety of oxaliplatin and capecitabine (XELOX), plus D2 gastrectomy, in localized resectable gastric cancer. METHODS: Patients aged 18-75 years with histologically-confirmed gastric adenocarcinoma (stage T2-4a/N+M0) were given eight cycles of XELOX (four preoperatively, four postoperatively). Each 3-week cycle comprised capecitabine 1,000 mg/m2 twice daily on days 1-14 and oxaliplatin 130 mg/m2 on day 1. Curative D2 gastrectomy was scheduled 2-4 weeks after the last preoperative cycle. The primary objective of the study was to determine the objective response rate (ORR) of XELOX in the preoperative setting. Sample size was calculated by assuming that a minimum of 47 cases would be required to increase the ORR by 15% (from 40% to 55%). With an estimated 10% dropout rate, 55 patients would have to be recruited. RESULTS: Fifty-five patients were enrolled, and one was excluded because of screening failure. R0 resections were achieved in 45 of 54 intent-to-treat patients (83.3%), and four patients received R1 resections (Fig. 1). There were no complete responses, 27 (50.0%) partial responses, 22 cases (40.7%) of stable disease, and 4 (7.4%) of progressive disease. The objective response rate was 50.0%. Median follow-up was 52.97 months; 30 patients (55.6%) had disease progression (Table 1), and median progression-free survival was 20.10 (95% confidence interval: 4.31-35.89) months; median overall survival was 30.77 months (95% confidence interval was not yet available) (Fig. 2). Fifty-four patients completed 209 cycles of preoperative chemotherapy; 42 patients received 133 cycles of postoperative chemotherapy (Table 3). The rate of grade 3-4 adverse events was 8.5% (29/342 cycles); the most frequent events were neutropenia (9/342 cycles) and leukopenia (4/342 cycles). CONCLUSION: These findings suggest that combination therapy with capecitabine and oxaliplatin as perioperative chemotherapy, followed by D2 gastrectomy, is effective and safe in late-stage, locally advanced gastric cancer. Although enrollment exceeded the 47 patients required to identify an increase in the ORR by 15% (from 40% to 55%), results did not meet the primary endpoint.

The role of oxaliplatin in the adjuvant setting of different Lauren's type of gastric adenocarcinoma after D2 gastrectomy: a real-world study.

BACKGROUND: To compare the efficacy of oxaliplatin-based and oxaliplatin-free adjuvant chemotherapies in patients with different Lauren type gastric cancers after D2 gastrectomy. METHODS: From our established gastric cancer database, patients with pathological stage II and III gastric cancer who received adjuvant chemotherapy after D2 gastrectomy at Zhongshan Hospital of Fudan University were analyzed. Patients who received different adjuvant chemotherapy regimens were divided into two subgroups: oxaliplatin-based and oxaliplatin-free subgroup. Clinical outcomes were analyzed according to pathological stage and different Lauren types. RESULTS: From Jan 2010 to June 2017, a total of 580 patients met all the eligibility criteria and were enrolled. The median DFS for all the patients was 24.37 months and the median OS was 56.70 months. In patients with intestinal type gastric cancer, the median DFS of the oxaliplatin-based subgroup was significantly longer than that of oxaliplatin-free subgroup (48.73 vs. 18.33 months, P < 0.001). The median OS was not reached in the oxaliplatin-based subgroup and 54.33 months in the oxaliplatin-free subgroup (P = 0.006). In patients with diffuse type gastric cancer, neither DFS nor OS differed significantly between two subgroups. In multivariate analysis, oxaliplatin-based adjuvant chemotherapy was independent positive predictor of DFS (HR 0.40; 95% CI 0.28-0.59; P < 0.001) and OS (HR 0.35; 95% CI 0.20-0.62; P < 0.001) in patients with intestinal type gastric cancer. CONCLUSIONS: The results of our study suggested that oxaliplatin-based adjuvant chemotherapy was more effective in patients with intestinal type gastric cancer after D2 gastrectomy but showed no more survival benefit in patients with diffuse type.

Identification of Potential Therapeutic Targets Among CXC Chemokines in Breast Tumor Microenvironment Using Integrative Bioinformatics Analysis.

BACKGROUND/AIMS: Breast cancer is a common cause of cancer mortality throughout the world. The cross-talk between cancer cells and interstitial cells exerts significant effects on neoplasia and tumor development and is modulated in part by chemokines. CXC is one of four chemokine families involved in mediating survival, angiogenesis, and immunosensitization by chemoattracting leukocytes, and it incentivizes tumor cell growth, invasion and metastasis in the tumor microenvironment. However, the differential expression profiles and prognostic values of these chemokines remains to be elucidated. METHODS: In this study, we compared transcriptional CXC chemokines and survival data of patients with breast carcinoma (BC) using the ONCOMINE dataset, Kaplan-Meier Plotter, TCGA and cBioPortal. RESULTS: We discovered increased mRNA levels for CXCL8/10/11/16/17, whereas mRNA expression of CXCL1/2/3/4/5/6/7/12/14 was lower in BC patients compared to non-tumor tissues. Kaplan-Meier plots revealed that high mRNA levels of CXCL1/2/3/4/5/6/7/12/14 correlate with relapse-free survival (RFS) in all types of BC patients. Conversely, high CXCL8/10/11 predicted worse RFS in BC patients. Significantly, high transcription levels of CXCL9/12/13/14 conferred an overall survival (OS) advantage in BC patients, while high levels of CXCL8 demonstrated shorter OS in all BC sufferers. CONCLUSIONS: Integrative bioinformatics analysis suggests that CXCL8/12/14 are potential suitable targets for precision therapy in BC patients compared to other CXC chemokines.

An Analysis of Relationship Between RAS Mutations and Prognosis of Primary Tumour Resection for Metastatic Colorectal Cancer Patients.

BACKGROUND/AIMS: Non-radical primary tumour resection (PTR) of asymptomatic metastatic colorectal cancer (mCRC) can prolong survival time of some patients. Patients with mutated RAS gene have worse survival outcome. This study aimed to investigate the impact of RAS gene mutations on the prognosis of asymptomatic unresectable mCRC patients who underwent PTR. METHODS: A retrospective observational cohort study was deduced among mCRC patients who experienced PTR or had intact primary tumour (IPT). All of them had the primary tumour tissue genotyping tested for RAS (KRAS and NRAS) gene mutations. The tumour-related overall survival (OS) time and progression-free survival (PFS) time was estimated. From January 2011 to June 2014, 421 mCRC patients with asymptomatic, unresectable, metastatic disease were enrolled in this study. Among them, 282 patients underwent PTR and 139 patients had IPT. RESULTS: The mutation rate of RAS was 53.8% (221/411). With a median followed-up time of 46.5 months, the overall survival time of mCRC patients harboring wtRAS or mtRAS was 28.0 versus 22.0 months (p = 0.043) in PTR group and was 21.6 versus 17.8 months (p=0.071) in IPT groups. A Multivariate regression analysis suggested that RAS gene (p=0.039, HR=1.288,95%CI [1.072∼2.911]), metastatic organ number (p=0.033, HR=3.091,95%CI [1.090∼5.755]) and systemic therapy response (p=0.019, HR=0.622,95%CI [0.525∼0.811]) were independent prognostic factors in PTR population. CONCLUSION: We found that wild-type RAS gene was a favorable factor for the asymptomatic unresectable mCRC patients experiencing PTR.

Efficacy after preoperative capecitabine and oxaliplatin (XELOX) versus docetaxel, oxaliplatin and S1 (DOS) in patients with locally advanced gastric adenocarcinoma: a propensity score matching analysis.

BACKGROUND: The aim of this study was to compare the efficacies of the XELOX and DOS regimens as preoperative chemotherapy in patients with locally advanced gastric cancer. METHODS: All cases of locally advanced gastric cancer treated with the XELOX or DOS regimen were reviewed retrospectively. Propensity score matching (PSM) was carried out to reduce selection bias based on age, gender, location, Lauren type, carcinoembryonic antigen level, clinical tumor stage, and clinical node stage. RESULTS: From January 2010 to December 2016, 248 patients were matched; 159 of them received the XELOX regimen and 89 the DOS regimen. The response rates in the XELOX and DOS groups were 34.5 and 38.1%, respectively (P = 0.823). After four cycles of chemotherapy, 111 patients (69.8%) in the XELOX group and 65 patients (73.0%) in the DOS group underwent radical surgery (P = 0.485). The median progression-free survival (33.0 months vs. 18.7 months, P = 0.0356) and the median overall survival (43.8 months vs. 29.1 months, P = 0.0003) were longer for patients who received the DOS regimen than for those who received the XELOX regimen. The occurrence of grade 3 to 4 toxicity was similar in the two groups. CONCLUSIONS: For locally advanced gastric cancer patients, the DOS regimen showed more benefit than the XELOX regimen as preoperative chemotherapy, without any added toxicity effects.

Primary Tumour Resection Could Improve the Survival of Unresectable Metastatic Colorectal Cancer Patients Receiving Bevacizumab-Containing Chemotherapy.

BACKGROUND: The effect of primary tumour resection (PTR) among metastatic colorectal cancer (mCRC) patients remains controversial. Combination chemotherapy with bevacizumab could improve the clinical outcomes of these patients, which might change the importance of PTR in the multi-disciplinary treatment pattern. METHODS: We performed a non-randomized prospective controlled study of mCRC pts whose performance status (PS) scored ≤2 and who received bevacizumab combination chemotherapy (FOLFOX/XELOX/FOLFIRI) as a first-line therapy. These patients were classified into the PTR group and the IPT (intact primary tumour) group according to whether they underwent PTR before receiving the systemic therapy. The progression free survival (PFS) time and overall survival (OS) time, which were recorded from the start of the primary diagnosis until disease progression and death or last follow-up, were analysed. We also compared severe clinical events (such as emergency surgery, radiation therapy, and stent plantation) between the two groups. RESULTS: One hundred and nighty-one mCRC pts (108 male patients and 93 female patients) were entered in this prospective observational study. The median age was 57.5 years old. The clinical characteristics (age, gender, performance status, primary tumour site, RAS status, and the number of metastatic organs) did not significantly differ between the two groups. The median PFS and OS times of the PTR group were superior than those of the IPT group (10.0 vs 7.8 months, p < 0.01 and 22.5 vs 17.8 months, p < 0.01, respectively). The incidences of adverse events associated with systemic therapy were similar between the two groups. Specifically, sixteen patients (21.9%, 16/73) with IPT developed significant primary tumour-related complications, such as bleeding, obstruction or even perforation. Among these patients, five underwent emergency surgery, three patients received a stent, and eight patients underwent radiation therapy. CONCLUSIONS: The mCRC patients who received PTR and bevacizumab combination chemotherapy had better clinical outcomes than patients who did not receive PTR. PTR also decreased the incidence of severe clinical events and improved quality of life.

Efficacy of Pyrotinib With/Without Trastuzumab in Treatment-Refractory, HER2-Positive Metastatic Colorectal Cancer: Result From a Prospective Observational Study.

BACKGROUND: Human epidermal growth factor receptor 2 (HER2) is a promising therapeutic target in metastatic colorectal cancer (mCRC). This study was to evaluate the efficacy and safety of pyrotinib alone or pyrotinib with trastuzumab in patients with HER2-positive mCRC. PATIENTS AND METHODS: In this prospective observational study, patients with HER2 positive, Ras Sarcoma Viral Oncogene Homolog (RAS) wild type mCRC who received at least one standard treatment of palliative chemotherapy were enrolled. Patients were treated with oral pyrotinib alone or pyrotinib with trastuzumab. The primary endpoint was progression free survival (PFS), and the secondary endpoints were overall survival (OS), confirmed objective response rate (ORR), and safety. This trial is registered with chitcr.org, number ChiCTR2100046381. RESULTS: From February 15, 2021, to January 10, 2023, 32 patients were enrolled in this study. Twenty (62.5%) patients were treated with pyrotinib, while 12 (37.5%) received pyrotinib and trastuzumab. As of June 24, 2023, with a median follow-up of 11.0 months, the median PFS was 5.7 months (95%CI 4.5-10.2), while OS was not evaluable (NE), ORR and disease control rate (DCR were 34.4% and 87.5%. Patients' PFS in the pyrotinib plus trastuzumab subgroup and pyrotinib monotherapy group were 8.6 and 5.5 months, OS was not evaluable (NE) and 10.9 months, ORR was 50.0% and 25.0%, respectively. Most treatment-related adverse events (TRAEs) were grade 1-2, diarrhea was the most frequent TRAE (81.3%, 26/32). Grade 3 TRAEs occurred in 11 patients: 9 for diarrhea, 1 for nausea, and 1 for oral mucositis. CONCLUSION: Pyrotinib with or without trastuzumab showed promising anti-tumor activity and acceptable toxicities in treatment-refractory, HER2-positive mCRC.

Clinical significance of peripheral T-cell receptor repertoire profiling and individualized nomograms in patients with gastrointestinal cancer treated with anti-programmed death 1 antibody.

Background: Immune checkpoint inhibitors (ICIs) have significant clinical benefit for a subset of patients with gastrointestinal cancers (GICs) including esophageal cancer, gastric cancer and colorectal cancer. However, it is difficult to predict which patients will respond favorably to immune checkpoint blockade therapy. Thus, this study was initiated to determine if peripheral T-cell receptor (TCR) repertoire profiling could predict the clinical efficacy of anti-programmed death 1 (PD-1) treatment. Methods: Blood samples from 31 patients with GICs were collected before anti-PD-1 antibody treatment initiation. The clinical significance of the combinatorial diversity evenness of the TCR repertoire [the diversity evenness 50 (DE50), with high values corresponding to less clonality and higher TCR diversity] from peripheral blood mononuclear cells (PBMCs) was evaluated in all the enrolled patients. A highly predictive nomogram was set up based on peripheral TCR repertoire profiling. The performance of the nomogram was assessed by receiver operating characteristic (ROC) curve, concordance index (C-index), and calibration curves, and decision curve analysis (DCA) was used to assess its clinical applicability. Results: Compared to non-responders [progression disease (PD)], the DE50 scores were significantly higher in responders [stable disease (SD) and partial response (PR)] (P=0.018). Patients with a high DE50 score showed better progression-free survival (PFS) than those with a low DE50 score (P=0.0022). The multivariable Cox regression demonstrated that high DE50 and low platelet-lymphocyte ratio (PLR) were significant independent predictors for better PFS when treated with anti-PD-1 antibody. Furthermore, a highly predictive nomogram was set up based on peripheral TCR repertoire profiling. The area under the curves (AUCs) of this system at 3-, 6- and 12-month PFS reached 0.825, 0.802, and 0.954, respectively. The nomogram had a C-index of 0.768 [95% confidence interval (CI): 0.658-0.879]. Meanwhile, the calibration curves also demonstrated the reliability and stability of the model. Conclusions: High DE50 scores were predictive of a favorable response and longer PFS to anti-PD-1 treatment in GIC patients. The nomogram based on TCR repertoire profiling was a reliable and practical tool, which could provide risk assessment and clinical decision-making for individualized treatment of patients.

Clinical Benefit of Avapritinib in KIT-Mutant Gastrointestinal Stromal Tumors: A Post Hoc Analysis of the Phase I NAVIGATOR and Phase I/II CS3007-001 Studies.

PURPOSE: The efficacy of the selective KIT/PDGFRA inhibitor avapritinib (300 mg once daily) was explored in patients with non-PDGFRA-mutant gastrointestinal stromal tumors (GISTs) from the phase I NAVIGATOR and phase I/II CS3007-001 trials. PATIENTS AND METHODS: Adults with unresectable/metastatic, KIT-only-mutant GISTs and progression following ≥1 tyrosine kinase inhibitors (TKIs) were included in this post hoc analysis. Baseline mutational status was identified in tumor and plasma. Primary endpoints were objective response rate (ORR) and progression-free survival (PFS) by blinded independent radiology review per modified RECIST v1.1 in patients harboring KIT activation-loop mutations (KIT exons 17 or 18) without ATP binding-pocket mutations (KIT exons 13 or 14; ALposABPneg), and other KIT mutations (OTHERS). RESULTS: Sixty KIT ALposABPneg and 100 KIT OTHERS predominantly heavily pretreated patients (61.3% with ≥3 prior TKIs) were included. ORR was significantly higher in KIT ALposABPneg than KIT OTHERS patients (unadjusted: 26.7% vs. 12.0%; P = 0.0852; adjusted: 31.4% vs. 12.1%; P = 0.0047). Median PFS (mPFS) was significantly longer in KIT ALposABPneg patients compared with KIT OTHERS patients (unadjusted: 9.1 vs. 3.5 months; P = 0.0002; adjusted: 9.1 vs. 3.4 months; P < 0.0001), and longer in second- versus later-line settings (19.3 vs. 5.6-10.6 months). Benefit with avapritinib was observed in patients with KIT exon 9 mutations in the ≥4 line settings (mPFS: 5.6 and 3.7 months for 4 line and >4 line, respectively). CONCLUSIONS: Avapritinib showed greater antitumor activity in patients with GISTs harboring KIT ALposABPneg mutations versus KIT OTHERS, and may be considered in the former subpopulation. Patients with KIT exon 9 mutations may also benefit in ≥4 line settings.