Shuangxi Li

A subset of gastric cancers with EGFR amplification and overexpression respond to cetuximab therapy

A preclinical trial identified 4 of 20 (20%) gastric cancer (GC) patient-derived xenografts responded to cetuximab. Genome-wide profiling and additional investigations revealed that high EGFR mRNA expression and immunohistochemistry score (3+) are associated with tumor growth inhibition. Furthermore, EGFR amplification were observed in 2/4 (50%) responders with average copy number 5.8 and >15 respectively. Our data suggest that a GC subtype with EGFR amplification and overexpression benefit from cetuximab treatment.

Prognostic value of metastatic lymph node ratio as an additional tool to the TNM stage system in gastric cancer

BACKGROUND Gastric cancer is one of most common malignancies in the world. Currently the prognostic prediction is entirely based on the TNM staging system. In this study, we evaluated whether metastatic lymph node ratio (rN) at the time of surgery would improve the prognostic prediction in conjunction with the TNM staging system. METHODS This retrospective study includes 745 patients, who had been referred for surgery due to gastric cancer between 1995 and 2007 and had at least 15 lymph nodes examined at the time of surgery without preoperative treatment. Clinicopathologic features and overall survival were analyzed using univariate and multivariate modes to identify the risk factors for overall survival. RESULTS Median overall survival of all patients analyzed is 57.8 months and 5-year overall survival is 49.5%. Tumor site, macroscopic type, pTNM stage, and rN stage are identified as independent prognostic factors. Increased positive lymph node ratio correlates with shorter survival in all patients and in each T and N stage. In stage III gastric cancer patients, rN stage shows additional prognostic value on overall survival (p < 0.001). CONCLUSIONS rN stage is a simple and promising prognostic factor of gastric cancer after surgery in addition to the TNM stage system especially in stage III patients. But the independent prognostic value of rN stage in stage I, II and IV gastric cancer is yet to be determined.

BGB-283, a Novel RAF Kinase and EGFR Inhibitor, Displays Potent Antitumor Activity in BRAF-Mutated Colorectal Cancers.

Oncogenic BRAF, which drives cell transformation and proliferation, has been detected in approximately 50% of human malignant melanomas and 5% to 15% of colorectal cancers. Despite the remarkable clinical activities achieved by vemurafenib and dabrafenib in treating BRAFV600E metastatic melanoma, their clinical efficacy in BRAFV600E colorectal cancer is far less impressive. Prior studies suggested that feedback activation of EGFR and MAPK signaling upon BRAF inhibition might contribute to the relative unresponsiveness of colorectal cancer to the first-generation BRAF inhibitors. Here, we report characterization of a dual RAF kinase/EGFR inhibitor, BGB-283, which is currently under clinical investigation. In vitro, BGB-283 potently inhibits BRAFV600E-activated ERK phosphorylation and cell proliferation. It demonstrates selective cytotoxicity and preferentially inhibits proliferation of cancer cells harboring BRAFV600E and EGFR mutation/amplification. In BRAFV600E colorectal cancer cell lines, BGB-283 effectively inhibits the reactivation of EGFR and EGFR-mediated cell proliferation. In vivo, BGB-283 treatment leads to dose-dependent tumor growth inhibition accompanied by partial and complete tumor regressions in both cell line-derived and primary human colorectal tumor xenografts bearing BRAFV600E mutation. These findings support BGB-283 as a potent antitumor drug candidate with clinical potential for treating colorectal cancer harboring BRAFV600E mutation. Mol Cancer Ther; 14(10); 2187–97. ©2015 AACR.

Controlling angiogenesis in gastric cancer: A systematic review of anti-angiogenic trials

PURPOSE Angiogenesis is a promising therapeutic target to inhibit tumor growth. This review summarizes data from clinical trials of anti-angiogenic agents in gastric cancer. DESIGN A systematic search of PubMed, Embase and conference databases is performed to identify clinical trials with specific anti-angiogenic agents in gastric cancer treatment RESULTS The risk of disease progression (37-52%) and death (19-22%) with ramucirumab as second-line treatment decreases in phase III trials in advanced gastric cancer. No significant improvement in overall survival (OS) with the addition of bevacizumab to chemotherapy is shown. Bevacizumab or ramucirumab combined with traditional chemotherapy is associated with higher adverse event rate compared to chemotherapy alone. Except for apatinib, phase II trials of other tyrosine kinase inhibitors (TKIs) may improve overall response rate, but there are no significant improvements in OS and progression-free survival (PFS) when combined with chemotherapy. CONCLUSION Phase III trials in advanced gastric cancer have demonstrated improved outcome with ramucirumab as second-line treatment. Most of the other studies on anti-angiogenic agents in gastric cancer have reported improvement in response rate but not in OS compared to chemotherapy alone. Future research is expected in optimizing the anti-angiogenic therapy combined with traditional treatment.

The extent of inflammatory infiltration in primary cancer tissues is associated with lymphomagenesis in immunodeficient mice

Xenotransplantation of human cancers into immunodeficient mice is a very useful approach for studying human tumor biology. However, the occasional occurrence of lymphomagenesis in some mice can spoil the model and must be investigated in detail. We found that a high percentage (32.5%, 26/80) of cancer patient-derived xenografts (PDXs) resembled lymphoma in NOD/SCID mice. Of the 26 xenografts, 23 were human-derived expressing human CD45 (hCD45+) and proved to be of the B-cell subtype (CD3-/CD20+), and they were all positive for Epstein - Barr virus (EBV). The remaining 3 xenografts proved to be mouse-derived for both hCD45- and negative amplification of a human gene. The most interesting finding is that gastric cancer had much higher rates (24/126, 19.0%) of lymphoma formation in the PDX model than did colorectal cancer (1/43, 2.3%). Statistical analysis revealed that cancer type and inflammation in the parent tumor are significantly associated with lymphomagenesis. Further validation discovered lymphomagenesis by inoculating only gastritis mucosa. Therefore, our findings suggest that it is necessary to take precautions when directly xenografting cancer tissues with remarkable baseline inflammation, such as gastric cancer into immunodeficient NOD/SCID strains. Further, the established xenograft models should be validated by both leukocyte markers and human gene signatures.

ABCC2 -24C > T polymorphism is associated with the response to platinum/5-Fu-based neoadjuvant chemotherapy and better clinical outcomes in advanced gastric cancer patients

Several studies have evaluated the efficacy of neoadjuvant treatment using oxaliplatin and fluoropyrimidines in advanced gastric cancer (GC). However, preoperative biomarkers predictive of clinical outcome remain lacking. We examined polymorphisms in the MTHFR, DPYD, UMPS, ABCB1, ABCC2, GSTP1, ERCC1, and XRCC1 genes to evaluate their usefulness as pharmacogenetic markers in a cohort of 103 GC patients treated with preoperative chemotherapy. DNA was extracted from peripheral blood cells, and the genotypes were analyzed using a SNaPShotTM assay, polymerase chain reaction amplification, and sequencing. The ABCC2-24C > T (rs717620) genotype was associated with pathologic response to neoadjuvant chemotherapy. Patients with the TT and TC genotypes responded to neoadjuvant chemotherapy 3.80 times more often than those with the CC genotype (95% CI: 1.27–11.32). Patients with the CC genotype also had poorer outcomes than those with other genotypes. Thus, ABCC2-24C > T polymorphism may help to predict the response to preoperative chemotherapy in GC patients.

Gastrectomy in comprehensive treatment of advanced gastric cancer with synchronous liver metastasis: a prospectively comparative study

BackgroundSystemic chemotherapy is the key treatment for advanced gastric cancer. The benefit of adjuvant surgery following preoperative chemotherapy in gastric cancer with liver metastasis has not been well established.MethodsForty-nine gastric cancer patients diagnosed with synchronous liver metastasis initially treated with chemotherapy were categorized into the following two groups: surgery group: 25 patients who underwent gastrectomy and subsequently received postoperative chemotherapy and control group: 24 patients who received chemotherapy alone.ResultsThe median overall survival of patients in the surgery group and control group was 20.5 and 9.1 months, respectively, (P = 0.006). The median progression-free survival in the surgery group was 10.9 months, with statistical significance when compared with 5.0 months in the control group (P = 0.001). Multivariate analysis demonstrated that response to chemotherapy was the only independent factor in predicting prognosis. The survival of patients who achieved partial response (PR) was prolonged if they received adjuvant surgery (P = 0.024). No significant difference in the survival of patients underwent combined hepatic resection when compared with patients performed gastrectomy only.ConclusionsFor gastric cancer with synchronous liver metastasis, adjuvant gastrectomy followed by chemotherapy might be beneficial for survival comparing with chemotherapy alone, especially in patients response to initial preoperative chemotherapy.

Laparoscopic versus open distal gastrectomy for locally advanced gastric cancer after neoadjuvant chemotherapy: safety and short-term oncologic results

BackgroundTo compare the safety and efficacy of laparoscopic distal gastrectomy (LDG) versus open distal gastrectomy (ODG) in treating locally advanced distal gastric cancer after neoadjuvant chemotherapy (NACT).MethodsForty-four patients with locally advanced distal gastric cancer were enrolled. The patients received neoadjuvant chemotherapy before undergoing surgery. Twenty patients were allocated into LDG after NACT group and 24 patients into ODG after NACT group. Radicalness of oncological resection, surgical safety and recovery were measured and compared.ResultsAll operations were successfully performed without severe postoperative complications. There were no significant differences in blood loss, mean operation time, complications, distal and proximal resection margin, and number of retrieved lymph nodes between LDG and ODG groups, but LDG group had shorter length of incision and the first aerofluxus time.ConclusionLaparoscopic distal gastrectomy after NACT has comparable results with open distal gastrectomy in safety and efficacy in the short term.

Preoperative chemotherapy with a trastuzumab-containing regimen for a patient with gastric cancer and hepatic metastases.

Gastric cancer is the fourth most common cancer worldwide and the leading cause of tumor-related death in China. Gastric cancer is a heterogeneous disease and therefore requires different treatments based on the subtype. We describe a patient who had gastric cancer with liver metastases. Biopsy and tumor analysis using the HercepTest revealed a human epidermal growth factor receptor 2 (HER2)-positive adenocarcinoma as confirmed by fluorescence in situ hybridization. The patient was treated with a regimen of trastuzumab, oxaliplatin, and S-1 (six cycles). When positron emission tomography findings suggested that the metastases had resolved, the patient underwent surgery. Histopathologically, no cancer cells were observed in the resected hepatic tissue. The patient underwent tumor resection surgery, during which the tumor and gastric lymph nodes with lesions were removed. The patient has remained disease-free for 3 months. Therefore, trastuzumab may be an effective agent in the chemotherapeutic treatment of liver metastases in patients with HER2-positive gastric adenocarcinoma.

Imatinib mesylate in clinically suspected gastric stromal tumors

Gastrointestinal stromal tumors (GISTs) occur most frequently in the stomach. Diagnosis of gastric GIST is not always clear before surgery. Flexible endoscopy may suggest the nature of the lesion (a bulky tumor with preserved mucosa); however, biopsy is rarely diagnostic. Therefore, diagnostic medication with safe drugs may provide a feasible way under such conditions after an informed consent is obtained. Based on the excellent efficacy of imatinib mesylate (IM) in the treatment of GIST, we successfully applied it in the diagnostic medication of two patients with clinically suspected gastric stromal tumors. In conclusion, the diagnostic medication with IM can be an alternative option for patients with suspected GIST that can not be confirmed pathologically.