Liu Yr

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.

S100A6 overexpression is associated with poor prognosis and is epigenetically up-regulated in gastric cancer.

S100A6 has been implicated in a variety of biological functions as well as tumorigenesis. In this study, we investigated the expression status of S100A6 in relation to the clinicopathological features and prognosis of patients with gastric cancer and further explored a possible association of its expression with epigenetic regulation. S100A6 expression was remarkably increased in 67.5% of gastric cancer tissues as compared with matched noncancerous tissues. Statistical analysis demonstrated a clear correlation between high S100A6 expression and various clinicopathological features, such as depth of wall invasion, positive lymph node involvement, liver metastasis, vascular invasion, and tumor-node metastasis stage (P < 0.05 in all cases), as well as revealed that S100A6 is an independent prognostic predictor (P = 0.026) significantly related to poor prognosis (P = 0.0004). Further exploration found an inverse relationship between S100A6 expression and the methylation status of the seventh and eighth CpG sites in the promoter/first exon and the second to fifth sites in the second exon/second intron. In addition, the level of histone H3 acetylation was found to be significantly higher in S100A6-expressing cancer cells. After 5-azacytidine or trichostatin A treatment, S100A6 expression was clearly increased in S100A6 low-expressing cells. In conclusion, our results suggested that S100A6 plays an important role in the progression of gastric cancer, affecting patient prognosis, and is up-regulated by epigenetic regulation.

Different kinetic patterns of BCR-ABL transcript levels in imatinib-treated chronic myeloid leukemia patients after achieving complete cytogenetic response

Bone marrow BCR‐ABL transcript levels were monitored serially by real‐time quantitative PCR in 46 imatinib‐treated chronic myeloid leukemia patients after achieving complete cytogenetic response (CCyR) for a median of 42 months (range: 9–53). Of 41 patients in continuous CCyR, 32 and nine could achieve a ≥3‐log (MMoR group) or 2‐ to 3‐log reduction (non‐MMoR group), respectively. The MMoR group had a significantly lower recurrence rate of Ph+ metaphase than the non‐MMoR group (6/32 vs. 7/9, P = 0.002), which was not significantly different between patients first achieving CCyR within or after 12 months of imatinib treatment (7/27 vs. 6/14, P = 0.086). Five patients suffered cytogenetic or hematological relapse. For all 46 patients, a >2‐log reduction but not time when CCyR was first achieved was related to a lower relapse rate (1/42 vs. 4/4, P < 0.001). We concluded that the depth of BCR‐ABL reduction after CCyR is more critical than when CCyR is first achieved. The kinetic pattern of BCR‐ABL transcript is a good predictor of disease stability.

Phospholipase A2 group IIA expression correlates with prolonged survival in gastric cancer

Xing X‐F, Li H, Zhong X‐Y, Zhang L‐H, Wang X‐H, Liu Y‐Q, Jia S‐Q, Shi T, Niu Z‐J, Peng Y, Du H, Zhang G‐G, Hu Y, Lu A‐P, Li J‐Y, Chen S & Ji J‐F 
(2011) Histopathology59, 198–206

Sandwich sign of Borrmann type 4 gastric cancer on diffusion-weighted magnetic resonance imaging

OBJECTIVE To assess the appearance of Borrmann type 4 (BT-4) gastric cancer on diffusion-weighted magnetic resonance imaging (DWI) and to investigate the potential of qualitative and quantitative DW images analysis to differentiate BT-4 gastric cancer from poorly distended normal stomach wall. MATERIALS AND METHODS DWI was performed on 23 patients with BT-4 gastric cancer and 23 healthy volunteers. The signal characteristics and correlated histopathological basis of the cancers on DWI were investigated. The contrast-to-noise ratios (CNR) of cancer were compared between DWI and T1WI/T2WI(.) The thickness and apparent diffusion coefficient (ADC) of cancer and normal stomach wall were compared. RESULTS All of the gastric cancers displayed hyperintensity compared to the nearby normal gastric wall on DWI. A three-layer sandwich sign that demonstrated high signal intensity in the inner and outer layer, and low signal intensity in the intermediate layer was observed in 69.6% of cancers on DWI. The low signal intensity represents the muscularis propria through the comparison with pathology, and it is postulated that scattering distribution of the cancer cells in this layer causes less damage and subsequently less restriction of water movement, which causes the low signal intensity on DWI. The CNR obtained with DWI was higher than that with T1WI and T2WI (P<0.001). The mean ADC value of BT-4 gastric cancer was significantly lower than the poorly distended normal stomach wall (1.12 ± 0.23 × 10(-3)mm(2)/s vs. 1.9 3 ± 0.22 × 10(-3)mm(2)/s, P<0.01). CONCLUSION DWI can highlight the signals of BT-4 gastric cancer which may present a characteristic three-layer sandwich sign, and ADC values are helpful in the discrimination of gastric cancer from poorly distended stomach wall.

Presence of S100A9-positive inflammatory cells in cancer tissues correlates with an early stage cancer and a better prognosis in patients with gastric cancer

BackgroundS100A9 was originally discovered as a factor secreted by inflammatory cells. Recently, S100A9 was found to be associated with several human malignancies. The purpose of this study is to investigate S100A9 expression in gastric cancer and explore its role in cancer progression.MethodsS100A9 expression in gastric tissue samples from 177 gastric cancer patients was assessed by immunohistochemistry. The expression of its dimerization partner S100A8 and the S100A8/A9 heterodimer were also assessed by the same method. The effect of exogenous S100A9 on motility of gastric cancer cells AGS and BGC-823 was then investigated.ResultsS100A9 was specifically expressed by inflammatory cells such as macrophages and neutrophils in human gastric cancer and gastritis tissues. Statistical analysis showed that a high S100A9 cell count (> = 200) per 200x magnification microscopic field in cancer tissues was predictive of early stage gastric cancer. High S100A9-positive cell count was negatively correlated with lymph node metastasis (P = 0.009) and tumor invasion (P = 0.011). S100A9 was identified as an independent prognostic predictor of overall survival of patients with gastric cancer (P = 0.04). Patients with high S100A9 cell count were with favorable prognosis (P = 0.021). Further investigation found that S100A8 distribution in human gastric cancer tissues was similar to S100A9. However, the number of S100A8-positive cells did not positively correlate with patient survival. The inflammatory cells infiltrating cancer were S100A8/A9 negative, while those in gastritis were positive. Furthermore, exogenous S100A9 protein inhibited migration and invasion of gastric cancer cells.ConclusionsOur results suggested S100A9-positive inflammatory cells in gastric cancer tissues are associated with early stage of gastric cancer and good prognosis.

Apoptosis index correlates with chemotherapy efficacy and predicts the survival of patients with gastric cancer

The objectives of this study are to investigate the apoptotic changes in gastric adenocarcinoma following neoadjuvant chemotherapy and to illuminate its correlation with response. One 67 gastric cancer patients with cT2-4 or TanyN1-3M0 between January 2006 and December 2007 were included. All patients had previous gastrectomy and D2 lymphadenectomy with curative intent performed. A total of 12 cycles of preoperative mFOLFOX7 chemotherapy was recommended for all patients, and 83 patients received only adjuvant chemotherapy. Resected specimens were subjected to in situ TUNEL assay and scanned with Applied Imaging Ariol SL-50. Apoptosis index (AI) was significantly higher in the patient received preoperative chemotherapy (CS group) than in the patient did not (S group). In the CS group, AI was found to have a strong positive correlation with the pathological response (rho = 0.403, P = 0.0002). A ROC curve presented a score of 49.4 as the AI cutoff value for response, dividing the CS group into two subgroups with significantly different prognoses (P = 0.003) and further allowing identification of 8 patients with significantly better prognosis out of 48 patients evaluated as grades 1a–b according to a pathological response evaluation (P = 0.022). In conclusion, AI is correlated with efficacy of preoperative chemotherapy and prognosis of gastric cancer patients following neoadjuvant chemotherapy. An AI cutoff value for response may be used as a complementary approach to current pathological response evaluations to help identify potential responders.

Validation of the Memorial Sloan-Kettering Cancer Center Nomogram to Predict Disease-Specific Survival after R0 Resection in a Chinese Gastric Cancer Population

Background Prediction of disease-specific survival (DSS) for individual patient with gastric cancer after R0 resection remains a clinical concern. Since the clinicopathologic characteristics of gastric cancer vary widely between China and western countries, this study is to evaluate a nomogram from Memorial Sloan-Kettering Cancer Center (MSKCC) for predicting the probability of DSS in patients with gastric cancer from a Chinese cohort. Methods From 1998 to 2007, clinical data of 979 patients with gastric cancer who underwent R0 resection were retrospectively collected from Peking University Cancer Hospital & Institute and used for external validation. The performance of the MSKCC nomogram in our population was assessed using concordance index (C-index) and calibration plot. Results The C-index for the MSKCC predictive nomogram was 0.74 in the Chinese cohort, compared with 0.69 for American Joint Committee on Cancer (AJCC) staging system (P<0.0001). This suggests that the discriminating value of MSKCC nomogram is superior to AJCC staging system for prognostic prediction in the Chinese population. Calibration plots showed that the actual survival of Chinese patients corresponded closely to the MSKCC nonogram-predicted survival probabilities. Moreover, MSKCC nomogram predictions demonstrated the heterogeneity of survival in stage IIA/IIB/IIIA/IIIB disease of the Chinese patients. Conclusion In this study, we externally validated MSKCC nomogram for predicting the probability of 5- and 9-year DSS after R0 resection for gastric cancer in a Chinese population. The MSKCC nomogram performed well with good discrimination and calibration. The MSKCC nomogram improved individualized predictions of survival, and may assist Chinese clinicians and patients in individual follow-up scheduling, and decision making with regard to various treatment options.

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.

Prognostic role of lymph node metastasis in early gastric cancer

OBJECTIVE To clarify the relationship between clinicopathological features and lymph node metastasis and to propose the potential indications of lymph node metastasis for prognosis in early gastric cancer (EGC) patients. METHODS We retrospectively observed 226 EGC patients with lymph node resection, and analyzed the associations between lymph node metastasis and clinicopathological parameters using the chi-square test in univariate analysis and logistic regression analysis in multivariate analysis. Overall survival analysis was determined using the Kaplan-Meier and log-rank test. We conducted multivariate prognosis analysis using the Cox proportional hazards model. RESULTS Of all the EGC patients, 7.5% (17/226) were histologically shown to have lymph node metastasis. The differentiation, lymphovascular invasion and depth of invasion were independent risk factors for lymph node metastasis in EGC. The 5- and 10-year survival rates were significantly lower in patients with lymph node metastasis than in those without and the patients also had shorter progress-free survival time. Lymph node metastasis and tumor size were independent prognostic factors for EGC. The status of the lymph nodes was a significant factor in predicting recurrence or metastasis after surgery. CONCLUSIONS The undifferentiated carcinoma and lymphovascular and/or submucosal invasion were associated with a higher incidence of lymph node metastasis in EGC patients, whom need to perform subsequent D2 lymphadenectomy or laparoscopic lymph node dissection and more rigorous follow-up or additional chemotherapy/radiation after D2 gastrectomy for poor prognosis and high recurrence/metastasis rate.