Whole-Exome Sequencing Among Chinese Patients With Hereditary Diffuse Gastric Cancer.

Importance: The E-cadherin gene, CDH1, and the α-E-catenin gene, CTNNA1, were previously identified as hereditary diffuse gastric cancer (HDGC) susceptibility genes, explaining 25% to 50% of HDGC cases. The genetic basis underlying disease susceptibility in the remaining 50% to 75% of patients with HDGC is still unknown. Objective: To assess the incidence rate of CDH1 germline alterations in HDGC, identify new susceptibility genes that can be used for screening of HDGC, and provide a genetic landscape for HDGC. Design, Setting, and Participants: This cohort study conducted retrospective whole-exome and targeted sequencing of 284 leukocyte samples and 186 paired tumor samples from Chinese patients with HDGC over a long follow-up period (median, 21.7 [range, 0.6-185.9] months). Among 10 431 patients diagnosed with gastric cancer between January 1, 2002, and August 31, 2018, 284 patients who met the criteria for HDGC were included. Data were analyzed from August 1 to 30, 2020. Main Outcomes and Measures: Incidence rate of CDH1 germline alterations, identification of new HDGC susceptibility genes, and genetic landscape of HDGC. Results: Among 284 Chinese patients, 161 (56.7%) were female, and the median age was 35 (range, 20-75) years. The frequency of CDH1 germline alterations was 2.8%, whereas the frequency of CDH1 somatic alterations was 25.3%. The genes with the highest incidence (>10%) of private germline alterations (including insertions and deletions) in the HDGC cohort were MUC4, ABCA13, ZNF469, FCGBP, IGFN1, RNF213, and SSPO, whereas previously reported germline alterations of CTNNA1, BRCA2, STK11, PRSS1, ATM, MSR1, PALB2, BRCA1, and RAD51C were observed at low frequencies (median, 4 [range, 1-12] cases). Furthermore, enrichment of the somatic variant signature of exposure to aflatoxin suggested potential interaction between genetics and environment in HDGC. Double-hit events in genes such as CACNA1D were observed, which suggested that these events might serve as important mechanisms for HDGC tumorigenesis. In addition, germline variants of FSIP2, HSPG2, and NCKAP5 and somatic alterations of FGFR3, ASPSCR1, CIC, DGCR8, and LZTR1 were associated with poor overall survival among patients with HDGC. Conclusions and Relevance: This study provided a genetic landscape for HDGC. The study's findings challenged the previously reported high germline alteration rate of CDH1 in HDGC and identified new potential susceptibility genes. Analyses of variant signatures and double-hit events revealed potentially important mechanisms for HDGC tumorigenesis. Findings from the present study may provide helpful information for further investigations of HDGC.

Increased number and function of endothelial progenitor cells in breast cancer patients and the linear correlation with VEGF level.

The number of circulating endothelial progenitor cells (EPCs) was found to increase in patients with breast cancer, but the alteration in EPC function remains to be elusive. We conducted this study to evaluate the number and function of peripheral EPCs of breast cancer patients and its possible underlying mechanism. Besides, the vascular endothelial growth factor (VEGF), VCAM-1, IL-6, and IL-34 levels were measured in blood samples and also in vitro in a medium of EPCs. We found that the number of circulating EPCs in breast cancer patients was significantly higher than that in normal control and remarkably augmented in a stage-dependent manner. Meanwhile, a similar enhancement was observed in the migratory, proliferative, and adhesive activity of circulating EPCs originating from breast cancer patients. More importantly, the VEGF level in blood samples was dramatically elevated in comparison to the control, which was correlated positively with the number and activity of circulating EPCs from breast cancer patients. Moreover, in vitro medium of EPCs from breast cancer patients highly expressed VEGF compared with that from the control, which also had a positive correlation with the number and activity of circulating EPCs from breast cancer patients. This is the first time to demonstrate that the number and function of circulating EPCs are promoted in breast cancer patients, which are positively related to an enhanced VEGF production. These may provide a novel target for improving the outcome of breast cancer.

Performance of common genetic variants in risk prediction for colorectal cancer in Chinese: A two-stage and multicenter study.

The efficacy of susceptible variants derived from genome-wide association studies (GWAs) optimizing discriminatory accuracy of colorectal cancer (CRC) in Chinese remains unclear. In the present validation study, we assessed 75 recently identified variants from GWAs. A risk predictive model combining 19 variants using the least absolute shrinkage and selection operator (LASSO) statistics offered certain clinical advantages. This model demonstrated an area under the receiver operating characteristic (AUC) of 0.61 during training analysis and yielded robust AUCs from 0.59 to 0.61 during validation analysis in three independent centers. The individuals carrying the highest quartile of risk score revealed over 2-fold risks of CRC (ranging from 2.12 to 2.90) compared with those who presented the lowest quartile of risk score. This genetic model offered the possibility of partitioning risk within the average risk population, which might serve as a first step toward developing individualized CRC prevention strategies in China.

Metastatic axillary lymph node ratio (LNR) is prognostically superior to pN staging in patients with breast cancer--results for 804 Chinese patients from a single institution.

The number of axillary lymph nodes involved and retrieved are important prognostic factors in breast cancer. The purpose of our study was to investigate whether the lymph node ratio (LNR) is a better prognostic factor in predicting disease-free survival (DFS) for breast cancer patients as compared with pN staging. The analysis was based on 804 breast cancer patients who had underwent axillary lymph node dissection between 1999 and 2008 in Sun Yat-Sen University Cancer Center. Optimal cutoff points of LNR were calculated using X-tile software and validated by bootstrapping. Patients were then divided into three groups (low-, intermediate-, and high-risk) according to the cutoff points. Predicting risk factors for relapse were performed according to Cox proportional hazards analysis. DFS was estimated using the Kaplan-Meier method and compared by the log-rank test. The 5-year DFS rate decreased significantly with increasing LNRs and pN. Univariate analysis found that the pT , pN, LNR, molecule type, HER2, pTNM stage and radiotherapy well classified patients with significantly different prognosis. By multivariate analysis, only LNR classification was retained as an independent prognostic factor. Furthermore, there was a significant prognostic difference among different LNR categories for pN2 category, but no apparent prognostic difference was seen between different pN categories in any LNR category. Therefore, LNR rather than pN staging is preferable in predicting DFS in node positive breast cancer patients, and routine clinical decision-making should take the LNR into consideration.

Low expression of tyrosine-protein phosphatase nonreceptor type 12 is associated with lymph node metastasis and poor prognosis in operable triple-negative breast cancer.

BACKGROUND: Low tyrosine-protein phosphatase nonreceptor type 12 (PTPN12) expression may be associated with breast cancer growth, proliferation, and metastasis. However, the prognostic value of PTPN12 in breast cancer has not been clearly identified. PATIENTS AND METHODS: 51 triple-negative breast cancer (TNBC) patients and 83 non-TNBC patients with a histopathology diagnosis from October 2001 to September 2006 were included in this study. Immunohistochemical staining for PTPN12 on tissue microarrays was conducted. RESULTS: High PTPN12 expression was seen in 39.2% of TNBC and 60.2 % of non-TNBC cases. Low PTPN12 expression was associated with lymph node status (p = 0.002) and distant metastatic relapse (p = 0.002) in TNBC patients. Similarly, low PTPN12 expression in non-TNBC patients was significantly correlated with lymph node status (p = 0.002), stage (p = 0.002) and distant metastatic relapse (p = 0.039). The high PTPN12 expression group was associated with longer DFS and OS compared with low PTPN12 expression group only in TNBC cases (p = 0.005, p = 0.015), according to univariate Cox regression analysis. CONCLUSION: These findings provide evidence that low expression of PTPN12 is associated with worse prognosis and may be used as a potential prognostic biomarker in TNBC patients.