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506 Background: This study evaluates the predictive performance of radiomic features in metastasis of T1 colorectal carcinoma (CRC) to lymph nodes. Methods: A total of 10 200 CRC patients from our clinical cancer center included in this analysis. 225 eligible cases diagnosed with T1 CRC were included and divided into two groups: computed tomography (CT) image group (n = 82) and magnetic resonance image (MRI) group (n = 143) based on the preoperative image data available. A total of 548 radiomic features were extracted from each case and analyzed, and then a panel of radiomic features associated with lymph node metastases (LNM) were selected using Mann-Whitney U test. Combining these selected radiomic features and clinical data, the predictive performance for LNM was calculated using receiver operating characteristic (ROC) curves. Results: The prediction accuracy for LNM of T1 CRC could be improved to 0.88 by area under the receiver operating characteristic curve (AUC) through integration of one radiomic feature and three clinical indicators in CT group. In the group of contrast enhanced T1-weighted MRI (T1w-MRI), combination of two radiomic features and three clinical parameters present an AUC value of 0.85. In the group of T2-weighted MRI (T2w-MRI), combination of four radiomic features and five clinical characteristics identified T1 tumors with LNM with an AUC value of 0.87. Conclusions: The current study present a good predictive performance of combination of radiomic features with clinic characteristic in identifying T1 CRC with LNM, which may provide an important opportunity for us to make clinical treatment decision-making for T1 CRC patients.

Purpose To conduct a systematic review of prospective studies assessing the association of vitamin D intake or blood levels of 25-hydroxyvitamin D [25(OH)D] with the risk of colorectal cancer using meta-analysis. Methods Relevant studies were identified by a search of MEDLINE and EMBASE databases before October 2010 with no restrictions. We included prospective studies that reported relative risk (RR) estimates with 95% CIs for the association between vitamin D intake or blood 25(OH)D levels and the risk of colorectal, colon, or rectal cancer. Approximately 1,000,000 participants from several countries were included in this analysis. Results Nine studies on vitamin D intake and nine studies on blood 25(OH)D levels were included in the meta-analysis. The pooled RRs of colorectal cancer for the highest versus lowest categories of vitamin D intake and blood 25(OH)D levels were 0.88 (95% CI, 0.80 to 0.96) and 0.67 (95% CI, 0.54 to 0.80), respectively. There was no heterogeneity among studies of vitamin D intake (P = .19) or among studies of blood 25(OH)D levels (P = .96). A 10 ng/mL increment in blood 25(OH)D level conferred an RR of 0.74 (95% CI, 0.63 to 0.89). Conclusion Vitamin D intake and blood 25(OH)D levels were inversely associated with the risk of colorectal cancer in this meta-analysis.

e15696Background: Colorectal cancer (CRC) is a malignant tumor resulting in third highest morbidity of all cancers. Driven by host’s genetic make-up and environmental exposures, the gut microbiome ...

e22131 Background: Cancer stem cells have been indicated in the initiation of tumors and are even found to be responsible for relapses after apparently curative therapies have been undertaken. In breast cancer, they may reside in the CD44+CD24−/low population. Oncolytic adenoviruses enter cells through infection and can kill both proliferating and quiescent cells. We investigated the role of E1B protein- dificient oncolytic adenovirus in breast cancer stem cells. Methods: MCF-7 cells were infected by E1B protein-dificient oncolytic adenovirus as infected group (MOI=100) and cultured routinely as control group simultaneously. The proportion of CD44+CD24- cells was assessed by flow cytometry (FCM) in two groups respectively. Meanwhile, mammosphere culture was done in two groups' cells to observe the size and number of mammospheres, calculate the mammosphere- forming efficiency (MFE). The proportion of CD44+CD24- cells in two groups' mammospheres was assessed by FCM. Results: The percentages of CD24-,CD44+, CD44+CD24- in the infected gruop were 43.9%, 63.26%, 22.19%, respectively. While in the control group, the percentages were 6.74%, 88.30%, 2.30%. In the infected group, the time of mammosphere's formation was earlier, the volumes of mammospheres were bigger and the MFE was higher than the control group (1.26%:0.9%). In two mammospheres' groups, the proportion of CD44+CD24- cells in experiment group and control group was 38.08% and 23.35%, respectively. Conclusions: E1B protein-dificient oncolytic adenovirus can kill MCF-7 cells in short time, mainly breast cancer differentiated cells. It maybe promote the growth of the breast cancer stem cells. It maybe accelerate the speed of self-renewed and differentiation of the breast cancer stem cells. No significant financial relationships to disclose.

1113 Objective: To explore the distribution of single nucleotide polymorphism (SNP) loci of estrogen receptor (ESR1) gene in breast cancer patients and to study the relationship between the SNP genotypes and the efficacy to endocrine therapy. Methods: Fifteen SNP loci ( rs872921 , rs2077647, rs3904766, rs2234693, rs11155816, rs827419 , rs2347867, rs3798759, rs1801132, rs985191 , rs9340931, rs9397463, rs722209 , rs3778099, and rs3798577) of ESR1 gene were selected as genetic markers. PCR-restriction fragment length polymorphisms, PCR-DNA sequencing and allele-specific real time PCR methods were employed to analyze the loci genotype of 240 patients with breast cancer accepted endocrine therapy. Results: The loci rs872921 and rs3904766 were abandoned for poor ploymorphisms, and the other 13 loci had polymorphisms. The frequencies of alleles and genotypes of rs2077647 and rs3798759 were significantly related with the efficacy of endocrine therapy (p < 0. 05). The linkage disequilibrium and the hapotype analysis showed that there were four linkage disequilibrium blocks in ESR1 gene. They were rs2077647∼rs2234693 (LD1), rs2234693∼rs11155816 (LD2), rs9397463∼ rs722209 (LD3), and rs3778099∼rs3798577 (LD4), and the hapotypes of LD2, LD3, s11155816- rs827419 , and rs2347867- rs1801132 were positively related with the efficacy of endocrine therapy (p < 0. 05). Conclusions: Some of the polymorphisms of ESR1 gene and the haplotypes are positively associated with the endocrine therapy efficacy, and maybe account for predicting the endocrine response in breast cancer. No significant financial relationships to disclose.

e22093 Background: The epithermal growth factor receptor(EGFR) signaling pathways has been implicated in self-renewal of breast cancer stem cells. It has been proved that the EGFR tyrosine kinase inhibitor-gefitinib significantly decreased the mammosphere- forming efficiency(MFE) in ductal carcinoma in situ (DCIS) derived cancer cells. We investigated the response of breast cancer stem cells in breast cancer cell line MCF-7 to EGFR MAbs C225(cetuximab). Methods: Cells were used for nonadherent (i.e.,mammosphere) culture and were divided into four groups according to the different culture medium whether or not including exogenous EGF and MAbs C225. MFE was calculated as the number of mammospheres (≥60um) and was expressed as a percentage. We Compared the percentage of CD44+/CD24- cells from the four groups, and measured the levels of the Wnt and Notch-3 gene expression of the four groups. Results: There was no significant difference of MFE between groups. In the presence of exogenous EGF, MAbs C225 significantly decreased the MFE and the percentage of CD44+/CD24- cells of mammospheres compared with exogenous EGF alone(0.7% versus 1.5%, P < 0.001 and 4% versus 11%P < 0.001;respectively). In the absence of exogenous EGF, MAbs C225 aslo statistically decreased the MFE and the percentage of CD44+/CD24- cells of mammospheres compared with that of lacking exogenous EGF and MAbs C225(0.53% versus 1.3%,P = 0.003 and 9% versus 3%, P < 0.01;respectively). And we observed that the Notch-3 gene expression was compensativly increased in the two groups of addition of MAb C225. No significant differences of Wnt gene expression were observed between groups. Conclusions: EGFR MAbs C225 could disrupt mammoshpere formation and decrease the percentage of CD44+/CD24- cells of mammoshpere cells. The expression of Notch-3 is increased with the EGFR antagonistics in breast cancer stem cells. No significant financial relationships to disclose.