The association between PLCE1 mRNA expression and mortality of ESCCs The association between PLCE1 protein expression and mortality of ESCCs Sa1934 Chromogranin a As a Predictor of Radiological Disease Progression in Neuroendocrine Tumors Roberta E. Rossi, Jorge Garcia-Hernandez, Nick Martin, Tim Meyer, Christina Thirlwell, Jennifer Watkins, Martyn Caplin, Christos Toumpanakis Introduction: Chromogranin A (CgA) is considered as the best and most sensitive general marker for the diagnosis and follow-up of neuroendocrine tumors (NETs) and is also of prognostic value. However, there are no available studies to date, which analysed the role of CgA as a predictor of radiological disease progression in all NETs. Aim: To investigate the prognostic value of CgA as a predictor of radiological disease progression in NET patients. Methods: Patients with metastatic NETs and evidence of Radiological Progression (RP) according to Radiological Evaluation Criteria In Solid Tumors (RECIST 1.1) were identified from our NETs database. Plasma CgA were measured 6 and 12 months before RP and at the event of RP. CgA was measured with the Supra-regional-Assay-Service radioimmunoassay (Hammersmith Hospital). In our laboratory, the reference value of CgA has been established as < 60 pmol/L. The tumors were graded according to the 2010 WHO classification, as G1 (Ki67<2%), G2 (Ki67: 2-20%), G3 (Ki67>20%). Results: 152 patients were evaluable includ- ing 91 midgut NETs (mNETs) and 61 pancreatic NETs (PNETs). Of these, 56 were G1 NETs, 65 G2, 10 G3, 21 of unknown histology. The majority of the patients (95.4%) had liver metastases, whereas bone and lung metastases were present in a smaller proportion of patients (27.6% and 9.9%, respectively). Median CgA for all NETs, 6 months before RP, S-333 AGA Abstracts was 213 pmol/L [Interquartile 1 (Q1)=67 and 3 (Q3)=664.5 pmol/L] compared to 166 pmol/L (Q1 52 and Q3 535 pmol/L) one year before RP (T=598.5, p=.07). Significant results were found for PNETs [median CgA 6 months before RP was 100 pmol/L (Q1 53 and Q3 286.25 pmol/L) and at 12 months was 52 pmol/L (Q1 36.25 and Q3 128 pmol/L), T=52, p=.048], but not for mNETs [median CgA 6 months before RP was 389.5 pmol/L (Q1 131.5 and Q3 791.5 pmol/L) and at 12 months was 319 pmol/L (Q1 158 and Q3 753 pmol/L), T=191, p=.39]. Both mNETs and PNETs CgA values were significantly higher at the time of RP, than a year before [267 pmol/L (Q1=66, Q3=777) vs 166 pmol/L (Q1=52, Q3=535) respectively, T= 394.5, p=.03]. Overall, G1 tumours had significantly higher median CgA value at 6 months, than at 12 months before RP [181 pmol/L (Q1=56.25, Q3=624) vs 149.5 pmol/L (Q1=44, Q3=247.25) respectively, T=70, p=.048]. Conclusions: CgA seems to have a predictive value 6 months prior to RP for PNETs and G1 tumours of any origin. This observation is of value to identify specific patients, who will benefit from a more aggressive follow-up or even an earlier intervention, in cases of increasing CgA levels. Prospective studies are needed to enable more definitive conclusions. Sa1935 Variation and Utility Ofchromogranin a Assays for Gastric Carcinoid Type 1 Roberta E. Rossi, Jorge Garcia-Hernandez, Dalvinder Mandair, Nick Martin, Christos Toumpanakis, Martyn Caplin Introduction: Chromogranin A (CgA) is not very accurate for the diagnosis of gastric carcinoid type 1 (GC1). Clinical interpretation of CgA results may be affected by the heterogeneity between commonly available CgA assays. The diagnostic accuracy of an assay depends upon antibody specificity and the molecular forms it recognizes. The commercial CgA assay, DAKO (DAKO, Denmark A/S, Glostrup, Denmark) is an ELISA which recognizes a 23 kD C terminal fragment of CgA, whilst the Imperial Supra-regional Assay Service radioimmunoas- say (SAS Hammersmith Hospital, Imperial College, London) is a competitive radioimmunoas- say raised against the whole pancreastatin molecule. Aim: To compare two different CgA assays, the CgA-DAKO and the CgA-SAS to determine their accuracy in the diagnosis of GC1. Methods: Patients with a confirmed diagnosis of GC1 and available plasma Chromogranin A (CgA) measurements according to two different assays (Imperial SAS and DAKO) were identified from a database at the Neuroendocrine Tumour Unit, Royal Free Hospital, London, United Kingdom and retrospectively reviewed. CgA values were ranked in 4 groups: 1. normal values, 2. increase <2 upper normal limit (ULN), 3.increase between 2-5 ULN, 4. increase>5 ULN. Results: A total of 26 patients, 17 female and 9 male, mean age 55 years old ± 11.75, with a histologically confirmed diagnosis of GC1 and available CgA measurements at the time of diagnosis according to both assays (DAKO and SAS) were identified. At diagnosis, median CgA-DAKO values were significantly higher than median CgA-SAS (81IU/l, normal range < 27 IU/l versus 34.5 pmol/l, normal range < 60 pmol/l) T=35.5, p < 0.001. When ranking the data, the results confirmed median CgA-DAKO significantly higher than median CgA-SAS: 3 versus 1, T=0, p <0.001. Sensitivity was 77% and 7.7% for CgA-DAKO and CgA-SAS, respectively. Conclusions: CgA-DAKO shows a better sensitivity than CgA-SAS for the diagnosis of GC1, whereas the use of CgA-SAS in the follow up of patients with chronic atrophic gastritis might misdiagnose GC1 in more than 92% of cases and should be abandoned. Further prospective studies are warranted highlighting the importance of variation between CgA assays. Sa1936 Effect of Visceral Obesity on Lymph Node Metastasis in Colon Cancer Eunyoung Doo, Hang Lak Lee, Dae Won Jun, Dong Soo Han, Byung Chul Yoon, Ho Soon Choi, Joon Soo Hahm, Se Woo Park Background & Aim: An association between obesity and unfavorable outcomes for various types of malignancy has been established. However, the relationship between fat distribution and lymph node metastasis has not been well studied. The aim of our study is to determine the impact of visceral obesity on lymph node metastasis and overall survival in colon cancer. Patients & Methods: This study reviewed medical records for consecutive patients who underwent radical resection for colon cancer between 2003 and 2008. Metastatic lymph node ratio (MLR) was defined as the number of involved nodes by tumor divided to the total number of resected lymph nodes. Visceral obesity was determined by measuring abdominal fat volume distribution via CT scan and then calculating the percentage of visceral fat (VF%) to total fat area. Results: 278 patients were divided into two groups: VFs (VF% ≤ 29, n = 81) and VFv (VF% > 29, n = 197). The baseline characteristics showed some differences between two groups with respect to body mass index, total cholesterol and the proportion of MLR. In the multivariate analysis, MLR significantly decreased with the higher VF% (OR = 0.406, 95% CI = 0.206-0.801, P = 0.009). In addition, MLR was significantly associated with HbA1c, differentiation, lymphovascular invasion and perineural invasion. There was significant difference in overall survival between patients with VF% ≤ 29 and those with VF% > 29 (P = 0.009). Conclusion: Visceral obesity was associated with a lower ratio of metastatic lymph nodes and higher overall survival. AGA Abstracts