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e13648 Background: To determine whether estrogen receptor (ER) (+) and ER (-) status relates to epigenetic changes in breast cancer-related genes and to correlate with molecular breast cancer subtypes. Methods: From January 2002 to June 2005, we quantified methylation levels ERS1 gene in serum of 92 pts breast cancer. A PCR quantitative technique was used to analyze levels of methylation gene. We also examined and correlationed the expression of ESR1 AND HER2+ in tumors by immunohistochemistry with molecular phenotype. Results: Median age was 58 years (32-88); 69% were postmenopausal women. Nodal involvement (N0;63%,N1;30%,N2;7%), tumor size (T1;58%, T2;35%, T3;4%, T4;4%) and grade (G1;20%, G2;37%, G3;30%). Of the cases, 37pts (40%) were Luminal A (LA), 32pts (33%) Luminal B (LB), 14pts (15%) triple-negative (TN), and 9pts (10%) HER2+. The methylated ESR1 in serum was significantly associated with ER(-) in breast tumors >80% (p=0.0179). Methylation ESR1 was preferably associated with TN (80%) and HER2+ (6...

e13151 Background: NSCLC is frequently chemoresistant. Multidrug resistance phenotype is involved in the development of chemoresistance. It has been related to several proteins expression, like P-glycoprotein (mdr1 gene). We examined whether elevated mdr1 expression levels in peripheral blood mononuclear cells (PBMC) predict treatment response. Methods: We studied mdr1 gene expression in PBMC of 23 patients with NSCLC, advanced stages in most of the cases, who had not received treatment previously. Blood extraction of 5ml was made to each patient before (hour 0) and after paclitaxel-carboplatin chemotherapy (hour 6). The mdr1 gene expression levels were assessed by quantitative reverse transcription polymerase chain reaction. Results: After treatment, we found mdr1 overexpression in 22 patients. Expression levels were randomly distributed, so that overexpression under 3 was considered low level of expression, and overexpression above 4 was considered high level of expression. High levels were found in 11 ...

e19072 Background: The gene expression profile in peripheral blood samples from lung cancer patients is a potential predictor to treatment response. Methods: The study has been developed using 10 healthy volunteers as the control group and 10 lung cancer patients (stage IV). Written informed consent was obtained being the protocol approved by the local Clinical Research and Ethics Committee. Peripheral blood samples were obtained from lung cancer patients before (T0) and after treatment (T15d). RNA from peripheral blood samples was extracted and purified selecting 28S/18S ratios>1.5 to obtain cDNA and cRNA for hybridization of the 20,000 genes included in Human 20K CodeLink. An array from each participant was obtained in duplicate. For each array, 2 μg of cRNA was compared to 2 μg of healthy cRNA.. Significant genes were found using Significance Analysis of Microarrays which uses repeated permutations of the data. Results: The selected genes were expressed >3-fold with a false discovery rate =0.05. Before treatment (T0) when patients were compared to healthy volunteers there was an increase in the expression of: histone 1 H4c, transforming growth factor beta 2, endothelial cell growth factor 1 (platelet-derived), glucose-6-phosphatase catalytic 2, Relaxin 3 receptor 1, Insulin-like growth factor binding protein 2, RAS-like family 11 member B, and ELK4. After treatment (T15d), when each lung cancer patient's results were compared to their own before treatment results (T0), there was an increase in the expression of: Bcl2, myosin light polypeptide 4; interferon alpha-inducible protein 27; interferon gamma receptor 1; RASSF5, ARHGEF6, IGFBP5, tumor protein p53 inducible nuclear protein 1, peroxisome proliferative activated receptor gamma. Conclusions: The data presented identifies biologically relevant over-expressed genes in lung cancer. A validation of these results and the analysis of the genes that identify patients who will respond positively to erlotinib treatment is being carried out. No significant financial relationships to disclose.

14041 Background: Preoperative CT improves survival in esophageal cancer. 50% of patients (pts) do not respond to cisplatin+5-FU (C+F). The reduction of fluorodeoxyglucose uptake after 14 days (d) of CT predicts clinical response (rsp). Our objective was to measure the rsp (rsp) rate after CT adjusted according to PET rsp. Methods: Eligible pts were ≥ stage II esophageal cancer and able to tolerate CT. By adjusting CT according to PET rsp, we expected an increase of rsp rate by 25%. Taking into account a confidence level of 90%, an error β of 20% and a minimal error of 15% (even with such a high error rate the data will exceed the standard results), we calculated a sample size of 23 pts. All underwent esophagoscopy, computed tomography and PET scan prior to C (100mg/m2 d1) +5-FU (1,000mg/m2 d1–5). If PET rsp after first cycle (uptake decreased ≥ 35%), we continued up to third C+F cycle, then if endoscopy rsp: C+F + concurrent radiation only if stage II or III. If no endoscopy rsp, surgery only if stage II or III. On the other hand, if the pts had no rsp in PET after first C+F cycle they continued with 2 cycles of docetaxel (35mg/m2 d 1 & 8) and irinotecan (50mg/m2 d 1 & 8) (D+I) every 21 d and then if endoscopy rsp: radiation + docetaxel only if stage II or III. If no endoscopy rsp, surgery. Results: Since 2/04, 23 pts have been enrolled. Location: 2 cervical, 4 upper thoracic, 7 mid-thoracic, 10 GE junction. PET stage: 7 IIA, 6 IIB, 2 III, 2 IVA, 6 IVB. Up-staging with PET in 6 pts, down-staging in 4 pts. Histology: 10 Adenocarcinoma, 13 squamous carcinoma. Improved swallowing function: from a total of 12 PET responders, 9 had a clinical rsp after C+F, 3 did not. From 11 PET non-responders, 7 had a clinical rsp after D+I, 4 did not. Global clinical rsp = 16/23 (70%). Endoscopy rsp (frequent inaccuracy by overstaging): from a total of 12 PET responders, 6 had a clinical rsp after C+F, 6 did not. From 11 PET non-responders, 7 had a clinical rsp after D+I, 4 did not. Global clinical rsp = 13/23 (57%). Conclusion: Our results suggest that it is possible to significantly increase the percentage of pts who respond to induction CT adjusted according to PET in esophagogastric cancer before concurrent chemoradiotherapy or esophagectomy, or both. No significant financial relationships to disclose.

3146 Background: The molecular profile of a cancer may give information pertinent to response to chemotherapeutic agents. Vascular endothelial growth factor is a endothelial mitogen, survival facto...