Introduction:The human epidermal growth factor receptor (HER-2) is a cell membrane surface-bound receptor tyrosine kinase which has been associated with increased breast cancer recurrence and a worse prognosis. Its presence also determines which patients are candidates for targeted therapy with trastuzumab. The purpose of this retrospective study was to determine the percentage of HER-2 status change in recurrent breast cancer.Methods:In this study, we retrospectively reviewed the charts of 2,652 patients diagnosed with breast cancer in our institutution between 2003 and 2009. Forty-four patients with recurrent breast cancer and available HER-2 status at the time of diagnosis and at recurrence were identified. HER-2 status was assessed by immunohistochemistry (IHC) and/or fluorescence in situ hybridization (FISH). When both methods were available, we used FISH as our reference.Results:A change in HER-2 status at recurrence was observed in six patients (13.6%). One patient (2.3%) changed from negative to positive. Five patients (11.3%) had a change from positive to negative. These five patients represented 50% of the patients with positive HER-2 at the time of initial diagnosis. HER-2 status remained unchanged in thirty-eight patients (86.4%).Conclusion:A change in HER-2 status can be noted at the time of recurrence. The exact mechanism is not yet well understood, and further studies are needed to identify it. Our data support the fact that patients with recurrent breast cancer should have their HER-2 status re-evaluated, since this affects therapeutic options. Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 5109.

1925 Introduction: Monoclonal gammopathy of undetermined significance (MGUS) is an asymptomatic premalignant clonal plasma cell proliferative disorder. It occurs in over 3 percent of the general population over the age of 50. MGUS can progress to multiple myeloma (MM) or related cancers at a rate of about 1.0 to 1.5 percent per year. There are no findings at diagnosis of MGUS that reliably distinguish patients who will remain stable from those who will progress to a malignant disease. Size and type of serum monoclonal protein, as well as serum free light chain ratio have been suggested in some studies as independent risk factors for disease progression. In this study, we tried to analyze the relationship between Mean Corpuscular Volume (MCV) and the risk of progression of MGUS into a malignant lymphoproliferative condition. Methods: A total of 1744 patients, from a single institution, with a first diagnosis of MGUS from April 18th, 1995 till June 24th, 2010 were included in this study. Patients analyzed were divided into two groups. Group 1 consisted of 345 patients with an elevated MCV (>100fL/red cell) and group 2 consisted of 1399 patients with a normal MCV (between 80fL/red cell and 100fL/red cell). Patients with short follow up (<3 months), low B12/folate levels, hypothyroidism, liver disease or a serum monoclonal protein >1.5g/dL were excluded. The Chi-square test was used to compare the proportion of patients who progressed in group 1 relative to group 2. Results: After a median follow up of 51 and 58 months for the high MCV and normal MCV respectively, there were 78 progressions (22.6%) versus 267 non-progressions (77.4%) among the high MCV patients (Group1) and 110 progressions (7.9%) versus 1289 non-progressions (92.1%) among the normal MCV patients (Group 2). The difference in progression between the two groups was statistically significant (Chi-square test p-value < 0.001). The odds ratio for the progression comparison of the high versus normal MCV groups was 3.4 with a 95% confidence interval of 2.5 to 4.7. Conclusion: In our single institution, retrospective study, there seems to be a higher incidence of malignant transformation in the subset of patients with MGUS having an elevated MCV. MCV is a cost effective method that might help identify, at presentation, patients with benign monoclonal gammopathies requiring stricter monitoring. Disclosures: No relevant conflicts of interest to declare.

Background: Cancer and Immune thrombocytopenic purpura (ITP) are two common disorders. However, the relationship between these two diseases has rarely been reported in the literature. The purpose of this retrospective study was to determine the association between cancer and ITP. Methods: We retrospectively reviewed the charts of 307 patients diagnosed with ITP in our institution between 2005 and 2009. The diagnosis of ITP was defined by a platelet count less than 140.109/l with normal or increased number of megakaryocytes on bone marrow aspirate, after exclusion of thrombocytopenia-induced medications or disorders, and absence of splenomegaly. Results: 32 patients (10.4 percent) were found to have cancer. Of these 32 patients, breast cancer accounted for 28.1 percent, prostate cancer for 18.8 percent, skin cancer for 15.6 percent, gastrointestinal cancer and multiple cancer history for 12.5 percent each, bladder cancer and lymphoma for 6.25 percent each. 12 patients (37.5 percent) had ITP before cancer diagnosis, and 16 patients (50 percent) after cancer diagnosis. Both diseases were concomitant in 4 patients (12.5 percent). Conclusion: 10.4 percent of patients with ITP have cancer. Breast cancer accounted for most of the cases followed by prostate cancer. Our data suggest an association between cancer and autoimmune platelet destruction, and further investigation is warranted to understand the exact mechanism. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1885. doi:10.1158/1538-7445.AM2011-1885

4317 Introduction: Inferior Vena Cava (IVC) filters have been available for almost 40 years but their clinical utility and safety have not been completely evaluated in patients with no previous history of deep vein thrombosis (DVT) or pulmonary embolism (PE). The role of anticoagulation in patients with IVC filter with no history of DVT/PE is questionable. In this study, we try to determine if there is a role or benefit from anticoagulation in patients with an IVC filter placed but without any other risk factor for deep vein thrombosis (DVT) or pulmonary embolism (PE). Methods: we retrospectively reviewed the charts of 562 patients who had an IVC filter placed between 2003 and 2005. 442 patients were excluded because they had a history of DVT/PE, or because of a hypercoagulable state (genetic predisposition, prolonged hospitalization/immobilization, surgery, or malignancy). Of the 120 remaining patients included in this study, 6 had their IVC filter removed. And therefore we only analyzed the charts of 114 patients who had a permanent IVC filter placed for prophylactic reasons. Group 1 consisted of 17 patients who received different forms of anticoagulation (subcutaneous heparin, low molecular weight heparin or coumadin). Group 2 consisted of the remaining 97 patients who did not receive any form of anticoagulation. Results: 2 out of 17 patients in group 1 had a DVT and 14 out of 97 patients in group 2 had a DVT. The incidence of DVT was 11.8% in group 1 versus 14.4% in group 2 (p-value 0.770). The median onset of DVT/PE after IVC filter placement was 31 days. The median time of follow up was 77.33 months. Conclusion: Patients who had a permanent prophylactic IVC filter placed but with no history or risk factors for DVT/PE appear to be at an elevated risk for new DVT/PEs. In these patients, the role of anticoagulation is questionable. With a median 6 year follow up, anticoagulation seemed to non significantly lower the risk of DVT/PE. Larger randomized prospective trials are needed to examine the efficacy and duration of anticoagulation in patients with a prophylactic IVC filter placed. Disclosures: No relevant conflicts of interest to declare.

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