1699 IDENTIFYING NOVEL DNA METHYLATION MARKERS TO MONITOR BLADDER CANCER RECURRENCE IN URINE SEDIMENTS FROM TURBT PATIENTS

logic subtype, carcinoma in situ (i.e., Tis), is present in 40% of total bladder cancers diagnosed. However, there is currently no ability at the time of initial diagnosis to identify which of these patients will respond to standard-of-care treatment, intravesical administration of Bacillus Calmette-Guerin (BCG). Thus, Tis bladder cancer patients are often treated subjectively using a “one size fits all” approach with only about a 60% success rate (i.e., tumor-free) among treated patients. The aim of the present study was is to correlate the BCG responsiveness of patients with Tis bladder cancer with measures of the tumor immune microenvironment at the time of initial diagnosis. METHODS: The immune microenvironments of tumor biopsies of 20 Tis bladder cancer patients responsive to BCG therapy (BCG ) were assessed relative to biopsies derived from 18 non-responsive patients (BCG-). Each tumor immune microenvironment was determined as a function of two immunohistochemical metrics: (i) The level of tumor eosinophil infiltration as well as the extent of eosinophil degranulation (i.e. Th2 effector arm) and (ii) The relative number of tumor-infiltrating GATA-3 (i.e., Th2-polarized) vs. T-bet (i.e., Th1 polarized) lymphocytes. RESULTS: The bladder biopsies of “normal” subjects displayed only a nominal eosinophil infiltrate with no evidence of degranulation or infiltrating lymphocytes. In contrast, Tis bladder tumors often displayed a robust tissue eosinophilia accompanied by degranulation. The tumor immune microenvironments were decidedly Th2 polarized with 3-fold more GATA-3 relative to T-bet lymphocytes. More importantly, each of these immune biomarkers had prognostic value in the evaluation of bladder cancer patients. Specifically, the data showed that the levels of each immune biomarker were statistically higher in patients subsequently shown to be BCG relative to BCGsubjects. In addition, an algorithm integrating these immune metrics (i.e., Th2 Signature) provided an unambiguous biomarker that stratifies bladder cancer patients prior to treatment decisions with a high degree of specificity. CONCLUSIONS: The immunohistochemical assessments of the Tis immune tumor microenvironment represents a clinically-relevant screening strategy of cancer patients as to their subsequent responsiveness to the standard-of-care treatment.