MP49-14 SMYD3 IS RESPONSIBLE FOR ANDROGEN-INDUCED H3K4 METHYLATION IN PROSTATE CANCER CELLS

measuring 22mm. Due to the frequent multifocality of prostate cancer, only few cancers were homogeneously ERG positive on a patient level. ERG expression was markedly more frequent in EO-PCA than in elderly patients. In EO-PCA, 11% of cancers were homogeneously and 67% were heterogeneously ERG positive. In elderly patients 2% of cancers were homogeneously and 58% were heterogeneously ERG positive (p1⁄40.0195). CONCLUSIONS: In summary, these data show, that about 20-25% of prostate cancer foci have ERG fusions occurring early e potentially at the stage of cancer initiation. Subpopulations with ERG fusions subsequently occur in about 50% of initially ERG negative cancer foci. Mostly due to the multifocality of prostate cancer, the vast majority of cancers are heterogeneous for TMPRSS2:ERG fusions on a patient level. This challenges the concept of classifying prostate cancer patients into “fusion type” from “non-fusion type” prostate cancer.