Image analysis discloses differences in nuclear parameters between ERG+ and ERG- prostatic carcinomas

Prostatic carcinoma (PC) is the most frequent urologic cancer and one of the most frequent cancers in males; it is a heterogeneous disease, in terms of molecular features, morphology and prognosis. About half of cases depends on TMPRSS2-ETS translocation which leads to a production of ERG transcription factor. ERG+ and ERG- cancers seem to differ in a number of features, which could lead to an altered nuclear structure; the aim of the study was to test this hypothesis. The material consisted of total 39 PC cases, representing ERG+ and ERG-, as well as Gleason pattern 3 and 4. Filtering by color deconvolution and automatic segmentation were used, and the properly detected nuclei were manually selected. From each case fifty nuclei were obtained; then geometric features and texture parameters were assessed. The analysis of the collected data showed differences both between ERG+/ERG- and Gleason pattern 3 and 4 cases in most of the features analyzed. Our results suggest that indeed the ERG status, thus likely TMPRSS2-ETS translocation, has an impact on morphology of nuclei in PC, and their differences are evident enough to be detectable by image analysis.