Prostate field cancerization (or field effect) is characterized by the presence of molecular alterations in histologically normal tissues adjacent to adenocarcinomas. Accordingly, our research indicates deregulated expression of several proteins that define this type of molecular pathology. The scope of the present study was to determine the expression of the key transcription factor and potential marker of field cancerization early growth response 1 (EGR-1) in human prostate tissues derived from prostatectomies and biopsy cores.
EGR-1 was detected by immunofluorescence using a polyclonal anti-human EGR-1 and Alexa Fluor 488-conjugated secondary antibodies. EGR-1 expression was quantitated by determining the pixel count per area (signal intensity) in digitized images using ImageJ software. In this proof-of-concept study, a total of 4 cases consisting each of prostatectomy and matched biopsy material, either containing or devoid of cancerous cells (malignant or benign) were analyzed. Expression levels and data distribution of EGR-1 were similar by region of interest analysis between malignant and benign prostatectomies (p = 0.28), but different between malignant and benign biopsies (p < 0.05). EGR-1 protein expression is similar in cancerous (malignant) and in histologically normal adjacent (benign) tissues from both prostatectomy and biopsy specimens. This supports the concept of field cancerization and indicates a potential organ-wide molecular change, regardless of the presence or absence of cancer cells. Markers of field cancerization, such as EGR-1, could be exploited as pre-surgical disease indicators in false negative biopsies, identify areas of repeat biopsy, and add molecular information to surgical margins.
Shoshan, Dor and Bisoffi, Marco, "Prostate Field Cancerization -- Thinking Outside the Tumor" (2014). Student Research Day Abstracts and Posters. 64.