Immunohistochemical study of the neural development transcription factors (TTF1, ASCL1 and BRN2) in neuroendocrine prostate tumors

Abstract

ObjectiveProstatic small-cell neuroendocrine carcinoma is an uncommon malignancy that constitutes 0.5–1% of all prostate malignancies. The median cancer-specific survival of patients with prostatic small-cell neuroendocrine carcinoma is 19 months, and 60.5% of the patients have metastatic disease. Neural development transcription factors are molecules involved in the organogenesis of the central nervous system and of neuroendocrine precursors of various tissues, including the suprarenal gland, thyroid glands, lungs and prostate. Material and methodsWe present 3 cases of this uncommon condition, applying the new World Health Organisation criteria. We conducted studies through hematoxylin and eosin staining and analysed the expression of the neural development transcription factors achaete-scute homolog like 1, thyroid transcription factor 1 and the class III/IV POU transcription factors, as a new research line in the carcinogenesis of prostatic neuroendocrine tumors. ResultsIn case 1, there was no TTF1 immunoexpression. Cases 2 and 3 had positive immunostaining for ASCL1, and Case 1 had negative immunostaining. BRN2 immunostaining was negative in case 1 and positive in cases 2 and 3. ConclusionThe World Health Organisation does not recognise any molecular or genetic marker with prognostic value. ASCL-1 is related to the NOTCH and WNT signaling pathways. ASCL-1, TTF1 and BRN2 could be used for early diagnosis and as prognostic factors and therapeutic targets.