Androgen receptors and growth fraction in metastatic prostate cancer as predictors of time to tumour progression after hormonal therapy.
Reliable predictors of response for prostate cancer patients undergoing hormone therapy are lacking. Since 80-90% of such patients do respond but the time between therapy and relapse (progression) is variable, our goal has been to predict the time to tumour progression after therapy rather than merely to predict whether a patient would respond. We investigated AR positivity and Ki-67 growth fraction of malignant epithelial cells as potential predictors of the time to progression; these studies are summarized in this chapter. The percentage of AR positive nuclei has no predictive value; however, the variance of AR immunostaining intensity within a certain specimen is an important discriminator between good responders (patients with a prolonged interval between initiation of therapy and relapse) and poor responders (short time to relapse). There is a trend towards a higher growth fraction in poor responders, but statistical significance is borderline at best. Growth fraction measurement might be more useful as a predictor if the rate of cell death could also be evaluated or if analysis could be limited to the androgen independent cells that continue to proliferate after hormone therapy and that ultimately are responsible for the clinical manifestation of tumour progression and relapse.
Sadi
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MV
Department of Urology, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205.
Barrack
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D001345:Autoradiography; D014408:Biomarkers, Tumor; D016923:Cell Death; D002455:Cell Division; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D009362:Neoplasm Metastasis; D009376:Neoplasms, Hormone-Dependent / Q000378:metabolism* / Q000473:pathology; D011379:Prognosis; D011471:Prostatic Neoplasms / Q000378:metabolism* / Q000473:pathology; D011944:Receptors, Androgen / Q000096:biosynthesis*
D014408:Biomarkers, Tumor; D011944:Receptors, Androgen