Blood and tissue levels of chromogranin A (CgA), a protein expressed by cells in certain tumors, may predict hormone refractory disease in patients newly diagnosed with prostate cancer who are on androgen deprivation therapy, Italian researchers say. In a study of 211 patients receiving LH-RH-A injections or a second-line hormone therapy, immunohistochemical CgA expression showed a significant correlation with the early onset of hormone refractory disease (prostate cancer that no longer responds to hormone therapy) and poor prognosis. CgA maintained its predictive power regardless of whether the patient received hormone therapy alone or with either radiation or prostatectomy. CgA levels in the blood correlated with CgA expression in tissue biopsies. Similarly, increasing blood levels of the marker also signaled earlier onset of hormone refractory disease and shortened survival.
Although previous studies have come to the same conclusion, the researchers recommend waiting for validation of their results in more patients before routinely measuring CgA in a clinical setting.
Source: Berruti A, Mosca A, Porpiglia F, et al. Chromogranin A Expression in Patients with Hormone Naïve Prostate Cancer Predicts the Development of Hormone Refractory Disease. Journal of Urology 2007;178:838–43. PMID: 17631319.
Originally published Oct. 1, 2007; Last reviewed April 12, 2011