Chromogranin A expression in familial versus sporadic prostate cancer

Objectives. To evaluate whether a significant difference in chromogranin A (CgA) levels exist between patients with familial and sporadic cancer. Methods. The study included 146 patients with clinically localized prostate adenocarcinoma (Stage T2N0M0), who underwent radical prostatectomy between June 1999 and June 2004. Patients were considered to have a positive family history for prostate cancer when the index patient confirmed the diagnosis of prostate cancer in a first-degree relative (brother or father). On the day of surgery, a blood sample for the determination of serum prostate-specific antigen and CgA levels (radioimmunoassay) was obtained from all patients. In a subgroup of 20 patients, CgA mRNA expression was also evaluated by reverse transcriptase-polymerase chain reaction at the prostatic tissue level. Results. A positive familial history was found in 28 (19.2%) of the 146 patients. The mean patient age in the familial group was significantly (P < 0.0001) lower than that in the sporadic group. No significant difference between the familial and sporadic groups was found in terms of prostate-specific antigen level (P = 0.9625) or Gleason score distribution (P = 0.4891). The familial group had significantly (P = 0.0013) lower serum CgA levels (43.3 +/- 12.7 ng/mL, median 39.9) compared with the sporadic group (55.9 +/- 19.4 ng/mL, median 54.1). The familial group also had significantly (P = 0.0432) lower expression of tissue CgA mRNA compared with the sporadic group. Conclusions. The result of significantly lower CgA expression in familial compared with sporadic prostate cancer cases suggests that neuroendocrine activity is not increased in familial cases and also confirms that familial cancer is not a more aggressive disease.