Antibody immunity to prostate cancer associated antigens can be detected in the serum of patients with prostate cancer.
OBJECTIVE
Several immune based therapies targeting prostate cancer associated proteins are currently undergoing clinical investigation. In general, however, little is known about the immunogenicity of prostate cancer or which prostate cancer associated proteins elicit immune responses. We determine whether patients with prostate cancer have antibody immunity to known prostate cancer associated proteins, what the prevalence of this immunity is and whether immunity to individual proteins is associated with the stage of disease.


METHODS
We evaluated the inherent humoral immune response against prostate specific antigen (PSA), prostatic acid phosphatase, p53 and HER-2/neu, all known prostate cancer associated proteins, in 200 patients with various stages of disease and male controls.


RESULTS
Antibody immunity to PSA was significantly different between the patient (11%, 22 of 200) and control populations (1.5%, 3 of 100, p = 0.02), and titers 1:100 or greater were particularly prevalent in the subgroup of patients with androgen independent disease (11%, 6 of 56). Antibody immunity to prostatic acid phosphatase and p53 was detected (5.5%, 11 of 200 and 6%, 12 of 200), and was not different from the control population (4%, 4 of 100, p = 0.57 and 7%, 7 of 100, p = 0.74). Antibody immunity to HER-2/neu was significantly higher in patients with prostate cancer (15.5%, 31 of 200) compared to controls (2%, 2 of 100, p = 0.0004), and titers 1:100 or greater were most prevalent in the subgroup of patients with androgen independent disease (16%, 9 of 56).


CONCLUSIONS
These findings suggest that prostate cancer is an immunogenic tumor. Moreover, for PSA and HER-2/neu the prevalence of antibody immunity was higher in patients with androgen independent disease, indicating that even patients with advanced stage prostate cancer can have an immune response to their tumor.
McNeel
D G
DG
Division of Oncology, University of Washington, Department of Biostatistics, Public Health Sciences Division, Fred Hutchinson Cancer Research Center and Department of Urology, University of Washington, Seattle, USA.
Nguyen
L D
LD
Storer
B E
BE
Vessella
R
R
Lange
P H
PH
Disis
M L
ML
D000135:Acid Phosphatase / Q000276:immunology; D000328:Adult; D000368:Aged; D000917:Antibody Formation; D000951:Antigens, Neoplasm / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D008297:Male; D008875:Middle Aged; D018739:Oncogene Proteins v-erbB / Q000276:immunology; D011467:Prostate / Q000201:enzymology; D017430:Prostate-Specific Antigen / Q000276:immunology; D011471:Prostatic Neoplasms / Q000097:blood / Q000276:immunology*; D016159:Tumor Suppressor Protein p53 / Q000276:immunology
D000951:Antigens, Neoplasm; D018739:Oncogene Proteins v-erbB; D016159:Tumor Suppressor Protein p53; D000135:Acid Phosphatase; D017430:Prostate-Specific Antigen