The role of an androgen receptor polymorphism in the clinical outcome of patients with metastatic prostate cancer.
ABSTRACT The androgen receptor plays a major role in the development and function of normal and malignant prostate cells. Due to the relationship of the androgen receptor and prostatic growth, it has been proposed that polymorphisms within the androgen receptor may play a role in an individual's susceptibility to developing prostate cancer. An inverse relationship has been established between a highly polymorphic trinucleotide repeat located in the first exon of the androgen receptor and the transactivaton function of the receptor. Serum samples were collected from 131 patients with histologically confirmed adenocarcinoma of the prostate, DNA was isolated, and the polymorphic CAG repeat was amplified by PCR and sequenced. The CAG repeat lengths were then compared with age at diagnosis, age at time of study, baseline log(10) PSA, Gleason score, time from diagnosis to initiation of hormonal therapy, time to progression after androgen ablation, and overall survival time. No correlation was found between CAG length and time to progression or overall survival time, but a significant correlation was found between Gleason score and CAG length suggesting that shorter CAG lengths may predict a higher histological grade of prostate cancer.