Interleukin-1 receptor antagonist polymorphism in patients with prostate cancer and benign prostatic hyperplasia: A case control study from north India

Objective: Some studies suggest that immunological components play a key role in the development of various cancers like gastric, cervical and ovarian cancers. Polymorphism in the IL-1 Ra gene has been reported to be associated with different malignant diseases. There are however, inadequate data for prostate cancer (CaP) till date. Methods: In a case control study we analyzed the polymorphism of interleukin-1 receptor antagonist (IL-1Ra) in 110 men with CaP; 92 with benign prostate hyperplasia (BPH) and 128 normal healthy controls. Genomic DNA fragments were amplified by polymerase chain reaction and visualized on 2% agarose gel. Results: The distributions of genotype and allele frequencies were significantly different between the CaP, BPH patients and the control group. In CaP and BPH patients Type B/B (410 bp) genotype is significantly dominant (51.8 and 54.3 vs. 28.9%) with greater than 3-fold risk. Type A/A (240 bp) genotype is dominant (48.4 vs. 14.5 and 19.6%) in normal controls. Allele D (325 bp) and E (595 bp) was completely absent in our study groups. There was no significant association between Gleason grade of CaP patients and frequency of different genotypes. Conclusions: Our data suggests that IL-1Ra gene polymorphism is directly implicated in the susceptibility but not in the clinical course of patients with CaP and BPH. Furthermore, it also suggests that Type B (410) allele acts as a risk factor for CaP as well as for BPH. The mechanism of this association, however, still remains a matter of speculation. Further studies are needed to confirm our findings and to elucidate the role of IL1-Ra gene polymorphism for the risk of CaP and BPH.