Serum 17β-estradiol fails as a marker in identification of aggressive tumour disease in patients with localized prostate cancer.

Background: There is evidence that obesity is associated with an aggressive prostate cancer (PC). Furthermore, preclinical studies suggest that oestrogens may play a pivotal role in this context. The biological processes underlying these observations are not fully understood. We prospectively evaluated whether obesity and/or preoperative estradiol levels are associated with high-grade cancer in patients with clinically localized PC at the time they underwent radical retropubic prostatectomy (RRP).
Methods: Preoperative sex hormone serum 17β-estradiol (E2) as well as body mass index (BMI) and waist circumference (WC) were assessed in a cohort of 746 consecutive men treated with RP from February 2011 to October 2014. The data were correlated with patient-specific and clinicopathologic variables.
Results: A total of 746 patients underwent RRP. Median age was 68.0 years. Median E2 serum level was 18.3 ng/l (IQR 12.9-24.2 ng/l). Median BMI was 26.6 kg/m(2) (IQR 24.6-29.1 kg/m(2)), and the median WC was 103 cm (IQR 96-110 cm). Serum E2 below or above the normal range was not found more frequently in obese patients (high BMI: p = 0.62; large WC: p = 0.83). E2 was not associated with BMI in our cohort of patients (r = 0.07, p = 0.10) or WC (r = 0.07, p = 0.10). There was no association between preoperative serum E2 levels and tumour stage (p = 0.86, Fisher's exact), tumour grade (p = 0.37), lymph node involvement (p = 0.59) or Gleason score (p = 0.44). However, obesity correlated with tumour stage and grade (p = 0.036, Fisher's exact) and nodal metastasis (p = 0.039, Fishers' exact).
Conclusion: Pretreatment serum 17β-estradiol (E2) cannot be considered as a suitable marker for aggressive tumour disease in patients with localized prostate cancer.