A combination of both testosterone and white blood count as predictive factors of overall survival in localized prostate cancer

129 Background: Low testosterone is generally associated with a higher overall mortality rate. We previously published that an increase in neutrophils is associated with lower overall survival in a large population of patients with localized prostate cancer. In this study, we tested a combination of both testosterone and neutrophils to predict for overall survival in a prospective cohort of patients treated with radiotherapy for localized prostate cancer. Methods: 414 patients from our institutional database were enrolled prospectively in phase 2 or 3 studies. To be included in this present analysis, patients had to have a baseline testosterone and complete blood count before enrollment in their respective study. Thirty-three patients were excluded for missing data for a total of 381 (92%) patients were included for analysis. Multivariate cox proportional hazards models were used to analyze the influence of white blood count (WBC = neutrophils + lymphocytes) and testosterone level on biochemical recurrence (Phoenix definition) and overall survival (OS). A cutoff level for testosterone of 10.4 nmol/l ( = 300ng/dL) was used as an indicator of hypogonadism and a WBC cutoff of 6.2 (109/L) representing the median value of this study population. Results were adjusted for cancer characteristics, comorbidities and androgen deprivation therapy. Results: Median age (range) was 71 (52-82) years. The median follow-up for biochemical recurrence and OS analysis were 72 and 78 months, respectively. WBC and testosterone were not predictive of biochemical recurrence, but CAPRA score 6-10 vs. ≤ 2 was (HR 5.39, 95% CI 1.19-24.45). WBC ≥ 6.2 alone was not associated with OS (HR 0.66, 95% CI 0.30-1.46), but when combined with a testosterone > 10.3 nmol/l, it was associated with a HR of 2.96 (95%CI 1.45-6.06) when compared to a WBC < 6.2, P-interaction = 0.01. Conclusions: A combination of high WBC and normal testosterone levels seem to be associated with increased mortality in patients with localized prostate cancer. Validation in larger samples is needed and could help to identify patients with increased risk of mortality within the first 6-7 years post treatment.