Commonly measured systemic inflammatory markers may aid in determining prostate cancer (PCa) risk and prognosis, according to a new study.1
In the prospective, population-based Prostate Cancer Study throughout Life (PROCA-life), which included a cancer-free cohort of 7270 men from Tromsø, Norway, increased levels of high-sensitivity C-reactive protein (hs-CRP) at study entry and a relatively large increase in hs-CRP levels during follow-up were associated with an increased risk for PCa. High levels of hs-CRP combined with high white blood cell (WBC) counts predicted an increased risk of both PCa and metastatic PCa, investigators reported in the International Journal of Cancer.
“Importantly, hs-CRP and WBC are often used in routine clinical practice, and thus easily accessible,” Einar Stikbakke, a PhD candidate at The Arctic University of Norway, and colleagues concluded. “Our findings contribute to understanding the relationship between inflammation and prostate cancer development, and may be useful in future research on prostate cancer etiology and possibly prevention.”
PCa developed in 509 of the 7270 men during a mean 11.8 years of follow-up. The mean age at diagnosis was 71.7 years. Prior to their diagnosis, men in the highest tertile of hs-CRP had a 30% increased risk for PCa (hazard ratio [HR], 1.30; 95% CI, 1.04-1.63) compared with those in the lowest tertile after multivariable adjustment. Each 1 mg/L increase in hs-CRP was associated with a 3% increased risk (HR, 1.03; 95% CI, 1.00-1.07). Men who experienced a 1 mg/L or higher increase in hs-CRP between study entry and a second hs-CRP measurement during follow-up had a 36% increased risk for PCa (HR, 1.36; 95% CI, 1.02-1.82) compared with those who had a change of less than 1 mg/L. The middle tertile of WBC count was associated with a 46% increased risk for PCa (HR, 1.46; 95% CI, 1.17-1.80) compared with the lowest tertile.
To evaluate the effect of using hs-CRP and WBC count in combination to determine risk, the investigators calculated a systemic inflammatory score (SIS), which was the sum of tertile rankings for both of these biomarkers. The score ranged from 2 to 6 points, with 2 to 4 being a low score and 5 or 6 being a high score. Compared with a low SIS, a high SIS was associated with a 28% increased risk of PCa (HR, 1.28; 95% CI, 1.06-1.53) and 68% increased risk of metastatic PCa (HR, 1.68; 95% CI, 1.04-2.73). Each 1-point increase in SIS was associated with a 9% (HR, 1.09; 95% CI, 1.02-1.17) and 25% (HR, 1.25; 95% CI, 1.02-1.51) increased risk of PCa and metastatic PCa, respectively.
The investigators acknowledged that their study was limited by a relatively small sample size. They also noted that the Tromsø population is mainly White, so their findings may not be relevant to men of other races.
- Stikbakke E, Richardsen E, Knutsen T, et al. Inflammatory serum markers and risk and severity of prostate cancer: The PROCA-life study. Int J Cancer. 2020;147(1):84-92. doi: 10.1002/ijc.32718.