MRI improves prognostication of prostate cancer metastases, death

An association exists between magnetic resonance imaging (MRI) findings of localized prostate cancer and clinically relevant long-term oncologic outcomes, a study has found.

“Combining MRI and clinicopathological data results in more accurate prognostication, which could facilitate individualized patient management,” the authors said.

A cohort of 3,406 consecutive men who underwent prostate MRI before prostatectomy (n=2,160) or radiotherapy (n=1,246) between 2001 and 2006 were included. The authors retrospectively interpreted and categorized T2-weighted MRI exams as no focal suspicious, organ confined focal lesion, focal lesion with extraprostatic extension, or focal lesion with seminal vesicle invasion.

Clinical risk was recorded based on European Association of Urology (EAU) guidelines and the Cancer of the Prostate Risk Assessment (CAPRA) scoring system. Cox models and inverse probability censoring weights were used to estimate survival probabilities and c-indices, respectively.

The median follow-up was 10.8 years. Higher MRI categories correlated with a higher risk of developing metastases (hazard ratio [HR], 3.5–18.1; p<0.001 for all MRI categories) and prostate cancer death (HR, 3.1–29.7; p<0.001–0.025). These associations were statistically independent of EAU risk categories, CAPRA scores, and treatment type (surgery vs radiation).

The combination of EAU risk or CAPRA scores and MRI categories resulted in significantly improved prognostication of metastases (c-indices: EAU, 0.798; EAU + MRI, 0.872; CAPRA, 0.808; CAPRA + MRI, 0.877) and prostate cancer death (c-indices: EAU, 0.813; EAU + MRI, 0.889; CAPRA, 0.814; CAPRA + MRI, 0.892; p<0.001 for all).