Age is associated with upgrading at confirmatory biopsy among men with prostate cancer treated with active surveillance

INTRODUCTION - Active surveillance is increasingly recommended for older men with low-risk prostate cancer. Although older men have higher all-cause mortality, they also have higher prostate cancer-specific mortality. We hypothesized that older age is associated with an increased risk of Gleason score upgrading at confirmatory biopsy when controlling for prostate volume.

METHODS - We retrospectively reviewed data from 1,130 patients with prostate cancer who were treated with AS from 1991 through 2011. We included 646 patients who had clinical Gleason ≤6 stage ≤T2a prostate cancer, a confirmatory biopsy within 2 years of diagnostic biopsy, and prostate MRI prior to the confirmatory biopsy. The primary outcome was Gleason score upgrading to ≥7 on confirmatory biopsy. We used logistic regression to estimate the effect of age on upgrading, adjusting for MRI prostate volume and other potential confounders.

RESULTS - Median age was 66 years (IQR 61-72) and MRI prostate volume was 41 mL (IQR 29-55). At confirmatory biopsy, 9% (55/646) of patients were upgraded, 45% (290/646) were unchanged, and 46% (297/646) had a negative biopsy. Older age was associated with higher odds of being upgraded (adjusted OR 1.05, 95% CI 1.01-1.09; p=0.009), and larger prostate volume was associated with lower odds of being upgraded (adjusted OR 0.80 per 10mL increase, 95% CI 0.7-0.9; p=0.012).

CONCLUSIONS - Our findings suggest that older age is associated with an increased risk of misclassification on diagnostic biopsy. Older men who are interested in AS should be counseled about the risks and benefits of having a confirmatory biopsy.

J Urol. 2015 Jun 25. pii: S0022-5347(15)04295-0. doi: 10.1016/j.juro.2015.06.084. [Epub ahead of print]

Anderson CB1, Sternberg IA1, Karen-Paz G1, Kim PH1, Sjoberg D2, Vargas HA3, Touijer K1, Eastham JA1, Ehdaie B4.

1 Urology Service, Department of Surgery.
2 Biostatistics and Epidemiology, Memorial Sloan Kettering Cancer Center, New York, New York.
3 Radiology.
4 Urology Service, Department of Surgery