Factors important in upgrading from low-risk prostate cancer

This study examined factors important in upgrading from low-risk prostate cancer. Authors reported that age, tissue samples, and blood test results are strong predictors of upgrading from low-risk prostate cancer.

Most men diagnosed with prostate cancer are categorized as low risk. Low-risk prostate cancer is generally defined by a low tumor stage, low PSA levels (prostate specific antigen; a protein elevated in the blood in prostate cancer), and a Gleason score of 6 or less (tissue samples indicating less aggressive cancer cells). Some definitions also include the number of tissue samples in a biopsy testing positive for cancer cells (percent positive cores).

Many men with low-risk prostate cancer benefit from active surveillance. This involves actively monitoring tumor growth without actually administering treatment. The aim is to minimize overt-treatment. The criteria for active surveillance could be improved by identifying specific factors that increase the risk of low-risk prostate cancer being upgraded to a higher tumor stage or Gleason score. Men at increased risk of upgrading are more likely to benefit from treatment early on.

This study examined the records of 10,273 men with low-risk prostate cancer undergoing prostate surgery. Complete tissue sample data was available from 5,581 men. The proportion of men upgraded between diagnosis and surgery was examined. Analysis also included predictive factors associated with an increased risk of upgrading. Average PSA at diagnosis was 5 ng/ml. 92.7% of men were categorized with tumor stage 1 and 7.3% with tumor stage 2a.

44% of men had disease upgraded to a Gleason score of 7 or more at surgery. 1.3% of men were upgraded to a Gleason score of 8 to 10. 9.7% of men were upgraded to a higher tumor stage. Of these, 88.4% were upgraded to tumor stage 3a, 14.4% to tumor stage 3b, and 1.4% to tumor stage 4. A further 3% of men showed cancer spread to local lymph nodes. Overall, 54% of men had low-risk disease with a Gleason score of 6 and tumor stage 2.

Age older than 60 increased the risk of upgrading to a higher tumor stage by 42% and to a higher Gleason score by 39%. PSA levels higher than 5 ng/ml increased the risk of upgrading to a higher tumor stage by 44% and to a higher Gleason score by 28%. More than 25% positive cores increased the risk of upgrading to a higher tumor stage by 2.26-fold and to a higher Gleason score by 76%.

Authors concluded that low-risk prostate cancer patients should be extensively screened with tissue samples and blood tests before considering active surveillance. Age, PSA, and percent positive cores were the strongest predictors associated with upgrading from low-risk prostate cancer.

The risk of upgrading may be higher in this group of men with low-risk prostate cancer already selected for prostate surgery.