Low-risk prostate cancer: Predictors of disease progression during active surveillance

This review examined predictors of disease progression in low-risk prostate cancer during active surveillance. Researchers concluded that certain blood markers, biopsy results, and ethnicity could help predict which patients were more likely to experience disease progression. 

Active surveillance of prostate cancer refers to actively monitoring tumor growth and development without actually administering treatment. Active surveillance is increasingly common due to advances in the early detection of prostate cancer. Early detection has led to a growing number of men living with low-risk prostate cancer. For many patients, low-risk prostate cancer either never requires treatment, or treatment can be delayed for a prolonged period. Blood tests measuring PSA levels (prostate-specific antigen, an indicator of prostate growth), along with rectal examinations and regular biopsies (tissue samples) from the prostate gland are typically used to detect disease progression. However, it is not clear what characteristics can predict who might experience disease progression. 

This review of evidence was conducted in an effort to find reliable predictors of disease progression during active surveillance. 

This analysis included 32 separate studies, involving a combined total of 24,236 men with early-stage prostate cancer under active surveillance. Men were followed for an average of 2 to 9 years. Results were combined to calculate predictors of disease progression. 

PSA levels alone were not found to be a reliable predictor of prostate cancer progression. However, PSA levels relative to prostate size (also called PSA density) were noted to be the strongest predictor of cancer progression. Men with high PSA density were 2.46 times as likely to later experience a progression of prostate cancer.

The number of tissue samples testing positive for cancer cells was another significant predictor of cancer progression. When at least two samples from a biopsy tested positive, the risk of progression increased by 54%. Results from magnetic resonance imaging were not found to be a reliable predictor of future cancer progression.

The risk of cancer progression was doubled for African-American men compared to Caucasian men. Age was not significantly associated with an increased risk of prostate cancer progression. 

Researchers concluded that PSA density, biopsy results, and patient ethnicity are strong predictors of disease progression.