Examining the rate of disease upgrading during active surveillance

This study analyzed the rates of disease upgrading after biopsy (tissue sample) tests in men with low-risk prostate cancer. Researchers concluded that men with low-risk prostate cancer have a very low risk of being upgraded during active surveillance.

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).

Many men with low-risk prostate cancer can benefit from active surveillance (AS). This involves actively monitoring tumor growth without actually administering treatment. The aim is to minimize over-treatment. Regular biopsies of the prostate gland are typically used to detect disease progression. The criteria for AS could be improved by better understanding the risk of low-risk prostate cancer being upgraded. Men at increased risk of upgrading are more likely to benefit from treatment early on.

The aim of this study was to analyze the rate of men undergoing AS upgraded from low-risk prostate cancer.

300 men undergoing AS for prostate cancer were included. 87% of men were classified as having either low or very low-risk prostate cancer. The rate of patients upgraded after biopsy tests during AS was analyzed. 47% of men underwent a biopsy before starting AS. The average time between diagnosis and the first biopsy test during AS was 20 months. Patients were followed for an average of 25 months after the second biopsy test.

16% of men were upgraded to a higher Gleason score after the first biopsy test during AS. Of these, 6% were upgraded from a previous Gleason score of 4 to 5. Men that underwent a biopsy prior to starting AS had a significantly reduced risk of any Gleason score upgrading.

A further 14% of men were upgraded to a higher Gleason score after the second biopsy test. Of these, 4% were upgraded from a previous Gleason score of 4 to 5. Overall, the 2-year rates of being upgraded to a higher Gleason score were 17%, and 3% for men with a previous Gleason score of 4 to 5.

28% of men later received treatment for prostate cancer. Of these, 42% were treated without evidence for Gleason score upgrading. Overall, 95% of men who showed no signs of Gleason score upgrading were recurrence-free (based on blood tests) at 5 years. 82% of men who were upgraded to a higher Gleason score were recurrence-free at 5 years. 70% of men who were specifically upgraded from a Gleason score of 4 to 5 showed the same result.

Researchers concluded that men with low-risk prostate cancer have a very low risk of being upgraded at biopsy tests during AS. The risk was lowest for men who underwent a biopsy test at diagnosis, before starting AS. The authors suggest these patients may be eligible for less intensive biopsy schedules.