Examining progression to metastatic disease in men undergoing active surveillance

This study examined the incidence of metastatic disease (cancer that spreads) progression in men undergoing active surveillance. Authors concluded that active surveillance is an appropriate management of selected patients with low- to intermediate-risk prostate cancer. Only 3.1% of men progressed over an average follow-up of 6.4 years.

Advances in early detection of prostate cancer have led to a growing number of men living with prostate cancer. Most men are diagnosed with low-risk disease and do not need immediate treatment. Active surveillance (AS) refers to actively monitoring tumor growth without actually administering treatment. The main aim of AS is to minimize over-treatment and thereby avoid or delay treatment-related side effects. In some cases, however, prostate cancer may progress and spread to other parts of the body (become metastatic) despite close monitoring.

The aim of this study was to describe the incidence of metastatic disease progression in men undergoing AS.

980 men undergoing AS were included in this study. Most men had low-risk prostate cancer. 21.5% of men had intermediate-risk disease. Patients were followed for an average of 6.4 years.

3.1% of men developed metastasis during the study period. Of these, 46.7% had intermediate-risk disease at the beginning of the study. 50% of the men who developed metastasis died of prostate cancer during the study period. The average time to metastasis was 6.3 years. 95.1% of men were metastasis-free at 10 years and 91.4% of men were metastasis-free at 15 years.

Men whose PSA levels (prostate specific antigen; a protein elevated in the blood in prostate cancer) doubled in less than 3 years were 3.7 times more likely to develop metastasis. Men with a greater cancer extent (based on tissue samples) were 2.7 times more likely to develop metastasis. More aggressive cancer cells (Gleason score of 7 or higher) also significantly increased the risk of progression to metastatic disease.

Authors concluded that progression to metastatic disease was rare in men managed with AS. Certain cancer markers (based on blood tests and tissue samples) are associated with an increased risk of progression.

SInce the analysis of risk factors associated with progression to metastasis during AS was based on only 30 cases, larger studies are needed to confirm these results.