PCa Deaths Rare Among Low-Risk Patients on Active Surveillance
Men receiving active surveillance were 24 times more likely to die from causes other than prostate cancer over 15 years.
Caucasian men with favorable-risk prostate cancer (PCa) who opt for active surveillance have a low risk of progression to lethal cancer for a decade after diagnosis, according to researchers.
H. Ballantine Carter, MD, and colleagues at Johns Hopkins Hospital in Baltimore prospectively studied 1,298 patients at their institution carefully selected for active surveillance. Among the men (median age 66), 926 had very-low-risk PCa (i.e., clinical stage T1c, PSA density [PSAD] less than 0.15 ng/mL, biopsy Gleason score 6 or lower, 2 or fewer positive biopsy cores, and no more than 50% cancer in any 1 core) and 372 had low-risk disease (i.e., T2a or lower, PSA less than 10 ng/ml, and Gleason score 6 or lower). No one had Gleason score 7 tumors.
The active surveillance program, started in 1995, included an annual 12- to 14-core biopsy along with semi-annual PSA testing and digital rectal exams. Recent advances in magnetic resonance imaging and the potential of biomarkers may make frequent biopsies unnecessary, the investigators suggested.
Only 2 deaths and 3 metastases from PCa occurred, according to results published online ahead of print in the Journal of Clinical Oncology. One patient died after 16 years on active surveillance with a clonally-distinct cancer, and the other died within 15 months of diagnosis having left the program. An additional 47 men died from cardiovascular disease or other causes. The cumulative risk of dying or experiencing metastasis from causes other than PCa was 24 to 1.
Overall, cancer-specific, and metastasis-free survival rates were relatively high: 93%, 99.9%, and 99.4% at 10 years and 69%, 99.9%, and 99.4%, respectively, at 15 years. Survival rates may change with longer follow-up, the researchers pointed out.
Reclassification to a higher grade of cancer occurred in 26% of patients at 10 years and 31% at 15 years. Older age, PSAD, and a greater number of positive biopsy cores were linked with a greater likelihood of cancer upgrading. PSAD and having more positive cores, indicators of cancer volume, increased the likelihood of intervention.
The investigators also assessed biochemical recurrence in a subset of patients and found rates were similar for men who underwent surgery or radiation after surveillance. The median treatment-free survival for all patients was 8.5 years.
For men with favorable-risk PCa, “the paradigm of immediate intervention must be replaced by one of immediate contemplation—a thoughtful assessment of prognostic risk, life expectancy, and the relative risks and benefits of available management options considered in the context of personal preferences,” the investigators concluded.
However, these findings only apply to Caucasian men, who made up 88% of patients. African American men have an increased risk of aggressive PCa and may require a different protocol. In an editorial accompanying the study, Anthony D'Amico, MD, of Brigham and Women's Hospital in Boston, recommended additional patient parameters such as ethnicity, family history, and comorbidities, until a reliable marker of disease progression is found.
- Tosoian, JJ; Mamawala, MM; Epstein, JI; et al. Journal of Clinical Oncology; doi: 10.1200/JCO.2015.62.5764.
- Anthony V. D'Amico. Journal of Clinical Oncology; doi:10.1200/JCO.2015.63.6118.
- Johns Hopkins News Release, August 31, 2015.