New research from The Cancer Institute of New Jersey suggests that more stringent criteria may be needed for African American men with prostate cancer when considering active surveillance of the disease. The findings, published in the latest online version of Urology (doi: 10.1016/j.urology.2012.12.046) found that the prevalence of advanced stage cancer in African American men who were considered to have a low-risk prostate cancer on initial consultation but chose to undergo a radical prostatectomy was nearly twice that of Caucasian men. These findings of more advanced disease, confirmed through analysis of tissue specimens collected during surgery, suggest that the definition of low-risk prostate cancer should not be the same for African American and Caucasian men. The Cancer Institute of New Jersey is a Center of Excellence of the University of Medicine and Dentistry of New Jersey-Robert Wood Johnson Medical School.
Recent studies have shown that just monitoring prostate cancer without aggressive intervention can be a viable treatment option for men with low risk disease. However, because African American men tend to have more aggressive disease than Caucasian men, it is unclear whether the same criteria for active surveillance should be applied to African American patients. Investigators at The Cancer Institute of New Jersey further explored this issue.
A retrospective analysis was performed using data from men who underwent a radical prostatectomy by surgeons at The Cancer Institute of New Jersey and Johns Hopkins medical institutions between 1997 and 2011. Out of 1,536 African American men identified, 196 men met eligibility criteria for active surveillance based on University of California - San Francisco (UCSF) guidelines, which include a prostate specific antigen (PSA) score of 10 ng/mL or less and a clinical stage T1/T2a tumor. A smaller cohort of 124 African American men met the eligibility criteria under National Comprehensive Cancer Network (NCCN) guidelines, which include a life expectancy of less than ten years with a PSA of less than 10 ng/mL. For comparison, 608 Caucasian men were identified, with 191 and 143 men meeting eligibility criteria under UCSF and NCCN guidelines respectively.
Investigators found that the rate of higher grade disease in African American men believed at first to have very low risk prostate cancer based on the UCSF and NCCN guidelines was slightly higher (37.2 to 46.0 percent) but not significantly different from that of Caucasian men (33.5 to 39.2 percent). However, the risk of advanced stage disease was almost twice as high in blacks (19.4 percent) as in whites (10.1 percent). Advanced stage is defined as T3 or greater, which indicates growth outside of the prostate. In other words, among patients who are believed before surgery to have low risk disease, blacks are twice as likely as whites to have what is in fact advanced prostate cancer.
A multivariate analysis also revealed that age, preoperative PSA level and number of positive biopsy cores were independent predictors of more advanced disease in African Americans.
"Considering these higher incidences of more advanced prostate cancer in African American men, our findings suggest that more stringent criteria may be needed for those in this population who are considering active surveillance," said senior author Isaac Yi Kim, MD, PhD, chief of the Section of Urologic Oncology at The Cancer Institute of New Jersey and associate professor of surgery at UMDNJ-Robert Wood Johnson Medical School. "We recommend a lower PSA cutoff and/or a single positive biopsy core be considered as inclusion criteria, although further study is needed," noted Dr. Kim, who is also the executive director of the Dean and Betty Gallo Prostate Cancer Center at The Cancer Institute of New Jersey.
The authors note limitations within the study including the lack of assessment of PSA velocity and density. They also believe that additional biomarkers and further refinement of imaging modalities are needed to better stratify the risk of those prostate cancer patients who are considering active surveillance. Despite these limitations, they say "more conservative active surveillance criteria should be adopted for African American men until these tools are developed and validated."
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