Men initially diagnosed with Gleason 7 disease who also had a small area of tertiary cancer seen on biopsy were found to have a more aggressive form of cancer.
"Men initially diagnosed with Gleason score 7 disease who also had a small area of tertiary grade 5 prostate cancer that was seen on biopsy were found to have a more aggressive form of cancer," said Anthony D'Amico, MD, PhD, professor of radiation oncology at Harvard Medical School and chair of the division of genitourinary radiation oncology at Brigham and Women's Hospital in Boston. "This additional component of disease greatly impacts prognosis."
Last year's study by Dr. D'Amico, Abhijit Patel, MD, PhD, and colleagues added relevant clinical evidence to support that recommendation.
Dr. D'Amico's team compared time to PSA failure or recurrence in men with tertiary grade 5 cancer to those without this additional component of disease. Their study comprised 2,370 men with localized or locally advanced prostate cancer who received treatment with radical prostatectomy, radiation therapy alone, or radiation therapy plus 6 months of androgen suppression therapy. Gleason scores were categorized as follows: men with Gleason <6, Gleason 7 without tertiary grade 5, Gleason 7 with tertiary grade 5, and Gleason 8 to 10.
At 4-year follow-up, the results showed that men with Gleason 7 prostate cancer and tertiary grade 5 disease relapsed, on average, in 5 years compared to 6.7 years in men without tertiary grade 5 disease. Furthermore, time to disease recurrence in men with Gleason score 7 and tertiary grade 5 disease was found to be comparable to that seen in men diagnosed with Gleason score 8 to 10 disease.
"The implications of this study for practicing urologists are that men with Gleason 7 and tertiary grade 5 should be counseled regarding treatment in the same way they would be counseled for men with Gleason grade 8, 9, or 10 prostate cancer," Dr. D'Amico advised. "A Gleason score of 8 to 10 is considered high-risk disease, and almost always requires more than surgery or radiation alone to fight it."
Another important point involves the role of the pathologist: Men with tertiary grade 5 prostate cancer should be reported if seen.
"Although most academic pathologists are aware that they should report tertiary grade 5 if present, I'm not sure all community pathologists are aware of this issue," said M. Scott Lucia, MD, director of the prostate diagnostic laboratory and associate professor of pathology at the University of Colorado Health Sciences Center, Denver.
"Greater awareness and uniformity in reporting of this additional component of disease allows physicians to more accurately predict time to disease recurrence and develop a more aggressive course of treatment," added Dr. D'Amico. "The next step in the research process would be to have a large sample size of men with Gleason 7 tertiary grade 5 disease to assess the results within each treatment modality."