Investigators have validated the prognostic utility of a 3-tiered subclassification of high-risk prostate cancer (PCa) in patients treated with radical prostatectomy (RP), according to a new report.
“These findings may help tailor treatment decision-making for men with favorable high-risk or very high-risk disease, potentially allow for more efficient clinical trial design, and help tailor the use of advanced imaging in the pre-operative evaluation of patients with unfavorable-risk prostate cancer,” investigators led by Vinayak Muradlidhar, MD, MSc, of the Harvard Radiation Oncology Program in Boston, Massachusetts, reported in Urology.
A previous study examined the prognostic value of 3 subgroups of high-risk PCa in a cohort of men treated with radiation therapy.
Dr. Muralidhar and colleagues identified 89,450 patients with PCa treated with RP (including some men with clinical T3 disease) from the National Cancer Database. Of these, 31,381 men had unfavorable intermediate-risk PCa (biopsy Gleason score 4+3 or more than 1 of these factors: cT2b-c, PSA 10-20 ng/mL, and Gleason 7). Another 10,296 men had favorable high-risk PCa, defined as cT1c with either biopsy Gleason 6 and PSA exceeding 20 ng/mL or Gleason 4+4 and PSA less than 10 ng/mL. A total of 30,260 men had standard high-risk disease, defined as cT3a, other cancers with Gleason 8 or higher, or PSA exceeding 20 ng/mL. Lastly, 7513 men had very high-risk PCa, defined as cT3b-T4 or biopsy primary Gleason pattern 5.
Patients with unfavorable intermediate-risk and favorable high-risk disease had similar rates of adverse pathologic features, including positive surgical margins, pT4 disease, or lymph node involvement: 7.6% vs 8.2%, respectively, Dr Muralidhar’s team reported. Patients with favorable high-risk disease, however, had a significantly lower rate of adverse pathology compared with patients with standard high-risk disease: 8.2% vs 15.9%, respectively (P <.001). As expected, patients with standard high-risk or very high-risk PCa had significantly higher rates of adverse pathology than the other subgroups (15.9% and 26.5%, respectively; P <.001).
Few patients in the overall cohort received adjuvant radiation or adjuvant androgen deprivation therapy (9.7% and 5.1%, respectively), but the rates varied by risk subgroup. Men with unfavorable intermediate-risk, favorable high-risk, standard high-risk, and very high-risk disease received adjuvant radiation in 5.1%, 7.0%, 12.4%, and 27.1% of cases, respectively (P <.001) and received adjuvant androgen deprivation therapy in 2.2%, 3.6%, 7.6%, and 17.9% of cases, respectively (P <.001).
Overall survival at 5 years was similar between patients with unfavorable intermediate-risk and favorable high-risk disease (95.7% vs 95.1%, respectively) but was significantly lower among standard and very high-risk patients (93.4% and 88.1%, respectively; P <.001).
“The validation of this three-tiered sub-classification in a surgically managed cohort of patients using pre-operative information suggests that it may be applied to all patients with high risk disease and act as a common stratification system with which to discuss prognosis and treatment options,” according to Dr Muralidhar’s team.
Disclosure: Several study authors declared affiliations with the pharmaceutical industry. Please see the original reference for a full list of authors’ disclosures.
Lamba N, Butler S, Mahal BA, et al. Three-tiered sub-classification system of high-risk prostate cancer in men managed with radical prostatectomy: implications for treatment decision-making. Urology. Published online August 3, 2020. doi:10.1016/j.urology.2020.07.040