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.
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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.
Reference
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
