Clinical Factors Associated With Pathological Grade Group 1 Patients in D'Amico Intermediate-Risk Group Following Robot-Assisted Radical Prostatectomy: A Retrospective Multicenter Cohort Study in Japan (The MSUG94 Group).

INTRODUCTION

We aimed to examine the relationship between D'Amico intermediate-risk and pathological grade group 1 (pGG1) after robot-assisted radical prostatectomy (RARP).

PATIENTS AND METHODS

In this retrospective multicenter cohort study, D'Amico intermediate-risk prostate cancer patients who did not receive neoadjuvant therapy, and underwent RARP at 10 institutions in Japan were examined for preoperative factors associated with pGG1.

RESULTS

In total, we enrolled 1161 D'Amico intermediate-risk prostate cancer patients. The pGG1 and pGG ≥2 groups comprised 73 (6.3%), and 1088 (93.7%) cases, respectively. Biochemical recurrence-free survival (BCRFS) of the pGG1 group was equivalent to that of the D'Amico low-risk patients. Among the 3 D'Amico intermediate-risk factors (IRF), the pGG1-rate was 24% with prostate-specific antigen (PSA) of 10 to 20 ng/mL alone, and 30% with cT2b alone. Both groups had significantly higher pGG1-rates than other groups. Down-grading from biopsy GG ≥2 to pGG1 was relatively rare (3.9%). Patients with pGG1 were further stratified by prostate volume (PV) (cutoff, 40 cc) among patients with one IRF and PSA of 10 to 20 ng/mL. Patients with one IRF, PSA of 10 to 20 ng/mL, and PV >40 cc had a relatively good BCRFS similar to that of the D'Amico low-risk group.

CONCLUSION

Among intermediate-risk prostate cancer patients, those with pGG1 have a good prognosis. Downgrading from biopsy GG ≥2 is rare, and definitive treatment may be recommended for patients with biopsy GG ≥2. Patients with one IRF, PSA of 10 to 20 ng/mL, and PV >40 cc who are eligible for RARP may be candidates for active surveillance.