前立腺癌の術後生化学的再発予測に対するD'Amico高リスク分類の細分類法に関する検討

Abstract

The D'Amico risk group classification was originally developed to estimate the risk of biochemical recurrence following treatment for localized prostate cancer. We validated the ability of the risk group to predict biochemical recurrence after radical prostatectomy for patients with high-risk prostate cancer. We retrospectively reviewed the medical records of 208 patients who underwent radical prostatectomy, excluding patients with neoadjuvant hormonal therapy, with adjuvant hormonal therapy or radiotherapy, and patients without significant clinical data at our institution between 1997 and 2005. Using the D'Amico risk criteria, 58 (28%), 100 (48%), 50 (24%) were stratified as low-, intermediate- and high-risk groups, respectively. The Kaplan-Meier analysis of biochemical progression-free survival showed that the high-risk group in the D' Amico risk criteria consisted of patients with various prognosis. Therefore, in this group, patients with two or more of three factors including clinical stage T2b or higher, preoperative PSA 10 ng/ml or greater, and biopsy Gleason score 7-10 were reclassified into the very-high-risk group, and those with only one of three factors were reclassified into the semi-high risk group. Patients in the very-high risk group had recurrence at a significantly higher rate than those in the semi-high risk group (p=0.021). In conclusion, further classification of the D'Amico high risk group into two subgroups has a potential to identify a patient group with very high risk of PSA recurrence after prostatectomy.