Is There a Role for Pelvic Irradiation in Localized Prostate Adenocarcinoma? Update of the Long-Term Survival Results of the GETUG-01 Randomized Study

Abstract

To report the long-term results of the French Genitourinary Study Group (GETUG)-01 study in terms of event-free survival (EFS) and overall survival (OS) and assess the potential interaction between hormonotherapy and pelvic nodes irradiation. Between December 1998 and June 2004, 446 patients with T1b-T3, N0pNx, M0 prostate carcinoma were randomly assigned to either pelvic nodes and prostate or prostate-only radiation therapy. Patients were stratified into 2 groups: "low risk" (T1-T2 and Gleason score 6 and prostate-specific antigen <3× the upper normal limit of the laboratory) (92 patients) versus "high risk" (T3 or Gleason score >6 or prostate-specific antigen >3× the upper normal limit of the laboratory). Short-term 6-month neoadjuvant and concomitant hormonal therapy was allowed only for high-risk patients. Radiation therapy was delivered with a 3-dimensional conformal technique, using a 4-field technique for the pelvic volume (46Gy). The total dose recommended to the prostate moved from 66Gy to 70Gy during the course of the study. Criteria for EFS included biologic prostate-specific antigen recurrences and/or a local or metastatic progression. With a median follow-up of 11.4years, the 10-year OS and EFS were similar in the 2 treatment arms. A higher but nonsignificant EFS was observed in the low-risk subgroup in favor of pelvic nodes radiation therapy (77.2% vs 62.5%; P=.18). A post hoc subgroup analysis showed a significant benefit of pelvic irradiation when the risk of lymph node involvement was <15% (Roach formula). This benefit seemed to be limited to patients who did not receive hormonal therapy. Pelvic nodes irradiation did not statistically improve EFS or OS in the whole population but may be beneficial in selected low- and intermediate-risk prostate cancer patients treated with exclusive radiation therapy.