Conventional external-beam radiation therapy alone or with androgen ablation for clinical stage III (T3, NX/N0, M0) adenocarcinoma of the prostate.
OBJECTIVE
To evaluate the outcome of clinical Stage III (T3, N0/NX, M0) prostate cancer treated by conventional radiation alone or with adjuvant androgen ablation.


METHODS
Three hundred forty-four men with T3, N0/NX, M0 adenocarcinoma of the prostate who received conventional radiation alone (260) or with androgen ablation (84) were analyzed for relapse or rising prostate-specific antigen (PSA), using univariate and multivariate techniques.


RESULTS
With a median follow-up of 68 months, the 260 men treated with radiation alone had a 10-year actuarial rate of relapse or rising PSA of 76%. Pretreatment PSA level (< or = 10 ng/ml vs. > 10 < or = 20 ng/ml vs. > 20 ng/ml) and radiation dose (< 68 Gy vs. > or = 68 Gy) were the only independently significant determinants of biochemical failure; Gleason score (2-7 vs. 8-10) was an additional determinant of metastatic relapse. Patients treated to doses < 68 Gy experienced 6-year failure rates exceeding 50% regardless of PSA level. Patients with PSA < or = 10 ng/ml and receiving 68-70 Gy had a 6-year failure of 24%, but those with PSA > 10 ng/ml had relapse rates exceeding 50% even at doses of 70 Gy. At a median follow-up of 44 months, the 84 patients treated with radiation and androgen ablation had a 6-year biochemical failure rate of 22%. The only significant determinant of outcome in this group was pretreatment PSA; patients with PSA < or = 80 ng/ml had a 6-year failure rate of only 12% compared to a failure rate of 53% for those with PSA > 80 ng/ml. The outcome for those treated with combined modalities was significantly better than for those treated with radiation alone in all PSA strata.


CONCLUSIONS
Conventional radiation alone has little curative potential for Stage III disease. Doses < 68 Gy are particularly ineffective. Patients with PSA < or = 10 ng/ml may be candidates for conventional radiation to a dose of 70 Gy. Other patients are probably best served by combined radiation-androgen ablation or high-dose conformal radiation.
Zagars
G K
GK
Department of Radiation Oncology, The University of Texas, M.D. Anderson Cancer Center, Houston 77030, USA.
Pollack
A
A
Smith
L G
LG
D000135:Acid Phosphatase / Q000097:blood; D000230:Adenocarcinoma / Q000097:blood / Q000473:pathology / Q000532:radiotherapy* / Q000601:surgery; D000368:Aged; D000704:Analysis of Variance; D000726:Androgen Antagonists / Q000627:therapeutic use; D018931:Antineoplastic Agents, Hormonal / Q000627:therapeutic use; D015331:Cohort Studies; D003131:Combined Modality Therapy; D005500:Follow-Up Studies; D007987:Gonadotropin-Releasing Hormone / Q000819:agonists; D006801:Humans; D008297:Male; D009364:Neoplasm Recurrence, Local / Q000097:blood; D009367:Neoplasm Staging; D009919:Orchiectomy; D017430:Prostate-Specific Antigen / Q000097:blood; D011471:Prostatic Neoplasms / Q000097:blood / Q000473:pathology / Q000532:radiotherapy* / Q000601:surgery; D020266:Radiotherapy, Conformal
D000726:Androgen Antagonists; D018931:Antineoplastic Agents, Hormonal; D007987:Gonadotropin-Releasing Hormone; D000135:Acid Phosphatase; D017430:Prostate-Specific Antigen