Wr. Lee et al., LOCALIZED PROSTATE-CANCER TREATED BY EXTERNAL-BEAM RADIOTHERAPY ALONE- SERUM PROSTATE-SPECIFIC ANTIGEN-DRIVEN OUTCOME ANALYSIS, Journal of clinical oncology, 13(2), 1995, pp. 464-469
Purpose: To determine the 5-year rate of survival with no evidence of
disease (NED) using strict biochemical criteria in men with prostate c
ancer treated by external-beam radiotherapy alone and to examine possi
ble clinical and treatment factors that predict the likelihood of NED
survival. Materials and Methods: Five hundred men with clinically loca
lized prostate cancer consecutively treated with external-beam radioth
erapy alone with no prior, concomitant, or adjuvant endocrine therapy
were identified. All patients had serial serum prostate-specific antig
en (PSA) values determined after treatment and 451 patients had pretre
atment PSA values determined. The median follow-up duration is 20 mont
hs (range, 2 to 72; mean, 36). Results: The 5-year rate of overall sur
vival in this group of patients was 80%. The 5-year rate of survival w
ithout clinical evidence of disease (cNED) was 72%. The 5-year rate of
survival without evidence of clinical, radiographic, or biochemical r
elapse (bNED) was 51%. Multivariate analysis demonstrated that a pretr
eatment serum PSA level less than or equal to 15 ng/mL was the most im
portant predictor of bNED survival (P<.0001). Patients with early-stag
e (T1,T2a/b) tumors and a pretreatment serum PSA less than 15 ng/mL ha
d a 9-year rate of bNED survival of 86%. The rate of bNED survival for
patients with a pretreatment PSA level greater than 15 ng/mL was 38%
at 3 years. Conclusion: Pretreatment serum PSA level is the most impor
tant predictor of treatment outcome in this group of patients treated
with definitive radiotherapy alone. External-beam radiation alone can
produce acceptable early rates of bNED survival in patients with clini
cally organ-confined tumors and a pretreatment PSA level less than or
equal to 15 ng/mL. To produce acceptable results in those patients wit
h pretreatment PSA levels more than 15 ng/mL, effective adjuvant treat
ments in addition to aggressive local treatments are necessary.