Survival advantage for prostate cancer patients treated with high-dose three-dimensional conformal radiotherapy.
OBJECTIVE
The value of treating prostate cancer has been questioned, and some insist that a survival benefit is demonstrated to justify treatment. Prospective dose-escalation studies with three-dimensional conformal radiotherapy technique have demonstrated improvement in biochemical freedom from disease and local control. We report the outcomes of high-dose treatment with three-dimensional conformal radiotherapy compared with low-dose treatment for biochemical freedom from disease, freedom from distant metastasis, cause-specific survival, and overall survival.


METHODS
The study design was retrospective, involving pairs matched on independent prognostic variables in which each patient treated with low-dose radiotherapy was matched with a patient treated with high-dose radiotherapy. Outcomes were compared for two groups of patients: Group I: Three-dimensional conformal radiotherapy treatment--296 patients treated with more than 74 Gy matched on stage, grade, and prostate-specific antigen level, to 296 patients treated with less than 74 Gy. Group II: Three-dimensional conformal radiotherapy treatment--357 patients treated with more than 74 Gy matched on stage and grade to 357 patients treated with less than 74 Gy.


RESULTS
Univariate analysis showed that dose is a significant predictor of biochemical freedom from disease, freedom from distant metastasis, and cause-specific survival for group I and biochemical freedom from disease, freedom from distant metastasis, cause-specific survival, and overall survival for group II. Multivariate analysis showed that dose is a significant independent predictor in group I for biochemical freedom from disease and freedom from distant metastasis and for biochemical freedom from disease, freedom from distant metastasis, cause-specific survival, and overall survival in group II.


CONCLUSIONS
These data provide strong support for the definitive treatment of prostate cancer with high-dose (> 74 Gy) three-dimensional conformal radiotherapy. These doses can be safely delivered with three-dimensional conformal radiotherapy techniques. Various institutions and industry must collaborate to expand the technology allowing the use of high-dose three-dimensional conformal radiotherapy in the national practice beyond centers of technological excellence.
Hanks
G E
GE
Department of Radiation Oncology, Fox Chase Cancer Center, Philadelphia, Pennsylvania 19111, USA.
Hanlon
A L
AL
Pinover
W H
WH
Horwitz
E M
EM
Schultheiss
T E
TE
D000368:Aged; D018572:Disease-Free Survival; D006801:Humans; D008297:Male; D015999:Multivariate Analysis; D011471:Prostatic Neoplasms / Q000401:mortality / Q000532:radiotherapy*; D011829:Radiation Dosage; D020266:Radiotherapy, Conformal; D012189:Retrospective Studies; D015996:Survival Rate; D016896:Treatment Outcome