Long-term androgen deprivation increases Grade 2 and higher late morbidity in prostate cancer patients treated with three-dimensional conformal radiation therapy.
OBJECTIVE
To determine whether the use of androgen deprivation (AD) increases late morbidity when combined with high-dose three-dimensional conformal radiation therapy (3D-CRT).


METHODS
Between May 1989 and November 1998, 1,204 patients were treated for prostate cancer with 3D-CRT to a median dose of 74 Gy. Patients were evaluated every 3-6 months. No AD was given to 945 patients, whereas 140 and 119 patients, respectively, received short-term AD (STAD; < or =6 months) and long-term AD (LTAD; > 6 months). Radiation morbidity was graded according to the Fox Chase modification of the Late Effects Normal Tissue Task Force late morbidity scale. Covariates in the multivariate analysis (MVA) included age, history of diabetes mellitus, prostate-specific antigen (PSA) level, Gleason score, T category, RT field size, total RT dose, use of rectal shielding, and AD status (no AD vs. STAD vs. LTAD).


RESULTS
The only independent predictor for Grade 2 or higher genitourinary (GU) morbidity in the MVA was the use of AD (p = 0.0065). The 5-year risk of Grade 2 or higher GU morbidity was 8% for no AD, 8% for STAD, and 14% for LTAD (p = 0.02). Independent predictors of Grade 2 or higher gastrointestinal (GI) morbidity in the MVA were the use of AD (p = 0.0079), higher total radiation dose (p < 0.0001), the lack of a rectal shield (p = 0.0003), and older age (p = 0.0009). The 5-year actuarial risk of Grade 2 or higher GI morbidity was 17% for no AD vs. 18% for STAD and 26% for LTAD (p = 0.017).


CONCLUSIONS
The use of LTAD seems to significantly increase the risk of both GU and GI morbidity for patients treated with 3D-CRT.
Feigenberg
Steven J
SJ
Department of Radiation Oncology, Fox Chase Cancer Center, Philadelphia, PA 19111, USA. S_Feigenberg@fccc.edu
Hanlon
Alexandra L
AL
Horwitz
Eric M
EM
Uzzo
Robert G
RG
Eisenberg
Debra
D
Pollack
Alan
A
D000368:Aged; D000369:Aged, 80 and over; D000726:Androgen Antagonists / Q000009:adverse effects* / Q000627:therapeutic use; D003131:Combined Modality Therapy; D006471:Gastrointestinal Hemorrhage / Q000209:etiology; D041981:Gastrointestinal Tract / Q000187:drug effects* / Q000528:radiation effects; D006801:Humans; D008297:Male; D008875:Middle Aged; D009017:Morbidity; D011471:Prostatic Neoplasms / Q000188:drug therapy* / Q000532:radiotherapy*; D011832:Radiation Injuries / Q000209:etiology*; D011879:Radiotherapy Dosage; D020266:Radiotherapy, Conformal / Q000009:adverse effects / Q000379:methods*; D012007:Rectum; D012044:Regression Analysis; D013997:Time Factors; D014566:Urogenital System / Q000187:drug effects* / Q000528:radiation effects
D000726:Androgen Antagonists