Potency preservation following conformal radiotherapy for localized prostate cancer: impact of neoadjuvant androgen blockade, treatment technique, and patient-related factors.
OBJECTIVE
Impotence is a familiar sequela of both definitive external-beam radiotherapy (EBRT) and radical prostatectomy for localized prostate cancer. Among surgical options, nerve-sparing radical prostatectomy (NSRP) offers the highest potency preservation rate of 70%. We report the change in potency over time in an EBRT-treated population, determine the significantly predisposing health and treatment factors affecting post-EBRT potency, and compare age- and stage-matched potency rates with those of NSRP-treated patients.


METHODS
Our results are from a retrospective study of 287 patients diagnosed with prostate cancer in clinical stages A to C and treated with conformal techniques to 6200 to 7380 cGy. Information regarding preradiotherapy potency, medical and surgical history, neoadjuvant antiandrogen use, and post-EBRT potency was documented for each patient. The median follow-up time was 34 months.


RESULTS
At months 1, 20, 40, and 60, actuarial potency rates were 96%, 75%, 59%, and 53%, respectively. Factors identified as significant predictors of post-EBRT impotence include pre-EBRT partial potency, diabetes, coronary artery disease, and anti-androgen medication usage. Among treatment factors, a trend toward potency preservation was noted for the six-field versus the four-field technique. Finally, age- and stage-matched comparisons of potency rates for our population and NSRP-treated patients were performed. For patients older than 70 years, 60.9% of EBRT patients and 32.9% of NSRP patients remained potent after treatment. Overall, EBRT patient potency preservation was 71.3%, versus 66.2% for NSRP patients.


CONCLUSIONS
Pre-EBRT partial potency, diabetes, coronary artery disease, and anti-androgen medication usage are significant predispositions to impotence in EBRT-treated prostate cancer patients. In comparing EBRT with NSRP for various age and stage groups, EBRT offers notably higher potency preservation rates than NSRP for patients older than 70 years.
Mantz
C A
CA
University of Chicago/University of Illinois/Michael Reese Hospitals, Department of Radiation and Cellular Oncology 60616, USA.
Nautiyal
J
J
Awan
A
A
Kopnick
M
M
Ray
P
P
Kandel
G
G
Niederberger
C
C
Ignacio
L
L
Dawson
E
E
Fields
R
R
Weichselbaum
R
R
Vijayakumar
S
S
D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D000726:Androgen Antagonists / Q000009:adverse effects / Q000627:therapeutic use*; D003131:Combined Modality Therapy; D004307:Dose-Response Relationship, Radiation; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D020360:Neoadjuvant Therapy / Q000009:adverse effects; D011468:Prostatectomy / Q000009:adverse effects / Q000379:methods; D011471:Prostatic Neoplasms / Q000188:drug therapy* / Q000503:physiopathology / Q000532:radiotherapy*; D011788:Quality of Life; D020266:Radiotherapy, Conformal / Q000009:adverse effects; D011882:Radiotherapy, High-Energy / Q000009:adverse effects; D012189:Retrospective Studies
D000726:Androgen Antagonists