PSA bounce and biochemical failure after brachytherapy for prostate cancer: a study of 820 patients with a minimum of 3 years of follow-up.
OBJECTIVE
To determine clinical or dosimetric factors associated with a prostate-specific antigen (PSA) bounce, as well as an association between a PSA bounce and biochemical relapse-free survival (bRFS), in patients treated with iodine-125 brachytherapy.


METHODS
A variety of clinical and treatment factors were examined in 820 patients who had a minimum of 3 years of PSA follow-up with T1-T2cN0M0 prostate cancer. Four different PSA threshold values were used for defining a PSA bounce: a PSA rise of ≥ 0.2, ≥ 0.4, ≥ 0.6, and ≥ 0.8 ng/mL.


RESULTS
A PSA bounce of ≥ 0.2, ≥ 0.4, ≥ 0.6, and ≥ 0.8 ng/mL was noted in 247 patients (30.1%), 161 (19.6%), 105 (12.8%), and 78 (9.5%), respectively. The median time to the first PSA rise was 17.4, 16.25, 16.23, and 15.71 months, respectively, vs. 34.35 months for a biochemical failure (p < 0.0001). A PSA rise of ≥ 0.2 ng/mL was the only definition for which there was a significant difference in bRFS between bounce and non-bounce patients. The 5-year bRFS rate of patients having a PSA bounce of ≥0.2 was 97.7% vs. 91% for those who did not have a PSA bounce (p = 0.0011). On univariate analysis for biochemical failure, age, risk group, and PSAs per year had a statistically significant correlation with PSA bounce of ≥ 0.2 ng/mL. On multivariate analysis, age and PSAs per year remained statistically significant (p < 0.0001 and p = 0.0456, respectively).


CONCLUSIONS
A bounce definition of a rise ≥ 0.2 ng/mL is a reliable definition among several other definitions. The time to first PSA rise is the most valuable factor for distinguishing between a bounce and biochemical failure.
Caloglu
Murat
M
Department of Radiation Oncology, Faculty of Medicine, Trakya University, Edirne, Turkey. caloglumurat@hotmail.com
Ciezki
Jay P
JP
Reddy
Chandana A
CA
Angermeier
Kenneth
K
Ulchaker
James
J
Chehade
Nabil
N
Altman
Andrew
A
Magi-Galuzzi
Christina
C
Klein
Eric A
EA
D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D001918:Brachytherapy / Q000379:methods*; D005500:Follow-Up Studies; D006801:Humans; D007457:Iodine Radioisotopes / Q000627:therapeutic use; D008297:Male; D008875:Middle Aged; D017430:Prostate-Specific Antigen / Q000097:blood*; D011471:Prostatic Neoplasms / Q000097:blood* / Q000532:radiotherapy*; D015996:Survival Rate; D013997:Time Factors; D017211:Treatment Failure
D007457:Iodine Radioisotopes; D017430:Prostate-Specific Antigen