PSA-nadir at 1 year as a sound contemporary prognostic factor for low-dose-rate iodine-125 seeds brachytherapy.
OBJECTIVE
To identify predictors of outcomes in patients with localized prostate cancer treated with iodine-125 brachytherapy in a longitudinal uncontrolled study.


METHODS
Between 2000 and 2011, 560 histologically confirmed patients were treated with brachytherapy of whom 305 with ≥24-month follow-up and localized tumor were evaluated after exclusion of those locally advanced and under androgen ablation.


RESULTS
Patients' mean age was 63.93 years (44-88), mean pretreatment prostate-specific antigen (PSA) was 6.34 ng/mL (0.67-33.09), overall median follow-up was 75.35 months (24-158.37), biochemical recurrence occurred in 17 patients (5.57 %), cancer-specific survival was 100 %, and overall survival was 98.03 %. At multivariate analyses, only PSA-nadir at 1 year and age were related to disease-free survival: To each unit of PSA-nadir, the risk increases 87.3 %-OR 1.87 (p < 0.001; 95 % CI 1.31-2.67), and risk was 4.7 times higher for those under 50 years (vs. >70)-OR 4.69 (p = 0.04; 95 % CI 1.39-18.47). Best cutoff for PSA-nadir at one year was 0.285 (AUC = 0.78; p < 0.001; 95 % CI 0.68-0.89). Kaplan-Meier analysis confirmed PSA-nadir (p < 0.001) as prognostic, while D'Amico's classification failed (p = 0.24). No grade 3 or 4 complication was reported, and only 31.4 % of patients had grade 2 urinary or rectal toxicity. PSA bounce ≥0.4 ng/mL occurred in 18.4 % with no impact on biochemical recurrence.


CONCLUSIONS
Half (50.49 %) of patients in the scenario of localized prostate cancer treated with iodine-125 brachytherapy reach PSA-nadir at 1 year <0.285, recognized as a key independent prognostic factor.
Faculty of Medicine (Urology), Center for Life Sciences, Pontifical Catholic University of Campinas (PUC-Campinas), Campinas, SP, Brazil, reisleo.l@gmail.com.
Leonardo Oliveira
LO
Reis
Brunno Cezar Framil
BC
Sanches
Emerson Luis
EL
Zani
Lisias Nogueira
LN
Castilho
Carlos Roberto
CR
Monti
D000230:Adenocarcinoma / Q000175:diagnosis / Q000378:metabolism / Q000532:radiotherapy*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000378:metabolism; D001706:Biopsy; D001918:Brachytherapy / Q000379:methods*; D018572:Disease-Free Survival; D005500:Follow-Up Studies; D006801:Humans; D007457:Iodine Radioisotopes / Q000627:therapeutic use; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D017430:Prostate-Specific Antigen / Q000378:metabolism*; D011471:Prostatic Neoplasms / Q000175:diagnosis / Q000378:metabolism / Q000532:radiotherapy*; D011829:Radiation Dosage; D012189:Retrospective Studies; D013997:Time Factors
D014408:Biomarkers, Tumor; D007457:Iodine Radioisotopes; D017430:Prostate-Specific Antigen