Endocrine Abstracts

Aim

We appreciate the effect of testosterone undecanoat 1000 mg intramuscular injection (Nebido^R; Bayer) on both prostatic volume (see Peretianu, this congress) and PSA (this study) in hypogonadic patients after up to 13 years.

Material and method

A. PSA (ng/ml) was done in Bucharest accredited laboratories, appreciated at 1 year. B. Prostatic volume (PV): ultrasound, 3–5 MHz, per abdominal, in 3D (cm3).

C. Statistical analysis: Student test, simple correlation, multiple regression.

Results

A. Patients at onset: 309 men, age: 18–96 years, average: 61.02 years; median: 62.

B. Prostatic volume: average: 33.05 cm3.

C. Average PSA (no patients): before treatment = 1.52 (309); 1y = 1.66 (164); 2y = 1.48 (113); 3y = 1.47 (82); 4y = 1.67 (65); 5y = 1.58 (59); 6y = 1.71 (47); 7y = 1.68 (44); 8y = 1.58 (35); 9y = 1.76 (23), 10y = 1.75 (19), 11y = 2.06 (11), 12y = 0.77 (decreased)(5), 13y = 0.7 (decreased)(3).

D. Statistical difference of PSA averages from T0 to 11y: nonsignificant: P = between 0.29–0.87. T0 v 12y P = 0.04, T0 v 13y P = 0.002.

E. Correlation between age and PSA was significant at: T0: r = 0.33; 1y: r = 0.2 and 8y P = 0.05; and nonsignificant in rest. Significance is depending on group size.

F. Correlation between PSA and prostatic volume was significant, both before and after treatment at 1, 2, 3, 5, 6, 8, 9, 10 years (depending on group size, r = 0.13–0.54).

G. Multiple regression test between PSA before/after treatment, prostatic volume before/after treatment and the age. Statistical significance: P values < 0.01 for all years (except 6y-NS and 13 y-non 5 patients). P << 0.05: R² = 0.28–0.82, F = 6.67–12.48.

Conclusions

1. Testosterone undecanoat 1000 mg injectable i.m. at 3 months did not increased PSA level after up to 13 years administrations.

2. Based on multiple regression data, PV & PSA post testosterone does not depend on testosterone administration but on the age and the PV before treatment and depend on the initial PSA level, i.e. before testosterone administration.

Comments

Since PV and PSA level did not depend on testosterone administration, but on age we thing that: a. there could be a therapeutic window for testosterone, considered before 80 years old, b. the moment of testosterone administration should depend on testosterone decreased slope, c. therefore, testosteronemia should be performed every year from 20 years old.