The impact of different formulations of goserelin on testosterone suppression in patients with prostate cancer: A real world observational research.

e17160 Background: The purpose of androgen deprivation therapy (ADT) is to reduce and stabilise serum testosterone. However, dosing nonadherence for various reasons may lead to insufficient testosterone suppression, thus affecting the outcome of patients with prostate cancer. The present study evaluated the differences in testosterone control by different dosage forms of goserelin. Methods: This analysis was conducted in real-world clinics, focusing on patients diagnosed with prostate cancer who had initiated goserelin acetate extended-release microspheres for injection dosed every 4 weeks (dosing intervals of 28, 56, and 84 days) and goserelin acetate sustained-release depot dosed every 12 weeks (dosing intervals of 84, 168, and 252 days) to compare the efficacy of different dosage forms of goserelin and the effect of dosing delay on testosterone control. We retrospectively analysed the testosterone testing intervals and results from a minimum of three testosterone tests collected within six months following the initial goserelin dosage. Results: A total of 53 prostate cancer patients were included in the study, with 23 patients assigned to the 4-week dose group and 30 patients assigned to the 12-week dose group. The study found no statistically significant difference in the efficacy of the two goserelin drugs in terms of testosterone control (≤50ng/dl and ≤20ng/dl). The chi-square test revealed a statistically significant difference in the proportion of punctual or delayed injections for profound testosterone lowering (≤20ng/dl) (P=0.010, χ2=8.140). Furthermore, the rate of delayed injections was lower in patients applying the 4-week dosage form than the 12-week dosage form (P=0.028, χ2=4.851). The mean and dispersion of delayed injection days were found to be greater in patients in the implant 12-week dosage form group. Additionally, within the same group, a trend towards a correlation between the level of de-escalation and delayed injection days was identified. The baseline patient profile and key findings can be found in Table 1. Conclusions: The present study examined the impact of delayed injection of goserelin on testosterone control. It is imperative to direct greater attention to the development of effective follow-up strategies and the enhancement of adherence to androgen deprivation therapy in prostate cancer patients, with a view to improving clinical outcomes. Goserelin acetate extended-release microspheres for injection dosed every 4 weeks Goserelin acetate sustained-release depot dosed every 12 weeks N 23 30 Median age (years) 73 (50-91) 73 (50-90) Median treatment cycles 7 (3-12) 4 (3-5) Median days of delayed injections 4 (2-9) 14 (7-35) Delayed injection rate 43.48% 73.00% Testosterone ≤50ng/dl 100% 100% Testosterone ≤20ng/dl 65.2% (15/23) 60.0% (18/30)