Factors Predicting the Prolonged Duration of Off-treatment in Intermittent Androgen Deprivation of Prostate Cancer Treatment

Lee, Joo Hwan; Hong, Joo Eui; Choi, Han Yong

Abstract

PURPOSE
The goal of intermittent androgen deprivation (IAD) therapy in prostate cancer patients is to delay the disease progression and improve the survival rate. Therefore, the duration of off-treatment is very important for the effective treatment outcome of IAD. We analyzed factors that influence the duration of off-treatment in IAD.
MATERIALS AND METHODS
We reviewed the medical records of 45 patients with prostate cancer who had completed at least 1 cycle of IAD. Uni- and multi-variate tests were used to determine the factors, which are predictive to the duration of off-treatment. These factors included: the patient's age, biopsy Gleasons score, initial PSA, presence of bone metastasis, PSA levels at 3 months following on-treatment and at 3 months following off-treatment, and the duration of on-treatment.
RESULTS
The average follow up duration was 34 months (15-71 months). The average off-treatment duration of each cycle was 11.1 (4-40), 7.5 (4-14), and 5.6 (3-10) months for the 1st, 2nd and 3rd cycles, respectively. Independent factors associated with the extension of duration of off-treatment, by univariate tests, included: initial PSA value, PSA values at 3 months following on-treatment, PSA at 3 months following off- treatment, and duration of on-treatment. The duration of off-treatment was inversely related to the serum PSA level at the start, 3 months following on-treatment, and 3 months following off-treatment, while it was directly related to the duration of on- treatment by multivariate tests.
CONCLUSIONS
The pretreatment serum PSA level and the serum PSA level at 3 months following on-treatment and off-treatment were valuable predictors for the duration of off-treatment in IAD.