Objective: To investigate the effect of intermittent hormonal therapy (IHT) for patients with different stage/grade prostate cancer (PCa).
Methods: The number of cycles and the duration of ON/OFF therapy for 45 PCa patients receiving IHT were observed. Maximal androgen blockade (MAB) therapies were used for six to nine months, and then stopped until the serum prostate specific antigen (PSA) was decreased below 0.2 microg/L, which lasted for three months. It was decided whether MAB went on according to the level of PSA.
Results: The average follow-up time was 40.7+/-13.4 months. Forty-one patients started the second cycle of treatment, of whom, 8 became androgen-independent and 7 were at T3-4M0 or M1 stages and the Gleason scores were above 8. Sixteen patients entered the third cycle, of whom, 14 were at lower than stage III and 13 had the Gleason scores below 7. From the first to the fourth courses of treatment, the average intervals were 8.7+/-5.4 (47.1%), 8.4+/-4.9 (49.3%), 7.0+/-3.4 (43.7%), and 3.7+/-0.6(42.5%) months respectively. Five patients developed bone metastasis. No one died up to now. According to the evaluation criteria, patients were divided into tolerance (n=16) and intolerance groups (n=29). Compared with the intolerance group, the patients who tolerated the treatment well had lower Gleason scores (P=0.002), lower PSA levels (P=0.053) and lower tumor stages (P=0.001). There was no evidence that age, lymph node metastasis, bone metastasis and the state of recurrence were associated with an increased risk of the outcome. Non-conditional Logistic regression analysis showed that the proportion of patients at stage IV was the only independent risk factor for the tolerance of the treatment (OR=12.113, 95%CI 1.330-110.312, P=0.027).
Conclusion: Intermittent hormonal therapy is more effective and proper for the patient with highly differentiated tumor and at lower stages (< or = III). The patients who progressed to hormone-independence are mostly at stage IV with poorly differentiated tumor. Intermittent hormone therapy could be more adaptive for the patients at lower than stage III.