Table 4.
Results of studies comparing intermittent androgen deprivation therapy (IADT) with continuous androgen deprivation therapy (CADT).
| Study | Arms | Patients randomized, n | Off-treatment period | Progression, n | Time to progression | Inference (IADT vs. CADT) |
Median follow-up time (year) |
Total number of deaths, n | Overall survival, median | Prostate cancer deaths, n, median | Prostate cancer survival |
|---|---|---|---|---|---|---|---|---|---|---|---|
| SEUG 9401 [20] | IADT | 314 | Median 52 weeks (50% patients); >36 months (29% patients) | 127 | HR (95%CI): 0.81 (0.63–1.05) for CADT vs. IADT; p = 0.11 | No significant difference in survival outcomes. No overall HRQoL benefit except improved sexual activity in IADT group | 4.25 | 170 | HR (95%CI): 0.99 (0.80–1.23) for CADT vs. IADT; p = 0.84 | 74 | HR (95%CI): 0.88 (0.63–1.23) for CADT vs. IADT. p value is not given in publication |
| CADT | 312 | 107 | 169 | 65 | |||||||
| TULP [24] | IADT | 97 |
Mean 1st cycle: 13 months (65% of cycle duration) 2nd cycle: 5 months (40% of cycle duration) 3rd cycle: 0.6 months (14% of cycle duration) |
NA | NA | IADT is not a good option for patients with low PSA nadir | 2.6 | NA | NA | NA | |
| CADT | 96 | NA | NA | NA | NA | ||||||
| Finn Prostate [23] | IADT | 274 | Median 23.6 weeks (57% of cycle duration) in cycle 1 and 11.1 weeks (27% of cycle duration) in cycle 12 | NA | 34.5 months | No significant difference in survival outcomes | 5.4 | 186 | 45.2 months | 117 | 45.2 months |
| CADT | 280 | NA | 30.2 months HR (95%CI): 1.08 (0.90–1.23) for CADT vs. IADT; p = 0.43) | 206 | 45.7 months; HR (95%CI): 1.15 (0.94–1.29) for CADT vs. IADT; p = 0.17 |
131 | 44.3 months; HR (95%CI): 1.17 (0.95–1.35) for CADT vs. IADT; p = 0.29 |
||||
| JPR.7 [17] | IADT | 690 |
Median 37.6 months (interquartile range 20.0–59.6 months) |
202 patients HR (95%CI): 0.81 (0.68–0.98) for IADT vs. CADT; p = 0.03 |
NA | IADT non-inferior to CADT in survival outcomes. Some HRQoL factors improved | 6.9 | 268 | 8.8 years | 120 | HR 1.23 (95%CI 0.94–1.66) IADT vs. CADT; p = 0.13 |
| CADT | 696 | 243 patients | 256 | 9.1 years; HR (95%CI): 1.02 (0.86–1.21) for IADT vs. CADT; p = 0.009 |
94 | ||||||
| TAP 22 [22] | IADT | 86 | Mean 126 days (54.6% of cycle duration) in cycle 1 and 85 days (42% of cycle duration) in cycle 7 | NA | 20.7 months (95%CI, 13.9–25.4 months) | No significant difference in survival outcomes | 3.7 | 49 | 42.2 months | NA | NA |
| CADT | 83 | NA | 15.1 months (95%CI, 12.1–22.7 months); (p = 0.74) |
45 | 52 months; p = 0.75 |
NA | NA | ||||
| SEUG 9901 [21] | IADT | 462 |
Median 162 weeks for PSA ≤1 ng/mL; 110 weeks for PSA 1-4 |
168 | NA | No significant difference in survival outcomes. Improved HRQoL (sexual activity) in IADT group | 5.5 | 258 | HR (95%CI): 0.90 (0.76–1.07) for overall survival; p = 0.252 | 82 | HR (95%CI): 0.93 (0.69–1.26) for overall survival; p = 0.648 |
| CADT | 456 | 131; HR (95%CI): 1.16 (0.93–1.47) for IADT vs. CADT; p = 0.195 |
NA | 267 | 82 | ||||||
| SWOG 9346 [25] | IADT | 770 | >40% of time | NA | 16.6 months | IADT inferior to CADT. In patients with extensive disease, IADT is non-inferior to CADT. Small HRQoL improvements with IADT | 9.8 | 483 | 5.1 years HR (95%CI): 1.10 (0.99–1.23) for overall survival in IADT group |
386 | NA |
| CADT | 765 | 11.5 months; p = 0.17 |
445 | 5.8 years | 325 | NA |
CI, confidence interval; HR, hazard ratio; HRQoL, health-related quality of life; NA, not available/applicable; PSA, prostate-specific antigen.