Table 2.
Treatment Used and Normalization of IGF-1 Index During Long-term Follow-up
| All (N = 266) | Group 1 (N = 136) | Group 2 (N = 130) | P | |
|---|---|---|---|---|
| Initial treatment modality | ||||
| Surgery | 259 (97.7%) | 132 (97.1%) | 127 (97.7%) | 1.000 |
| Preoperative medical therapy | 45 (17.4%) | 13 (9.8%) | 32 (25.2%) | 0.001 |
| Medical therapy only (no surgery) | 7 (2.6%) | 4 (2.9%) | 3 (2.3%) | 1.000 |
| Treatment after surgery | ||||
| Observation (no second-line therapy)a | 78 (30.1%) | 30 (22.7%) | 48 (37.8%) | 0.008 |
| Repeat surgery (%)b | 40 (15.4%) | 28 (21.1%) | 12 (9.4%) | 0.010 |
| Radiation therapy (%)b | 90 (34.7%) | 62 (47.0%) | 28 (22.0%) | <0.001 |
| Medical therapy (any time after surgery (%) | 165 (63.7%) | 88 (66.7%) | 77 (60.6%) | 0.312 |
| Medical therapy subgroup | ||||
| SSA | 151 (91.5%) | 81 (92.0%) | 70 (90.9%) | 0.794 |
| Dopamine agonist | 75 (45.4%) | 36 (40.9%) | 39 (50.6%) | 0.210 |
| Cabergoline | 69 (41.8%) | 30 (34.1%) | 39 (50.6%) | 0.031 |
| Bromocriptine | 6 (3.6%) | 6 (6.8%) | 0 | 0.030 |
| Pegvisomant | 69 (41.8%) | 38 (43.2%) | 31 (40.3%) | 0.704 |
| Normalization of IGF-1 index over time | ||||
| Prevalence of normal IGF-1 at last follow-up | 248 (93.2%) | 130 (95.6%) | 118 (90.8%) | 0.118 |
| Time to last follow-up (years) | 9.9 [5.0–15.0] | 15.0 [11.0–20.0] | 6.0 [3.0–8.6] | <0.001 |
Abbreviations: IGF-1, insulin-like growth factor-1; SSA, somatostatin analogs. aAll patients who received no treatment after surgery had a normal IGF-1 index at last follow-up. bOverall 27 (10.4%) patients had both repeat surgery and radiation therapy after first surgery, 21 (15.9%) in group 1 vs 6 (4.7%) in group 2; P = 0.003.