Distribution of progressive IMI-APPROACH patients across clusters.
| Cluster (members) | No progression | Only pain | Only structure | Both |
| C1 (69) | 39 (57%) | 20 (29%) | 7 (10%) | 3 (4%) |
| C2 (84) | 45 (54%) | 21 (25%) | 16 (19%) | 2 (2%) |
| C3 (68) | 30 (44%) | 25 (37%) | 7 (10%) | 6 (9%) |