Table 1.
Patient baseline disease and treatment characteristics. Values are n (%) unless otherwise indicated.
| Statistic | 4 weekly BTA | 12 weekly BTA | |
|---|---|---|---|
| N | 133 | 130 | |
| Age | Median (range) | 67 (26, 97) | 68 (30, 92) |
| Sex | N (%) Female | 81 (60.9) | 79 (60.8) |
| Baseline serum creatinine, mg/dL | Mean (sd) | 0.83 (0.22) | 0.90 (0.30) |
| Disease characteristics | |||
| Cancer type | N (%) Breast | 81 (60.9) | 79 (60.8) |
| CRPC | 52 (39.1) | 51 (39.2) | |
| Hormonal Status, Breast Patients (n = 160) | N (%) ER | 76 (93.8) | 73 (92.4) |
| PR | 64 (79.0) | 55 (69.6) | |
| HER2 | 12 (14.8) | 12 (15.2) | |
| Months from initial bone metastases diagnosis to randomisation | Median (range) | 15.3 (0, 93.5) | 7.0 (0, 86.8) |
| N (%) < 3 | 31 (23.3) | 42 (32.3) | |
| 3–5.9 | 10 (7.5) | 19 (14.6) | |
| 6–11.9 | 13 (9.8) | 13 (10.0) ) |
|
| 12–23.9 | 36 (27.1) | 21 (16.2 | |
| ≥24 | 43 (32.3) | 35 (26.9) | |
| Months from initial bone metastases diagnosis to randomisation, prostate cancer patients | Median (range) | 22.4 (1.0, 81.0) | 19.2 (0, 86.8) |
| N (%) < 3 | 1 (1.9) | 9 (17.7) | |
| 3–5.9 | 5 (9.6) | 3 (5.9) | |
| 6–11.9 | 5 (9.6) | 7 (13.7) | |
| 12–23.9 | 18 (34.6) | 11 (21.6) | |
| ≥24 | 23 (44.2) | 21 (41.2) | |
| Months from initial bone metastases diagnosis to randomisation, breast cancer patients | Median (range) | 8.9 (0, 93.5) | 4.1 (0, 71.8) |
| N (%) < 3 | 30 (37.0) | 33 (41.8) | |
| 3–5.9 | 5 (6.2) | 16 (20.3) | |
| 6–11.9 | 8 (9.9) | 6 (7.6) | |
| 12–23.9 | 18 (22.2) | 10 (12.7) | |
| ≥24 | 20 (24.7) | 14 (17.7) | |
| Prior SSEs | N (%) Any | 60 (45.1) | 54 (41.5) |
| RT to bone to reduce fracture risk | 0 (0.0) | 2 (1.5) | |
| RT to bone to bone for pain | 51 (38.4) | 46 (35.4) | |
| RT to bone to bone, other | 1 (0.8) | 2 (1.5) | |
| Pathological fracture | 6 (4.5) | 6 (4.6) | |
| Surgery to bone | 3 (2.3) | 2 (1.5) | |
| Spinal cord compression | 4 (3.0) | 3 (2.3) | |
| Hypercalcaemia | 1 (1.7) | 1 (1.9) | |
| Treatment characteristics | |||
| Type of BTA | N (%) Denosumab | 77 (57.9) | 71 (54.6) |
| Pamidronate | 25 (18.8) | 27 (20.8) | |
| Zoledronate | 31 (23.3) | 32 (24.6) | |
| Prior use of parenteral BTA | N (%) Yes | 73 (54.9) | 54 (41.5) |
| If yes, number of prior parenteral BTA injections | Median (IQR), maximum | 1 (0, 7), 48 | 0 (0, 5), 46 |
| Mean (sd) | 5.0 (8.5) | 4.5 (8.9) | |
| Baseline Anti-Cancer Treatment and SSEs characteristics by tumour type* | |||
| Breast cancer patients | N | 55 | 54 |
| Endocrine therapy | N (%) | 33 (60.0) | 28 (51.9) |
| Chemotherapy** | N (%) | 18 (32.7) | 20 (37.0) |
| Trastuzumab-based anti-her2 therapy alone | N (%) | 9 (16.4) | 11 (20.4) |
| Number of pre-randomization SREs | N (%) 0 | 30 (54.6) | 31 (57.4) |
| 1 | 17 (30.9) | 16 (29.6) | |
| 2 | 2 (3.6) | 5 (9.3) | |
| 3 | 4 (7.3) | 2 (3.7) | |
| 4 | 2 (3.6) | 0 (0) | |
| Type of pre-randomization SREs | Radiotherapy to the bone | 34 | 27 |
| Spinal Cord Compression | 3 | 3 | |
| Surgery to bone | 1 | 1 | |
| Hypercalcaemia | 1 | 1 | |
| Pathologic Fracture | 2 | 0 | |
| Prostate cancer patients | N | 27 | 26 |
| Androgen Receptor Antagonists | N (%) | 24 (88.9) | 22 (84.6) |
| Chemotherapy | N (%) | 1 (3.7) | 0 (0) |
| Radium-223 | N (%) | 3 (11.1) | 4 (15.4) |
| Number of pre-randomization SREs | N (%) 0 | 10 (37.0) | 11 (42.3) |
| 1 | 13 (48.2) | 9 (34.6) | |
| 2 | 4 (14.8) | 4 (15.4) | |
| 3 | 0 (0) | 1 (3.9) | |
| 4 | 0 (0) | 1 (3.9) | |
| Type of pre-randomization SREs | Radiotherapy to the bone | 19 | 23 |
| Spinal Cord Compression | 2 | 0 | |
| Surgery to bone | 0 | 1 | |
sd = standard deviation, IQR = interquartile range, *for Ottawa site only, **includes patients receiving chemotherapy and concurrent anti-her2 therapy