Table 1.
Patients’ characteristics
| All patients (n = 45) | OBR patients (n = 37) | non-OBR patients (n = 8) | p-value | |
|---|---|---|---|---|
| Age (years) | 73 (67–78) | 73 (65–78) | 73.5 (71–75.8) | 0.52 |
| Females | 34 (76%) | 28 (76%) | 6 (75%) | 1.0 |
| Histology | 0.56 | |||
| Adenocarcinoma | 41 (91%) | 34 (92%) | 7 (88%) | |
| Non-adenocarcinoma | 4 (8.9%) | 3 (8.1%) | 1 (13%) | |
| Type of EGFR mutations | 0.35 | |||
| exon 19 deletions | 26 (58%) | 23 (62%) | 3 (38%) | |
| L858R | 16 (36%) | 12 (32%) | 4 (50%) | |
| Others | 3 (6.7%) | 2 (5.4%) | 1 (13%) | |
| Staging | 0.65 | |||
| IVB | 36 (80%) | 30 (81%) | 6 (75%) | |
| Recurrence | 9 (20%) | 7 (19%) | 2 (25%) | |
| Brain metastasis | 16 (36%) | 13 (35%) | 3 (38%) | 1.0 |
| Number of bone metastasis | 0.26 | |||
| 1 | 11 (24%) | 8 (22%) | 3 (38%) | |
| 2 | 3 (6.7%) | 3 (8.1%) | 0 (0%) | |
| 3 | 10 (22%) | 8 (22%) | 2 (25%) | |
| 4 | 4 (8.9%) | 2 (5.4%) | 2 (25%) | |
| ≥ 5 | 17 (38%) | 16 (43%) | 1 (13%) | |
| ALP (IU/L) | 274 (113–347) | 274 (113–335) | 295 (143–428) | 0.55 |
| Ca (mg/dL) | 9.5 (9.3–9.7) | 9.5 (9.3–9.6) | 9.6 (9.4–9.7) | 0.51 |
| CEA (ng/mL) | 51 (9.9–175) | 43 (9.9–175) | 73 (39–320) | 0.58 |
| RECIST at the first CT evaluation | 0.010 | |||
| CR | 1 (2.2%) | 1 (2.7%) | 0 (0%) | |
| PR | 39 (87%) | 34 (92%) | 5 (63%) | |
| SD | 1 (2.2%) | 1 (2.7%) | 0 (0%) | |
| PD | 4 (8.9%) | 1 (2.7%) | 3 (38%) | |
| Time from osimertinib initiation to the first CT evaluation (months) | 2 (1–3) | 3 (2–3) | 1 (0.75–1.5) | 0.040 |
| Denosumab use | 36 (80%) | 31 (84%) | 5 (63%) | 0.33 |
ALP Alkaline phosphatase, Ca calcium, CEA carcinoembryonic antigen, CR complete response, CT computed tomography, OBR osteoblastic bone reaction, PD progression disease, PR partial response, RECIST Response Evaluation Criteria in Solid Tumors, SD stable disease