Table 2 Characteristics of the developing cohort patients and the validation cohort patients with brain metastases from non-small cell lung cancer
Characteristics | Developing cohort (n = 223) | Validation cohort (n = 112) | |
|---|---|---|---|
N (%) | p value | N (%) | |
Gender | Â | 0.013 | Â |
 Male | 144 (64.6%) |  | 73 (65.2%) |
 Female | 79 (35.4%) |  | 39 (34.8%) |
Age of BM diagnosis(years) | Â | 0.311 | Â |
  < 60 | 134 (60.1%) |  | 61 (54.5%) |
  ≥ 60 | 89 (39.9%) |  | 51 (45.5%) |
KPS (%) | Â | <0.001 | Â |
  ≥ 80 | 99 (44.4%) |  | 45 (40.6%) |
  < 80 | 124 (55.6%) |  | 67 (59.4%) |
Interval from NSCLC diagnosis to BM diagnosis | Â | 0.044 | Â |
 Synchronous | 159 (71.3%) |  | 86 (76.8%) |
 Metachronous | 64 (28.7%) |  | 26 (23.2%) |
Time from neural symptom onset to BM diagnosis(months) | Â | 0.759 | Â |
  ≤ 1 | 159 (71.3%) |  | 81 (72.3%) |
 1–3 | 45 (20.2%) |  | 25 (22.3%) |
  > 3 | 19 (8.5%) |  | 6 (5.4%) |
ECM when BM diagnosis | Â | 0.009 | Â |
 Yes | 85 (38.1%) |  | 35 (31.3%) |
 No | 138 (61.9%) |  | 77 (68.8%) |
Number of BM | Â | 0.925 | Â |
 1 | 148 (66.3%) |  | 70 (62.5%) |
 2 | 11 (5.0%) |  | 14 (12.5%) |
 3 | 64 (28.7%) |  | 28 (25.0%) |
Tumor size(cm) | Â | 0.348 | Â |
  ≤ 2 | 62 (27.8%) |  | 26 (23.2%) |
  > 2 | 124 (55.6%) |  | 67 (59.8%) |
 Unknown | 37 (16.6%) |  | 19 (17.0%) |
Histology | Â | 0.006 | Â |
 Adenocarcinoma | 116 (52.2%) |  | 75 (67.0%) |
 Squamous cell lung cancer | 25 (11.2) |  | 20 (17.9%) |
 Poorly differentiated carcinoma or histology can’t be distinguished | 82 (36.8%) |  | 17 (15.1%) |