Table 1.
Patient and tumor characteristics
| Characteristic | All patients (n = 358) | Adjuvant WBRT groupa (n = 142) | Observation group (n = 216) | P value* |
|---|---|---|---|---|
| Sex, n (%) | ||||
| Male | 208 (58) | 67 (32) | 141 (68) | 0.001 |
| Female | 150 (42) | 75 (50) | 75 (50) | |
| Age, median (range), y | 55 (17–91) | 54 (18–79) | 55 (17–91) | 0.50 |
| ≥55 | 177 (49) | 69 (39) | 108 (61) | 0.79 |
| <55 | 181 (51) | 73 (40) | 108 (60) | |
| RPA, n (%) | ||||
| I | 171 (48) | 76 (44) | 95 (56) | 0.08 |
| II | 187 (52) | 66 (35) | 121 (65) | |
| Evidence of systemic disease, n (%) | ||||
| Yes | 230 (64) | 69 (30) | 161 (70) | <0.001 |
| No | 128 (36) | 73 (57) | 55 (43) | |
| Primary cancer, n (%) | ||||
| Lung | 105 (29) | 65 (62) | 40 (38) | <0.001 |
| Breast | 39 (11) | 27 (69) | 12 (31) | <0.001 |
| Melanoma | 75 (21) | 23 (31) | 52 (69) | 0.07 |
| Kidney | 71 (20) | 1 (1) | 70 (99) | <0.001 |
| Gastrointestinal | 20 (6) | 9 (45) | 11 (55) | 0.62 |
| Otherb | 48 (13) | 17 (35) | 31 (65) | 0.42 |
| Relative tumor radiosensitivityc, n (%) | ||||
| Sensitive | 197 (55) | 117 (59) | 80 (41) | <0.001 |
| Resistant | 161 (45) | 25 (16) | 136 (84) | |
| Interval from diagnosis of primary to brain metastasis, median (range), months | 19 (0–399) | 19 (0–337) | 18 (0–399) | 0.17 |
| <6 | 77 (22) | 25 (32) | 52 (68) | 0.15 |
| ≥6 | 281 (78) | 117 (42) | 164 (58) | |
| Brain tumor location, n (%) | ||||
| Supratentorial | 292 (82) | 112 (38) | 180 (62) | 0.29 |
| Infratentorial | 66 (18) | 30 (45) | 36 (55) | |
| Tumor functional grade, n (%) | ||||
| I (noneloquent) | 128 (36) | 52 (41) | 76 (59) | 0.33 |
| II (near-eloquent) | 145 (40) | 62 (43) | 83 (57) | |
| III (eloquent) | 85 (24) | 28 (33) | 57 (67) | |
| Brain tumor maximal diameter, pre-op median (range), cm | ||||
| >3 | 87 (24) | 44 (51) | 43 (49) | 0.017 |
| ≤3 | 271 (76) | 98 (36) | 173 (64) | |
Abbreviation: WBRT, whole-brain radiation therapy; RPA, recursive partitioning analysis.
aMedian time from surgery to adjuvant WBRT in the adjuvant WBRT treatment group was 0.6 months (0.1–4.1 months).
bOne case each with lung, ovarian, and prostate cancer were grouped with sarcoma for a total of 12 cases of sarcoma. Other primary cases included gynecologic nonsarcoma cases (12); testicular cancer (9); lymphoma (2); carcinoma of prostate (3); ureter (1); thyroid (2); larynx (2); tonsils (2); soft palate (1); tongue (1); unknown primary (1).
cSee Table 2 for a grouping of sensitivities to radiotherapy.
*P values in bold denote statistical significance.