Table 1.
Demographic and clinical characteristics of elderly patients with GBM in our SEER–Medicare cohort
| Clinical and Demographic Factors | Frequency (%) for the Entire Cohort, n = 1375 | Frequency (%) for those with Craniotomy, n = 1079 | Frequency (%) for those with Biopsy, n = 296 |
|---|---|---|---|
| Age at diagnosis | |||
| 65–69 | 398 (29.0) | 318 (29.5) | 80 (27.0) |
| 70–74 | 482 (35.1) | 385 (35.7) | 97 (32.8) |
| 75–79 | 336 (24.4) | 254 (23.5) | 82 (27.7) |
| 80 or above | 159 (11.6) | 122 (11.3) | 37 (12.5) |
| GBM histological subtypes | |||
| Classical GBM | 1331 (96.8) | 1038 (96.2) | 293 (99.0) |
| Giant cell GBM | 11 (0.80) | 9 (0.83) | <5 (<1.7)a |
| Gliosarcoma | 33 (2.40) | 32 (3.0) | <5 (<1.7)a |
| Racial groups | |||
| Caucasian | 1270 (92.4) | 1002 (92.9) | 268 (90.5) |
| African American | 35 (2.6) | 22 (2.0) | 13 (4.4) |
| Hispanic | 17 (1.2) | 16 (1.5) | <5 (<1.7)a |
| Other racial group | 53 (3.9) | 39 (3.6) | 14 (4.7) |
| Residence in metropolitan areas | 1245 (90.6) | 972 (90.1) | 273 (92.2) |
| Socio-economic status | |||
| Lowest quintile | 274 (19.9) | 207 (19.2) | 65 (22.0) |
| Second quintile | 266 (19.4) | 232 (21.5) | 54 (18.2) |
| Third quintile | 277 (20.2) | 212 (19.7) | 65 (22.0) |
| Fourth quintile | 286 (20.8) | 203 (18.8) | 63 (21.3) |
| Highest quintile | 272 (19.8) | 225 (20.9) | 49 (16.6) |
| Marital status | |||
| Not married | 403 (29.3) | 321 (29.8) | 82 (27.7) |
| Married | 946 (68.8) | 739 (68.5) | 207 (69.9) |
| Marital status unknown | 26 (1.9) | 19 (1.8) | 7 (2.4) |
| Comorbidity scores | |||
| 0 | 776 (56.4) | 615 (57) | 161 (54.4) |
| 1 | 405 (29.5) | 315 (29.2) | 90 (30.4) |
| 2 | 194 (14.1) | 149 (13.8) | 45 (15.2) |
| Tumor location | |||
| Frontal lobe | 286 (20.8) | 234 (21.7) | 52 (17.6) |
| Temporal lobe | 377 (27.4) | 334 (31.0) | 43 (14.5) |
| Parietal lobe | 249 (18.1) | 180 (16.7) | 69 (23.3) |
| Occipital lobe | 92 (6.7) | 77 (7.1) | 15 (5.1) |
| Ventricle, brainstem, or cerebellum | 14 (1.0) | 8 (0.8) | 6 (2.1) |
| Involvement of two lobes or bihemispheres | 273 (19.9) | 202 (18.7) | 71 (24.0) |
| Brain location not specified (NOS) | 84 (6.1) | 44 (4.1) | 40 (13.5) |
| Tumor size (mm) | |||
| < 30 | 237 (17.2) | 170 (15.8) | 67 (22.6) |
| 30–41 | 193 (14.0) | 151 (14.0) | 42 (14.2) |
| 42–53 | 231 (16.8) | 201 (18.6) | 30 (10.1) |
| ≥ 54 | 224 (16.3) | 192 (17.8) | 32 (10.8) |
| Size unknown | 490 (35.6) | 365 (33.8) | 125 (42.2) |
| Weeks from surgery to initiation of radiation | |||
| Within 1 week | 142 (10.3) | 61 (5.7) | 81 (27.4) |
| 1–2 weeks | 439 (31.9) | 322 (29.4) | 117 (39.5) |
| 2–3 weeks | 394 (28.7) | 341 (31.6) | 53 (17.9) |
| 3–4 weeks | 190 (13.8) | 177 (16.4) | 13 (4.4) |
| 4–5 weeks | 117 (8.5) | 102 (9.5) | 15 (5.1) |
| 5–6 weeks | 60 (4.4) | 49 (4.5) | 11 (3.7) |
| > 6 weeks | 33 (2.4) | 27 (2.5) | 6 (2.0) |
| Types of surgery | |||
| Biopsy | 296 (21.5) | N/A | N/A |
| Subtotal resection | 485 (35.3) | ||
| Gross total resection | 574 (41.8) | ||
| NOS | 20 (1.5) | ||
| Administration of chemotherapy | 370 (26.9) | 307 (28.5) | 63 (21.3) |
NOS, natural orifice surgery.
aPer SEER–Medicare regulation, counts with <5 patients must be stated as “< 5” instead of the actual numbers.