Distribution of matching variables and variables from the Spitz risk model among cases and controls in the MDACC and MGH populations
| MDACC overall (N = 995) | MGH overall (N = 511) | |||||
|---|---|---|---|---|---|---|
| Case (N = 527) | Controls (N = 468) | P | Case (N = 239) | Controls (N = 272) | P | |
| Matching variables | ||||||
| Sex, n (%) male | 260 (49.3) | 243 (51.9) | 0.951 | 107 (44.8) | 114 (41.9) | 0.515 |
| Age, mean ± SD | 62 ± 10.8 | 59 ± 12.1 | <0.001 | 65 ± 10.7 | 64 ± 11.0 | 0.222 |
| Smoking status, n (%) | ||||||
| Never | 111 (21.1) | 104 (22.2) | 37 (15.5) | 60 (22.1) | ||
| Former | 221 (41.9) | 185 (39.5) | 118 (49.4) | 122 (44.8) | ||
| Current | 195 (37.0) | 179 (38.3) | 0.738 | 84 (35.1) | 90 (33.1) | 0.166 |
| Spitz model variables | ||||||
| Second-hand smoke, n (%) | N = 111 | N = 104 | N = 37 | N = 60 | ||
| among NS | 86 (77.5) | 84 (80.8) | 0.553 | 27 (73.0) | 47 (78.3) | 0.626 |
| Quitting age, n (%) | ||||||
| among FS | N = 221 | N = 185 | N = 117 | N = 122 | ||
| <42 | 75 (40.5) | 65 (29.4) | 45 (38.5) | 63 (51.6) | ||
| 42–53 | 51 (27.6) | 68 (30.8) | 30 (25.6) | 32 (26.2) | ||
| ≥54 | 59 (31.9) | 88 (39.8) | <0.001 | 42 (35.9) | 27 (22.1) | 0.045 |
| Emphysema, n (%) | N = 416 | N = 364 | N = 167 | N = 212 | 0.004 | |
| among FS and CS | 91 (21.9) | 25 (6.8) | <0.001 | 31 (18.6) | 18 (8.5) | |
| Dust exposure, n (%) | N = 416 | N = 364 | N = 202 | N = 212 | 0.809 | |
| among FS and CS | 81 (19.5) | 44 (12.1) | 0.005 | 26 (12.9) | 29 (13.7) | |
| No hay fever, n (%) | N = 416 | N = 364 | N = 212 | |||
| among FS and CS | 374 (89.9) | 312 (85.7) | 0.073 | NA | 32 (15.1) | |
| Asbestos exposure, n (%) | N = 195 | N = 179 | N = 84 | N = 90 | ||
| among FS and CS | 59 (30.3) | 25 (14.0) | <0.001 | 14 (16.7) | 18 (20.0) | 0.571 |
| Family history of cancer, n (%) | N = 332 | N = 289 | N = 150 | N = 182 | 0.240 | |
| among NS and FS | 101 (30.4) | 64 (22.2) | 0.020 | 51 (34.0) | 51 (28.0) | |
| Family history of smoking-related cancers, n (%) | N = 195 | N = 179 | N = 80 | N = 90 | ||
| among CS | 75 (38.5) | 57 (31.8) | 0.181 | 23 (28.7) | 23 (25.6) | 0.640 |
| Pack-years, n (%) | ||||||
| among CS | N = 195 | N = 179 | N = 69 | N = 90 | ||
| <28 | 36 (18.5) | 76 (42.5) | 18 (26.1) | 49 (54.4) | ||
| 28–41.9 | 45 (23.1) | 38 (21.2) | 17 (24.6) | 16 (17.8) | ||
| 42–57.4 | 56 (28.7) | 35 (19.6) | 16 (23.2) | 16 (17.8) | ||
| ≥57.5 | 58 (29.7) | 30 (16.8) | <0.001 | 18 (26.1) | 9 (10.0) | 0.002 |
Abbreviations: P, P value from the χ2 test of association (for categorical variables) and Student test (for continuous variables); NS, never smokers; FS, former smokers; CS, current smokers.