Table 2. Factors associated with use of adjuvant chemotherapy.
| Factor | Adjuvant chemotherapy (n=3,481) No. (%) |
None (n=549) No. (%) |
Univariate analysis | Multivariate analysis | |||
|---|---|---|---|---|---|---|---|
| p-value | Exp(B) | 95% CI | p-value | ||||
| Lower | Upper | ||||||
| Age (yr) | < 0.001 | ||||||
| ≤ 50 | 2,189 (89.9) | 247 (45.0) | |||||
| > 50 | 1,292 (81.2) | 300 (54.6) | 0.556 | 0.434 | 1.713 | < 0.001 | |
| Unknown | 2 (0.4) | ||||||
| T stage | < 0.001 | ||||||
| T1 | 1,728 (79.9) | 435 (20.1) | |||||
| T2 | 1,756 (93.9) | 114 (6.1) | 3.166 | 2.371 | 4.228 | < 0.001 | |
| Histologic grade | < 0.001 | ||||||
| I | 141 (25.9) | 57 (28.8) | |||||
| II | 795 (82.5) | 169 (17.5) | 1.959 | 1.317 | 2.915 | 0.001 | |
| III | 2,125 (92.4) | 175 (7.6) | 4.428 | 2.981 | 6.577 | < 0.001 | |
| Unknown | 423 (74.1) | 148 (25.9) | |||||
| LVI | < 0.001 | ||||||
| No | 2,264 (85.7) | 377 (14.3) | |||||
| Yes | 548 (92.7) | 43 (7.3) | 1.534 | 1.057 | 2.227 | 0.024 | |
| Unknown | 672 (83.9) | 129 (16.1) | |||||
| Operation | <0.001 | ||||||
| Mastectomy | 1,403 (83.8) | 271 (16.2) | |||||
| BCS | 2,057 (88.2) | 275 (11.8) | 1.385 | 1.074 | 1.787 | 0.012 | |
| Unknown | 24 (88.9) | 3 (0.5) | |||||
CI=confidence interval; LVI=lymphovascular invasion; BCS=breast-conserving surgery.