Table 1.
Background characteristics of study patients stratified receipt of adjuvant chemotherapy. Categorical variables are expressed as count (percentage) and continuous variables as median (interquartile range)
| Variable | No Adjuvant Chemotherapy (n=811) (%) |
Adjuvant Chemotherapy (n=922) (%) |
p-value |
|---|---|---|---|
| Age (median [IQR]) | 67(60-75) | 62(55-70) | <0.001 |
| Sex (female) | 115(14) | 103(11) | 0.07 |
| Race/ethnicity | 0.63 | ||
| White | 771(96) | 888(97) | |
| Black | 20(3) | 17(2) | |
| Other | 11(1) | 11(1) | |
| Year of diagnosis | 2007(2006-2010) | 2008(2005-2010) | 0.93 |
| Charlson-Deyo score | 0.002 | ||
| 0 | 533(66) | 657(71) | |
| 1 | 211(26) | 224(24) | |
| ≥2 | 67(8) | 41(4) | |
| Insurance | <0.001 | ||
| Private | 301(38) | 482(53) | |
| Government | 484(61) | 417(46) | |
| None | 12(1) | 10(1) | |
| Academic center | 454(57) | 404(44) | <0.001 |
| Pathologic T status | 0.24 | ||
| T1 | 178(22) | 173(19) | |
| T2 | 172(21) | 182(20) | |
| T3 | 446(55) | 549(60) | |
| T4 | 15(2) | 18(2) | |
| Tumor size (mm) | 38(25-50) | 38(25-55) | 0.49 |
| Grade | 0.923 | ||
| Low | 24(3) | 29(3) | |
| Moderate | 286(37) | 323(36) | |
| High | 462(60) | 542(61) | |
| Annualized center volume | 6(3-16) | 4(2-10) | <0.001 |
| Lymph node ratio (%) | 19(8-40) | 21(10-40) | 0.10 |
| Number of nodes examined | 14(9-20) | 15(10-21) | 0.12 |
| Number of nodes positive | 2(1-4) | 3(1-5) | 0.001 |
| Adjuvant radiation | 80(10) | 650(71) | <0.001 |
| Number of radiation treatments | 28(25-30) | 26(25-28) | N/A |
| Radiation dose (Gy) | 50.4(45.0-50.4) | 45.0(45.0-50.4) | N/A |
| Unplanned 30-day readmission | 70(9) | 50(5) | 0.01 |
| Postoperative length of stay | 11(8-18) | 9(7-13) | <0.001 |