Table 3.
Use of GEP Testing and Adjuvant Chemotherapy Among Eligible Women (n = 393)
| Characteristic | Use of GEP |
Use of Adjuvant Chemotherapy |
||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| No. | % | Odds Ratio | 95% CI | P | No. | % | Odds Ratio | 95% CI | P | |
| Age, years | 98 | 24.9 | 0.84 | 0.66 to 1.09 | .49 | 153 | 38.9 | 0.68 | 0.52 to 0.89 | < .001 |
| 35-49 | 37 | 27.0 | 72 | 52.6 | ||||||
| 50-65 | 61 | 23.8 | 81 | 31.6 | ||||||
| Menopausal status | .42 | < .001 | ||||||||
| Premenopausal | 41 | 27.2 | Ref | 80 | 53.0 | Ref | ||||
| Postmenopausal | 57 | 23.6 | 1.42 | 0.64 to 3.14 | 73 | 30.2 | 0.90 | 0.40 to 1.99 | ||
| Income | .01 | .09 | ||||||||
| < $40,000 | 17 | 19.1 | 0.34 | 0.16 to 0.73 | 37 | 41.6 | 1.27 | 0.56 to 2.87 | ||
| $40,000-$74,999 | 28 | 20.1 | 0.34 | 0.17 to 0.67 | 42 | 30.2 | 0.75 | 0.34 to 1.67 | ||
| $75,000-$124,999 | 22 | 26.2 | 0.45 | 0.22 to 0.92 | 39 | 46.4 | 1.68 | 0.73 to 3.91 | ||
| ≥ $125,000 | 27 | 41.5 | Ref | 25 | 38.5 | Ref | ||||
| Health plan type | .76 | .06 | ||||||||
| Health maintenance organization | 25 | 23.8 | 1.04 | 0.59 to 1.83 | 49 | 46.7 | 1.51 | 0.87 to 2.62 | ||
| Other plan type* | 73 | 25.4 | Ref | 104 | 36.1 | Ref | ||||
| Comorbidity score | .20 | .18 | ||||||||
| 0 | 81 | 27.1 | Ref | 124 | 41.5 | Ref | ||||
| 1 | 12 | 17.1 | 0.54 | 0.27 to 1.09 | 21 | 30.0 | 0.80 | 0.42 to 1.54 | ||
| ≥ 2 | 5 | 20.8 | 0.83 | 0.27 to 2.55 | 8 | 33.3 | 0.92 | 0.36 to 2.33 | ||
| Cancer stage | .24 | < .001 | ||||||||
| I | 83 | 26.4 | Ref | 100 | 31.9 | Ref | ||||
| II | 15 | 20.3 | 0.71 | 0.36 to 1.38 | 48 | 64.9 | 5.67 | 2.87 to 11.18 | ||
| Breast cancer surgery | .79 | .002 | ||||||||
| Lumpectomy | 65 | 24.5 | Ref | 89 | 33.6 | Ref | ||||
| Mastectomy | 33 | 25.8 | 1.08 | 0.63 to 1.86 | 64 | 50.0 | 1.68 | 0.98 to 2.88 | ||
| HER2 test result | .98 | .33 | ||||||||
| Negative | 55 | 24.8 | Ref | 87 | 39.2 | Ref | ||||
| Intermediate | 10 | 27.8 | 1.25 | 0.54 to 2.92 | 17 | 47.2 | 1.53 | 0.69 to 3.37 | ||
| Positive | 8 | 25.0 | 0.82 | 0.36 to 1.85 | 15 | 46.9 | 1.80 | 0.71 to 4.58 | ||
| GEP result | < .001 | |||||||||
| Not done | 115 | 37.8 | Ref | |||||||
| Low | 14 | 23.7 | 0.55 | 0.26 to 1.16 | ||||||
| Medium | 17 | 77.3 | 8.21 | 1.99 to 33.83 | ||||||
| High | 7 | 87.5 | 13.48 | 2.32 to 78.35 | ||||||
| Region | .18 | .14 | ||||||||
| Northeast | 21 | 25.0 | 1.25 | 0.67 to 2.33 | 41 | 48.8 | 1.39 | 0.75 to 2.58 | ||
| Midwest | 23 | 34.3 | 2.25 | 1.15 to 4.40 | 21 | 31.3 | 0.57 | 0.28 to 1.20 | ||
| South | 41 | 21.0 | Ref | 75 | 38.5 | Ref | ||||
| West | 13 | 27.7 | 1.22 | 0.55 to 2.71 | 16 | 34.0 | 0.89 | 0.40 to 1.96 | ||
NOTE. Eligible women were those with a tumor that was estrogen receptor positive, lymph node negative, and < 1.5 cm in size if HER2 positive or of any size if HER2 negative, intermediate, or unknown.
Abbreviation: GEP, gene expression profiling.
*
Includes point of service, indemnity, and preferred provider organization plans.