Table 3.
Effect of Chemotherapy and Other Factors on Mortality in Women With Node-Positive Operable Breast Cancer Diagnosed in 1992–1996 in SEER Areas, by Age Groups (65–69 Years and 70+ Years)
| Risk (Cox Proportional HR and 95% CI)* | ||
|---|---|---|
| Patient and Tumor Characteristics | Women Aged 65–69 Years (N = 1440) | Women Aged 70 Years or Older (N = 4024) |
| Chemotherapy | ||
| No | 1.00 (reference) | 1.00 (reference) |
| Yes | 0.70 (0.57–0.88) | 0.96 (0.83–1.09) |
| Age (continuous) | 0.96 (0.90–1.04) | 1.06 (1.05–1.07) |
| Race | ||
| White | 1.00 (reference) | 1.00 (reference) |
| Black | 1.19 (0.85–1.67) | 1.12 (0.90–1.39) |
| Other | 1.56 (0.87–2.77) | 0.85 (0.59–1.23) |
| Marital status | ||
| Married | 1.00 (reference) | 1.00 (reference) |
| Unmarried | 1.36 (1.10–1.67) | 1.33 (1.19–1.49) |
| Unknown | 1.29 (0.69–2.42) | 1.44 (1.01–2.04) |
| Tumor stage | ||
| II | 1.00 (reference) | 1.00 (reference) |
| IIIA | 1.00 (0.73–1.37) | 1.20 (1.04–1.39) |
| Tumor size, cm | ||
| <1.0 | 1.00 (reference) | 1.00 (reference) |
| 1.0–<2.0 | 1.00 (0.61–1.63) | 1.20 (0.89–1.62) |
| 2.0–<3.0 | 1.26 (0.78–2.04) | 1.58 (1.18–2.12) |
| 3.0–<4.0 | 1.32 (0.79–2.21) | 1.99 (1.47–2.69) |
| 4.0+ | 2.00 (1.20–3.32) | 1.91 (1.41–2.59) |
| Unknown size | 1.35 (0.72–2.53) | 1.34 (0.92–1.94) |
| Number of positive nodes | ||
| 1 | 1.00 (reference) | 1.00 (reference) |
| 2–4 | 1.30 (0.99–1.71) | 1.11 (0.98–1.25) |
| 5–9 | 2.07 (1.52–2.80) | 1.38 (1.19–1.61) |
| 10–43 | 2.56 (1.86–3.52) | 1.94 (1.65–2.28) |
| Unknown no. but positive | 2.12 (0.99–4.55) | 1.72 (1.19–2.48) |
| Tumor grade | ||
| Well differentiated | 1.00 (reference) | 1.00 (reference) |
| Moderately differentiated | 1.38 (0.82–2.31) | 0.99 (0.78–1.25) |
| Poorly differentiated | 1.77 (1.06–2.97) | 1.30 (1.03–1.65) |
| Unknown | 1.46 (0.86–2.47) | 1.14 (0.89–1.44) |
| Hormone receptor status | ||
| Positive | 1.00 (reference) | 1.00 (reference) |
| Negative | 2.13 (1.65–2.74) | 1.76 (1.53–2.02) |
| Unknown | 1.02 (0.76–1.36) | 1.22 (1.07–1.39) |
| Surgery and radiation | ||
| BCS alone | 1.00 (reference) | 1.00 (reference) |
| BCS with radiation | 0.61 (0.38–1.00) | 0.81 (0.62–1.05) |
| Mastectomy alone | 0.79 (0.51–1.21) | 0.94 (0.75–1.18) |
| Mastectomy with radiation | 0.82 (0.50–1.34) | 0.91 (0.70–1.19) |
| Comorbidity scores | ||
| 0 | 1.00 (reference) | 1.00 (reference) |
| 1 | 1.13 (0.81–1.57) | 1.20 (1.03–1.38) |
| 2 | 1.78 (1.06–2.96) | 1.28 (1.03–1.58) |
| ≥3 | 1.42 (1.08–1.86) | 1.16 (1.02–1.31) |
| Household income | ||
| 1st quartile (≤$27,669) | 1.00 (reference) | 1.00 (reference) |
| 2nd quartile ($27,670–$34,464) | 1.20 (0.87–1.65) | 0.98 (0.83–1.14) |
| 3rd quartile ($34,465–$43,974) | 1.06 (0.73–1.53) | 0.93 (0.78–1.11) |
| 4th quartile (>$43,974) | 1.20 (0.81–1.76) | 1.01 (0.83–1.23) |
| Unknown | 1.52 (0.86–2.70) | 1.22 (0.95–1.58) |
| Total | ||
*
Mortality among women with node-positive operable breast cancer, by age. Cox proportional HR was adjusted for those variables listed, plus 11 SEER areas (categorized) and year of diagnosis (continuous).
SEER = The National Cancer Institute's Surveillance, Epidemiology, and End Results cancer registry; HR = hazard ratio; CI = confidence interval; BCS = breast-conserving surgery.