Table 3.
Multivariable analysis of associations between receipt of chemotherapy and demographic, tumor, and oncologist characteristics among elderly patients who had high-risk and low-risk breast cancer (n=37,806)
| HIGH RECURRENCE RISK | LOW RECURRENCE RISK | ||||
|---|---|---|---|---|---|
| Characteristics | Odds Ratio | 95% CI | Odds Ratio | 95% CI | |
| a. Surgeon characteristics | |||||
| Degree | |||||
| DO | 1.00 | Referent | 1.00 | Referent | |
| MD | 1.19 | 0.73–1.94 | 0.77 | 0.54–1.10 | |
| US-trained | |||||
| No | 1.00 | Referent | 1.00 | Referent | |
| Yes | 0.85 | 0.68–1.07 | 0.74* | 0.65–0.86 | |
| Type of practice | |||||
| Non-private | 1.00 | Referent | 1.00 | Referent | |
| Private | 1.55* | 1.22–1.98 | 1.35* | 1.16–1.56 | |
| #patients in practice | |||||
| 1–40 | 1.00 | Referent | 1.00 | Referent | |
| >40 | 0.93 | 0.76–1.13 | 1.03 | 0.73–0.98 | |
| Sex | |||||
| Male | 1.00 | Referent | 1.00 | Referent | |
| Female | 1.12 | 0.87–1.42 | 0.97 | 0.83–1.14 | |
| Year of graduation | |||||
| <1975 | 1.00 | Referent | 1.00 | Referent | |
| ≥1975 | 1.25* | 1.02–1.52 | 1.42* | 1.25–1.62 | |
| b. Patient demographic characteristics | |||||
| Age at diagnosis | |||||
| 65–69 | 1.00 | Referent | 1.00 | Referent | |
| 70–74 | 0.62* | 0.49–0.77 | 0.52* | 0.47–0.56 | |
| 75–79 | 0.36* | 0.27–0.45 | 0.28* | 0.25–0.32 | |
| 80+ | 0.11* | 0.08–0.14 | 0.07* | 0.06–0.09 | |
| Race | |||||
| White | 1.00 | Referent | 1.00 | Referent | |
| Black | 0.99 | 0.73–1.33 | 1.12 | 0.92–1.37 | |
| Hispanic | 1.39 | 0.53–1.82 | 1.01 | 0.70–1.47 | |
| Residence | |||||
| Metropolitan | 1.00 | Referent | 1.00 | Referent | |
| Non-metropolitan | 1.26 | 0.92–1.73 | 0.99 | 0.84–1.18 | |
| Marital status | |||||
| Unmarried | 1.00 | Referent | 1.00 | Referent | |
| Married | 0.10* | 0.94–1.31 | 1.20 | 1.11–1.30 | |
| Socioeconomic status | |||||
| Lowest quartile | 1.00 | Referent | 1.00 | Referent | |
| 2nd quartile | 1.26* | 1.02–1.55 | 1.16* | 1.03–1.31 | |
| 3rd quartile | 1.22 | 0.98–1.54 | 1.24* | 1.11–1.40 | |
| Highest quartile | 1.37* | 1.06–1.75 | 1.32* | 1.17–1.49 | |
| c. Patient clinical characteristics | |||||
| Stage | |||||
| I | - | - | 1.00 | Referent | |
| II | 1.00 | Referent | 10.03* | 9.03–11.14 | |
| III | 1.85* | 1.46–2.34 | - | - | |
| Grade | |||||
| Well/moderately differentiated | 1.00 | Referent | 1.00 | Referent | |
| Poorly differentiated | 1.36* | 1.12–1.66 | 1.59* | 1.46–1.73 | |
| Unknown | 0.83 | 0.61–1.14 | 0.80* | 0.71–0.90 | |
| Comorbidity score | |||||
| 0 | 1.00 | Referent | 1.00 | Referent | |
| 1 | 0.79* | 0.66–0.96 | 0.97 | 0.89–1.06 | |
| >1 | 0.58* | 0.47–0.73 | 0.67* | 0.59–0.76 | |
*
P-Value <0.01
Each variable was corrected for the other listed characteristics and year of diagnosis.
DO=Doctor of Osteopathic Medicine; ER=estrogen receptor; PR=progesterone receptor.
Low Risk: ER/PR Pos; Stage I-II - N=28859
High Risk ER/PR Neg; Stage II-III – 2947