Table 2.
Independent predictors associated with the receipt of chemotherapy (chemotherapy vs. no chemotherapy) between 2004 and 2012 in the SEER database (n = 8524).
| Variables | OR | 95%CI | P |
|---|---|---|---|
| Year of diagnosis | |||
| 2004 | 1 | ||
| 2005 | 0.459 | 0.136–1.555 | 0.211 |
| 2006 | 0.738 | 0.244–2.227 | 0.589 |
| 2007 | 1.255 | 0.428–3.681 | 0.679 |
| 2008 | 0.955 | 0.329–2.777 | 0.933 |
| 2009 | 0.961 | 0.331–2.785 | 0.941 |
| 2010 | 0.741 | 0.255–2.150 | 0.581 |
| 2011 | 0.755 | 0.261–2.183 | 0.604 |
| 2012 | 0.725 | 0.251–2.097 | 0.553 |
| Age (years) | |||
| 65-69 | 1 | ||
| 70-74 | 0.685 | 0.581–0.808 | <0.001 |
| >74 | 0.357 | 0.284–0.448 | <0.001 |
| Race/ethnicity | |||
| Non-Hispanic White | 1 | ||
| Non-Hispanic Black | 1.171 | 0.899–1.527 | 0.243 |
| Hispanic (all) | 1.189 | 0.902–1.568 | 0.219 |
| Other | 0.960 | 0.716–1.288 | 0.785 |
| Grade | |||
| Well differentiated | 1 | ||
| Moderately differentiated | 1.754 | 1.404–2.193 | <0.001 |
| Poorly/undifferentiated | 3.187 | 2.503–4.059 | <0.001 |
| Tumor stage | |||
| T1 | 1 | ||
| T2 | 1.361 | 1.161–1.596 | <0.001 |
| PR status | |||
| Negative | 1 | ||
| Positive | 0.782 | 0.652–0.939 | 0.008 |
| 21-gene RS classification | |||
| Low-risk | 1 | ||
| Intermediate-risk | 4.207 | 3.012–5.875 | <0.001 |
| High-risk | 36.237 | 25.684–51.125 | <0.001 |
CI, confidence interval; OR, odds ratio; PR, progesterone receptor; RS, recurrence score; T, tumor.