Table 2.
Comparison of oestrogen and progesterone receptor phenotypes with response in a neoadjuvant trial of tamoxifen versus letrozole
| Letrozole | Tamoxifen | ||||
| Phenotype | n | RR (%) | n | RR (%) | P |
| ER+/PgR+ | 54/85 | 64 | 33/81 | 41 | 0.005 |
| ER+/PgR- | 18/34 | 53 | 16/41 | 39 | 0.331 |
| ER-/PgR+ | 2/4 | 50 | 2/2 | 100 | NS |
| ER-/PgR- | 1/12 | 8 | 0/16 | 0 | NS |
| ErbB1 or 2+/ER+ | 15/17 | 88 | 4/19 | 21 | 0.0004 |
| ErbB1 and 2-/ER+ | 55/101 | 54 | 42/100 | 42 | 0.08 |
| ErbB1 or 2+/ER- | 0/9 | 0 | 0/10 | 0 | - |
ER, oestrogen receptor; NS, not significant; PgR, progesterone receptor; RR, response rate. Data from Ellis and coworkers [32].