Table 4.
The preoperative endocrine prognostic index*
| Pathology, biomarker status | RFS |
BCSS |
||
| HR | Points | HR | Points | |
| Pathological tumor size | ||||
| T1/2 | — | 0 | — | 0 |
| T3/4 | 2.8 | 3 | 4.4 | 3 |
| Node status | ||||
| Negative | — | 0 | — | 0 |
| Positive | 3.2 | 3 | 3.9 | 3 |
| Ki67 level | ||||
| 0%–2.7% (0–1†) | — | 0 | — | 0 |
| >2.7%–7.3% (1–2†) | 1.3 | 1 | 1.4 | 1 |
| >7.3%–19.7% (2–3†) | 1.7 | 1 | 2.0 | 2 |
| >19.7%–53.1% (3–4†) | 2.2 | 2 | 2.7 | 3 |
| >53.1% (>4†) | 2.9 | 3 | 3.8 | 3 |
| ER status, Allred score | ||||
| 0–2 | 2.8 | 3 | 7.0 | 3 |
| 3–8 | — | 0 | — | 0 |
To obtain the preoperative endocrine prognostic index (PEPI) score, risk points for relapse-free survival (RFS) and breast cancer–specific survival (BCSS) were assigned depending on the hazard ratio (HR) given in Table 3. The points scale was adapted from the cardiovascular literature on predicting outcomes for myocardial infarction (11). The total PEPI score assigned to each patient is the sum of the risk points derived from the pT stage, pN stage, Ki67 level, and estrogen receptor (ER) status of the surgical specimen. An HR in the range of 1–2 receives one risk point; a HR in the 2–2.5 range, two risk points; a HR greater than 2.5, three risk points. The total risk point score for each patient is the sum of all the risk points accumulated from the four factors in the model. For example, a patient with a T1N0 tumor, a Ki67 staining percentage of 1 and an ER Allred score of 6 will have no risk points assigned. In contrast, a patient with a T3N1 tumor, a Ki67 staining percentage of 25, and an ER Allred score of 2 will have a total relapse score of 3 + 3 + 2 + 3 = 11.
The natural logarithm interval corresponding to the percent Ki67 values on the original percentage scale.