Abstract 216P
Background
Neoadjuvant hormone therapy is effective in in locally advanced Her2(-) luminal breast cancer (LA HnLBC). The role of neoadjuvant chemotherapy (NAC) and mPEPI score after NAC is unclear in LA HnLBC. We evaluated prognostic and predictive factors for NAC in LA HnLBC retrospectively.
Methods
All patients (pts) had doxorubicin +/- taxane as NAC. They were grouped for pathologic response rate (A: pCR, n:26, and B: non pCR, n:116) and categorized for PR, ki67, ki67 decline & mPEPI score. Ki67 cutoffs were taken as 20 (from literature) and median values in our study.
Results
142 LA HnLBC pts were included. Median age was 51 years for A, 53 years for B. 57.7% in A, 54.3% in B were postmenopausal. pCR rate was 18.3%. Median ER/PR/ki67 were 90/40/40 %. Ki67 cutoffs were 20 (by literature) and 40 (median level for both basal & postoperative). Basal features for A and B were similar except T stage and grade (G) (p=0.03, p=0.03). Group A had more T2 (73%), G3 (69%), and B had more T3 (21%), G2 (46%) tumors. A had lower mPEPI (3.5 vs 5, p=0.05). 5y-DFS was 69% (93.8% vs 63.4%, p=0.012). 5y-OS was 77% (100% vs 72%, p=0.018). In univariate analysis, high basal / (po) ki67 levels, ki67 decline and mPEPI score were significant poor prognostic factors for DFS (p=0.01, p< 0.001, p=0.017, p<0.001) and OS (p=0.006, p=0.003, p=0.05, p=0.001) in group B. Cox regression analysis by po ki67 cutoffs as 20 (model 1) and 40 (model 2) is shown in the table. Prognostic cutoffs were determined as 40 for basal ki67 (DFS & OS), 20 for po ki67 (DFS), 4 for mPEPI (DFS) & 30 for ki67 decline (OS). Table: 216P
| Model1 | DFS | p | OS | p | |
| HR 95% CI | HR 95% CI | ||||
| ER | |||||
| <10 | 1.00 | 0.768 | 1.00 | 0.359 | |
| ≥10 | 0.857 (0.307-2.389) | 0.584 (0.185-1.844) | |||
| Ki 67 | |||||
| <40 | 1.00 | 0.016 | 1.00 | 0.039 | |
| ≥40 | 3.256 (1.244-8.521) | 3.394 (1.062-10.846) | |||
| Ki 67 po | |||||
| <20 | 1.00 | 0.004 | 1.00 | 0.025 | |
| ≥20 | 8.312 (1.941-35.585) | 10.110 (1.329-76.919) | |||
| ki 67 decline % | |||||
| ≥30 | 1.00 | 0.731 | 1.00 | 0.752 | |
| <30 | 0.783 (0.194-3.154) | 1.303 (0.252-6.745) | |||
| mPEPI | |||||
| ≤4 | 1.00 | 0.175 | NA | NA | |
| >4 | 4.879 (0.495-48.123) | NA | |||
| Model 2 | |||||
| Ki 67 | |||||
| <40 | 1.00 | 0.005 | 1.00 | 0.006 | |
| ≥40 | 3.967 (1.518-10.368) | 5.445 (1.612-18.390) | |||
| ki 67 po | |||||
| <40 | 1.00 | 0.105 | 1.00 | 0.772 | |
| ≥40 | 2.159 (0.851-5.480) | 1.213 (0.327-4.501) | |||
| Ki 67 decline % | |||||
| ≥30 | 1.00 | 0.901 | 1.00 | 0.022 | |
| <30 | 1.090 (0.278-4.278) | 4.579 (1.244-16.862) | |||
| mPEPI | |||||
| ≤4 | 1.00 | 0.014 | NA | NA | |
| >4 | 12.541 (1.678-93.706) | NA |
Conclusions
Favorable prognostic factors were defined as lower basal ki67 level (<40%) and higher ki67 decline rate (<30%) for OS; lower basal ki67 level (<40%), po ki 67 level (<20%) & mPEPI score (≤4) for DFS after NAC in LA HnLBC. Different prognostic cutoffs for basal and po ki67 is striking. mPEPI score may also have a role after NAC, as if after neoadjuvant hormone therapy in selected LA HnLBC pts. Prospective clinicals trials are needed in this area.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.