A Review of Current Literature and Real-World Outcomes With Neoadjuvant Chemotherapy in Hormone Receptor Positive, HER2 Negative Breast Cancer.

BACKGROUND

Neoadjuvant chemotherapy has been used to downstage locally advanced ER+/HER2- breast cancer with low response rates. The optimal neoadjuvant regimen for this population is unknown.

PATIENTS AND METHODS

Between 2017 and 2022, 192 patients (ages 28-78) with stage II/III ER+/Her2- breast cancer at our institution were evaluated. Patients were divided into 4 groups based on the neoadjuvant chemotherapy regimen used (AC-T, TC, TAC, or other). The responses were categorized as complete (ypT0/is ypN0), partial, no response, or progressive disease.

RESULTS

The choice of neoadjuvant chemotherapy was not predictive of pCR (P = .3864), even among those with more advanced nodal disease. No significant difference was noted in OS or IDFS at 24 or 48 months between the AC-T and TC groups. In the AC-T group (n = 130), 9 patients had a CR (6.98%), while no patients in TC group had a CR. Those who were premenopausal were more likely to achieve pCR compared to those postmenopausal. Race significantly impacted IDFS.

CONCLUSIONS

In this single center study, we found no differences in IDFS or OS when comparing neoadjuvant TC to AC-T. The AC-T regimen group had a higher pCR rate of 6.98% compared to 0% in TC regimen group. Further exploration is needed to understand why non-white populations have inferior IDFS.