# Adjuvant T-DM1 versus trastuzumab in patients with residual invasive disease after neoadjuvant therapy for HER2-positive breast cancer: subgroup analyses from KATHERINE.

**Autores:** Mamounas EP, Untch M, Mano MS et al.
**Revista:** Ann Oncol (2021)
**PMID:** 33932503 | **PMCID:** —
**DOI:** [10.1016/j.annonc.2021.04.011](https://doi.org/10.1016/j.annonc.2021.04.011)
**Fuente:** PubMed (abstract only — full text vía DOI)

## Relevancia
Análisis de respuesta axilar y conversión a ypN0 en cáncer de mama HER2+ tratado con quimioterapia neoadyuvante anti-HER2; relevante para definir candidatas a desescalada quirúrgica axilar.

## Abstract
In the KATHERINE study (NCT01772472), patients with residual invasive early breast cancer (EBC) after neoadjuvant chemotherapy (NACT) plus human epidermal growth factor receptor 2 (HER2)-targeted therapy had a 50% reduction in risk of recurrence or death with adjuvant trastuzumab emtansine (T-DM1) versus trastuzumab. Here, we present additional exploratory safety and efficacy analyses.

KATHERINE enrolled HER2-positive EBC patients with residual invasive disease in the breast/axilla at surgery after NACT containing a taxane (&#xb1; anthracycline, &#xb1; platinum) and trastuzumab (&#xb1; pertuzumab). Patients were randomized to adjuvant T-DM1 (n&#xa0;= 743) or trastuzumab (n&#xa0;= 743) for 14 cycles. The primary endpoint was invasive disease-free survival (IDFS).

The incidence of peripheral neuropathy (PN) was similar regardless of neoadjuvant taxane type. Irrespective of treatment arm, baseline PN was associated with longer PN duration (median, 105-109 days longer) and lower resolution rate (&#x223c;65% versus &#x223c;82%). Prior platinum therapy was associated with more grade 3-4 thrombocytopenia in the T-DM1 arm (13.5% versus 3.8%), but there was no grade &#x2265;3 hemorrhage in these patients. Risk of recurrence or death was decreased with T-DM1 versus trastuzumab in patients who received anthracycline-based NACT [hazard ratio (HR)&#xa0;= 0.51; 95% confidence interval (CI): 0.38-0.67], non-anthracycline-based NACT (HR&#xa0;= 0.43; 95% CI: 0.22-0.82), presented with cT1, cN0 tumors (0 versus 6 IDFS events), or had particularly high-risk tumors (HRs ranged from 0.43 to 0.72). The central nervous system (CNS) was more often the site of first recurrence in the T-DM1 arm (5.9% versus 4.3%), but T-DM1 was not associated with a difference in overall risk of CNS recurrence.

T-DM1 provides clinical benefit across patient subgroups, including small tumors and particularly high-risk tumors and does not increase the overall risk of CNS recurrence. NACT type had a minimal impact on safety.

## Acceso
Vía [DOI](https://doi.org/10.1016/j.annonc.2021.04.011) o suscripción institucional.

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*Datos de PubMed. Citar: doi 10.1016/j.annonc.2021.04.011*
