Tucatinib in Patients With Locally Advanced or Metastatic HER2-positive Breast Cancer Who Received at Least Two Prior Anti-HER2 Treatment Regimens.

The objective of this non-interventional study (NIS) is to evaluate tucatinib (TUKYSA®) combined with trastuzumab and capecitabine in adult patients with locally advanced or metastatic HER2-positive breast cancer who have been previously treated with at least two anti-HER2 treatment regimens in a real-world setting,

TRACE will collect real-world data on the treatment of tucatinib/trastuzumab/capecitabine in a broad patient population including older patients and patients with more comorbidities as compared to the pivotal trial HER2CLIMB. In contrast to HER2CLIMB, TRACE will also include patients receiving tucatinib/trastuzumab/capecitabine during 1st and 2nd palliative therapy line who were primarily diagnosed with early breast cancer and therefore already have received two prior anti-HER2 based treatment regimens before enrollment. Until today, no reliable data is available for these patient population. TRACE will primarily focus on HRQoL using the validated EORTC QLQ C30 + QLQ-BR23 + EQ-5D-5L questionnaires. Further aims are to evaluate effectiveness and safety in distinct subgroups focusing on effectiveness of tucatinib/trastuzumab/capecitabine in patients who have experienced prior therapies with trastuzumab and neratinib or capecitabine and HER2-targeted TKIs in the neoadjuvant, adjuvant or palliative setting, respectively.

Study sites may retrospectively include patients within 9 weeks (corresponds to 3 cycles) after start of study treatment up to 6 months after activation of respective site. Retrospectively included patients may have already completed study treatment or may have already deceased at the time of inclusion.

Eligibility Criteria:
Inclusion Criteria:

* Aged 18 years or older.
* Histologically confirmed HER2+ breast cancer with HER2 positivity defined as a 3+ score by immunohistochemistry (IHC) or a positive result by in situ hybridization (ISH), optionally combined with a IHC2+ score.
* Diagnosis of locally advanced or metastatic HER2+ breast cancer, including patients with brain metastases.
* Prior treatment with at least two prior anti-HER2-based regimens.
* Decision for treatment with tucatinib in combination with trastuzumab and capecitabine according to current SmPC of tucatinib either in

  1st/2nd palliative treatment line (Cohort 1) or 3rd/4th palliative treatment line (Cohort 2).
* Progression after or intolerance of last systemic anti-HER2-based therapy.
* Indication for treatment with tucatinib as assessed by the treating physician.
* Signed written informed consent (only if patient is alive at time of inclusion, not applicable for retrospective inclusion of deceased patients).
* Knowledge of German language.
* Other criteria according to current SmPC of tucatinib

Exclusion Criteria:

* Contraindications according to SmPC of tucatinib
* Participation in an interventional clinical trial within 30 days prior to enrolment or simultaneous participation in an interventional clinical trial.
* Treatment with tucatinib/trastuzumab/capecitabine (=study treatment) in 5th or higher palliative therapy line.
* Onset of tucatinib treatment later than 22 days after start of therapy line (in case tucatinib administration is started later than trastuzumab and/or capecitabine for any reason)