What second line treatment would you choose for a post menopausal woman with HR+ HER2+ metastatic breast cancer with low burden disease treated with first line aromatase inhibitor and trastuzumab?

The TAnDEM trial did prove that triple-positive metastatic breast cancer should be treated with both anti-HER2 therapy and endocrine therapy. Although there is no direct data in the setting of the above-described case to my knowledge, we can extrapolate from the large body of evidence that exists fo...