Would you consider stopping chemotherapy and continuing trastuzumab alone in a patient with metastatic HER2 positive GEJ cancer who had a complete response to chemotherapy and trastuzumab?

Since there are no data for a) stopping palliative chemotherapy in patients who achieve a clinical complete response (CR) or b) trastuzumab therapy alone, clinical practice is unburdened by any evidence.

The rare patients I have had who have achieved a CR tend to have had small-volume metastatic disease at baseline. In such patients, I have considered stopping trastuzumab and chemotherapy entirely after an endoscopy and/or PET/CT to confirm a clinical CR.

I have generally not continued trastuzumab monotherapy given the absence of clear data that this is helpful but also mostly because the goal is to provide patients with a treatment-free interval. Of these patients, between 1/2 - 2/3 have maintained a CR several years off therapy.

Clearly, ...