Materials & methods: We recently reported the largest trial of breast cancer patients with HER2 positive leptomeningeal metastases (LM) treated with trastuzumab. An additional treatment indication was explored as part of a single institution retrospective case series of HER2 positive esophageal adenocarcinoma LM (n = 2). Results: One patient received intrathecal trastuzumab (80 mg twice weekly) as part of their treatment regimen with durable long-term response and clearance of circulating tumor cells in the cerebral spinal fluid. The other patient demonstrated rapid progression and death as previously described in the literature. Conclusion: Intrathecal trastuzumab is a well-tolerated and reasonable therapeutic option worthy of further exploration for patients with HER2 positive esophageal carcinoma LM. An associative, but not a causal relationship, can be made regarding therapeutic intervention.
Keywords: HER2; circulating tumor cells; esophageal cancer; intrathecal; leptomeningeal metastases; trastuzumab.
Cancer of the esophagus, the tube that connects the mouth to the stomach, tends to be aggressive. Very rarely, this cancer can spread to the lining that surrounds your brain, called the leptomeninges. Previous reports of patients who have experienced this specific spreading pattern of esophageal cancer to the leptomeninges are quite grim, with patients experiencing rapid decline and death within weeks to months. However, we write with two cases of esophageal cancer with this leptomeningeal spreading pattern, one of which involves a patient treated with a medication known as trastuzumab. As part of his long and complex course of treatment, this patient was given trastuzumab through a tube traveling directly to the area of the leptomeninges. This patient, now almost 2 years out from his initial diagnosis, has responded well to the treatment. As such, we believe that this specific treatment regimen as well as the ways in which our clinical team tracked this patient’s response to medications are worth exploring further.