Cancer-related microangiopathic hemolytic anemia in patients with advanced gastric cancer: A retrospective single-center analysis.

Background: Microangiopathic hemolytic anemia (MAHA) with thrombocytopenia and organ failure caused by tumor-associated thrombotic microangiopathy (TMA) is a life-threatening oncological emergency. Rapid diagnosis and precise distinction from other forms of TMA is crucial for appropriate therapy, which aims at treating the underlying malignancy. However, the prognosis of patients with cancer-related (CR)-MAHA is limited. To date, less than 50 patients with gastric cancer and CR-MAHA have been reported, mainly as single case reports, and detailed information on treatment strategies and outcome are scarce. We analyzed the characteristics and outcomes data of CR-MAHA patients with gastric cancer treated at our center between 2012 and 2019.

Aim: To gain knowledge about CR-MAHA and the course of disease.

Methods: We retrospectively analyzed patients using an institutional prospectively maintained database. Patients who had CR-MAHA but other cancer types or cancer of unknown primary were excluded. The basic requirements for inclusion were: Histologically proven gastric adenocarcinoma; and clinical diagnosis of hemolytic anemia with schistocytes with or without thrombocytopenia. The observation period for each patient started with the first day of documented symptoms. The follow-up period for this analysis ended on February 1, 2020.

Results: We identified eight patients with a median age of 54 years. Histologically, all patients had (partial) diffuse subtypes of gastric adenocarcinoma with partial or complete signet cell morphology. All patients had metastatic disease and one patient had a microsatellite instability-high (MSI-H) tumor. In three patients, clinical signs of MAHA preceded the diagnosis of cancer, and in two patients, CR-MAHA indicated recurrent disease. All patients had severe hemolytic anemia and thrombocytopenia. Six patients experienced severe bone pain, and five patients had dyspnea. Systemic, 5-fluorouracil-based combination chemotherapy was initiated in six patients, which resulted in rapid initial response with significant improvement of clinical symptoms and blood values. Progression-free survival (PFS) of the whole cohort was 1.9 wk and median overall survival (OS) was 1.9 wk. For patients with chemotherapy, PFS was 9.0 wk and OS was 10.3 wk. The patient with the MSI-H tumor has been undergoing immunotherapy for more than 3 years.

Conclusion: The benefit of chemotherapy in CR-MAHA patients is limited. Immunotherapy for patients with MSI-H tumors may lead to long-term tumor control even in CR-MAHA patients.