Tumor lysis Syndrome in a Patient with Metastatic Breast Cancer Treated with Alpelisib

Tumor lysis syndrome following letrozole for locally advanced breast cancer: a case report

BACKGROUND

Letrozole, an aromatase inhibitor, is used to treat breast cancer in postmenopausal women. Tumor lysis syndrome (TLS) is a complication that can trigger multiple organ failure caused by the release of intracellular nucleic acids, phosphate, and potassium into the blood due to rapid tumor cell disintegration induced by drug therapy. TLS is uncommon in solid tumors and occurs primarily in patients receiving chemotherapy. Herein, we report a rare occurrence of TLS that developed in a patient with locally advanced breast cancer following treatment with letrozole.

CASE PRESENTATION

An 80-year-old woman with increased bleeding from a fist-sized left-sided breast mass presented to our hospital. Histological examination led to a diagnosis of invasive ductal carcinoma of the luminal type. The patient refused chemotherapy and was administered hormonal therapy with letrozole. Seven days after letrozole initiation, she complained of anorexia and diarrhea. Blood test results revealed elevated blood urea nitrogen (BUN) and creatinine (Cr) levels, and she was admitted to our hospital for intravenous infusions. On the second day after admission, marked elevations of LDH, BUN, Cr, potassium, calcium, and uric acid levels were observed. Furthermore, metabolic acidosis and prolonged coagulation capacity were observed. We suspected TLS and discontinued letrozole, and the patient was treated with hydration, febuxostat, and maintenance hemodialysis. On the third day after admission, her respiratory status worsened because of acute respiratory distress syndrome associated with hypercytokinemia, and she was intubated. On the fourth day after admission, her general condition did not improve, and she died.

CONCLUSIONS

Although TLS typically occurs after chemotherapy initiation, the findings from the present case confirm that this syndrome can also occur after hormonal therapy initiation and should be treated with caution.

Fatal Tumour Lysis Syndrome Induced by Brigatinib in a Lung Adenocarcinoma Patient Treated With Sequential ALK Inhibitors: A Case Report

Tumour lysis syndrome (TLS) represents a group of fatal metabolic derangements resulting from the rapid breakdown of tumour cells. TLS typically occurs soon after the administration of chemotherapy in haematologic malignancies but is rarely observed in solid tumours. Here, we report a case of brigatinib-induced TLS after treatment with sequential anaplastic lymphoma kinase (ALK) inhibitors in a patient with advanced ALK-rearranged lung adenocarcinoma. The patient was treated sequentially with crizotinib, alectinib, and ensartinib. High-throughput molecular profiling after disease progression indicated that brigatinib may overcome ALK resistance mutations, so the patient was administered brigatinib as the fourth-line treatment. After 22 days of therapy, he developed oliguria, fever, and progressive dyspnoea. Clinical manifestations and laboratory findings met the diagnostic criteria for TLS. The significant decrease in the abundance of ALK mutations in plasma indicated a therapeutic response at the molecular level. Consequently, the diagnosis of brigatinib-induced TLS was established. To the best of our knowledge, this is the first case of TLS induced by sequential targeted therapy in non-small cell lung cancer. With the extensive application of sequential therapy with more potent next-generation targeted therapeutic drugs, special attention should be given to this rare but severe complication.