Tumor lysis syndrome following trastuzumab and pertuzumab for metastatic breast cancer: a case report

BACKGROUND Tumor lysis syndrome is a rare and potentially fatal complication of oncologic treatments, especially in solid tumors. To the best of our knowledge, tumor lysis syndrome has never been reported after trastuzumab and pertuzumab combination therapy. Knowledge of risk factors and active prevention proceedings is of utmost importance to avoid fatal outcomes. CASE PRESENTATION We present the case of a chemo-naive 58-year-old Belgian woman developing hypovolemic shock and multiple organ failure due to tumor lysis syndrome after a single dose of trastuzumab and pertuzumab in the context of the treatment of a metastatic breast cancer and resulting in fatal outcome despite optimal management. CONCLUSIONS Considering that targeted cancer therapies become increasingly effective, oncologists should be extremely cautious when treating patients at high risk of tumor lysis syndrome, even if they are not treated with cytotoxic chemotherapy, and determine appropriate prophylaxis.