Case Presentation: A 74-year-old man with a medical history of hepatitis C cirrhosis post-treatment was evaluated after he was found to have hepatocellular carcinoma on abdominal MRI. The carcinoma occupied almost the entire right hepatic lobe with macrovascular invasion without evidence of metastatic disease. The initial alpha-fetoprotein level exceeded 2000 nanograms per milliliter. Subsequently, the patient was initiated on an immunotherapy regimen with atezolizumab and bevacizumab. After completing two cycles of this therapy, he was admitted to the hospital due to deteriorating mental status. An MRI of the brain showed features indicative of treatment-associated encephalopathy. Cerebrospinal fluid analysis ruled out meningeal carcinomatosis and infection. Owing to persistent confusion and altered mental status, both atezolizumab and bevacizumab were held. The patient’s mental status quickly improved following the cessation of immunotherapy. The patient was also started on 60 mg of prednisone, which was later tapered over four months. During the assessment of cancer status, the patient’s alpha-fetoprotein levels normalized, indicating a positive response to the initial immunotherapy. Subsequent CT of the abdomen and pelvis revealed reduced tumor size and upper abdominal lymphadenopathy, with no new hepatic mass. Presently, the patient receives ongoing care from both the oncology and neurology departments on an outpatient basis.
Discussion: The FDA approved atezolizumab and bevacizumab in May 2020 as a treatment of choice for individuals with unresectable locally-advanced or metastatic hepatocellular carcinoma who have not previously received immunotherapy. However, the occurrence of encephalitis and treatment-related encephalopathy due to this combination is rare and has limited documentation in the existing literature. While there are no established guidelines for treatment, these side effects have been managed by discontinuing the drug, using high-dose steroid pulse therapy, administering intravenous immunoglobulin, plasmapheresis, or employing medications such as infliximab or rituximab.
Conclusions: While instances of these cerebral toxicities demand heightened attention from healthcare providers due to their potentially life-threatening risks, recent studies indicate improved tumor response and enhanced survival in patients who encounter immune-related adverse events (irAE). Further research remains crucial to refining our understanding of irAEs, as they may not always represent unfavorable cancer outcomes.