Anti-PD-1 Therapy Achieved Disease Control After Multiline Chemotherapy in Unresectable KRAS-Positive Hepatoid Lung Adenocarcinoma: A Case Report and Literature Review

Hepatoid adenocarcinoma of the lung (HAL) is extremely rare and standardized treatment strategy for HAL has not been established. Patients with unresectable HAL have a shorter survival time ranges from 1 to 36 months. Here, we reported a 65-year-old female patient with unresectable alpha-fetoprotein-producing HAL harboring KRAS-G12V and no other targetable driver mutations. The patient was treated with multiple lines of chemotherapies followed by PD-1 inhibitor, sintilimab, due to positive staining of PD-L1, and achieved an overall survival of 52 months. Although the disease was under control, the patient experienced fifth-grade pneumonia and died after 6 months of anti-PD-1 treatment. This is the first case of KRAS-positive HAL patient achieved stable disease by PD-1 inhibitor, which may provide valuable information for the treatment strategy development of advanced HAL patients, and highlights the importance of molecular diagnosis in treatment decision-making.