Case Report: Personalized treatment in an advanced lung adenocarcinoma patient with EGFR exon 21 L858R mutations based on the patient-derived tumor organoids.

Lung cancer is the most frequently diagnosed cancer and the leading cause of cancer deaths worldwide. Despite substantial therapeutic advances, the prognosis of lung cancer patients remains dismal. Here, we report a case of advanced lung adenocarcinoma harboring EGFR exon 21 L858R mutations who finally achieved partial response (PR) in the lung lesion following patient-derived tumor organoid (PDTO)-guided personalized therapy, even after multiple lines of systemic treatment. In May 2021, a 52-year-old woman was diagnosed with right lung adenocarcinoma (cT3N2M1c IVB), accompanied by multiple metastases. Although Osimertinib was initiated as first-line therapy based on the identified EGFR exon 21 L858R mutations, the patient experienced disease progression. Subsequent treatment with ivonescimab plus pemetrexed disodium was administered, but disease progression persisted. Based on serial organoid drug sensitivity testing, repeated adjustments to the therapeutic regimen were made, and the patient ultimately achieved PR in the lung lesion. Our case demonstrates that the lung cancer organoids serve as a powerful preclinical platform for individualized treatment selection in patients with advanced lung adenocarcinoma via rapid functional drug screening. This personalized strategy shows great potential to optimize clinical outcomes for heavily pretreated patients.