Advanced Lung Adenocarcinoma Complicated with Primary Ovarian Cancer: A Case Report and Clinical Insights

We report a 57-year-old Asian female patient with advanced lung adenocarcinoma complicated by primary ovarian cancer, detailing her full-course diagnosis and treatment. Six years ago, she was diagnosed with advanced lung adenocarcinoma (cT4N2M1 Stage Ⅳ) harboring an EGFR exon 19 deletion, which responded to the first-generation tyrosine kinase inhibitor (TKI) gefitinib for 16 months. After resistance developed, sequential therapies including chemotherapy combined with anti-angiogenic therapy, immunotherapy, and the third-generation TKI osimertinib (guided by the EGFR T790M mutation) achieved long-term disease control. One year ago, she was diagnosed with primary ovarian endometrioid carcinoma (FIGO Stage Ⅲ). High-intensity focused ultrasound (HIFU) combined with chemotherapy significantly reduced the ovarian tumor, but subsequent chemotherapy adjustment due to adverse reactions led to disease progression. This case highlights the importance of individualized treatment for double primary malignancies, the efficacy of HIFU in local tumor control, and the need for optimal management of chemotherapy tolerance.