Single-molecule targeted therapy shrinks lung lesions and improves bone metastases: A case report.

Rationale: Bone metastasis is a common metastatic mode of advanced lung cancer and poses a great threat to the survival and quality of life of patients with this disease. However, the available literature has limited treatment options for advanced lung cancer with bone metastases.

Patients Concerns: A 76-year-old married male patient was underwent CT due to cough and sputum for 1 month. On CT, space-occupying lesions were found in the left inferior lobe of the lung, as well as multiple bone metastases in the vertebral body and ilium.

Diagnoses: Pathologic sectioning of the lung lesion after puncture revealed invasive lung adenocarcinoma, and a genetic test revealed EGFR exon 21: L858R (64.60%).

Interventions: Considering that the disease was not suitable for radiotherapy (extensive metastasis) and could not be treated with chemotherapy (poor underlying condition), the patient was given molecularly targeted therapy with osimertinib.

Outcomes: After 10 months of standard treatment (80 mg orally, once a day), the lung lesions of the patients became significantly smaller, and the bone metastases distinctly improved. And the patient's condition has not shown any signs of rebound with the one-year follow-up.

Lessons Subsections: In the present case, the bone metastases from lung adenocarcinoma almost completely disappeared after treatment with a single molecular targeted therapy agent, increasing the confidence in the treatment of advanced lung cancer.