Stage 4 small-cell lung cancer: ongoing response to immunotherapy

What happened, in summary

A 54-year-old Chinese man presented on December 26, 2022, with cough, blood-stained sputum, hoarse voice, shortness of breath with activity, and more than 1 month of pain in the posterior lumbar back and right epigastrium. He had a long smoking history of more than 30 years and excessive drinking for more than 40 years. CT showed a central tumor in the lower lobe of the left lung with obstructive pneumonia, invasion of the left pulmonary artery and vein, mediastinal regional lymph nodes, and liver metastases. Bone scan showed widespread bone metastases involving the left scapula, sternum, ribs, cervical, thoracic and lumbar vertebrae, and pelvis. Brain MRI initially showed no brain metastases. Bronchoscopic biopsy confirmed small-cell lung cancer with negative PD-L1 expression. The diagnosis was extensive-stage SCLC, Stage IVB, cT4N3M1c2. From January 5 to March 28, 2023, he received 4 cycles of serplulimab, carboplatin, and etoposide, with only moderate gastrointestinal reactions. CT showed complete response. He then began serplulimab maintenance every 21 days. PET-CT in October 2023 showed complete response in the primary lung, liver, and bone lesions but partial response in left hilar and mediastinal nodes and new brain lesions. Brain MRI confirmed oligoprogressive brain metastases. He received head SIB-IMRT, consolidative thoracic radiotherapy, Sr-89 chloride radionuclide therapy, and monthly bisphosphonate therapy while continuing serplulimab. By February 2024, brain MRI showed complete response of the treated brain metastases. After about 20 months of first-line immunotherapy, he had no deterioration and maintained high quality of life. Maintenance immunotherapy was planned until disease progression or intolerable toxicity.