What happened, in summary

A 59-year-old man presented in February 2022 after 6 months of persistent dry cough. CT showed a large tumor in the left upper lung with enlarged hilar lymph nodes. Biopsy showed a malignant spindle-cell tumor consistent with pulmonary sarcomatoid carcinoma, classified as Stage III. Testing found PIK3CA and TP53 mutations, with PD-L1 expression at 5%.

He received 2 cycles of tislelizumab with albumin-bound paclitaxel and cisplatin. The lung tumor and hilar nodes shrank substantially, meeting criteria for a partial response. He then underwent left upper lobectomy with systematic lymph-node dissection in April 2022.

Surgical pathology showed a major treatment response with about 10% residual tumor. The remaining tumor had a carcinosarcoma pattern, containing both squamous carcinoma and rhabdomyosarcoma-like components. Sampled lymph nodes did not contain active cancer.

After surgery, he received 4 cycles of immunotherapy plus platinum-based chemotherapy followed by 7 additional cycles of immunotherapy. He did not develop an immune-related adverse reaction. During postoperative follow-up, no recurrence was detected for more than 29 months.