ROS1-Positive Stage III Lung Adenocarcinoma With Pathologic Complete Response

What happened, in summary

A 49-year-old man developed cough and sputum in May 2023. He had a history of a gastric malignancy treated with subtotal gastrectomy, but the new problem was in the lung. CT showed a rapidly enlarged mass in the left lower lobe with hilar and mediastinal lymph-node involvement. Bronchoscopy supported lung adenocarcinoma, and evaluation found no distant metastases. The lung cancer was classified as Stage III.

He began neoadjuvant chemotherapy with lobaplatin and paclitaxel. Tumor testing then found a ROS1 fusion, so crizotinib was added as targeted therapy. After 30 days of crizotinib, CT showed that the main lung mass had disappeared radiographically, leaving only a small thin-walled cavity, while the enlarged hilar and mediastinal nodes had markedly decreased.

He then underwent left lower lobectomy with hilar and mediastinal lymph-node dissection. Surgery was technically difficult because of dense fibrosis around the hilum, and conversion to open surgery caused rib fractures and short-term severe chest pain. Pathology nevertheless showed no residual cancer cells in the lung specimen and no cancer in the sampled lymph nodes, representing a pathologic complete response.

He continued oral crizotinib. At 10 months of treatment and standardized follow-up, no tumor recurrence had been detected.