Results of intention-to-treat pulmonary metastasectomies in northern Finland revealing significant number of new lung primary carcinomas: time to move on from wedge resections?

Background: A considerable proportion of intended pulmonary metastasectomies is known to turn out as new incidental primary lung cancers in final pathology. We aimed to analyse the trends and results of pulmonary metastasectomies using the intention-to-treat approach with an emphasis on final histopathological findings. Methods: All intention-to-treat pulmonary metastasectomies performed in Oulu University Hospital between 2000 and 2020 were included in the study. Long term survival was analysed with the Kaplan-Meier method and log-rank tests. A binary logistic regression analysis was performed to calculate odds ratios for incidental primary lung cancer in final histology. Results: A total of 154 intended pulmonary metastasectomies were performed to 127 individual patients. There was an increasing trend in pulmonary metastasectomies during the study period. Despite the increasing trend in comorbidities of the operated patients, the length of hospital stays decreased, and the postoperative complication rates remained stable. In final pathology reports, 9.7% were new primary lung cancers and 13.0% were benign nodules. A long disease-free interval (≥24 months) and smoking history were associated with incidental primary lung cancer in final histology. The short-term 30- and 90-day mortalities after pulmonary metastasectomy were 0.7%. The 5-year survival after pulmonary metastasectomy from all histologies was 52.8%, and from colorectal cancer metastasectomies (n=34) it was 73.5%. Conclusions: The significant amount of new primary lung cancer lesions in pulmonary metastasectomy specimens highlight the diagnostic importance of pulmonary metastasectomy. A segmentectomy could be considered as a primary procedure in pulmonary metastasectomy in patients with a long disease-free interval and a heavy smoking history.