Combined surgery and radiotherapy for synchronous multiple primary lung cancers: a clinical retrospective study

Abstract Background The recommended treatment strategy for early-stage synchronous multiple primary lung cancers (sMPLC) involves multiple resections of all lesions, if possible. However, some patients with sMPLC cannot tolerate multiple surgeries due to comorbidities or deterioration in lung functions. We aimed to analyze the outcomes of the combination of surgery and radiotherapy for sMPLC. Methods The clinical data of patients who underwent treatment with a combination of surgery and radiotherapy for sMPLC at a single center were collected, and the outcomes were analyzed. Results Among 3578 patients with non-small cell lung cancer who underwent surgical resection with curative intent, 332 had sMPLC. Of these, 20 received a combination of surgery and radiotherapy for each tumor. Sixteen patients were male, and four were female. The median patient age was 74 years (range: 60–84 years). The median follow-up period after pulmonary resection was 42 months (range: 7–184 months). The median tumor size was 18.5 mm (range, 10–55 mm) in the first cancer and 11.9 mm (range, 4–29 mm) in the second. Pulmonary resection was performed in the first cancer, with lobectomy for nine patients, and segmentectomy and wedge resection were performed for seven and four patients, respectively. Radiotherapy was administered in the second cancer. Stereotactic body radiation therapy, 3-dimensional conformal radiation therapy, and particle radiotherapy were performed in ten, eight, and two patients, respectively. Six patients died, while 14 patients were alive. Four patients died from lung cancer and two died from other diseases. The 3-year overall survival rate was 72.4%, and the 3-year progression-free survival rate was 69.6%. The 3-year local control rate for the second cancer was 95.0%. Conclusions: Treatment with a combination of surgery and radiotherapy is a viable option for sMPLC, when surgical resection cannot be performed for all lesions.