K. Toosi4, F. O. Velez-Cubian2, E. Ng4, C. C. Moodie1, J. Garrett1, J. P. Fontaine1,2,3, E. M. Toloza1,2,3 1Moffitt Cancer Center,Thoracic Oncology,Tampa, FL, USA 2University Of South Florida Morsani College Of Medicine,Surgery,Tampa, FL, USA 3University Of South Florida Morsani College Of Medicine,Oncologic Sciences,Tampa, FL, USA 4University Of South Florida Morsani College Of Medicine,Tampa, FL, USA
~~Introduction: We investigated efficacy of lymph node (LN) dissection, detection of occult LN metastasis, and survival of patients after robotic-assisted thoracoscopic pulmonary lobectomy for non-small cell lung cancer (NSCLC).
Methods: We retrospectively analyzed all patients who underwent robotic-assisted lobectomy for NSCLC by one surgeon over a 44-month period. Clinical stage was determined by history & physical, computerized tomography (CT), positron-emission tomography (PET), brain imaging studies (MRI), and endobronchial ultrasonography (EBUS). Pathologic stage was determined by intraoperative findings & final pathology. Patient survival was assessed through chart reviews, cancer registries, and national obituary searches. Kaplan Meier curves were generated for clinical and pathologic stages.
Results: Of 249 patients (mean age 67.8±0.6yr; range 39-87) who underwent robotic assisted pulmonary lobectomy for NSCLC, mean tumor size was 3.2±0.1cm (range 0.5-11.0cm), most commonly adenocarcinoma (62.7%), squamous cell carcinoma (21.7%), and neuroendocrine carcinoma (8.0%). Assessment of ≥3 mediastinal (N2) stations occurred in 245 or 98.4% of our cohort, with 218 (87.6%) of the patients having ≥3 N2 stations reported. Mean N2 stations assessed was 4.1±0.1 stations with a mean N2 stations reported of 3.6±0.1 stations. Our overall mean of LN stations (N1+N2) with actual lymph nodes retrieved was 5.5±0.1 stations. The mean individual mediastinal lymph nodes retrieved was 7.7±0.3 LNs, for a total of 13.9±0.4 N1+N2 LNs. There were 159 (63.9%) patients who were clinical stage 1 versus 134 (53.8%) who were pathologic stage 1, with 67 (26.9%) of patients upstaged (including 20 patients from N0 to N1, 17 patients from N0 to N2, and 4 patients from N1 to N2) and 37 (14.9%) downstaged. Using clinical stage, a statistically significant difference in survival only existed between Stage I and Stage IV patients; however, using pathologic stage shows a statistically significant difference in survival between Stage I and Stage III, Stage I and Stage IV, Stage II and Stage III, and Stage II and Stage IV patients. For pathological stage, 1-year and 3-year survival with 95% confidence intervals were as follows: Stage I 92% (87-97%) and 75% (63-87%), Stage II 83% (70-96%) and 73% (49-97%), Stage III 75% (63-87%) and 44% (26-62%), and Stage IV 67% (37-97%) and 0%. For clinical and pathologic stages, 1-year and 3-year survival improved the lower the stage.
Conclusion: Mediastinal LN dissection during robotic-assisted lobectomy results in more LNs and LN stations assessed with greater upstaging than during VATS or thoracotomy. Upstaging has a direct effect on patient survival.