Prevalence and quantity of lymph nodes at mediastinal stations in patients with lung cancer: lessons from 181 bilateral mediastinal lymphadenectomies.

BACKGROUND: This study evaluated the prevalence and quantity of lymph nodes at particular stations of the mediastinum in patients with lung cancer. These data are important to radiologists, pathologists, and thoracic surgeons because they can serve as a benchmark when assessing the completeness of lymph node dissection. However, relevant data in the literature are scarce. METHODS: Data regarding the number of lymph nodes derived from two randomised trials of bilateral mediastinal lymph node dissection, the BML-1 and BML-2 study, were included in this analysis. Detectable nodes at particular stations of the mediastinum and the number of nodes at these stations were analysed. RESULTS: The mean number of removed nodes was 28.67 (range, 4-88). Detectable lymph nodes were present at stations 2R, 4R, and 7 in 93%, 98%, and 99% of patients, respectively. Nodes were rarely present at stations 9 L (33%), and 3 (35%). The largest number of nodes was observed at stations 7 and 4R (mean, 5 nodes). CONCLUSION: The number of mediastinal lymph nodes in patients with lung cancer may be greater than that in healthy individuals. Lymph nodes were observed at stations 2R, 4R, and 7 in more than 90% of patients with lung cancer. The largest number of nodes was observed at stations 4R and 7. Detectable nodes were rarely observed at stations 3 and 9 L. TRIAL REGISTRATION: ISRCTN 86,637,908.

Influence of bilateral mediastinal lymph node dissection on survival in non-small cell lung cancer patients - Randomized study.

OBJECTIVES: This study aimed to analyze the effect of bilateral mediastinal lymphadenectomy (BML) on survival of non-small cell lung cancer (NSCLC) patients. The hypothesis was: BML offers survival benefit as compared with SLND. METHODS: A randomized clinical trial including stage I-IIIA NSCLC patients was performed. All patients underwent anatomical lung resection. BML was performed during the same operation via additional cervical incision (BML group). In the control group, standard lymphadenectomy (systematic lymph node dissection, SLND) was performed. RESULTS: In total, 102 patients were randomized. No significant difference was found in the type of lung resection, blood loss, chest tube output, air leak, pain, and complications (p = 0.188-0.959). In the BML group, the operative time was longer (318 vs 223 min, p < 0.001) with higher number of removed N2 nodes (24 vs 14, p < 0.001). The 5-year survival rate was 72 % in the BML group vs 53 % in the SLND group (OR 2.33, 95 % CI 0.95-5.69, p = 0.062). Separate comparisons for different lobar locations of the tumor have shown no significant difference in survival for the right lung tumors and left upper lobe tumors. For the left lower lobe tumors, survival time was longer in the BML group (p = 0.021), and the 5-year survival rate was 90.9 % vs 37.5 %, (OR 16.66, 95 % CI 1.36-204.04, p = 0.0277). CONCLUSIONS: In patients with NSCLC located in the left lower lobe, bilateral lymph node dissection may be associated with better survival. The invasiveness of BML is comparable to that of SLND.