Involvement of the 12u lymph nodes around the upper lobe bronchi in patients with lung cancer of the right middle lobe, right lower lobe, or left lower lobe

In Japan, the lymph nodes around the upper lobe bronchi, known as the 12u nodes, are not included in the nodes recommended for dissection in patients with right middle lobe carcinoma, right lower lobe carcinoma, or left lower lobe carcinoma. However, histologic examination has revealed involvement of these nodes in pneumonectomy patients whose carcinoma originated in the right lower lobe. We histologically examined the lymph nodes from 152 patients with lung cancer to determine the incidence of involvement of the 12u lymph nodes. These nodes were found to be involved in 14 (9.2%) of the 152 patients. The rate of involvement was significantly higher in those with T2-T4 disease than in those with T1 disease, and was also significantly higher in patients with N2 disease than in those with N1 disease. There were two long-term survivors without recurrence, and one other patient who lived for more than 5 years before succumbing to the disease. In conclusion, to ensure removal of all the cancer tissue, it is recommended that the 12u lymph nodes be included in the nodes routinely dissected in patients with right lower lobe carcinoma, right middle lobe carcinoma, or left lower lobe carcinoma.