Validity of omission of subcarinal lymph node dissection in patients with cancer of the right upper lobe or left upper division of the lung

Background. Starting in 1991, we began to omit dissection of the subcarinal lymph node (#7) in patients with non small-cell lung cancer of the right upper lobe and left upper division. Objective. To review the validity of the omission of subcarinal lymph node dissection. Methods. We reviewed 627 patients with resected lung cancer located in the upper lobes or upper division and which took place from 1980 to 2002. Subcarinal lymph node dissection was performed in 335 cases and was omitted in 292 cases. We reviewed metastasis frequency, outcome, recurrence pattern, and relationship of postoperative ischemic changes at the bronchial stumps. Results. There was a low frequency of subcarinal lymph node metastasis occurring in only 11 out of 335 cases (3.3%). The overall 5-year survival rate for subcarinal lymph node positive patients was only 18%. The postoperative ischemic change in the bronchial stumps and the subcarinal lymph node dissection exhibited a close correlation (P = 0.001). The 5-year survival rate (%) based on the pathological stage of both groups did not exhibit any significant differences. Results were: stage IA; 87%:91% (p = 0.40), stage IB; 76%:79% (p = 0.75), stageII; 53%:63% (p = 0.33). and stage IIIA; 51%:37% (p = 0.20). Subcarinal lymph node dissection was found not to be an independent prognostic factor. The rate of recurrence in the cases with no subcarinal lymph node dissection cases was 83 out of 292 cases (28.4%). Distant recurrence occurred in 65 cases, while 18 cases had local recurrence. However, in the 18 cases with local recurrence, no subcarinal lymph node onset recurrence was noted. Conclusion. As no significant increase in risk was noted when subcarinal lymph node dissection was not performed in patients with lung cancer of the right upper lobe or left upper division, this may be the correct procedure to follow during lung cancer resection surgeries.