Potential errors in staging primary pulmonary adenocarcinomas by sublobar resection

Abstract

There is increasing interest in treating patients with stage I pulmonary adenocarcinoma with sublobar resection and staging lymphadenectomy (StLN), but there is no information on the potential impact of this approach on staging. A total of 241 consecutive wedge resections followed by immediate completion lobectomy (n = 225), bilobectomy (n = 3), or trisegmentectomy (n = 13) ("second specimens") and StLN were retrieved from our database. Tumor location, size, pT, and distance to closest margin (D) in the wedge specimens were compared with the presence of residual and/or additional tumor nodules in the lung and metastatic tumor in N1 lymph nodes of the "second specimens." Residual tumor (n = 14), additional tumor nodules (n = 9), and both (n = 1) were present in the lung parenchyma of 24 "second specimens." Problems orienting residual tumor to tumor in the wedge made it difficult to accurately determine overall tumor size and final pT in some cases. In 10 of the 241 cases, metastatic tumor was present only in N1 lymph nodes in the "second specimen." Sublobar resections with StLN would have potentially understaged 19 (7.9%) of 241 patients (9 as pT1 or pT2 instead of pT3, 9 as pN0 instead of pN1, and 1 as pT1N0 instead of pT3N1). Preoperative positron emission tomography/computed tomography suggested the presence of more than 1 parenchymal tumor nodule and/or metastatic tumor in N1 lymph nodes of the "second specimen" in only 5 of these cases. Sublobar resections may miss additional tumor nodules and positive lymph nodes and understage a small proportion of pulmonary adenocarcinoma patients.