Objectives: Lung cancers with diaphragmatic invasion are categorized as T3 lesions, but the surgical results have not been well known. We retrospectively surveyed patients with resected primary lung cancers involving the diaphragm.
Methods: A total of 16,771 patients underwent surgical resection for lung carcinoma between 1986 and 1995 at 31 institutions of the Lung Cancer Surgical Study Group in Japan. By investigating the database, we identified 63 patients (0. 38%) who underwent resection of T3 lung cancer invading the diaphragm. These patients constituted the study population, and their clinical and pathologic records were retrospectively analyzed.
Results: Tumor invasion to the diaphragm was diagnosed before operation only in 17 patients (27.0%). Complete resections of the primary lung tumors with the invaded diaphragm were performed in 55 patients (87.3%), of whom 26 had T3 N0 M0 diseases and 29 had T3 Nl-2 M0 diseases. The operative mortality was 1.6% in all patients. The 5-year survival of patients with complete resection was 22.6%, but there was no 4-year survivor in patients with incomplete resection (P =.024). The survivals of patients with completely resected T3 N0 M0 and T3 N1-2 M0 tumors were 28.3% and 18.1%, respectively (P =.013). In those patients, the depth of diaphragmatic involvement significantly affected the prognosis. The 5-year survival of the patients with shallow invasion (parietal pleura or subpleural tissue involvement) was 33.0%, whereas that of the patients with deep invasion (muscle or peritoneal infiltration) was 14.3% (P =.036).
Conclusions: In selected patients with lung carcinoma and diaphragmatic invasion, combined resection of the lung and diaphragm offers the prospect of cure with acceptable mortality. However, primary lung tumors with diaphragmatic invasion, especially invasion of the muscle layer or deeper tissue, are not considered to be T3 lesions, because these cancers are generally technically resectable but oncologically almost incurable.