[Survival after surgical treatment of bilateral synchronous multiple primary non-small cell lung cancers]

To explore the clinical characteristics of patients with bilateral synchronous multiple primary non-small cell lung cancer (NSCLC) and identify the prognostic indicators associated with survival.

From January 2010 to December 2014, clinicopathological data of 96 patients with bilateral synchronous multiple primary NSCLC, who met the modified Martini-Melamed criteria and underwent radical surgical resection, were retrospectively reviewed. Survival was estimated using the Kaplan-Meier method, and the clinical parameters associated with survival were analyzed using a log-rank test. Cox proportional hazards regression models were used to identify the risk factors for this cancer.

Of the 96 patients, two patients who died of severe postoperative complications were excluded, and 94 patients were analyzed. Of the 94 cases, a two-stage operation was performed in 93 patients, while a single-stage bilateral surgery was performed in only one patient using video-assisted thoracic surgery (VATS). 79 patients had 2 tumors and the other 15 patients had 3 or more tumors. There were 82 patients with synchronous tumors located in different lobes and 12 patients had at least two tumors located in the same lobe. Seventy-six patients were found to have multiple lung adenocarcinoma and 12 patients had multiple squamous cell carcinoma (SCCs). Five patients had adenocarcinoma and SCC, and one patient had adenocarcinoma and adenosquamous carcinoma simultaneously. Univariate analysis showed that the large maximum tumor diameter, highest pT stage and lymph node involvement were associated with an unfavorable DFS (P<0.01 for all), while female gender, small maximum tumor diameter, early highest pT stage and pN0 were associated with a better overall survival (OS). Multivariate analysis showed that highest pT stage and lymph node metastasis were independent prognostic factors for DFS and OS. Patients with a lower highest pT stage and negative lymph node metastasis had longer DFS and OS (P<0.05 for both).

The diagnosis for patients with bilateral synchronous multiple primary NSCLCs should be made very carefully. Two stage surgical treatment is safe, reasonable and effective for patients with bilateral synchronous multiple primary NSCLCs in a relatively early stage. The highest pT stage and pN status are important predictors for long-term survival. Adequate pulmonary tissue resection with complete resection of multiple nodules and systematic lymphadenectomy are suggested.