Purpose: To examine the significance of the proposed International Association for the Study of Lung Cancer, American Thoracic Society, and European Respiratory Society (IASLC/ATS/ERS) histologic subtypes of lung adenocarcinoma for patterns of recurrence and, among patients who recur following resection of stage I lung adenocarcinoma, for postrecurrence survival (PRS). Patients and Methods: We reviewed patients with stage I lung adenocarcinoma who had undergone complete surgical resection from 1999 to 2009 (N = 1,120). Tumors were subtyped by using the IASLC/ATS/ERS classification. The effects of the dominant subtype on recurrence and, among patients who recurred, on PRS were investigated. Results: Of 1,120 patients identified, 188 had recurrent disease, 103 of whom died as a result of lung cancer. Among patients who recurred, 2-year PRS was 45%, and median PRS was 26.1 months. Compared with patients with nonsolid tumors, patients with solid predominant tumors had earlier (P = .007), more extrathoracic (P < .001), and more multisite (P = .011) recurrences. Multivariable analysis of primary tumor factors revealed that, among patients who recurred, solid predominant histologic pattern in the primary tumor (hazard ratio [HR], 1.76; P = .016), age older than 65 years (HR, 1.63; P = .01), and sublobar resection (HR, 1.6; P = .01) were significantly associated with worse PRS. Presence of extrathoracic metastasis (HR, 1.76; P = .013) and age older than 65 years at the time of recurrence (HR, 1.7; P = .014) were also significantly associated with worse PRS. Conclusion: In patients with stage I primary lung adenocarcinoma, solid predominant subtype is an independent predictor of early recurrence and, among those patients who recur, of worse PRS. Our findings provide a rationale for investigating adjuvant therapy and identify novel therapeutic targets for patients with solid predominant lung adenocarcinoma.

Purpose: To perform competing risks analysis and determine short- and long-term cancer- and noncancer-specific mortality and morbidity in patients who had undergone resection for stage I non–small-cell lung cancer (NSCLC). Patients and Methods: Of 5,371 consecutive patients who had undergone curative-intent resection of primary lung cancer at our institution (2000 to 2011), 2,186 with pathologic stage I NSCLC were included in the analysis. All preoperative clinical variables known to affect outcomes were included in the analysis, specifically, Charlson comorbidity index, predicted postoperative (ppo) diffusing capacity of the lung for carbon monoxide, and ppo forced expiratory volume in 1 second. Cause-specific mortality analysis was performed with competing risks analysis. Results: Of 2,186 patients, 1,532 (70.1%) were ≥ 65 years of age, including 638 (29.2%) ≥ 75 years of age. In patients < 65, 65 to 74, and ≥ 75 years of age, 5-year lung cancer–specific cumulative incidence of death (CID) was 7.5%, 10.7%, and 13.2%, respectively (overall, 10.4%); noncancer-specific CID was 1.8%, 4.9%, and 9.0%, respectively (overall, 5.3%). In patients ≥ 65 years of age, for up to 2.5 years after resection, noncancer-specific CID was higher than lung cancer–specific CID; the higher noncancer-specific, early-phase mortality was enhanced in patients ≥ 75 years of age than in those 65 to 74 years of age. Multivariable analysis showed that low ppo diffusing capacity of lung for carbon monoxide was an independent predictor of severe morbidity ( P < .001), 1-year mortality ( P < .001), and noncancer-specific mortality ( P < .001), whereas low ppo forced expiratory volume in 1 second was an independent predictor of lung cancer–specific mortality ( P = .002). Conclusion: In patients who undergo curative-intent resection of stage I NSCLC, noncancer-specific mortality is a significant competing event, with an increasing impact as patient age increases.

Overexpression of the serine/threonine kinase GLK/MAP4K3 in human lung cancer is associated with poor prognosis and recurrence, however, the role of GLK in cancer recurrence remains unclear. Here, we report that transgenic GLK promotes tumor metastasis and cell migration through the scaffold protein IQ motif–containing GTPase-activating protein 1(IQGAP1). GLK transgenic mice displayed enhanced distant metastasis. IQGAP1 was identified as a GLK-interacting protein; two proline-rich regions of GLK and the WW domain of IQGAP1 mediated this interaction. GLK and IQGAP1 colocalized at the leading edge including filopodia and lamellipodia of migrating cells. GLK directly phosphorylated IQGAP1 at Ser-480 enhancing Cdc42 activation and subsequent cell migration. GLK-induced cell migration and lung cancer metastasis were abolished by IQGAP1 depletion. Consistently, human NSCLC patient tissues displayed increased phospho-IQGAP1, which correlated with poor survival. Collectively, GLK promotes lung cancer metastasis by binding to, phosphorylating, and activating IQGAP1.Significance: These findings show the critical role of the GLK–IQGAP cascade in cell migration and tumor metastasis, suggesting it as a potential biomarker and therapeutic target for lung cancer recurrence.

GLK/MAP4K3 overexpression associates with recurrence risk for non-small cell lung cancer