The purpose of this study is to evaluate the impact of systematic sampling of lymph nodes vs. lymphadenectomy on outcome according to intraoperative frozen pathology for pulmonary invasive adenocarcinoma with ground-glass opacity (GGO) after VATS lobectomy.

On HRCT screening, early lung adenocarcinoma often contains a nonsolid component called ground-glass opacity (GGO). In 2011, pulmonary adenocarcinomas were classified into atypical adenomatous hyperplasia (AAH), adenocarcinoma in situ (AIS), minimally invasive carcinoma (MIA) and more extensively invasive adenocarcinoma (IAC) [1]. Early adenocarcinomas with GGO-dominant always mean low-grade malignancy and have an extremely favorable prognosis [2-5]. Previous studies have shown that patients with AAH, AIS and MIA have excellent survival rates (5-year survival rate is approximate 95%) after resection, and only 0.83% - 2.91% patients have lymph node metastasis [6-9]. At present, lymphadenectomy is always undergone in patients with pulmonary adenocarcinoma with ground-glass opacity. However, for MIA patients (especially in T1a-b stage), the appropriate use of lymphadenectomy continues to be debated.

Nowadays, intraoperative frozen pathology is widely used during operation. However, whether sampling of lymph nodes or lymphadenectomy should be performed for GGO lesions according to intraoperative pathological diagnosis is unclear. The aim of this prospective study is to evaluate whether there are any trends regarding the impact of subtypes of invasive adenocarcinoma according to intraoperative frozen pathology in sampling of lymph nodes vs. lymphadenectomy.

Inclusion Criteria:

1. A peripheral nodular lesion;
2. The maximum diameters of whole GGO lesions and solid components on lung windows were no more than 3 cm (T1 stage);
3. VATS lobectomy
4. 25%≦Consolidation/Tumor ratio ≦50%
5. ECOG performance status 0-2;
6. Without distant metastasis;
7. Intraoperative frozen pathology confirmed invasive or minimally invasive adenocarcinoma.
8. No operation contraindication
9. Cardiovascular: Cardiac function normal
10. Renal: Creatinine clearance greater than 60 ml/min
11. The expected survival after surgery ≥ 6 months
12. Must be able to sign written informed consent form

Exclusion Criteria:

1. Age less than 18 years old
2. Known hereditary bleeding disorder with history of post-operative hemorrhage
3. Patients maintained on chronic anticoagulation (eg Coumadin therapy)
4. Known hematogenous disorder
5. Known primary or secondary malignancy
6. Pregnant or breast-feeding women;
7. Clinically significant heart disease;
8. Patients who are unwilling or unable to comply with study procedures;
9. Receiving immunosuppressive therapy;
10. HIV/AIDS.
11. Multiple lesions in lung