[Multivariate survival analysis of patients with stage I NSCLC]

The effectiveness of adjuvant chemotherapy in providing survival advantage for stage I non-small cell lung cancer (NSCLC) patients, especially those with stage Ib NSCLC, remains to be determined. The seventh edition of the Tumor Node Metastasis (TNM) Classification of Malignant Tumors is due to be published in 2009. The aim of the current study is to validate the value of this classification in Chinese early-stage NSCLC. The benefits of adjuvant chemotherapy to patients with early-stage NSCLC were also assessed.

The new staging project was validated in 433 patients who underwent complete surgical resection for early-stage NSCLC at the Single Institution of Shanghai Chest Hospital from June 1998 to June 2010. This new parameter was combined with other well-established prognostic factors, and multivariate survival analysis were performed. Variables in the analysis included age, gender, history of smoking, pathologic type, type of resection (pneumonectomy, lobectomy, bilobectomy, and sleeve resection), tumor size (largest tumor dimension), T-status, lymphovascular vessel invasion, and adjuvant chemotherapy.

The three-year overall survival rates for females and males are 89.22% and 77.53%, respectively (P=0.001,8). Elder patients have worse prognoses: the survival rates for those aged ≥70 and <70 are 70.64% and 85.85%, respectively (P=0.000,1). The three-year overall survival rates of patients whose tumors measured no larger than 2 cm in biggest diameter or larger than 2 cm but no larger than 3 cm are 95.15% and 85.71%, respectively. For those with tumors larger than 3 cm but smaller than 5 cm or larger than 5 cm but smaller than 7 cm, the survival rates are 74.80% and 60.47%, respectively (P<0.000,1). Multivariate analysis reveals that age, gender, vascular vessel invasion, pathologic type, and visceral pleural involvement are significant predictive factors of the overall survival.

The tumor size and pathologic type are significant independent prognostic factors in stage I NSCLC. The survival rates of patients with adenocarcinoma are higher than those of patients with other types of NSCLC. Female patients and those without a history of smoking have a better outcome. Results suggest that patients with the Ib stage of the disease can benefit from adjuvant chemotherapy.