Objective  This work aimed to investigate the negative prognostic factors of bronchioloalveolar carcinoma (BAC) and adenocarcinoma with BAC characteristics, based on the 2004 pathological classification by the World Health Organization (WHO), which were further verified with the new pathological classification of lung adenocarcinoma (WHO 2011), to identify crucial factors that determine the prognosis of BAC and adenocarcinoma with BAC features, and to prove the coherence of the two pathological classifications in assessing clinical prognosis.

  Methods  Upon pathological diagnosis, some of the 193 cases of BAC or adenocarcinoma with BAC features were categorized into adenocarcinoma in situ (AIS) or minimally invasive adenocarcinoma (MIA), based on the 2011 WHO classification. Gender, age, tumor size, familial cancer history, smoking history, TNM stage, symptoms, duration of symptoms, and the choice of treatment were recorded and analyzed for prognosis. The survival rate was calculated by Kaplan-Meier method. Log-rank test was introduced to compare the survival rate. Univariate and multivariate factors for the survival rate were analyzed by Cox proportional hazards regression model.

  Results  The overall 1-, 3- and 5-year survival rates were 84.3%, 60.6%, and 45.6%, respectively. Cox univariate analysis revealed that the tumor size, symptoms, TNM stage, pathological outcomes, and the choice of treatment were all prognostic factors. Cox multivariate analysis revealed that TNM stage was an independent prognostic factor for patients with BAC. Data from patients with AIS and MIA revealed better survival.

  Conclusion  The overall survival rate of BAC and adenocarcinoma with BAC features are superior to that of other non-small cell lung cancer (NSCLC). The clinical symptoms are non-specific compared with other types of NSCLC. Clinical stage at diagnosis is a key prognostic factor, such that early correct diagnosis significantly improves survival. The new classification criteria of WHO, released in 2011, is more elaborate and more conducive to clinical practice.