Prognostic implications of histopathologic subtyping in patients with surgically treated stage I or II adenocarcinoma of the lung.

The prognostic impact of histopathologic subtyping of pulmonary adenocarcinoma according to the World Health Organization classification was evaluated among 137 consecutive patients with radically resected stage I or II tumors. Median observation time in the 55 patients who are alive is 47 months (range 25 to 80). All tumors were subtyped, the most frequent being acinar adenocarcinoma (57% of patients), followed by bronchioloalveolar carcinoma (18%), solid carcinoma with mucus formation (14%), and papillary adenocarcinoma (12%). Patients having bronchioloalveolar carcinoma had the longest median survival (44 months), while survival was shortest for patients having solid carcinoma with mucus formation (median 10 months); in this latter group there were significantly fewer 1-year survivors compared with all other subtypes. Survival time was intermediate for patients having acinar and papillary adenocarcinoma (medians 31 and 32 months). Patients with solid carcinoma with mucus formation have an unfavorable prognosis and may be considered potential candidates for studies on adjuvant therapy, although the relative influence of other prognostic factors may be considered as well.