The prognostic implication of histopathologic subtyping of pulmonary adenocarcinoma according to the classification of the World Health Organization. An analysis of 259 consecutive patients with advanced disease.

The prognostic impact of subtyping pretreatment histologic material in adenocarcinoma of the lung (ACL) according to WHO was evaluated in 259 consecutive, inoperable, Stage III patients. One hundred thirty patients (50%) had acinar adenocarcinoma, 23 (9%) had papillary adenocarcinoma, 13 (5%) had bronchioloalveolar carcinoma, and 32 (12%) had solid carcinoma with mucus formation; five patients (2%) had other types of lung cancer. Subtyping was impossible due to cytology or insufficient histologic material in 56 patients (22%). Bronchioloalveolar carcinoma had the longest median duration of response to chemotherapy (47 weeks), time to progression (33 weeks), and median survival (40 weeks). Corresponding values for solid carcinoma with mucus formation were 8, 12, and 22 weeks. Acinar and papillary adenocarcinoma were intermediate. Survival curves and response rates were similar (P greater than 0.05). Bronchioloalveolar carcinoma had 46% 1-year survivors compared to 16% to 22% for other subtypes. The subtypes may have an impact on the prognosis of ACL, but further evaluation is required.