Comparative analysis of clinical features and prognostic factors in resected bronchioloalveolar carcinoma and adenocarcinoma of the lung.

BACKGROUND

Over the past few years, clinical, radiological and pathological classification of lung adenocarcinoma and its subtypes, particularly bronchioloalveolar carcinoma (BAC), has radically changed.

PATIENTS AND METHODS

Out of a series of 384 non-small cell lung cancer (NSCLC) patients, submitted to surgical resection and followed-up in our Department from 1981 to 1999, the data of 151 adenocarcinomas (35 BAC and 116 non-BAC) were reviewed and analyzed for prognosis.

RESULTS

BAC and non-BAC series were similar in clinical and radiographic findings, type of resection and stage. Stage I was a dominant favorable prognostic factor (10-year survival: 58% of BAC, 41.2% of non-BAC), albeit associated with a significant risk of second primary metachronous lung tumor (10-year risk: 25% of BAC, 32% of non-BAC). Other independent prognostic factors were: absence of lymph node involvement for BAC and stage III-IV for non-BAC. In term of prognosis, advantages of BAC over non-BAC were fewer cases with lymph node involvement, increased presence of "well-differentiated" cells (p = 0.016) and lower incidence of a second primary metachronous tumor. Moreover BAC patients with a single nodule or mass also had a higher survival expectancy (mean survival: 77 months versus 56 for non-BAC). An unfavorable feature was the higher incidence of diffuse or multicentric radiological forms (p = 0.012). For both groups the presence of multiple or satellite nodules remain a diagnostic and surgical challenge: in BAC cases the evaluation of clonality is recommended.