The association between atypical adenomatous hyperplasia and primary lung cancer

Atypical adenomatous hyperplasia (AAH) has been suggested as the adenoma in an adenoma-carcinoma sequence in the lung periphery. From 1989-1998, we un dertook a systematic, prospective search for AAH in lungs resected for canc er. AAH was found in 57 of 554 patients (12.1%) with primary lung carcinoma (9.2% in male patients and 19.0% in females). AAH was found in lungs beari ng adenocarcinoma (23.2%) more frequently than with large cell undifferenti ated carcinoma (12.5%) or squamous carcinoma (3.3%). A greater percentage o f females with adenocarcinoma had AAH (30.2%) than did males with adenocarc inoma (18.8%). Numbers of AAH ranged from 1-42 per patient and more patient s had small numbers of AAH, although 12 patients had 6 or more AAH foci, La rger numbers of AAH tended to be found in adenocarcinoma-bearing lungs. Ten of the 67 patients with AAH and primary lung carcinoma (15%) had multiple primary cancers (range 2-6), all of which were adenocarcinoma. Synchronous cancers were rare in lung tumour-bearing resections without AAH. Patients w ith AAH show no difference in post-operative survival to those without, for all stages of carcinoma and for Stage I disease alone. This study provides evidence for a strong association between atypical adenomatous hyperplasia and primary lung adenocarcinoma and lends weight to the AAH/adenoma-carcin oma hypothesis. (C) 2000 Cancer Research Campaign.