HIGH-LEVELS OF HEPATOCYTE GROWTH-FACTOR SCATTER FACTOR IN DIFFUSE-TYPE BRONCHIOLOALVEOLAR CELL-CARCINOMA

BACKGROUND. Hepatocyte growth factor/scatter factor (HGF/SF) is a pote nt mitogen for Various neoplastic cells, including neoplastic bronchia l epithelia. METHODS. Immunoreactive hepatocyte growth factor/scatter factor (HGF/SF) was measured in extracts prepared from 129 nonsmall ce ll lung carcinoma (NSCLC) specimens, using an enzyme-linked immunosorb ent assay. These specimens rep resented 5 cases of solitary/localized bronchioloalveolar cell carcinoma (BAC), 4 cases of diffuse/infiltrati ve BAC, 90 cases of nan-BAC adenocarcinoma, 25 cases of squamous cell carcinoma, and 5 cases of large cell carcinoma. RESULTS. The mean conc entration of immunoreactive HGF/SF was more than 19-fold higher in tis sue extracts from diffuse-type BAC (265.0 +/- 110.2 ng/100 mg protein) than in those from solitary-type BAC (13.9 +/- 15.9, P < 0.005), non- BAC adenocarcinoma (13.8 +/- 14.9, P < 0.001), squamous cell carcinoma (13.2 +/- 14.4, P < 0.001), or large cell carcinoma (11.2 +/- 6.5, P < 0.005). When immunohistochemical staining for HGF/SF was performed, intense HGF/SF staining was uniformly observed in diffuse-type BAC tum or cells, but not in solitary-type BAC. CONCLUSIONS. Although BAC is i ncluded as a subtype of adenocarcinoma in the World Health Organizatio n classification, diffuse-type BAC should be considered a distinct bio logic entity, at least in terms of HGF/SF expression, from solitary-ty pe BAC or non-BAC adenocarcinoma. In addition, the solitary and diffus e forms of BAC are known to be associated with different prognoses; fo r the latter, the prognosis is much poorer than for the former. The re sults of this study may at least partly explain this difference in pro gnosis. Cancer 1998;83:2091-8. (C) 1998 American Cancer Society.