The Early Detection of Second Primary Lung Cancers by Sputum lmmunostaining

¹ From the Departments of Environmental Health Sciences, Oncology and Pathology, The Johns Hopkins Medical Institutions, Baltimore
² From the Department of Pathology, the Hospital of the University of Pennsylvania, Philadelphia
³ From Biomarkers and Early Detection Branch/EDCOP, Division of Cancer Prevention and Control, NCI/NIH, Bethesda, Md
⁴ From the H. Lee Moffitt Cancer Center and Research Institute, University of South Florida, Tampa

Study objective: To determine whether monoclonal antibody (Mab) detection of tumor-associated antigen expressed on sputum epithelial cells precedes clinical presentation of second primary lung cancer.

Design Setting/Participants: Eleven oncology centers collaborate in the accrual of 1,000 patients with stage I non-small cell lung cancer (NSCLC) who had undergone resection. The Mabs examined in this study (624H12, 703D4) detect two promising oncofetal/differentiation markers (ie, a difucosylated Lewis X and a 31-Kd glycoprotein antigen).

Interventions: Induced sputum specimens are evaluated for quality, then are Papanicolaou and immunostained by independent central laboratories at enrollment and annually thereafter. The predictive value of Mab markers is compared with routine morphologic study for detection of second primary lung cancer during an anticipated 3 years of accrual and 1 year of follow-up.

Measurements and results: Five hundred eighty of an anticipated 1,000 patients have been accrued on schedule. Patients are primarily white (88.6%), former smokers (75.9%), men (55.6%), with a median age of 66.7, and joined the study at an average of 3.7 years following resection of a stage 1 NSCLC (34.4% squamous, 43.6% adenocarcinoma). Central laboratories found less dysplasia and more unsatisfactory specimens (27.3%) than do the accrual institution laboratories. Immunostaining identifies more suspicious cells than does morphologic study. However, only two second primary lung cancers (eight total deaths) have occurred to date.

Conclusions: Halfway through the accrual, we describe the study design and preliminary observations. This study illustrates rational selection of carcinogenesis markers by linkage of marker expression on preneoplastic specimens with subsequent expression on tumor tissue.