The Journal of Thoracic and Cardiovascular Surgery, Vol 73, 216-220, Copyright © 1977 by The American Association for Thoracic Surgery and The Western Thoracic Surgical Association
Techniques for localized injections and topical applications of carcinogens at specific endobronchial sites in dogs
M Okita, JR Benfield, T Jensen, K Matsumura, E Shors and AH Cohen
We seek to create a canine lung cancer model with sharply localized
carcinomas analogous to human lung cancers. Toward this goal techniques for
recurrent endobronchial transbronchoscopic submucosal injections and
topical applications of the carcinogens 3,4-benzo(a)pyrene and N-
methyl-nitrosourea have been developed. After 2 years of experience with
2,868 endoscopic manipulations and varying dosage schedules in 59 dogs,
safe effective techniques for recurrently delivering carcinogens and
sequential biopsies of the same sites have evolved. Predominantly during
the first year of experience, 10 dogs died as a consequence of technical
problems such as exsanguinations after 1 mm. punch biopsies. There were
also 39 instances of nonlethal technical complications of endoscopy in the
face of immunosuppression and local irritation caused by the carcinogens.
By the techniques and dosage schedules described, it has now become
possible reliably and safely to create impressive localized bronchial
preneoplasia with squamous metaplasia and atypia among the prominent
features.