Suggested procedures for reducing the pathology workload in a carcinogen bioassay program, Part II: Incorporating blind pathology techniques and analysis for animals with tumors.

Large testing programs have been set up to help assess the carcinogenic potential of chemicals introduced into the environment. Most test protocols used in these programs require extensive pathologic evaluations of all test and control animals. In Part I we proposed modifications to such complete pathology protocols which would allow substantial reduction in pathology workload while making only small changes in the operational character of the screen. The modifications suggested did require that slides from controls and treatment animals be handled differently and they did not call for a total tumor analysis (i.e. they do not allow blind pathology). In this paper we discuss how blind pathology can be incorporated and suggest a procedure to recover the "total tumor" aspect. It is emphasized that these modifications should be regarded as a starting point for further discussion and that we encourage comments from all interested scientists.