Releasing carcinogenesis test results: timing and extent of reporting

A carcinogenic in an animal bioassay is usually characterized by gradaul accumulation of a tumor incidence significantly in excess in the treated versus the control animals. In some cases, a definite response is realized relatively early, prior to planned sacrifice. In others, positive results are found at termination. In both cases, a long delay may occur before the information is ready to reach the public due to the time needed to complete pathology, data analysis, publication of a report. Since the finding that a chemical is carcinogenic may have serious implications for public health and technology, reports of carcinogenesis bioassays should be thoroughly and critically reviewed before being issued. A delicate ethical dilemma confronts scientists in selecting the proper timing and extent for the release of carcinogenesis test results. Early findings may not be confirmed and may cause technological and economic problems and unnecessary anxiety. On the other hand, delaying public notification of highly suspicious findings until a final, detailed report is published, may delay preventive actions that could protect exposed populations from unnecessary risks. To meet differing requirements in regard to timing and extent of reporting, procedures were developed to issue reports on National Cancer Institute (NCI) carcinogenesis bioassays when the findings are clearly identified and well documented in the following forms: a) reports of preliminary findings, when the evidence is strongly suggestive; b) summary reports of completed bioassays; and c) detailed technical reports. Availability of such reports, particularly for preliminary findings, will be announced in the Federal Register and in a press release. The reports will be submitted for publication in the scientific literature.