abstract: Priorities for cancer prevention: lifestyle choices versus unavoidable exposures

Priorities for cancer prevention: lifestyle choices versus unavoidable exposures:
Source: The Lancet Oncology

"Although cancer prevention in the USA and other developed countries focuses on disease attributable to lifestyle factors such as smoking, alcohol intake, sun exposure, and obesity, cancer caused by involuntary exposures is a concern. The term environmental is ambiguously used to distinguish between lifestyle and unavoidable exposures. The general community is said to be vulnerable to carcinogens encountered in pollution, contaminated food, and consumer products. In view of these concerns, assessments of the carcinogenicity of particular chemicals are of little assistance in prevention of cancer. Appraisal of cancer attributable to widespread and localised pollution, pesticides, endocrine disrupting chemicals, and consumer products yields diverse outcomes, from established causation to absence of harm. The precautionary principle is not a practicable approach for unknown carcinogenic risks. Procedures for individuals to reduce exposure to recognised or suspect carcinogens in consumer products are not effective measures for cancer prevention. Anxiety concerning insidious cancer causation could divert attention from proven means of cancer prevention."

abstract: Preventable Exposures Associated With Human Cancers

Abstract:

Information on the causes of cancer at specific sites is important to cancer control planners, cancer researchers, cancer patients, and the general public. The International Agency for Research on Cancer (IARC) Monograph series, which has classified human carcinogens for more than 40 years, recently completed a review to provide up-to-date information on the cancer sites associated with more than 100 carcinogenic agents. Based on IARC’s review, we listed the cancer sites associated with each agent and then rearranged this information to list the known and suspected causes of cancer at each site. We also summarized the rationale for classifications that were based on mechanistic data. This information, based on the forthcoming IARC Monographs Volume 100, offers insights into the current state-of-the-science of carcinogen identification. Use of mechanistic data to identify carcinogens is increasing, and epidemiological research is identifying additional carcinogens and cancer sites or confirming carcinogenic potential under conditions of lower exposure. Nevertheless, some common human cancers still have few (or no) identified causal agents.

NCI Cancer Bulletin - Expert Panel Reports on Knowledge Gaps for 20 Suspected Carcinogens

In a monograph released July 15, a coalition of leading health organizations called for more research into the possible cancer-causing effects of exposure to 20 chemical agents. Some of the named agents are commonly found in the environment, whereas others are more often limited to occupational exposures. A summary paper in Environmental Health Perspectives provides an overview of the technical report.

The monograph, titled Identification of research needs to resolve the carcinogenicity of high-priority IARC carcinogens, summarizes available evidence and provides specific guidance on the appropriate studies needed to definitively classify these agents. Several overarching issues were identified that pertain to multiple agents, including recognizing that carcinogenic agents can act through multiple pathways and mechanisms of toxicity.

“This report highlights the importance of conducting research in occupational settings to identify human carcinogens,” said Dr. Debra Silverman, a co-author of the report and chief of the Occupational and Environmental Epidemiology Branch in NCI’s Division of Cancer Epidemiology and Genetics. “Findings from such occupational studies often allow experts to extrapolate the possible effects of low-level exposure to these agents in the general environment.”

“There is significant concern among the public about substances or exposures in the environment that may cause cancer, and there are some common occupational agents and exposure circumstances where evidence of carcinogenicity is substantial but not yet conclusive for humans,” added the report’s lead author, Dr. Elizabeth Ward, from the American Cancer Society (ACS).

The project originated as part of the National Institute for Occupational Safety and Health’s National Occupational Research Agenda to enhance occupational cancer research, and it involves collaboration with NCI, the International Agency for Research on Cancer (IARC), the ACS, and the National Institute of Environmental Health Sciences.