Adele Green is a Senior Scientist at QIMR Berghofer Institute of Medical Research in Brisbane, Australia (www. qimrberghofer.edu.au) and is a Senior Research Scientist at Cancer Research UK Manchester Institute (www. cruk.manchester.ac.uk) and Professor of Epidemiology at the University of Manchester (www.manchester.ac.uk). She trained in medicine and her research career has focused on the causes, management and prevention of cancer, especially melanoma and other skin cancers, ovarian cancer and cancer in Aboriginal and Torres Strait Island people for which she has received various awards. her current research program includes studies of prevention of skin cancers in organ transplant recipients and survival and quality of life of patients with high-risk primary melanoma, as well as collaborative studies of gynaecological cancer, cancer risk prediction and clinico-pathologic studies of melanoma. She has served on many IARC committees including the Scientific Council, and is currently a member of the International Commission on Non-Ionizing Radiation Protection (ICNIRP); Chair of Cancer Australia's Research and Data Advisory group, and a Member of the Australian Paediatric Cancer Registry Advisory Committee and the Australian Radiation Health and Safety Advisory Council.

ABSTRACT

Effective primary prevention of cancer requires
1) identification of likely causal or protective agents that potentially can be modified in the target population;
2) demonstration of likely benefit from appropriate intervention; and
3) that cultural, social, political or economic barriers to preventive activities can be surmounted. Each of these steps presents challenges.
1) For some common cancers eg certain haematological cancers, prostate cancer, few if any modifiable causal factors have been identified by epidemiologic studies, though future collaborations with molecular biologists /epigeneticists may extend current knowledge.
2) In various populations, studies of attributable and preventive fractions of cancer show a sizable proportion may be prevented each year if exposure to common causal factors were  avoided. However these studies have been limited by lack of international consensus about various causal associations and inadequate prevalence data for candidate exposures. Also the unknown but lengthy latent periods between exposure and disease means that optimal timing for preventive intervention is uncertain.
3) Even when causal agents are known or strongly suspected, ingrained socio-cultural traditions eg dietary customs, and lifestyle habits eg smoking and sunbathing, resist change. Far greater investment in prevention research is required to improve knowledge about effective implementation of preventive strategies, while political will for long-term primary prevention also needs evidence that such programs are economically sound investments compared with the cost-effectiveness of late-stage cancer treatment. Finally wide cooperation between governments, not-for-profit and other non-communicable disease (diabetes, heart disease) organisations is needed to sustain the concerted action needed to lower the incidence rates of common cancers.