Over 6 million people around the world die from cancer each year (Murray and Lopez, 1996). There is overwhelming evidence that lifestyle factors impact cancer risk and that positive, population-wide changes can significantly reduce the cancer burden (Curry et al, 2003). Current epidemiologic evidence links behavioural factors to a variety of malignancies, including the most common cancers diagnosed in the developed world – lung, colorectal, prostate, and breast cancer (Ezzati et al, 2002). Owing to the tremendous impact of modifiable factors on risk, especially for the most prevalent cancers, it has been estimated that 50% of cancer is preventable (Colditz et al, 1996). However, to bring about dramatic reductions in cancer incidence, widespread lifestyle changes are necessary.
Multiple observations attest to the success and marked benefit of population-wide prevention strategies. For example, the reductions in lung cancer rates in the US, seen first in young men, then in older men, and finally in women, mirror changes in cigarette smoking patterns (Wingo et al, 1999). Introduction of the Papanicolaou test in the 1950s was followed by a dramatic decline in cervical cancer in those countries that made widespread screening available (Laara et al, 1987). The decline in Australian melanoma mortality for those born after 1950 is an additional example of effective intervention at the population level (Giles et al, 1996).
Behaviour change is possible and offers great potential for cancer prevention. This paper summarises the major factors that can be modified to decrease cancer risk. Current recommendations include reducing tobacco use, increasing physical activity, controlling weight, improving diet, limiting alcohol, utilising safer sex practices, getting routine cancer screening tests, and avoiding excess sun exposure. Many of these cancer prevention strategies not only reduce the risk of multiple cancers but also significantly influence the risk of other chronic diseases. Global mortality data are included as an indication of the general impact of each lifestyle factor on health.