Overview of cancer prevention

Authors:

Details:

1. Cancer Council Victoria, Victoria.
2. University of Melbourne, Victoria.


The lessons learnt from now over 50 years’ experience in cancer prevention, particular with tobacco and skin cancer, and more recently in cancer screening, have laid the foundation for guiding many public health interventions outside of cancer control. For this reason, this edition of Cancer Forum will be of interest to anyone working in public health.

The tobacco experience shows that to change people’s behaviour, you need a lot more than social marketing, we need a sound policy framework to shape government thinking and action and good instruments to measure effectiveness. Unless we pull on all these levers with vigour at the same time, we are not going to get the very significant benefits that come with cancer prevention in terms of lives saved and cancer reduced.

In a period where there has been considerable public debate about the benefits and costs of mammographic screening, Roder presents convincing evidence that current efforts in mammographic and cervical screening, are indeed delivering a good return in terms of reduced cancer mortality.1 In terms of breast cancer mortality, the benefit to screening participants could be as much as 35%. There is no doubt also that there are limitations to screening which women have a right to know.  And, as with any cancer control strategy, the ongoing effectiveness of cancer screening modalities needs to be kept under review.

Miller’s paper highlights the benefits of refreshing and updating health warnings to the general public, as well as the importance of using mass media on an ongoing basis to reinforce and motivate behaviour change.2 However importantly, some health warnings on cigarette packets are better than others in terms of their ability to provide information to smokers, engage smokers and influence smokers’ cognitions, feelings and behavioural intentions.

Tobacco has also lead the way in utilising the skills of public health lawyers to influence policy change. As Daveron and Antonopoulos point out, law reform has been a very significant lever in motivating sustainable positive behaviour change to reduce cancer incidence over the long term.3 Whether that is through taxation, penalties or restricting supply and marketing. Law reform also can have very clear negative consequences in influencing cancer outcomes, as we have seen more recently with the proliferation of liquor sales outlets coinciding with the freeing up of liquor licensing laws. Given the potential impact, utilising the skills of lawyers in public health advocacy can play a very useful role in influencing regulatory reform.

No matter what the intervention in place, whether it is to promote physical activity or encourage bowel cancer screening, without appropriate surveillance, pre-testing of messages and measurement of impact, you will never know whether you are making a difference. This is why the measurement of overweight and obesity and physical activity among secondary school students, as described by Scully et al is such an important piece of work.4 Not only has this study, the first of its kind conducted in Australia, shown the work we have to do to improve current physical activity and diets of Australian secondary school students, but the study also paves the way for measuring future impacts of interventions relating to physical activity and nutrition into the future. This will be necessary to curb the escalating rates of obesity we are seeing in our community.

An issue that has gone largely unnoticed in public health policy and mainstream media is Hepatitis B (HBV) infection. Carville and Cowie present a very convincing case that more public health effort is required to stem the significant rise in HBV infection in Australia.5 About 170,000 Australians live with chronic HBV infection, and of those 25% will develop cirrhosis and/or liver cancer. HBV infection has the fastest growing incidence of any cancer reported. There are good treatments available, but there are many who should be treated who are not, with only 3% of the 170,000 Australians living with chronic HBV infection being adequately treated.

Another area where there is significant opportunity to improve survival is with the National Bowel Cancer Screening Program. In the paper by Courtney et al paper, it is clear that Australia is falling behind, not just because the current program is restricted to specific age groups (50,55,65), but also because of low population participation rates compared to other countries that have adopted similar programs.6

Australian studies show that a comprehensive bowel screening program would significantly improve detection and downstage the disease among participants detected with bowel cancer. The greatest opportunity for future increases in Faecal Occult Blood Test screening participation largely relies on opening the program to the entire at-risk population (and all those aged between 50-74 years) for repeated screening to enable investment in social marketing to increase awareness and participation.

Youl, Baade and Meng demonstrate that not only will the financial and human cost of cancer in our community continue to grow at significant levels based on population growth and an ageing population,7 but there is also a significant gain to be made if more effort is made towards primary prevention in the areas of tobacco consumption, sun protection, physical activity and screening. For example, large scale and long-term preventive strategies, if fully implemented, have the potential to prevent nearly 66,000 new cases by 2025 alone.

There is no question, despite all we know about cancer prevention and the impact that it can have on reducing cancer incidence into the future, it will take considerable time and effort on behalf of government and health agencies to reduce the preventable burden of cancer on our community. Fortunately, we do know based on experience gained thus far, that this effort will be well rewarded with significant future reductions in the human and financial costs associated with cancer in our community.

References

  1. Roder D. Impact of population screening programs on cancer outcomes. Cancer Forum. 2012;36(1):4-9.
  2. Miller C. Market impact of tobacco pack warning – current warnings labels and beyond. Cancer Forum. 2012;36(1):10-13.
  3. Davoren S, Antonopoulos N. Alcohol and food regulation in Australia – legal issues in cancer prevention. Cancer Forum. 2012;36(1):14-16.
  4. Scully M, Morley B, Niven P, Pratt IS, Okley AD, Wakefield M, NaSSDA Study Team. Overweight/obesity, physical activity and diet among Australian secondary students – first national dataset 2009-10. Cancer Forum. 2012;36(1):17-20.
  5. Carville KS, Cowie BC. Recognising the role of infection: preventing liver cancer in special populations. Cancer Forum. 2012;36(1):21-24.
  6. Courtney RJ, Paul CL, Sanson-Fisher RW, Carey ML, Macrae FA, Yoong SL. Community approaches to increasing colorectal screening uptake: A review of the methodological quality and strength of current evidence. Cancer Forum. 2012;36(1):25-33.
  7. Youl P, Baade P, Meng X. Impact of prevention on future cancer incidence in Australia. Cancer Forum. 2012;36(1):34-38.

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