Cancer is a major cause of morbidity and mortality in England and Wales with 223,609 new cases of cancer registered in 2000. A new briefing paper The contribution of smoking, diet, screening and treatment to cancer mortality in the under-75s published by the Health Development Agency (UK) today reviews the impact that various measures have had in the treatment and reduction of certain types of cancer.

For men, lung, prostate and colorectal cancers account for about 50% of all cancer deaths and for women breast, lung and colorectal cancers account for 46% of all deaths. Lung, breast, colorectal, stomach and prostate cancers cause most deaths and it follows that public health approaches should focus on these cancers.

In addition to tobacco related cancer deaths, which account for one third of all cancer deaths, other lifestyle factors are significant risk factors for many cancers. For instance, it has been estimated that changes in diet could help prevent a third of all cancers. It is estimated that changes in diet could help prevent a third of all cancers. It is estimated that cancer mortality, attributable to specific factors or groups of factors in developed countries was tobacco 30%, diet and obesity 30%, alcohol 3%, inactivity 3% and occupational factors 5%. Research shows that overall, primary prevention seems to be around seven times more effective than secondary prevention.

Professor Mike Kelly, Director of Evidence and Guidance at the Health Development Agency said:

'Primary prevention such as media campaigns or government legislation are effective with cancers such as lung cancer where not starting to smoke will drastically reduce your chances of developing lung cancer, whereas secondary disease detection, such as screening is not effective with lung cancer.

'It is known after five years, men with lung cancer have a survival rate of only 5-7 %, as there is no really effective treatment for lung cancer. Whereas with breast cancer, treatment combined with screening (secondary prevention) can have a positive effect on survival rates.'

Incidence and survival have an impact on mortality rate. Incidence is a measure of the number of new cases in any given time period. Survival is a measure of the time from diagnosis to death. This complex interaction between incidence and survival provides the key to determining the extent to which primary or secondary prevention, or treatment, provide the most appropriate approach to tackling this disease.

The majority of people (65%) diagnosed with cancer are over the age of 65 and cancer is predominantly a disease of older people, this will affect future mortality and morbidity trends. We have an ageing population and it is important that strategies for prevention and treatment take this into account.

Possible implications on policy based on the reviewed patterns of cancer mortality include:

-- Different types of cancer need to be separated and the relative importance of incidence and survival examined if we are properly assess varying importance of factors such as smoking, diet, inactivity screening and treatment to cancer mortality.

-- An aggressive approach to reduce smoking will continue to drive down numbers of lung and other cancers. This will also impact on coronary heart disease. There should also be greater emphasis on smoking reduction in deprived areas as smoking is an inequalities issue. In poorer areas people are more likely to die form smoking related diseases than they are in richer areas.

-- Primary prevention of cancers associated with diet, lack of exercise, obesity and exposure to the sun could be effective.

-- Screening programmes for breast and cervical cancer should continue but the evidence does not support screening for lung or prostate cancer.

-- Treatment options need to be continually developed in areas where, up to now there has been limited success.

On the basis of the existing evidence and exposure trends, primary and secondary prevention have already reduced cancer mortality by almost 13% in comparison to the rates which would have been reached in the absence of these measures. In the next 20 years, a further reduction of about 29% is potentially achievable, mostly through primary prevention.

ENDS

Notes to editors:

1 The briefing paper is available on the Health Development Agency website: hda.nhs.

2 The Health Development Agency is the national authority on what works to improve people's health and to reduce health inequalities. We work in partnership across sectors to support informed decision making at all levels and the development of effective practice.

For further information: Please contact James Thomson or Dr Tonya Gillis at the HDA Press Office on 020 7061 3108/3117