Changes in beliefs about cancer in Western Australia, 1964–2001

Despite modern advances in the treatment of cancer, a comparison of standardised death rates between 1973 and 1993 indicated a slight increase in the proportion of Australians dying of cancer (from 173 to 180 deaths per 100 000 population).1 In 2001, standardised death rates from cancer remained static, with cancer consistently accounting for just over a quarter of deaths in Australia.2,3 By comparison, the death rate from cardiovascular disease has almost halved since the 1970s.1 The unchanged death rates from cancer have largely been attributed to the fact that Australians are not dying from other causes of death at earlier ages.1

As many cancers at advanced stages remain incurable, preventive measures, such as early screening programs and changes in lifestyle, are the most effective ways to reduce cancer deaths. Knowledge of cancer risk factors and perceptions of the likelihood of surviving various types of cancer have been consistently associated with higher participation rates in cancer screening for breast cancer,4 cervical cancer5 and bowel cancer.6 These higher participation rates justify the extensive resources that Australia has invested in public cancer-awareness campaigns over the past several decades.

During this time there have also been marked changes in health education and practice. For example, 90% of doctors in 1961 had a policy of not revealing a diagnosis of cancer to their patients,7 but by 1979 over 98% of doctors disclosed a diagnosis of cancer.8 It is therefore interesting to assess how the general knowledge, beliefs and attitudes of Australians towards cancer have changed over time.

Several studies have examined changes in public cancer-related knowledge over time; for example, one study found that, in NSW from 1989 to 2000, community knowledge about mammography as a screening test for breast cancer improved.9 However, few studies have explored changes in knowledge over a period of decades. We aimed to replicate an investigation conducted in 1964 of Perth residents’ beliefs about cancer to determine what changes may have resulted from several decades of health education.

The demographic characteristics of the 2001 survey sample closely matched those of the Perth adult population in the 2001 census (Box 1),12 except that there was a higher proportion of university graduates in our sample. As a result, responses were calculated separately for university graduates and non-graduates for each item. The average difference in responses across all nine items was negligible (± 2.6%), negating the need to weight the data by education level.

Box 2 compares the responses of the 1964 and 2001 samples of Perth residents. Major improvements were observed in knowledge about the causes of cancer, with several myths dispelled (eg, cancer is contagious or is caused by “a knock”), and there was a marked increase in the proportions of respondents citing lifestyle factors such as smoking, sun exposure and diet as contributing to cancer. Great improvements were noted in participation rates for cancer screening, with a greater than fourfold increase in the proportion of respondents who had ever had a cancer check-up. Participants’ source of knowledge about cancer had also changed, with the proportion indicating television as a source of information increasing markedly, and newspapers no longer being the major source of information. There was a doubling of the proportion of respondents nominating parents and relatives as a source of knowledge about cancer. Very few respondents believed that cancer was incurable.

Although the 1964 survey was conducted face-to-face and the 2001 survey was conducted via telephone interviews, previous studies have demonstrated that subjects’ responses to each survey method are very similar.13,14 Thus, it is reasonable to infer that differences observed between the 1964 and 2001 samples do not reflect the different methods used. The 2001 survey suffered from a relatively low participation rate compared with the 1964 survey. However, given that the demographic characteristics of the 2001 survey sample closely match those of 2001 census data, it is reasonable to assume that the results can be generalised to the broader Perth population. Compared with the 1964 survey,10 the small difference caused by education level suggests that the disparity in cancer-related knowledge between the least and most educated in Perth has narrowed substantially in the past several decades.

While some misconceptions remain, Perth residents in 2001 appear to be generally better informed about cancer than in 1964: they are better informed about the causes of cancer, have greater awareness of the role of lifestyle factors in cancer development, and more of them have participated in cancer screening. Our data complement those of previous published reports suggesting that increased knowledge is associated with greater participation rates in cancer-screening activities.4-6 Confidence in cancer treatments has increased, but expectations about curability appear more realistic. Overall, the data convincingly suggest that, while death rates from cancer remain stable, improved education of the public in health matters in the intervening four decades has had a major and positive impact on public knowledge about cancer and has dispelled many misconceptions.