Poor awareness of risk factors for cancer in Irish adults: results of a large survey and review of the literature

Abstract

Background: Knowledge of cancer risk factors is unknown in Ireland. An understanding of risk factors could help inform cancer prevention programs.

Aims and methods: A 48-question online survey was designed to gather data to assess levels of public knowledge about cancer risk factors.

Results: There were 748 participants (648 women, 100 men). Mean age was 37 years (range: 18-74 years). For the public, 81% were concerned about developing cancer; however, 20% believed that cancer is unavoidable if a family history exists, 27% believed that >50% of cancers are inherited, and 54% believed that 10%-20% of cancers are inherited; 20% were unaware that risk increases with age. The top five risk factors listed by respondents were smoking (87%), diet (76%), genetics (47%), alcohol (42%), and obesity (33%). Only 32% of the public were aware that obesity is a risk factor, and 33% did not think the location of fat was important. Moreover, 29% and 48% believed that risk could be increased by wearing a tight bra and by a blow to the breast, respectively. In addition, 85% and 86% believed that stress and that mobile phones, respectively, "strongly" increase risk; 12% believed that luck is important in avoiding cancer; 35% thought that "detox" diets could reduce risk; and 61% believed that organic food reduces risk. The majority were aware that physical activity of 30 minutes per day can reduce risk.

Conclusion: A sizable portion of the population is misinformed about cancer risk. Most participants were aware of classic risk factors (e.g., smoking, diet); however, many overestimated risk attributable to genetics, environment, and stress and underestimated age, obesity, and sunlight. One in seven participants believed that lifetime risk of cancer is not modifiable.

Keywords: Attitudes; Cancer; Diet; Knowledge; Lifestyle; Myths; Risk.

Figure 1.

The top 10 risk factors listed by members of the public (n = 622) in answer to the open-ended question, “In your opinion, what are the top 5 risk factors for cancer?”

Figure 2.

Illustration of the perceived increased risk of cancer according to factors listed by investigators. Abbreviation: GM, genetically modified.