Background: The aim of the study was to investigate patients' attitudes to and use of nonproven therapies (NPTs) in view of their opinions about causes of cancer.
Material and methods: A comparative questionnaire-based study was given to patients with non-malignant disease (n = 305) seen in general practice and cancer patients (n = 252) seen at the Department of Oncology, University Hospital of Tromsø.
Results: Among non-cancer patients significantly more NPT-positive than NPT-negative patients considered the environment to be an important cancer cause (74% versus 52%) and that food and drink may be carcinogenic (57% versus 40%). For cancer patients, there was no such difference. 60% of non-cancer patients and 35% of cancer patients believed that life style changes could alter the natural course of cancer. In both groups of patients, the NPT-positive believed, to a higher degree than the NPT-negative, that the outcome of cancer could be improved by a change in life style (69% and 48% versus 53% and 29%).
Conclusion: Patients positive to NPTs have firmer beliefs with respect to the importance of environmental factors than non-believers/-users. Moreover, these patients believed more strongly than NPT-negative patients that change of lifestyle may influence the outcome of cancer positively.