Social and psychological differences between cancer and noncancer patients: cause or consequence of the disease?

83 female patients with breast tumors were interviewed prior to biopsy. The interview contained a psychological instrument measuring action control as an indicator for the patients' reaction to stress together with questions about the expected diagnosis. Using multiple-regression analysis we estimated the explained variance of the variables relating to the histological result of the biopsy. Since most of the patients gave a correct prognosis of the nature of their disease-this variable proved to be very important-most of the social psychological findings have to be interpreted as consequences rather than causes of cancer.