PSYCHOLOGICAL FACTORS IN RELATION TO CANCER INCIDENCE, MORTALITY AND QUALITY OF LIFE

Abstract

The link between mental health and cancer risk/mortality is a subject of persistent interest and debate. There is no proof that one disease causes/deteriorates the other, although psychosocial risk factors for cancer have been investigated in numerous epidemiological studies. As an important cancer outcome, quality of life (QoL) has been found to be associated with adherence to treatment and prognosis. Response shift was suggested to be one of methodological problems that plague longitudinal QoL research. This thesis demonstrated that poor psychological status, especially depression, should be appropriately considered a causal risk factor related to cancer risk/mortality in a Singapore community-living elderly population. Response shift phenomena were demonstrated during one year treatment journey in breast cancer patients. The psycho-neuro-immunological model of cancer postulated that the down-regulation effect of mental states on immune functioning could ultimately affect cancer progression in the elderly.