Illness perceptions matter: understanding quality of life and advanced illness behaviors in female patients with late-stage cancer.

Patients with late-stage cancer are living longer, making it important to understand factors that contribute to maintaining quality of life (QOL) and completing advanced illness behaviors (eg, advance directives). To examine whether illness perceptions-the cognitive beliefs that patients form about their cancer-may be more important guides to adjustment than clinical characteristics of the cancer. In a cross-sectional study, 105 female patients diagnosed with stage III (n = 66) or IV (n = 39) breast (n = 44), gynecological (n = 38), or lung (n = 23) cancer completed self-report measures of illness perceptions, QOL, and advanced illness behaviors. Clinical data was obtained from medical records. Despite modest associations, patients' beliefs about the cancer were clearly unique from the clinical characteristics of the cancer. Illness perception variables accounted for a large portion of the variance (PS < .01) for QOL and advanced illness behaviors, whereas clinical characteristics did not. QOL scores were predicted by patients' reports of experiencing more cancer related symptoms (ie, illness identity), believing that their cancer is central to their self-identity, and higher income. Higher completion of advanced illness behaviors was predicted by higher income, the cancer being recurrent, and participants perceiving their cancer as more severe but also more understandable. This study was limited by a cross-sectional design, small sample size, and focus on female patients. Addressing patients' beliefs about their cancer diagnosis may provide important targets for intervention to improve QOL and illness behaviors in patients with late-stage cancer.