RESUMEN
INTRODUCTION: Chronic diseases such as cancer have a strong influence on both physical health and quality of life, which together comprise the concept of health-related quality of life (HRQoL) - in other words, the complete state of physical, social, and psychological functioning. Herein, we review the literature on the theory of HRQoL in relation to oncological diseases. MATERIAL AND METHODS: A literature search of English-language publications that included an analysis of the conceptual models of HRQoL was performed using PubMed. The data were screened and synthesized by all authors and relevant papers were selected. RESULTS: We outline the theoretical models most often used to conceptualize HRQoL, including the Centre for Health Promotion model from the University of Toronto, the conceptual model of Wilson and Cleary and the contextual model of Ashing-Giwa formulated specifically for cancer patients. CONCLUSIONS: Understanding the theoretical basis of HRQoL is indispensable for valid research in this area.