Survival-Weighted Health Profiles in Nasopharyngeal Cancer Patients

INTRODUCTION: In treating nasopharyngeal cancer (NPC) patients, excellent tumor control and patient survival rates can be achieved in the era of intensity-modulated radiotherapy (IMRT). However, treatment-related toxicities affect the quality of life (QoL) of NPC survivors. This study was devised to estimate the life expectancy (LE), quality-adjusted life expectancy (QALE) and survival-weighted psychometric scores (SWPS) in NPC patients. METHODS: A sample of 875 non-metastatic NPC patients diagnosed between January 1, 2009 and June 30, 2013 was collected for estimation of lifetime survival function. All patients were followed up until death or censored on December 31, 2015. To obtain the utility and psychometric score for estimation of LE, QALE, and SWPS, 99 patients were measured with the Taiwanese version of the EuroQol instrument (EQ-5D) and the Taiwan Chinese versions of the European Organization for Research and Treatment of Cancer (EORTC) Quality of Life Questionnaire (QLQ)-C30 and QLQ-H&N35 between October 1, 2013 and December 31, 2017. By utilizing linear extrapolation of a logit-transformed curve, the LE of NPC patients can be estimated. The QALE and SWPS can be obtained by combining the LE and the corresponding QOL function. RESULTS: The mean age of the 875 non-metastatic NPC patients was 50.3 years. The estimated average LE and QALE for NPC patients and for the reference population were 15.5 years and 14.3 quality-adjusted life years (QALYs) and 29.5 years and 29.5 QALYs, respectively. On average, the estimated lifelong duration of pain and painkiller use were 6.0 years and 2.2 years. The estimated lifelong duration of impairment of swallowing, speech, smell and taste were 14.0, 9.8, 8.7, and 7.5 years, respectively. The estimated lifelong duration of problems with dry mouth, teeth, emotion, fatigue, sleep, and social contact were 13.4, 10.1, 9.1, 12.3, 6.7, and 4.5 years, respectively. The estimated lifelong duration of tube-feeding was 1.3 months. CONCLUSIONS: The estimated LE and QALE for NPC patients were 15.5 years and 14.3 QALYs. Furthermore, SWPS could help people understand more about the impact of radiotherapy on NPC patients. These data could also be useful for policy makers to allocate limited resources in health care.