Abstract
Purpose: As survival alone does not give a holistic view on the complete picture associated with outcomes of a treatment, the main purpose of this study is to interpret the evidence of quality adjusted life year (QALY) and disability adjusted life year (DALY) on the outcomes of the nasopharyngeal carcinoma patients (NCP) treated with definitive chemo radiation therapy (chemoRT) with or without neoadjuvant induction chemotherapy. Methods: Retrospective analysis of 85 NCPs treated by concurrent chemoRT (60 %), induction chemo followed by concurrent chemoRT (23.5 %) and hospice (16.5 %) at an academic state institution. Overall survival (OS) was estimated by using Kaplan–Meier method and the differences between survival curves were calculated by log-rank test. The SPSS 24.0 software was used for data analysis. QALYs are calculated by multiplying the utility value associated with a given nasopharyngeal carcinoma phase by the years lived in that state. DALYs are calculated by combining measures of life expectancy (LE) and the adjusted quality of life during the disease phase. The relationship between QALYs gained and DALYs saved were calculated from age of the disease onset, duration of the disease, quality of life and disability weights. Results: Of the total 85 eligible NCPs of this cohort, the frequency distribution as per WHO classification was for keratinizing SCCa (Type I) 41.2 %, non-keratinizing SCCa (Type II) 42.4 % and undifferentiated carcinoma (Type III) 16.5 %. The OS median follow up for this cohort was 24 months. WHO Type I had OS of 48.6 %, Type II 29 % and Type III 39.7 % (P = 0.042). The OS of concurrent chemoRT was 32.8 % and induction chemo followed by concurrent chemoRT 14.8 % (P = 0.029) Average LE for 85 NCP cohort is 34.56 years, average DALYs saved with treatment is 20.06 years and average QALYs gained with treatment is 11.72 years. The average DALYs saved with concurrent chemoRT is 12.2 years vs 5 years with induction chemo followed by concurrent chemoRT. The average QALYs gained with concurrent chemoRT is 6.9 years vs 3.1 years with induction chemo followed by concurrent chemoRT. Summary and Conclusion: This study is significant for the following: 1. This study uses QALYs and DALYs calculated not by using survey forms but alternative methods. 2. It shows that concurrent chemoRT is superior to induction chemotherapy followed by concurrent chemoRT using outcomes based on QALYs and DALYs. Our retrospective cohort OS reports similar findings to previous studies by Liang et.al and Tan et.al, that induction chemo has not shown to improve OS compared to definitive chemoRT. In addition, our data show that patients treated with concurrent chemoRT had an increased quality of life when compared to the patients treated with induction chemo followed by concurrent chemoRT. The average DALYs saved are higher in the patients treated with concurrent chemoRT over patients treated with induction chemo followed by concurrent chemoRT.
Citation Format: Mary R Nittala, Madhava R Kanakamedala, Eswar K Mundra, Srinivasan Vijayakumar. Qalys and dalys are better with concurrent chemoRT than induction chemo followed by chemoRT in nasopharyngeal carcinoma [abstract]. In: Proceedings of the Twelfth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2019 Sep 20-23; San Francisco, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(6 Suppl_2):Abstract nr C016.