Abstract
Background: Breast and ovarian cancers are common cancers in female. In Thailand, breast cancer is the most common type of cancer and ovarian cancer is identified at 6th rank in female. BRCA1/BRCA2 are the most common types of hereditary cancer. The prognosis of woman who inherited mutations in the BRCA1/BRCA2 genes could be predicted; as the group with high risk of developing breast cancer (80%) and ovarian cancer (15-40%) in their life time. The detection of germline BRCA1/BRCA2 could lend the opportunity for offering choices of prophylactic treatments. Moreover, recent advance in development of technique for detecting BRCA1/BRCA2 with a lower price raises the question whether this intervention is affordable at the national level in Thai context. Method: The objectives of this study were to evaluate the cost-utility of testing for BRCA1/BRCA2 followed by preventive interventions compared to no genetic test in both high-risk breast cancer patients and their first-degree relatives and to estimate government budget impact using an economic model. A Markov model was used to estimate relevant costs and health outcomes using a lifetime horizon from the societal perspective for Thai healthcare system. Direct medical and non-medical costs were included. Health outcome was quality adjusted life years (QALYs). The results were presented as incremental cost effectiveness ratio (ICER) in Thai baht per QALY gained. One-way sensitivity and probabilistic sensitivity analyses were performed to investigate effects of model variable uncertainties on the results. Results: The results of this study showed that genetic testing for BRCA1/BRCA2 in high-risk breast cancer patients who should be screened for the BRCA1/BRCA2 gene mutations followed by preventive intervention was cost-effectiveness when compare with no genetic testing. The ICER of this intervention was 18,591 Baht/QALY gained which accounted as cost effective based on current willingness to pay (WTP) threshold in Thailand (160,000 Baht/QALY gained). Moreover, offering genetic testing in first-degree relatives of patients with BRCA1/BRCA2 gene mutations was found to be dominant and a cost-saving option compared to no genetic testing. The estimated five years budget impact is approximately 1,011 million Thai baht at BRCA1/BRCA2 testing cost of 21,340 baht. Policy recommendation: The results of this study suggested that providing BRCA1/BRCA2 genetic testing in high-risk breast cancer patients who should be screened for the BRCA1/BRCA2 gene mutations and first-degree relatives of patients with BRCA1/BRCA2 gene mutations detected should include in the National benefit package in Thailand.
