Cost-Effectiveness of Combining MRI with Mammography for Breast Cancer Screening Among High-Risk Population in Ottawa

Abstract

Background: Based on previous research, conventional mammography screening has been found to be ineffective for women at high risk, mainly because high-risk women have high breast density and a fast progression rate of breast cancer. Recently, MRI screening was proposed as an additional complementary screening for high-risk women in Ottawa. The addition of MRI to mammography to screen the high-risk population is worth exploring as it may well address the limitations of mammography, especially since MRI has higher sensitivity. Purpose: The goal of this study is to assess the cost-effectiveness off adding MRI to mammography screening for early detection among women of the high-risk population in Ottawa by using conventional values for the society’s/government’s willingness to pay for one life year gained (US$ 50,000). Methods: A discrete-event simulation model was developed to evaluate the cost-effectiveness of adding MRI screening to mammography for high risk women breast screening in Ottawa. Three risk groups were considered; BRCA1, BRCA2 and other high risk. Based on breast annual incidence, screening features, breast cancer progression among high-risk women, treatment and breast cancer survival rates, the model simulates a hypothetical cohort consisting of 5000 women progressing from age 30 to 100 (or to natural death) and calculates the accumulated life years and costs in order to predict the cost of one life year gained by each screening strategy. Univariate sensitivity analysis was performed on the key parameters to determine the robustness of the simulation outcomes. Paired t-tests were used to determine whether the parameters’ variations are statistically significant or not. Results: In the base-case scenario, the incremental cost-effectiveness ratio (ICER) of mammography compared to both screening was CAN$30,043.48 /life year gained (95%CI ±2524.40) which means the addition of MRI to mammography is a cost-effective intervention according to the commonly used willingness-to-pay threshold of US$50,000 per life-year gained. The findings of the sensitivity analysis indicate that the cost-effectiveness of adding MRI screening is statistically significant for most of the parameter variations, however, the degree of change in the ICER is not hugely impactful as in all cases the ICER remained well below the commonly used willingness-to-pay threshold per life year gained. Conclusion: Study results suggested that the addition of MRI has an important role in improving high risk women screening in terms of increasing life years gained compared to receiving mammography screening only. The results of this study support the recommendations of Cancer Care Ontario and the Ontario Health Technology Advisory Committee guidelines of expanding the Ontario Screening Program to integrate MRI with mammography screening for high risk women aged 30 to 69 years.