OBJECTIVES : This study aims to examine the cost-effectiveness of five versus ten years of tamoxifen for hormone receptor positive early stage breast cancer from the perspective of health care system.

METHODS : A markov model was built to simulate the disease progression of early breast cancer. Over a forty years’ span, a cost effectiveness analysis was performed to access the two treatments’ costs and outcomes. The data of cost, utility, transition probability, relative risk and other parameters are from randomized clinical trials and literatures. One-way sensitive analysis and probabilities sensitivity analysis are made to explore the stability of results.

RESULTS : The effectiveness and cost of ten years tamoxifen is 127177.3yuan and 14.07QALYs, the effectiveness and cost of five years tamoxifen is 135954.2yuan and 13.86QALYs. Compared with five years tamoxifen, ten years tamoxifen can improve the QALY of 0.21, and costs little. These results from Markov model are robust to the parameters and assumptions in one-way sensitivity analysis and probabilities sensitive analysis.

CONCLUSIONS : Long-term forecast research shows that, compared with five years tamoxifen, ten years tamoxifen has advantages on the QALY gained, reducing risk of recurrences and breast cancer death. In other words, it has higher effect with lowest cost. Therefore, from the perspective of health care system, ten years tamoxifen is cost effective.