Purpose: To examine the cost-effectiveness of radiation therapy following conservative surgery for early-stage breast cancer.
Methods: Using a Markov model, a cost-utility analysis was performed to compare a strategy of radiation therapy versus no radiation therapy in a hypothetical cohort of 60-year-old women following conservative surgery. Local recurrence, distant recurrence, and survival rates used in the model were derived from randomized trial data. Utilities for the nonmetastatic health states were collected from actual patients. Direct medical costs were estimated using data from a single institution. Transportation and time costs were also estimated. Years of life, quality-adjusted life-years (QALYs), costs, and incremental cost/QALY over a 10-year time horizon were calculated by the model for each strategy.
Results: The addition of radiation therapy results in a cost increase of $9,800 per patient, no change in life expectancy, and an increase of 0.35 QALYs per patient, which leads to an incremental cost-effectiveness ratio of $28,000/QALY, which is well below $50,000/QALY, a commonly cited threshold for cost-effective care. Sensitivity analysis shows the ratio to be heavily influenced by the cost of radiation therapy and the quality-of-life benefit that results from decreased risk of local recurrence.
Conclusion: Radiation therapy following conservative surgery is cost-effective compared with other accepted medical interventions. This study illustrates the importance of considering an intervention's effect on quality of life, as well as survival in defining cost-effectiveness.