Purpose: This study determines the survival benefit and cost-effectiveness of adjuvant chemotherapy in elderly women with breast cancer. In addition, the analysis measures the impact of substituting active life expectancy for survival in the clinical decision.
Patients and methods: Two cohorts of women with estrogen receptor (ER)-negative, stage I breast cancer from age 60 to 80 years were monitored using a Markov process. One group received standard chemotherapy following primary therapy, and the other had no postoperative treatment. Data were derived from recently published clinical trials and a major meta-analysis. Outcome included the average survival, active life-expectancy, and incremental cost/quality-adjusted life-year (cost/QALY).
Results: Adjuvant chemotherapy prolongs survival in older women, but to a lesser extent compared with younger women. The average gain in quality-adjusted months was 1.8 months in a 75-year-old cohort at a cost/QALY of $4,400. These small benefits were not substantially altered when univariate changes were made in toxicity, recurrence risk, or effectiveness of chemotherapy. When active life expectancy replaced survival as an end point, the benefit for 75-year-old women decreased to 2 weeks at a cost of more than $96,000/QALY.
Conclusion: There is a small survival benefit for adjuvant chemotherapy in elderly patients. The cost of this benefit is high, but within the range of commonly reimbursed procedures until a point between 75 and 80 years old. The use of active life expectancy as the primary outcome reduces the benefit and adds to the cost. If physicians and policymakers agree that active life expectancy is a relevant outcome, withholding chemotherapy for patients > or = 70 years old is a reasonable approach.