Treatment of early-stage breast cancer in the elderly: a health-outcome-based approach

To evaluate the post-lumpectomy treatment of a nonpalpable, stage I, T1b tumor, mammographically detected, in a 74-year-old woman without comorbidities.

A Markov process, through 120 monthly cycles, was used to model patient progression through a treatment program, employing literature data and a health-outcome utility. Treatments considered were: observation; radiation totaling 5,000 cGy over six weeks; tamoxifen, 20 mg/day, for five years; simple mastectomy; and radiation therapy plus tamoxifen. Health states included absence of disease (NED), loco-regional recurrence, distant metastasis, age-sex-race (ASR)-adjusted death, cancer mortality, treatment complications, and post-mastectomy death. Transition probabilities were established from the literature. Health-state utilities were determined from the responses of health care professionals to a basic reference gamble.

Quality-adjusted life years (QALYs) were determined to be 8.19 for radiation plus tamoxifen, decreasing to 8.04 for mastectomy, a difference of only a 0.15 years (1.8 months). Sensitivity analysis, however, showed relative stability in the ranking among treatment options.

Although the model showed little difference between QALYs with the treatments, the combination of radiation and tamoxifen provides the optimal therapy for this case.