Understanding the utility of adjuvant systemic therapy for primary breast cancer

Purpose: Physicians and patients require quantitative information on the expected benefits of adjuvant therapy for primary breast cancer to make appropriate treatment decisions. To date, there has not been any widely available method for estimating the benefits from adjuvant systemic therapy, in terms of long-term disease-free survival probabilities, in patients with primary breast cancer. Methods: Baseline prognostic information for primary breast cancer patients was estimated by asking 11 breast cancer specialists to complete a questionnaire on baseline prognosis and then using mean values. Data on the relative benefits of adjuvant therapy were culled from systematic reviews and randomized controlled trials. A computer algorithm was developed to calculate 10-year absolute outcome data. Results from this evaluation were compared with a previously described actuarial algorithm. Results: Individual prognostic estimates varied within a group of breast cancer specialists, but mean values of their estimates closely followed published data. Translation of expected benefits of adjuvant therapy from relative to absolute terms was performed with a simple computer algorithm. The data were translated into tabular forms to facilitate user-friendly clinical use. Conclusion: The provided data should facilitate a better understanding of the absolute magnitude of benefit for available systemic adjuvant therapies in individual women with primary breast cancer. This should allow patients to make more informed decisions about their options.