Findings were based on a US study of 2,838 breast cancer patients treated between 1995 and 2001 at the Anderson Cancer Center in Houston, Texas.
Researchers assessed outcomes of the women after five years of adjuvant therapy, which have included hormone therapy.
After a 28 month follow-up period, 216 women developed recurrent disease. The five-year risk of relapse for women with stage I was 7%, 11% for women with stage II disease and 13% for women with stage III disease.
Women with hormone receptor positive cancer were at higher risk, pointing to an area of unmet clinical need. There is also a need for more risk-reduction strategies for premenopausal women.
Authors wrote: ‘This study demonstrates that patients with early stage breast cancer who are disease free at five years after [adjuvant systemic therapy] have a substantially increased residual risk of recurrence.’
Journal of the National Cancer Institute (2008) 100: 1179-1183