Community-based use of chemotherapy and hormonal therapy for early-stage breast cancer: 1987-2000.

Purpose: We describe trends in the use of chemotherapy and hormonal therapy by nodal and estrogen receptor (ER) status in women with early-stage breast cancer.

Methods: Cases were randomly sampled from the population-based Surveillance, Epidemiology and End Results (SEER) program and physician verified treatment was examined. A total of 9,481 women, aged 20 years and older, diagnosed with early-stage breast cancer in 1987 to 1991, 1995, and 2000 were included in the study.

Results: The use of chemotherapy plus tamoxifen increased between 1995 and 2000 for women with node-negative, ER-positive breast cancer > or = 1 cm (8% to 21%). Nearly 23% of women with node-negative and ER-positive tumors > or = 1 cm received no adjuvant therapy. The use of chemotherapy alone increased to nearly 60% in women with node-negative, ER-negative tumors > or = 1 cm (48% to 59%). However, in 2000, 16% of women with node-positive and ER-negative tumors received no adjuvant therapy and an additional 6% received tamoxifen alone. The influence of age can clearly be seen. Chemotherapy is given much less often in women 70 years or older.

Conclusion: The results from SEER areas across the United States suggest that physicians quickly responded to publications and guidelines regarding breast cancer therapy. The lack of definitive findings from clinical trials on the use of adjuvant therapy in women 70 years and older may explain the lower use in this group of women.