Adjuvant therapy for breast cancer: practice patterns of community physicians

We evaluated the use of adjuvant therapy for breast cancer using the National Institutes of Health (NIH) Consensus Development Conference statements as guideposts for assessing how rapidly community physicians adopt recommended therapies.

Women with stage I through IIIA breast cancer diagnosed in 1987 through 1991 and in 1995 were randomly sampled from the population-based National Cancer Institute Surveillance, Epidemiology, and End-Results program. A total of 8,106 women were included in the study with younger women, < or = 50 years, being oversampled. Their treating physicians were asked to verify whether chemotherapy, hormonal therapy, or both were given.

After adjusting for clinical and nonclinical factors, the use of 1985 recommendations for adjuvant therapy in women with node-positive disease was already high at 80% in 1987 and increased slightly to 84% by 1995. Use of combined multidrug chemotherapy plus tamoxifen increased. In contrast, the use of 1990 recommendations for adjuvant therapy for node-negative disease was slightly less than 13% in 1987 and increased markedly to 57% by 1995. For women with node-negative tumors > or = 1 cm in size diagnosed in 1995, 40% received tamoxifen, 16% combination chemotherapy, and 7% both, an increase from 10%, 5%, and 0.4%, respectively, in 1987.

Community physicians began prescribing adjuvant chemotherapy and hormonal therapy in advance of publication of the NIH consensus statement in 1990. Adoption of recommended treatments for node-negative disease has been less complete compared with node-positive tumors, perhaps reflecting the more complex nature of the clinical trials data or the smaller anticipated benefit from adjuvant therapy for this disease subset.