Factors influencing treatment recommendations in node-negative breast cancer

To assess factors influencing recommendations for adjuvant chemotherapy (CT) in relation to perceived benefits in women with stage 1 breast cancer and to determine the degree to which recommendations were followed.

Recommendations from multidisciplinary team meetings at Royal North Shore Hospital (Sydney, Australia) during 2007 and 2008 for postoperative patients with invasive, primary breast cancer were reviewed. Treatment data were collected from patients' medical records. Estimated benefits of adjuvant CT on 10-year survival for node-negative patients were calculated using Adjuvant! Online. Univariate and multivariate analyses were performed using SPSS.

Of 345 patients (mean age, 59 years), 51 were unsuitable for CT as a result of comorbidity and/or age > 80 years. All 93 patients with nodal macrometastases who were suitable for CT and 20 (80%) of 25 with micrometastases were recommended for CT, compared with 92 (53%) of 175 node-negative patients. Tumor size > 2 cm, grade 3, estrogen receptor negativity, and age less than 45 years were independent factors influencing CT recommendation. The mean estimated benefit of CT in node-negative patients who received this recommendation was 5.7% versus 1.3% in patients not recommended for CT. Twenty-one (23%) node-negative patients declined CT after discussion with a medical oncologist. A higher proportion of node-negative patients were recommended for CT in 2008 versus 2007 (60% v 44%, P = .04).

Grade, tumor size, estrogen receptor status, and younger age are the most significant factors influencing CT recommendation in node-negative patients. The minimum level of benefit to recommend CT is approximately 2%. A significant proportion of patients do not proceed with CT after individualized review.