Purpose The 21-gene recurrence score (RS) assay quantifies the likelihood of distant recurrence in women with estrogen receptor‐positive, lymph node‐negative breast cancer treated with adjuvant tamoxifen. The relationship between the RS and chemotherapy benefit is not known. Methods The RS was measured in tumors from the tamoxifen-treated and tamoxifen plus chemotherapy‐ treated patients in the National Surgical Adjuvant Breast and Bowel Project (NSABP) B20 trial. Cox proportional hazards models were utilized to test for interaction between chemotherapy treatment and the RS. Results A total of 651 patients were assessable (227 randomly assigned to tamoxifen and 424 randomly assigned to tamoxifen plus chemotherapy). The test for interaction between chemotherapy treatment and RS was statistically significant (P .038). Patients with high-RS ( 31) tumors (ie, high risk of recurrence) had a large benefit from chemotherapy (relative risk, 0.26; 95% CI, 0.13 to 0.53; absolute decrease in 10-year distant recurrence rate: mean, 27.6%; SE, 8.0%). Patients with low-RS ( 18) tumors derived minimal, if any, benefit from chemotherapy treatment (relative risk, 1.31; 95% CI, 0.46 to 3.78; absolute decrease in distant recurrence rate at 10 years: mean, 1.1%; SE, 2.2%). Patients with intermediate-RS tumors did not appear to have a large benefit, but the uncertainty in the estimate can not exclude a clinically important benefit.

https://ascopubs.org/doi/pdfdirect/10.1200/JCO.2005.04.7985

Gene Expression and Benefit of Chemotherapy in Women With Node-Negative, Estrogen Receptor–Positive Breast Cancer

Polychemotherapy for early breast cancer: an overview of the randomised trials

PURPOSE: To assess patient and tumor characteristics associated with a complete pathologic response (pCR) in both the breast and axillary lymph node specimens and the outcome of patients found to have a pCR after neoadjuvant chemotherapy for locally advanced breast cancer (LABC). PATIENTS AND METHODS: Three hundred seventy-two LABC patients received treatment in two prospective neoadjuvant trials using four cycles of doxorubicin-containing chemotherapy. Patients had a total mastectomy with axillary dissection or segmental mastectomy and axillary dissection followed by four or more cycles of additional chemotherapy. Patients then received irradiation treatment of the chest-wall or breast and regional lymphatics. Median follow-up was 58 months (range, 8 to 99 months). RESULTS: The initial nodal status, age, and stage distribution of patients with a pCR were not significantly different from those of patients with less than a pCR (P > .05). Patients with a pCR had initial tumors that were more likely to be es...

Clinical Course of Breast Cancer Patients With Complete Pathologic Primary Tumor and Axillary Lymph Node Response to Doxorubicin-Based Neoadjuvant Chemotherapy

Purpose: The National Surgical Adjuvant Breast and Bowel Project Protocol B-27 was designed to determine the effect of adding docetaxel after four cycles of preoperative doxorubicin and cyclophosphamide (AC) on clinical and pathological response rates and on disease-free and overall survival of women with operable breast cancer. Patients and Methods: Women (N = 2,411) with operable primary breast cancer were randomly assigned to receive either four cycles of preoperative AC followed by surgery (group I), or four cycles of AC followed by four cycles of docetaxel, followed by surgery (group II), or four cycles of AC followed by surgery and then four cycles of docetaxel (group III). Clinical and pathologic tumor responses to preoperative therapy were assessed. Results: Mean tumor size (4.5 cm) and other key characteristics were evenly balanced among the three treatment arms. Grade 4 toxicity was observed in 10.3% of 2,400 patients during AC treatment, and in 23.4% of 1584 patients during docetaxel treatment....

The Effect on Tumor Response of Adding Sequential Preoperative Docetaxel to Preoperative Doxorubicin and Cyclophosphamide: Preliminary Results From National Surgical Adjuvant Breast and Bowel Project Protocol B-27

The estrogen receptor (ER) assay has become a standard practice in the management of advanced breast cancer. Tumors lacking ER respond infrequently to endocrine therapy, whereas response rates of 50 to 60 percent are observed in ER+ tumors. Recent studies indicate that the ER status of the primary tumor is a good predictor of the endocrine dependence of metastatic tumors at the time of clinical relapse. Furthermore, the absence of ER in the primary tumor is an important independent prognostic indicator of higher rate of recurrence and shorter survival. Quantitative analysis of Er and an assay for progesterone receptor (PgR) are two methods for increasing the accuracy of selecting or rejecting patients for hormonal therapy; tumors with a high quantitative ER content or those with a positive PgR display the highest objective response rates. Preliminary analysis suggests that the presence of PgR may be a better marker of tumor hormone dependence than quantitative ER.

The value of estrogen and progesterone receptors in the treatment of breast cancer

In a retrospective study we determined the relation between estrogen receptors and the response rate to cytotoxic chemotherapy in 70 patients with metastatic breast cancer. Thirty-four of 45 patients with low or absent estrogen-receptor values (less than 10 fmol per milligram of cytoplasmic protein) had objective responses to chemotherapy, whereas only three of 25 patients with higher values (greater than 10 fmol per milligram of cytoplasmic protein) responded (P less than 0.0001). There were no statistically significant differences between the two groups in age, menopausal status, disease-free interval, Karnofsky index or prior therapy. Differences in sites of involvement or type of chemotherapy did not account for the increased response rate in receptor-negative patients. We conclude that estrogen-receptor values are an important predictor of response to cytotoxic chemotherapy in metastatic breast cancer.

The Relation between Estrogen Receptors and Response Rate to Cytotoxic Chemotherapy in Metastatic Breast Cancer

The possibility of an association between steroid hormone receptor status and disease-free interval was examined in 292 patients with breast cancer. Estrogen receptor positivity was associated with a prolonged disease-free interval. This association was independent of age, menopausal status, tumor size, or nodal status. There was no association between the presence or absence of progesterone, androgen, or glucocorticoid receptor and disease-free interval.

E B Thompson

Papers

The Relation between Estrogen Receptors and Response Rate to Cytotoxic Chemotherapy in Metastatic Breast Cancer

Association between steroid hormone receptor status and disease-free interval in breast cancer.