Highlights from recent National Surgical Adjuvant Breast and Bowel Project studies in the treatment and prevention of breast cancer

Findings from major National Surgical Adjuvant Breast and Bowel Project studies in women with breast cancer and negative axillary nodes are reported and discussed. Results of the B-13 and B-19 studies demonstrated that systemic chemotherapy (either with methotrexate and sequentially administered fluorouracil followed by leucovorin, or with cyclophosphamide plus methotrexate and fluorouracil) increased overall disease-free survival in women 49 years of age or younger, as well as in those 50 years old or older. Women older than 50 also experienced a survival advantage with chemotherapy. Moreover, women who received systemic chemotherapy after lumpectomy plus radiation therapy were significantly less likely to develop an ipsilateral recurrence of tumor. The B-14 study established the benefit of tamoxifen. When chemotherapy was added to tamoxifen in the B-20 trial there was an increased benefit. The B-18 trial demonstrated that the outcome of patients who received preoperative chemotherapy was comparable to that of patients who received the same therapy postoperatively. Moreover, results suggested that breast tumor response to preoperative chemotherapy correlated with outcome. Also, larger tumors were sufficiently downstaged by preoperative chemotherapy to permit lumpectomy rather than mastectomy. The B-17 study in women with ductal carcinoma in situ concluded that radiation therapy should follow lumpectomy in women with localized, mammographically detected lesions. The P-1 Breast Cancer Prevention trial showed that tamoxifen was effective in significantly reducing the incidence of both invasive and noninvasive breast tumors in women at high risk for the disease. Although many questions remain, and a new study, P-2, has been designed to compare tamoxifen and raloxifene, it is appropriate to offer tamoxifen to women who are similar to those in the P-2 study and who may benefit from it.