Which of the following conclusion(s) can be drawn from the results of the NSABP prospective randomized trials completed in the 1970’s and 1980’s?

a. Delay of axillary node dissection until there is clinical evidence of disease does not influence overall survival

b. Removal of clinically negative nodes has no therapeutic benefit 

d. Modified radical mastectomy offers no advantage of lumpectomy with axillary node dissection

The scientific basis of local-regional treatment strategies for stage I and stage II breast cancer was established by a series of studies conducted during the 1970’s and 1980’s by the NSABP. In the first of these protocols, total mastectomy with delayed node dissection only for nodes that subsequently turned positive, total mastectomy with localregional radiation therapy, and radical mastectomy were clinically equivalent. Furthermore, the finding that delay of axillary node dissection until there is clinical evidence of disease does not influence survival emphasizes that the role of axillary dissection in clinically node negative patients is solely for staging. The removal of clinically negative nodes has no therapeutic benefit if regional recurrences are detected and treated promptly. In the second of these protocols, modified radical mastectomy, lumpectomy with axillary node dissection, and lumpectomy, axillary node dissection, and breast or irradiation were compared in small breast cancers. Modified radical mastectomy offered no advantage over other treatments when analyzed by disease-free or overall survival in either node-negative or node-positive patients. Breast irradiation after lumpectomy reduced the likelihood of in-breast tumor recurrence from 39% to 10% but did not affect overall survival when compared with lumpectomy alone.