As a participating Institution in the Primary Breast Cancer Therapy Group, (NSABP) we are contributing data from patients entered into the various group protocols. We have made a major contribution to protocol 4, evaluating the relative efficacy of radical mastectomy versus total mastectomy with radiation, versus total mastectomy alone, in patients with clinically negative axillary nodes. A comparison between radical mastectomy and total mastectomy with irradiation is also made in positive node patients. Within nodal groups, no treatment has emerged as superior, and subsequently, a trial (protocol 6) is underway to compare the value of segmental mastectomy with and without breast irradiation versus total mastectomy. All patients undergo axillary dissection and those with histologically positive nodes will receive adjuvant chemotherapy. In addition, a sequential series of adjuvant chemotherapy protocols is underway. Protocol 5 evaluated L-Pam versus placebo in positive node patients. Protocol 7 evaluated L-Pam and 5 FU versus L-Pam alone. Protocol 8 compared L-Pam and 5 FU versus L-Pam, 5 FU and methotrexate. protocol 9 compared the two drug regimen versus L-Pam, 5 FU and tamoxifen, also obtained definitive information on estrogen receptor values in over 1800 patients. protocol 10 compared the same standard two drugs against L-Pam, 5 FU and C Parvum. The present application seeks funding: a) To permit continued patient accrual in ongoing protocols. b) To continue followup of patients entered into the protocols which are terminated. c) Collect appropriate biological material and information relative to such protocols. The new protocols are Nos. 11-12 in positive node patients comparing L-Pam and 5 FU, versus L-Pam, 5 FU and adriamycin. Patients with positive estrogen receptors receive tamoxifen in both groups. Protocol 13, in negative node patients, those with negative estrogen receptor will be treated with sequential methotrexate and 5 FU, versus a control arm. Protocol 14, for patients with +ER positive status, will receive tamoxifen or placebo. The overall aim is evaluation of surgical and adjuvant therapies to enhance disease-free survival and overall survival, and minimize surgical and psychological morbidity in breast cancer treatment. An ancillary aim is to enhance the multi disciplinary capabilities of this Institution in clinical trials.