The document summarizes key landmark breast cancer trials that helped establish modern standards of care. The NSABP B-04 trial showed that modified radical mastectomy was as effective as radical mastectomy. The NSABP B-06 and Milan trials established breast-conserving surgery plus radiation as an equivalent alternative to mastectomy. The NSABP B-32 trial demonstrated sentinel node biopsy alone had similar outcomes as axillary dissection for node-negative cancer. Subsequent trials like ALMANAC and Z011 found sentinel node biopsy reduced arm morbidity without compromising survival. These trials provided critical evidence supporting less invasive surgical approaches for breast cancer.