Bupivacaine vs Placebo for Unilateral Mastectomy Surgical Site Post-operative Pain Control

Inclusion Criteria: * Patients ≥ 18 years of age * Patients undergoing unilateral mastectomy with or without SLNB or axillary dissection * Patients scheduled for surgery at the JRSC or MSK Monmouth * Previously enrolled patients \> 6 months from contralateral mastectomy Exclusion Criteria: * Patients who are non-English speaking * Patients having any immediate breast reconstructive procedure * Patients are having bilateral mastectomy * Patients who report a baseline pain score \> 3, unrelated to a breast procedure * Patients who take long acting opioid medication use * Patients will be excluded if they are having their mastectomy performed with tumescence * Patients weighing \< 40kg as 20cc of bupivacaine 0.5% is greater than the maximum allowed dose * Patients within 6 months of previous enrollment for surgery for contralateral mastectomy