The goal of this research study is to learn about how dexmedetomidine (a standard of care sedative) affects your immune system (your defenses against cancer) by measuring your white blood cell levels before and after surgery.

Dexmedetomidine is a type of sedative used as part of anesthetic care. It is sometimes used to help lower the amount of pain killers and other anesthetics that are given to a patient during surgery. Researchers want to study how this drug works in cancer patients and review the patient's chart for pain levels and medication use after surgery. Part of this research involves studying the immune system of surgery patients.

If you agree to take part in this study, blood (about 1 tablespoon) will be drawn before you have surgery and the morning after surgery while you are still in the hospital. This blood will be used to learn more about how your immune system works.

After your second blood draw, your participation in this study will be over.

This is an investigational study.

Up to 20 participants will be enrolled in this study. All will take part at MD Anderson.

Inclusion Criteria:

3.1.1 - Women undergoing unilateral mastectomy for malignancy at MD Anderson Cancer Center.

3.1.2 - Patients 18 years of age and older. There will be no upper age restriction.

3.1.3 - Patients must sign a study-specific consent form.

Exclusion Criteria:

3.2.1 - ASA 4

3.2.2 - Contraindication to the use of dexmedetomidine.

3.2.2.1. Decompensated congestive heart failure.

3.2.2.2. Second and third degree heart block.

3.2.2.2. Known allergy to dexmedetomidine or any of the medications used in the study

3.2.3 - Patients taking clonidine for treatment of arterial hypertension.

3.2.4 - Patients that are pregnant.

3.2.5 - Patients taking opioids at the time of surgery.

3.2.6 - Patients having plastic surgical reconstruction.

3.2.7 - Recent chemotherapy (< 4 weeks).

3.2.8 - Active autoimmune or immunological disease including but not limited to systemic lupus erythematous, rheumatoid arthritis and Sjogren's disease

3.2.9 - Patient refusal to participate in the study.

Women undergoing unilateral mastectomy for malignancy at MD Anderson Cancer Center in Houston, Texas.