Surgical site infection (SSI) after breast and axillary surgery occurs more often than for other clean surgical procedures. Infection in the setting of sick woman could delay the adjuvant therapy and result increase morbidity and mortality. Also this increased costs associated with health care.Surgical drains have been noted as a potential source for surgical site infections. The primary aim of the study is to determine if chlorhexidine occlusive dressings applied to the intervention drain sites effectively decreases rates of bacterial colonization in drain fluid and drain tips compared to standard care.

Following approval by the National Cancer Institute Review Board, eligible subjects will be recruited prospectively from the Breast Cancer Department at National Cancer Institute, México from November 2016 to November 2017. Individuals with confirmed cancer undergoing total mastectomy (TM), modified radical mastectomy (MRM) and/or axillary lymph node dissection (ALND) in which surgical drains are going to be used will be identified through the surgical scheduling sheet. If the subjects are eligible according to the inclusion criteria, the will be interviewed by one of the main researchers. In the initial interview the informed consent will be read and signed. Also the study coordinator will collect the data of interest from the medical records and will register it in a data collection sheet specially created for this project.

Following informed consent, participants will be randomize to either the standard drain care regimen or the drain antisepsis regimen by a computerized randomization program, using dynamic allocation and stratifying by surgical procedure (radical surgery or conservative surgery). Subjects who had bilateral cancer underwent to the same regimen for both sides. The operating surgeon will know the assigned treatment arm at the end of the surgery.

The surgery will consist on placing a chlorhexidine gluconate occlusive adhesive dressing to the drains side at the end of the surgery. The dressing will be changed each 7 (+-1) days until the drain is removed.

All the participants and the principal take-carers, despite of the group of participation, will be personal instructed by a member of the research team in the first hours of the postoperative, before the departure. In addition, they will be given paper based instructions for the general care of the drain and the surgery wound.

For the experimental group, the dressing will be changed each 7(+-1) days; The site of the insertion must be cleaned with 70% concentration isopropyl alcohol towels. The evaluation and quantification of the drained fluid will be done every 12 hours as it is done usually in these patients.

The patients will be followed for 30 days from the surgery until the resolution of the infectious complication, if it occurs. The patients will go at the end of the first postoperative week (POP 7+-1). In each visit, the coordinator of the study will register the information of the patient in the register sheet. In each visit the patient will be evaluated, the characteristics of the surgical wound and the characteristics of drain fluid will be consigned in the protocol register sheet. The investigator will verify that the participants have correctly done the clean-up the drain.

All patients will undergo semiquantitative cultures of the drain bulb at the first and second week postoperative. Also the investigators will take the distal part of the internal segment of each removed drainage tube for semiquantitative culture. All participants will be evaluated for clinical signs of infection and for any adverse reactions to the drain antisepsis at the follow-up visits. In case of a surgical site infection, the patient will receive the right treatment and will remain in surveillance until the resolution.

Inclusion Criteria:

• Females minimum age 18 able to give informed consent
• Breast cancer confirmed by histopathology
• Patients undergoing unilateral or bilateral mastectomy with or without immediate expander reconstruction.

Exclusion Criteria:

• Males
• Patients who deny informed consent
• Prior radiation therapy to the sick breast.
• Pregnant or breastfeeding women
• Patients undergoing immediate breast reconstruction with Deep Inferior
• Epigastric Perforator (DIEP) o Transverse Rectus Abdominal Muscle techniques (TRAM) .
• Emergency procedures
• Documented allergy to chlorhexidine gluconate
• Antibiotic use in the fourteen days prior to surgical date
• Patients with a history or suspicion of breast cancer surgery outside the INCan in the previous three months.
• Patients who do not speak spanish, diagnosed with a psychiatric disorder and in whom a minimum follow-up of 14 days couldn't be feasible because of operative difficulties (eg.

place of residence or reference to other health institutions).

Results at the end of study