The goal of this observational study is to examine any clinical differences in the outcomes of breast reconstruction surgeries using Acellular Dermal Matrix (ADM) processed by CO2 supercritical fluid technology compared to other ADM products that have been washed with detergents. The study will also assess safety outcomes.

The total number of study subjects is 100, with 50 people recruited prospectively into the test group and 50 people retrospectively into the control group.

The test group will consist of 50 patients aged 20 to 80 who have undergone total mastectomy for breast cancer and are scheduled to undergo immediate breast reconstruction using implants. These subjects will receive SC Derm (ADM processed by DOF Inc.) during the implant-based breast reconstruction surgery.

The control group will consist of 50 patients who will be retrospectively and consecutively selected from medical records of patients who underwent implant breast reconstruction using ADM from other companies between June 1, 2021, and November 9, 2021.

Patients who fall into the following categories cannot participate in this clinical study because they meet the exclusion criteria:

1. Patients who have received an organ transplant and are taking any immunosuppressants.
2. Patients whose mental condition may affect the progress of the clinical study due to alcohol or drug abuse.
3. Individuals who are unable to complete the survey conducted in this clinical study.
4. Patients who participated in other clinical trials within the previous 120 days at the time of screening.
5. Patients for whom the investigator determines participation in the study is not appropriate.

Among breast cancer patients who decide to undergo implant-based breast reconstruction after total mastectomy at our hospital, the investigator will fully explain the study to these patients during outpatient visits and recruit those who voluntarily express their willingness to participate.

Before any screening or enrollment, all subjects must confirm their willingness to participate by signing the informed consent form.

Inclusion Criteria:

1. Patients aged 20 to 80 who undergo immediate breast reconstruction using implants after taking total mastectomy

Exclusion Criteria:

Patients who fall into the five categories below cannot participate in this clinical study because they meet the exclusion criteria for research subjects.

1. Patients who have received an organ transplant and are taking any immunosuppressant.
2. Patients whose mental condition may affect the progress of clinical study due to alcohol or drug abuse.
3. People who are unable to complete the survey conducted in this clinical study.
4. Patients who participated in other clinical trials within the previous 120 days at the time of screening.
5. If the investigator determine for a patient not to participate this clinical study since participation of the study is not appropriate.

The study is scheduled to include 50 prospective and 50 retrospective subjects. The retrospective recruitment period for subjects is from June 1, 2021 to November 9, 2021. Patients who meet the inclusion criteria will be consecutively selected from patients who underwent breast reconstruction with implants. The basis for calculation of retrospective patients was not statistically calculated, but considering that the number of implant breast reconstruction patients at our hospital is 500 per year, when only patients who completed follow-up for more than 1 year were included, approximately 5-10% were enrolled in the study. This was expected and calculated to be possible.