The Association Between Radiation Dermatitis and Skin Microbiome in Breast Cancer Patients

Study Overview
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Brief Summary
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The breast cancer patients who received radiotherapy after mastectomy and breast reconstruction will be enrolled. The skin microbiome before radiotherapy and its changes after radiotherapy will be analyzed systematically to find out whether the skin microbiome is associated with the severity of radiation dermatitis.

Detailed Description
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Radiotherapy is an important treatment for breast cancer patients. About 95% of patients receiving radiotherapy will develop a degree of radiation dermatitis. Radiation dermatitis is usually limited to the site of radiation treatment. Symptoms vary and can range from itching, burning and pain to open or bleeding ulcers, which can greatly affect the quality of life of patients. Severe acute radiation dermatitis can lead to interruption or delay of treatment. At present, there is no standard for the prevention and treatment of radiation dermatitis. Our skin is home to millions of bacteria, fungi and viruses which compose the skin microbiota. Skin microbiota interacts with skin and affects physiology and immunity of the skin. Previous studies have reported the effects of radiotherapy on skin and immune system. However, so far, no studies have analyzed the effects of radiotherapy on skin microbiome and how skin microbiome affects the skin immune responses after radiotherapy. In this study, the breast cancer patients who received radiotherapy after mastectomy and breast reconstruction will be enrolled. The skin microbiome before radiotherapy and its changes after radiotherapy will be analyzed systematically to find out whether the skin microbiome is associated with the severity of radiation dermatitis. The long-term goal of this study is to deepen the understanding of the role of skin microbiome in the occurrence and development of radiation dermatitis, and provide a basis for subsequent exploration to reduce radiation dermatitis by regulating skin microecology.

Official Title
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The Association Between Radiation Dermatitis and Skin Microbiome in Breast Cancer Patients Receiving Radiation After Mastectomy and Reconstructive Surgery

Conditions
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Radiation Dermatitis, Skin Microbiome, Breast Cancer, Reconstructive Surgery

Intervention / Treatment
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* Radiation: post-operative radiotherapy


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Female patients Invasive breast cancer confirmed by pathology Underwent mastectomy and breast reconstruction Radiotherapy after breast reconstruction ECOG score 0-1 Signed informed consent Exclusion Criteria: Previous breast or chest radiotherapy Other serious skin diseases (systemic lupus erythematosus, skin sclerosis, et al) and cannot receive radiotherapy Pregnant women Patients who are unwilling or unable to receive regular follow-up.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 70 Years

Sexes Eligible for Study
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Female

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Severe radiation dermatitis<br>RTOG/EORTC grade 2 and above | Radiation: post-operative radiotherapy<br>* Breast cancer patients who have received reconstructive surgery will receive post-operative radiotherapy.<br>|
| No or mild radiation dermatitis<br>RTOG/EORTC grade 0 or 1 | Radiation: post-operative radiotherapy<br>* Breast cancer patients who have received reconstructive surgery will receive post-operative radiotherapy.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Skin microbiome differences between patients with and without >=2 acute radiation dermatitis | Acute radiation dermatitis will be graded per the Toxicity Criteria of the Radiation Therapy Oncology Group (RTOG) | 3 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Skin microbiome differences between patients with and without >=2 late radiation dermatitis | Late radiation dermatitis will be graded per the Toxicity Criteria of the Radiation Therapy Oncology Group (RTOG) | 5 years |