Prophylactic Mastectomy: Prospective Evaluation of the Correlation Between Skin Flap Thickness, Residual Glandular Tissue and Skin Necrosis by Imaging and Clinical Examination

Study Overview
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Brief Summary
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Breast cancer is the most common form of cancer among women. Five to ten percent of all breast cancers are due to hereditary factors, with pathogenic variants in the breast cancer genes BRCA1/2 accounting for 2-5% of all breast cancer. Women with pathogenic variants in BRAC1/2 and other pathogenic gene mutations leading to an increased risk of breast cancer can undergo prophylactic mastectomy, reducing the risk of breast cancer up to 90%. Among women who have undergone prophylactic mastectomy, 1-1,9% are diagnosed with breast cancer, but little is known about the correlation between residual glandular tissue and skin flap thickness, as well as the oncological risk of residual glandular tissue. Furthermore, there is a balance between how much subcutaneous tissue should be resected to achieve maximal reduction of glandular tissue, while leaving viable skin flaps. In addition, there are established surveillance guidelines for women with pathogenic variants in BRCA1/2 who do not undergo risk-reducing surgery, but no published consensus or guidelines regarding appropriate medical follow-up for those who opt for prophylactic mastectomy. The aim of this study is to investigate the correlation between skin flap thickness, residual glandular tissue and skin flap necrosis following prophylactic mastectomy in women with results from postoperative magnetic resonance tomography, ultrasound and physical examination, as well as evaluate patient satisfaction and quality of life pre- and postoperatively with different questionnaires.

Official Title
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Prophylactic Mastectomy: Prospective Evaluation of the Correlation Between Skin Flap Thickness, Residual Glandular Tissue and Skin Necrosis by Imaging and Clinical Examination

Conditions
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Prophylactic Mastectomy

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Women that are recommended prophylactic mastectomy at the Department of Plastic Surgery at Umeå University hospital due to hereditary factors that have been investigated by clinical geneticists. Age between 18-74 years Exclusion Criteria: Women undergoing mastectomy due to cancer. Age < 18 years or > 74 years.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 74 Years

Sexes Eligible for Study
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Female

Study Plan
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How is the study designed?
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What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Presence of residual glandular tissue | Residual glandular tissue will be reported as being present or not present through postoperative evaluation with magnetic resonance tomography, ultrasound and mammography. The quadrants of the left and right breast will be examined after which the findings will be documented in pre-printed templates. | Residual glandular tissue will be evaluated 1 year postoperatively | 
| Presence of residual glandular tissue | Residual glandular tissue will be reported as being present or not present through postoperative evaluation with magnetic resonance tomography, ultrasound and mammography. The quadrants of the left and right breast will be examined after which the findings will be documented in pre-printed templates. | Residual glandular tissue will be evaluated 3 years postoperatively | 
| Measurement of skin flap thickness | The skin flap thickness will be evaluated postoperatively with magnetic resonance tomography, ultrasound and mammography. The quadrants of the left and right breast will be examined after which the findings will be documented in pre-printed templates. The skin flap thickness will be defined as the thickness of the skin (epidermis, dermis, subcutaneous tissue) measured at the examinations rather than the thickness of the skin flaps perioperatively. All measurements will be made in mm. | Skin flap thickness will be evaluated 1 year postoperatively | 
| Measurement of skin flap thickness | The skin flap thickness will be evaluated postoperatively with magnetic resonance tomography, ultrasound and mammography. The quadrants of the left and right breast will be examined after which the findings will be documented in pre-printed templates. The skin flap thickness will be defined as the thickness of the skin (epidermis, dermis, subcutaneous tissue) measured at the examinations rather than the thickness of the skin flaps perioperatively. All measurements will be made in mm. | Skin flap thickness will be evaluated 3 years postoperatively | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in evaluation of patient satisfaction | Patient satisfaction will be evaluated pre- and postoperatively with four different validated questionnaires; BREAST-Q, BRECON23, QLQ-C30 and Cancer-worry scale. | Change in patient satisfaction will be evaluated pre- and postoperatively. The women will receive the questionnaires 1 month preoperatively, 1 year postoperatively and 3 years postoperatively. | 
| Change in evaluation of patient quality of life | Patient quality of life will be evaluated pre- and postoperatively with four different validated questionnaires; BREAST-Q, BRECON23, QLQ-C30 and Cancer-worry scale. | Change in patient quality of life will be evaluated pre- and postoperatively. The women will receive the questionnaires 1 month preoperatively, 1 year postoperatively and 3 years postoperatively. | 
| Number of participants with acute postoperative complications | Postoperative complications will be evaluated postoperatively by clinical examination and documented in pre-printed templates, and pictures will be taken. The complications will include breast related complications (skin flap necrosis, infection, hematoma, seroma and implant loss) and non-breast related complications (deep vein thrombosis, pulmonary embolism). | Clinical examination will be performed 2-4 weeks postoperatively. | 
| Number of participants with long term postoperative complications | Postoperative complications will be evaluated postoperatively by clinical examination and documented in pre-printed templates, and pictures will be taken. The complications will include breast related complications (skin flap necrosis, infection, hematoma, seroma and implant loss) and non-breast related complications (deep vein thrombosis, pulmonary embolism). | Clinical examination will be performed 1 year postoperatively. | 
| Number of participants with long term postoperative complications | Postoperative complications will be evaluated postoperatively by clinical examination and documented in pre-printed templates, and pictures will be taken. The complications will include breast related complications (skin flap necrosis, infection, hematoma, seroma and implant loss) and non-breast related complications (deep vein thrombosis, pulmonary embolism). | Clinical examination will be performed 3 years postoperatively. |