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Breast cancer

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Breast cancer is a disease that begins in the tissues of the breast. It is currently the leading type of cancer among women worldwide. In 2018 alone, there were two million new cases and 627,000 deaths reported.

Pink ribbon
Pink ribbon

While it is much more common in women than in men, it can affect men too. For transgender individuals on gender-affirming hormone therapy, the rates vary significantly. It is five times more common in cisgender women than in transgender men. It is also 46 times more common in transgender women than in cisgender men.

Most breast cancers develop in specific structures within the breast. About 85% of cases are known as ductal carcinomas. These cancers arise from the lining of the milk ducts, which are the tubes that carry milk. About 10% are lobular carcinomas, which start in the lobules. Lobules are the parts of the breast that supply milk to the ducts.

Lobules and ducts of the breast
Lobules and ducts of the breast

There are more than 18 other sub-types of breast cancer. These include rarer forms like mucinous carcinoma, which is surrounded by mucin. Other types include tubular, medullary, and papillary carcinomas. Some cancers are also classified as carcinoma in situ. This means the cancerous cells have not yet spread beyond their original location.

Lobules and ducts of the breast
Lobules and ducts of the breast

Detecting breast cancer early is a critical part of managing the disease. Many people have no symptoms at the time of diagnosis. Instead, their tumors are found through screening tests. The most common screening is mammography, which uses low-dose X-ray imaging.

MammographyinprocessGraphic
MammographyinprocessGraphic

During a mammogram, each breast is pressed between two plates. Radiologists look for dense areas, distorted tissue, or small flecks called microcalcifications. They often use the Breast Imaging-Reporting and Data System, or BI-RADS, to report results. A higher BI-RADS number indicates a greater risk of cancer.

Mammo breast cancer wArrows
Mammo breast cancer wArrows

Screening is very effective, as it can reduce breast cancer deaths by at least 20%.

If a screening test shows a possible tumor, doctors must confirm the diagnosis. They often use additional imaging like ultrasound or a diagnostic mammogram. The definitive step is a biopsy, where a sample of tissue is removed.

Needle Breast Biopsy
Needle Breast Biopsy

This is typically done using a core needle biopsy with a hollow needle. In some cases, doctors use fine-needle aspiration for fluid-filled areas. About 10% to 20% of these biopsies turn out to be positive for cancer. Most biopsies actually reveal benign conditions, such as fibrocystic breast changes. These are non-cancerous growths or pockets of fluid.

Once cancer is confirmed, doctors use several methods to treat it. Treatment options include surgery, radiation therapy, chemotherapy, hormonal therapy, and targeted therapy. Surgical options range from breast-conserving surgery to a mastectomy, which is the removal of the breast.

Mastectomie 02
Mastectomie 02

Some patients may also undergo breast reconstruction at the time of surgery or later.

Breast reconstruction 15
Breast reconstruction 15

For patients whose cancer has spread to other parts of the body, treatment focuses on comfort and quality of life. This spread is called metastasis. Cancer can move to the bones, liver, lungs, or brain. For example, bone metastases can cause pain and even fractures.

Many factors can influence the risk of developing breast cancer. Some are related to lifestyle, such as obesity, lack of exercise, or alcohol consumption. Others are related to biology, such as older age or early menstruation. A small group of people, about 5% to 10%, have an inherited genetic predisposition. This often involves mutations in genes like BRCA.

NIHR-infographic-breast-risk-factors
NIHR-infographic-breast-risk-factors

Doctors can also use medications like tamoxifen or raloxifene to help prevent cancer in high-risk individuals. In some cases, surgical removal of the breasts is used as a preventive measure.

Medical science uses complex systems to classify and grade tumors. Doctors grade tumors based on how much they look like healthy tissue. They look at how many cells are replicating and the appearance of the cell nucleus. This helps determine if a cancer is slow-growing or aggressive.

Signal transduction pathways
Signal transduction pathways

They also test for specific proteins using immunohistochemistry. These include the estrogen receptor (ER), progesterone receptor (PR), and HER2. Knowing if a tumor is "hormone receptor-positive" helps doctors choose the right hormone therapies. This detailed classification is essential for determining a person's prognosis and the best path forward.

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🖼️ Images & Media (16)
File:Early signs of breast cancer hariadhi svg.svg
Early signs of breast cancer hariadhi svg.svg
File:MammographyinprocessGraphic.jpg
MammographyinprocessGraphic.jpg
File:Mammo breast cancer wArrows.jpg
Mammo breast cancer wArrows.jpg
File:Needle Breast Biopsy.png
Needle Breast Biopsy.png
File:Mastectomie 02.jpg
Mastectomie 02.jpg
Breast Cancer - Project Wiki Women.webm
File:Breast reconstruction 15.jpg
Breast reconstruction 15.jpg
File:NIH standard drink comparison.jpg
NIH standard drink comparison.jpg
File:Lobules and ducts of the breast.jpg
Lobules and ducts of the breast.jpg
File:Signal transduction pathways.svg
Signal transduction pathways.svg
File:NIHR-infographic-breast-risk-factors.png
NIHR-infographic-breast-risk-factors.png
Breast cancer incidence by age.tif

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