Breast cancer

Editor-In-Chief: Prab R Tumpati, MD
Obesity, Sleep & Internal medicine
Founder, WikiMD Wellnesspedia &
W8MD medical weight loss NYC and sleep center NYC

A common form of cancer originating in breast tissue

Breast cancer
Synonyms	Breast carcinoma
Pronounce	N/A
Field	Oncology
Symptoms	Breast lump, breast pain, nipple discharge, changes in skin
Complications	Metastasis, lymphedema, recurrence
Onset	Variable; more common after age 40
Duration	N/A
Types	N/A
Causes	Multifactorial: genetics, hormonal, environmental factors
Risks	Female sex, age, BRCA mutations, family history, hormone therapy, obesity, alcohol
Diagnosis	Mammography, ultrasound, biopsy, MRI
Differential diagnosis	N/A
Prevention	N/A
Treatment	Surgery, radiation therapy, chemotherapy, targeted therapy, hormonal therapy
Medication	N/A
Prognosis	Generally good if detected early
Frequency	1 in 8 women (lifetime risk)
Deaths	N/A

Breast cancer is a malignant tumor that originates in the cells of the breast tissue. It is the most common cancer among women worldwide and the second leading cause of cancer-related death in women after lung cancer. Though rare, it can also affect men. Early detection, accurate diagnosis, and timely treatment are crucial for improving survival outcomes.

Diagram of early signs of breast cancer

Mammogram image showing tumor

Historical Background

Breast cancer has been known for millennia. Descriptions of tumors believed to be breast cancer appear in the Edwin Smith Papyrus from ancient Egypt, dating to around 1600 BCE. Early treatments were mostly surgical, and until the 19th century, options were limited. The modern surgical era began with William Stewart Halsted's radical mastectomy technique in the 1880s. Since then, approaches have evolved to include lumpectomy, chemotherapy, radiotherapy, and targeted therapy.

Types

Breast cancer can present in different forms. The main types include:

• Ductal carcinoma in situ (DCIS): Non-invasive; confined to milk ducts.
• Lobular carcinoma in situ (LCIS): Abnormal cells in the lobules; a marker for increased risk.
• Invasive ductal carcinoma: Cancer has spread beyond ducts; most common type.
• Invasive lobular carcinoma: Begins in lobules and invades nearby tissue.
• Inflammatory breast cancer: Rare and aggressive; presents with redness and swelling.
• Paget's disease of the breast: Affects the nipple; often associated with underlying carcinoma.
• Triple-negative breast cancer: Lacks estrogen, progesterone, and HER2 receptors; often more aggressive.

Causes and Risk Factors

The exact cause is unknown, but several risk factors increase the likelihood of developing breast cancer:

• Female gender
• Age over 50
• Family history (especially with BRCA1 or BRCA2 mutations)
• Long-term exposure to estrogen
• Early menstruation (before age 12) or late menopause (after age 55)
• Lack of pregnancy or late pregnancy
• Use of hormone replacement therapy
• Obesity and physical inactivity
• Alcohol consumption
• Previous history of breast abnormalities or biopsies
• Radiation exposure to the chest

Symptoms

Signs of breast cancer may include:

• A lump or mass in the breast or underarm
• Change in the size or shape of the breast
• Nipple retraction, discharge (especially bloody)
• Skin changes: dimpling, redness, or texture resembling an orange peel
• Pain in the breast or nipple area (less common)

These symptoms can also be caused by benign conditions such as fibrocystic breast disease or mastitis.

Diagnosis

Diagnosis involves a combination of clinical and imaging techniques:

• Clinical breast examination – Manual palpation by a healthcare provider
• Mammography – X-ray imaging to detect tumors
• Ultrasound – Useful in distinguishing solid from cystic masses
• MRI – Used in high-risk women or ambiguous cases
• Biopsy – Definitive diagnosis via fine needle aspiration, core needle biopsy, or surgical excision

Needle biopsy under guidance

Staging

Breast cancer is staged from 0 to IV using the TNM staging system:

• Stage 0: DCIS or LCIS
• Stage I–III: Local or regional spread
• Stage IV: Metastatic cancer; spread to distant organs such as bone, liver, lungs, or brain

Stage I

Stage IV

Treatment

Treatment plans depend on the type, stage, hormone receptor status, and patient preferences.

Surgical Options

• Lumpectomy – Removal of tumor with margin of normal tissue
• Mastectomy – Removal of one or both breasts
• Sentinel lymph node biopsy – Identifies first lymph nodes cancer may spread to
• Axillary lymph node dissection – Removes lymph nodes for staging and treatment

Post-mastectomy

Post-reconstruction

Radiation Therapy

Usually follows surgery to reduce recurrence:

• External beam radiation
• Internal radiation (brachytherapy)

Chemotherapy

Drugs like doxorubicin, cyclophosphamide, paclitaxel target rapidly dividing cells. Used before (neoadjuvant) or after (adjuvant) surgery.

Hormonal Therapy

Used for estrogen receptor (ER)-positive cancers:

• Tamoxifen – selective estrogen receptor modulator (SERM)
• Aromatase inhibitors – such as letrozole, anastrozole

Targeted Therapy

Used in HER2-positive cancers:

• Trastuzumab (Herceptin)
• Pertuzumab
• T-DM1

Prognosis

Prognosis varies with the stage and subtype:

• 5-year survival rate:
  • Nearly 99% for localized Stage I
  • Around 28% for metastatic Stage IV

Other factors influencing outcome include tumor size, lymph node involvement, receptor status, and response to treatment.

Prevention

There is no sure way to prevent breast cancer, but steps can reduce risk:

• Maintain healthy weight and active lifestyle
• Limit alcohol intake
• Avoid long-term hormone replacement therapy
• Breastfeed if possible
• Regular screening mammograms beginning at age 40–50
• Breast self-examination and annual clinical breast exams
• Genetic counseling and testing for high-risk individuals

Breast Cancer in Men

Though rare, men can develop breast cancer. Risk factors include age, Klinefelter syndrome, radiation exposure, BRCA2 mutations, and liver disease. Symptoms and treatment are similar to those in women.

Breast Reconstruction

Women who undergo mastectomy may choose breast reconstruction surgery using:

• Breast implants
• Autologous tissue transfer (e.g., DIEP flap)
• Combination of both

Support and Resources

Living with breast cancer can be physically and emotionally challenging. Support groups, counseling, and survivorship programs are essential components of care.

Glossary of Breast Cancer Terms

This glossary provides definitions and descriptions of key terms related to breast cancer, encompassing medical procedures, classifications, therapies, notable people, and research initiatives. Each entry includes an internal link where applicable.

A

• Abortion–breast cancer hypothesis: A discredited theory suggesting a link between induced abortion and increased breast cancer risk.
• Alcohol and breast cancer: Refers to the increased risk of breast cancer associated with alcohol consumption.
• Antiestrogen withdrawal response: A paradoxical tumor response in some patients where stopping antiestrogen therapy leads to temporary tumor regression.

B

• Basal-like carcinoma: A subtype of triple-negative breast cancer lacking estrogen receptor, progesterone receptor, and HER2 expression.
• Before I Say Goodbye: A memoir by Ruth Picardie documenting her battle with breast cancer.
• Bovine Meat and Milk Factors: Hypothesized dietary factors from cows potentially linked to cancer development.
• BRCA mutation: Genetic mutations in the BRCA1 or BRCA2 genes, associated with a significantly higher risk of breast and ovarian cancer.
• BRCA1: A tumor suppressor gene; mutations are linked to hereditary breast–ovarian cancer syndrome.
• BRCA2: Another tumor suppressor gene whose mutations increase the risk of breast cancer, especially in male breast cancer.

C

• Clinical Breast Cancer: A peer-reviewed medical journal covering research in the field of breast cancer.
• Comedocarcinoma: A subtype of ductal carcinoma in situ characterized by necrosis and high-grade cells.
• Cancer Diagnostic Probe: A tool developed to enhance accuracy in identifying cancerous tissue.
• Connie Johnson (fundraiser): Australian cancer advocate and co-founder of the Love Your Sister campaign.
• Breast cancer chemotherapy: Systemic use of drugs to destroy cancer cells in breast cancer.
• Breast cancer classification: Classification based on histological type, grade, and receptor status (ER, PR, HER2).
• Breast cancer management: Multidisciplinary approach to treatment including surgery, chemotherapy, radiation, and hormone therapy.
• Breast cancer research stamp: A fundraising initiative by the USPS to support breast cancer research.

D

• Dressed to Kill (book): A controversial book claiming links between bras and breast cancer, not supported by scientific consensus.
• Ductal carcinoma in situ (DCIS): A non-invasive breast cancer confined to the milk ducts.
• Dynamic angiothermography: A non-invasive imaging technique used in breast cancer screening.

E

• Epidemiology of breast cancer: The study of the distribution and determinants of breast cancer in populations.
• Erin Kennedy: A patient advocate and journalist who chronicled her experiences with breast cancer.
• Europa Donna: The European Breast Cancer Coalition advocating for improved services and screening.

F

• Fluoroestradiol F-18: A radiotracer used in PET scans to assess estrogen receptor expression in breast cancer.

G

• Global Pink Hijab Day: An awareness event combining breast cancer awareness with Muslim cultural identity.

H

• HEPACAM: A gene implicated in some cancer pathways, including breast cancer.
• HER2: A receptor protein overexpressed in some breast cancers, often targeted with therapies such as trastuzumab.
• Henda's Law: A Texas law requiring women to be informed of their breast tissue density after a mammogram.
• Hereditary breast–ovarian cancer syndrome: A genetic predisposition caused by BRCA1 and BRCA2 mutations.
• Hereditary lobular breast cancer: A rare genetic form of lobular carcinoma not caused by BRCA mutations.

I

• Inflammatory breast cancer: A rare, aggressive form of breast cancer characterized by redness and swelling.
• Invasive carcinoma of no special type: The most common histological form of invasive breast cancer.
• Invasive cribriform carcinoma of the breast: A rare, low-grade subtype of invasive breast cancer.
• Invasive lobular carcinoma: A type of breast cancer that begins in the milk-producing lobules.
• In the Family (2008 film): A documentary exploring the impact of BRCA mutations on family members.

L

• Lobular carcinoma in situ (LCIS): A non-invasive lesion that indicates increased risk of developing invasive breast cancer.
• Lumpectomy: Breast-conserving surgery to remove a tumor and a small margin of surrounding tissue.
• Living Proof (2008 film): A film based on the development of Herceptin for treating HER2+ breast cancer.

M

• Male breast cancer: A rare form of breast cancer that affects men.
• Medullary breast carcinoma: A rare breast cancer subtype with a better prognosis than other types.
• Metaplastic carcinoma: A heterogeneous group of breast cancers containing both glandular and non-glandular elements.
• Metastatic breast cancer: Stage IV breast cancer that has spread beyond the breast to other organs.
• My Left Breast: A documentary chronicling the life of breast cancer survivor Gerry Rogers.

N

• Nancy Cappello: Advocate for breast density notification laws after being diagnosed with advanced-stage cancer missed by mammography.
• Nottingham Prognostic Index: A prognostic tool used to determine survival in patients with breast cancer.

P

• Paget's disease of the breast: A rare form of breast cancer involving the skin of the nipple.
• Papillary carcinomas of the breast: Rare forms of breast cancer characterized by papillary structures.
• Pink Ribbons, Inc.: A documentary examining the commercialization of breast cancer awareness.
• Pinkwashing (breast cancer): The use of breast cancer awareness campaigns by companies to improve their public image.
• Preventive mastectomy: Surgical removal of the breast(s) to reduce the risk of developing cancer.
• Protein-bound paclitaxel: A formulation of paclitaxel used in the treatment of metastatic breast cancer.
• Pure apocrine carcinoma of the breast: A rare type of breast cancer characterized by apocrine cell features.

Q

• Quadrantectomy: A form of breast-conserving surgery removing a quarter of the breast tissue.

R

• Risk factors for breast cancer: Factors including age, genetics, lifestyle, and reproductive history that influence breast cancer risk.

S

• Sentinel lymph node: The first lymph node to which cancer cells are most likely to spread from a primary tumor.
• Secretory carcinoma: A rare type of breast cancer with secretory features, often occurring in younger patients.
• Stewart–Treves syndrome: A rare lymphangiosarcoma arising in chronic lymphedema, often post-mastectomy.
• Study of Tamoxifen and Raloxifene: A large clinical trial comparing these drugs for prevention in high-risk women.
• Symphony (Agendia): A genomic test used to guide treatment decisions in breast cancer.

T

• Targeted intra-operative radiotherapy: A technique delivering radiation during surgery to minimize exposure.
• Tomosynthesis: A 3D imaging technique used in breast cancer screening.
• Triple test score: Combines clinical exam, imaging, and biopsy to evaluate a breast lesion.
• Triple-negative breast cancer: Lacks estrogen, progesterone, and HER2 receptors; more aggressive with fewer treatment options.
• Tubular carcinoma: A subtype of invasive breast cancer with tubular structures; often slow-growing.

V

• Vacuum-assisted breast biopsy: A minimally invasive technique using suction to obtain breast tissue samples.

Related Articles

• Mammography
• Cancer staging
• Chemotherapy
• Oncology
• Breast reconstruction
• Genetic testing
• Lymph nodes
• Triple-negative breast cancer
• Hormone therapy
• HER2

External Links

• National Cancer Institute – Breast Cancer
• BreastCancer.org
• American Cancer Society – Breast Cancer