breast cancer

breast cancer
Name	Breast cancer
Field	Oncology
Symptoms	Lump in breast, skin changes, nipple discharge
Complications	Metastasis to lungs, liver, bones, brain
Onset	Mostly adults
Risks	BRCA1, BRCA2, obesity, alcohol use
Diagnosis	Clinical exam, mammography, biopsy
Treatment	surgery, radiation therapy, chemotherapy, endocrine therapy
Medication	trastuzumab, tamoxifen, letrozole
Frequency	Common

breast cancer Breast cancer is a malignant neoplasm originating in the breast tissue that presents with variable clinical courses and requires multidisciplinary care. It is studied across oncology, pathology, radiology, surgery and public health programs led by organizations such as World Health Organization and American Cancer Society. Management strategies reflect advances linked to discoveries by researchers at institutions like Memorial Sloan Kettering Cancer Center, Johns Hopkins Hospital, MD Anderson Cancer Center and regulatory approvals by bodies including the Food and Drug Administration and European Medicines Agency.

Signs and symptoms

Common presentations include a palpable lump, skin dimpling, nipple inversion, and abnormal nipple discharge reported in clinics such as Mayo Clinic, Cleveland Clinic, Royal Marsden Hospital and community centers tied to Susan G. Komen initiatives. Patients may notice axillary lymphadenopathy evaluated by specialists from American Society of Clinical Oncology and European Society for Medical Oncology guidelines; systemic symptoms like weight loss or bone pain prompt imaging at centers using CT scan, MRI, and PET scan. Clinical pathways implemented in hospitals like St Bartholomew's Hospital and Peter MacCallum Cancer Centre emphasize triple assessment with history, examination, and histopathology by laboratories affiliated with Royal College of Pathologists.

Causes and risk factors

Risk is influenced by genetic mutations such as BRCA1, BRCA2, TP53 (Li‑Fraumeni syndrome), and hereditary syndromes identified in cohorts studied at Baylor College of Medicine and University of Cambridge. Environmental and reproductive factors documented by cohorts like the Nurses' Health Study and analyses by International Agency for Research on Cancer include nulliparity, early menarche, late menopause, exogenous hormones reviewed by Women's Health Initiative, alcohol intake cited by World Cancer Research Fund, and adiposity linked to metabolic studies at Harvard T.H. Chan School of Public Health. Prior chest irradiation for conditions treated at centers such as Memorial Sloan Kettering Cancer Center increases risk similar to exposures studied after incidents like Hiroshima and Chernobyl in radiation epidemiology.

Pathophysiology and subtypes

Malignancy arises from ductal or lobular epithelium with molecular classifications developed through work at The Cancer Genome Atlas and laboratories at Broad Institute and Wellcome Sanger Institute. Major histologic subtypes include invasive ductal carcinoma and invasive lobular carcinoma described in textbooks from Oxford University Press and monographs by American Cancer Society. Molecular subtypes—hormone receptor–positive (estrogen receptor, progesterone receptor), HER2‑positive, and triple‑negative—are characterized by assays standardized by College of American Pathologists and inform targeted therapies such as trastuzumab and platinum agents evaluated in trials run by groups like the European Organisation for Research and Treatment of Cancer and National Cancer Institute.

Diagnosis and screening

Diagnostic algorithms rely on imaging with mammography, supplemental ultrasound, and MRI following protocols from U.S. Preventive Services Task Force and European Society of Breast Imaging; tissue diagnosis uses core needle biopsy with pathology reporting per AJCC staging and receptor testing accredited by CAP. Population screening programs in countries such as United Kingdom, Sweden, Australia and Japan use organized mammography registries; randomized trials like the Canadian National Breast Screening Study have influenced policy debates. Genetic testing pathways for BRCA1/BRCA2 cascade testing are coordinated by clinics affiliated with Genetics Clinics and counseling services guided by American College of Medical Genetics and Genomics.

Treatment

Therapeutic options integrate surgery (lumpectomy, mastectomy) performed by surgical teams trained at centers like Guy's Hospital and Royal Marsden Hospital; radiation delivered by departments using protocols from American Society for Radiation Oncology; systemic therapy including endocrine agents (tamoxifen, aromatase inhibitors), cytotoxic chemotherapy regimens developed in trials by NSABP and ECOG‑ACRIN, and targeted therapies (HER2 directed agents such as trastuzumab and antibody‑drug conjugates assessed by FDA approvals). Multidisciplinary tumor boards modeled after programs at Johns Hopkins Hospital integrate input from medical oncologists, radiation oncologists, geneticists, and palliative care teams developed at institutions like Hospices of Hope.

Prognosis and survival=

Prognostic factors include stage at diagnosis (TNM staging endorsed by AJCC), tumor grade, receptor status, and genomic assays such as Oncotype DX developed by Genomic Health; survival improvements documented in registry data from Surveillance, Epidemiology, and End Results Program and national statistics from Office for National Statistics reflect advances in screening and therapy. Longitudinal cohort studies at Fred Hutchinson Cancer Research Center and survivorship programs at Dana-Farber Cancer Institute address late effects and quality of life metrics promoted by National Comprehensive Cancer Network survivorship guidelines.

Epidemiology and prevention

Incidence and mortality vary globally with data compiled by Global Burden of Disease Study, World Health Organization, and national cancer registries in India, China, United States, and Brazil. Prevention strategies include risk‑reducing surgery for high‑risk carriers as practiced at specialty centers like Royal Marsden Hospital, chemoprevention trials such as those reported by NSABP, lifestyle interventions advocated by World Cancer Research Fund, and vaccination and public awareness campaigns coordinated with NGOs including Breast Cancer Now and Susan G. Komen.

Category:Cancer