Breast cancer
Breast Cancer
Classification and external resources
Mammograms showing a normal breast (left) and a breast
cancer (right).
Breast cancer (malignant breast neoplasm) is cancer originating from breast tissue, most
commonly from the inner lining of milk ducts or the lobules that supply the ducts with milk.
Cancers originating from ducts are known as ductal carcinomas; those originating from lobules
are known as lobular carcinomas.
Signs and symptoms
Breast cancer showing an inverted nipple, lump, skin dimpling
The first noticeable symptom of breast cancer is typically a lump that feels different from the rest
of the breast tissue. More than 80% of breast cancer cases are discovered when the woman feels
a lump.[14] By the time a breast lump is noticeable, it has probably been growing for years. The
earliest breast cancers are detected by a mammogram.[15] Lumps found in lymph nodes located in
the armpits[14] can also indicate breast cancer.
Symptoms of inflammatory breast cancer include pain, swelling, warmth and redness throughout
the breast, as well as an orange-peel texture to the skin referred to as peau d'orange.[14]
Risk factors
The primary epidemiologic and risk factors that have been identified are sex,[22] age,[23] lack of
childbearing or breastfeeding,[24][25] higher hormone levels,[26][27] race and economic status.
In addition to the risk factors specified above, demographic and medical risk factors include:
Personal history of breast cancer: A woman who had breast cancer in one breast has an
increased risk of getting cancer in her other breast.
Family history: A woman's risk of breast cancer is higher if her mother, sister, or
daughter had breast cancer. The risk is higher if her family member got breast cancer
before age 40. An Australian study found that having other relatives with breast cancer
(in either her mother's or father's family) may also increase a woman's risk of breast
cancer and other forms of cancer, including brain and lung cancers. [40]
Diagnosis
In a clinical setting, breast cancer is commonly diagnosed using a "triple test" of clinical breast
examination (breast examination by a trained medical practitioner), mammography, and fine
needle aspiration cytology. Both mammography and clinical breast exam, also used for
screening, can indicate an approximate likelihood that a lump is cancer, and may also identify
any other lesions. Fine Needle Aspiration and Cytology (FNAC), which may be done in a GP's
office using local anaesthetic if required, involves attempting to extract a small portion of fluid
from the lump. Clear fluid makes the lump highly unlikely to be cancerous, but bloody fluid may
be sent off for inspection under a microscope for cancerous cells. Together, these three tools can
be used to diagnose breast cancer with a good degree of accuracy.
Other options for biopsy include core biopsy, where a section of the breast lump is removed, and
an excisional biopsy, where the entire lump is removed.
In addition vacuum-assisted breast biopsy (VAB) may help diagnose breast cancer among
patients with a mammographically detected breast in women.
Screening
Breast cancer screening refers to testing otherwise-healthy women for breast cancer in an attempt
to achieve an earlier diagnosis. The assumption is that early detection will improve outcomes. A
number of screening test have been employed including: clinical and self breast exams,
Treatment
Breast cancer is usually treated with surgery and then possibly with chemotherapy or radiation,
or both. Hormone positive cancers are treated with long term hormone blocking therapy.
Treatments are given with increasing aggressiveness according to the prognosis and risk of
recurrence.
Stage 1 cancers (and DCIS) have an excellent prognosis and are generally treated with
lumpectomy and sometimes radiation.[66] The aggressive HER2+ cancers should be treated with
the trastuzumab (Herceptin) regime[67] but chemotherapy is otherwise uncommon.
Stage 2 and 3 cancers with a progressively poorer prognosis and greater risk of recurrence are
generally treated with surgery (lumpectomy or mastectomy with or without lymph node
removal), chemotherapy (plus trastuzumab for HER2+ cancers) and sometimes radiation
(particularly following large cancers, multiple positive nodes or lumpectomy).
Stage 4, metastatic cancer, (i.e. spread to distant sites) is not curable and is managed by various
combination of all treatments from surgery, radiation, chemotherapy and targeted therapies.
However, stage 4 breast cancer management has been very disappointing, with only a 6 month
increase in median survival following these treatments. There is about 8 percent of living. [68]
