Cancer, Breast

100 times more common in women than men.

Besides skin cancer, most common cancer in USA for women; 1 in 8 women develop breast cancer; a man’s lifetime risk is about 1 in 1000.

Most significant risk factors for breast cancer are gender and growing older. About 2 out of 3 women with invasive breast cancer are 50 y or older when the cancer is found.

Racial predilection: non-Hispanic whites > African Americans > Asians, Hispanics, and Native Americans.

African Americans are more likely to die of breast cancer because their cancers tend to be more aggressive and of a more advanced stage that is diagnosed at a younger age.

Of breast cancers, 5–10% are directly due to inherited mutations of the BRCA1 and BRCA2 gene, which tend to occur more often in younger women.

Increased with family Hx among close blood relatives; personal Hx increases the risk of developing a new cancer in the same or other breast.

>85% are diagnosed in women with no family Hx (genetic mutations secondary to aging and life in general rather than inherited).

Associated with increased risk: Obesity, aging, high alcohol consumption, estrogen exposure, and long-term heavy smoking.

Mortality: very rare

Lymphedema of arm following axillary node dissection

Ipsilateral brachial plexus injury from extensive abduction of the arm, or iatrogenic

Injury to long thoracic and/or thoracodorsal n. during surgical dissection of axilla

Rare incidence of unrecognized pneumothorax

Breast surgery is associated with postop N/V, with incidence as high as 60%

Neuropathic pain, postmastectomy pain syndrome (up to 20–30% may develop symptoms)

Systemic or regional effect of metastasis to lungs, brain, or bones.

High incidence of postop N/V

NMB and identification of major nerves.

Access to an upper extremity may be restricted or limited

Potential adverse effects of chemotherapeutic drugs and chest radiation therapy

Two types of invasive breast cancer, which account for 95%: invasive ductal carcinoma at around 80% and invasive lobar carcinoma at around 10%.

Abnormal growth of adenomatous tissue that results in systemic symptoms and metastasizes to the liver, bones, lungs, and brain.

Early detection of breast cancer offers a greater range of treatment options, increasing survival time.

Mammography: reduces the risk of dying from breast cancer by 15–20%

Physical exam and mammography are complementary

Needle biopsies provide histologic diagnosis.

Presurgical needle localization may be necessary for nonpalpable lesions.

Most breast biopsies yield benign diagnosis.

Exact cause of most breast cancers is still unknown.

Inherited and acquired genetic mutations increase the risk of developing breast cancer.