Breast cancer

The first symptom, or subjective sign, of breast cancer is typically a lump that feels different from the surrounding breast tissue. According to the The Merck Manual, more than 80% of breast cancer cases are discovered when the woman feels a lump. According to the American Cancer Society, the first medical sign, or objective indication of breast cancer as detected by a physician, is discovered by mammogram. Lumps found in lymph nodes located in the armpits[8] can also indicate breast cancer.
Indications of breast cancer other than a lump may include changes in breast size or shape, skin dimpling, nipple inversion, or spontaneous single-nipple discharge. Pain ("mastodynia") is an unreliable tool in determining the presence or absence of breast cancer, but may be indicative of other breast health issues.
When breast cancer cells invade the dermal lymphatics—small lymph vessels in the skin of the breast—its presentation can resemble skin inflammation and thus is known as inflammatory breast cancer (IBC). 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.
Another reported symptom complex of breast cancer is Paget's disease of the breast. This syndrome presents as eczematoid skin changes such as redness and mild flaking of the nipple skin. As Paget's advances, symptoms may include tingling, itching, increased sensitivity, burning, and pain. There may also be discharge from the nipple. Approximately half of women diagnosed with Paget's also have a lump in the breast.
Occasionally, breast cancer presents as metastatic disease, that is, cancer that has spread beyond the original organ. Metastatic breast cancer will cause symptoms that depend on the location of metastasis. Common sites of metastasis include bone, liver, lung and brain. Unexplained weight loss can occasionally herald an occult breast cancer, as can symptoms of fevers or chills. Bone or joint pains can sometimes be manifestations of metastatic breast cancer, as can jaundice or neurological symptoms. These symptoms are "non-specific", meaning they can also be manifestations of many other illnesses.
Most symptoms of breast disorder do not turn out to represent underlying breast cancer. Benign breast diseases such as mastitis and fibroadenoma of the breast are more common causes of breast disorder symptoms. The appearance of a new symptom should be taken seriously by both patients and their doctors, because of the possibility of an underlying breast cancer at almost any age.

Causes

The primary risk factors that have been identified are sex, age, childbearing, hormones, a high-fat diet, alcohol intake, obesity, and environmental factors such as tobacco use, radiation and shiftwork.
No etiology is known for 95% of breast cancer cases, while approximately 5% of new breast cancers are attributable to hereditary syndromes. In particular, carriers of the breast cancer susceptibility genes, BRCA1 and BRCA2, are at a 30-40% increased risk for breast and ovarian cancer, depending on in which portion of the protein the mutation occurs.
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. Having other relatives with breast cancer (in either her mother's or father's family) may also increase a woman's risk.
Certain breast changes: Some women have cells in the breast that look abnormal under a microscope. Having certain types of abnormal cells (atypical hyperplasia and lobular carcinoma in situ [LCIS]) increases the risk of breast cancer.
Race: Breast cancer is diagnosed more often in Caucasian women than Latina, Asian, or African American women.
No physical activity: Women who are physically inactive throughout life may have an increased risk of breast cancer. Being active may help decrease risk by preventing weight gain and obesity.
Antiperspirant use: British scientists found that aluminum, a common ingredient added to antiperspirants to stop the skin from sweating, may be linked to breast cancer. Deposits of aluminum in high concentration near the underarm have been found in outer breast tissue in patients who used antiperspirants. Researchers believe the aluminum is being absorbed from antiperspirant sprays and roll-ons since aluminum is not normally found in the human body.
Pork consumption: People who eat an average of just over one ounce of pork daily have a significantly higher risk for cancer.
Processed meat consumption: The sodium, nitrates and nitrites in processed meats may irritate cells and initiate DNA changes that can lead to cancer. The risk is even higher when these foods are cooked at high temperatures for extended periods. High-heat grilling and pan-frying generates heterocyclic amines (HCAs), which are known carcinogens.
Tamoxifen may interact unfavorably with certain antidepressants when used for prevention of breast cancer recurrence.