Breast cancer is a rapid, uncontrolled growth of abnormal cells in one or both breasts.  It is life-threatening because it quickly spreads to vital organs.

The years since World War II have seen a tremendous increase in the incidence of breast cancer, so efforts on identifying its causes often focus on changes in our society that have occurred since then, such as the increased use of pesticides, the advent of birth control pills, changes in diet, and different styles and materials in women’s clothing.  Researchers have identified lots of risk factors (such as age, diet, cigarette smoking, alcohol intake, and family history), but the specific causes of breast cancer remain elusive. 

Cancers are divided into different groups, called stages, based on whether the cancer is invasive or non-invasive, the size of the tumor, how many lymph nodes are involved, and whether there is spread to other parts of the body.  The stages identify tumor types that have a similar outlook and are treated in a similar way. There are five main stages of breast cancer. If breast cancer is detected in its early stages, the 5 year survival rate is greater than 95%.

Breast cancer is more easily treated and often curable if it is found early. Monthly breast self-examinations should begin at age 20.  Recommended screening methods include breast self-examination and mammography.  A mammogram is the most effective way to find breast cancer early, up to 2 years before the lump is even large enough to feel.  Sometimes a doctor will discover a lump in a woman’s breast during a routine examination or a patient might come to the doctor with questions about a lump she found.  If clinical examination and mammography both reveal benign findings, biopsy may be unnecessary.  

Treatment for breast cancer usually depends on the type of cancer and whether the cancer has spread outside of the breast to the rest of the body.  Treatment options include surgery, radiation, chemotherapy, and endocrine/anti-hormone therapy.  Treatment usually starts with anticancer drugs, or chemotherapy.  The prognosis (chance of recovery) and treatment options depend on the stage of the cancer, the size of the tumor and whether it is in the breast only or has spread to lymph nodes or other places in the body.  It’s very important to diagnose inflammatory breast cancer quickly so that treatment can begin.  After surgery, radiation treatment is used to try to kill any remaining cancer cells.

Possible surgical treatments are either a mastectomy (complete removal of the breast) or breast conserving therapy.  Even if a mastectomy is needed (about 30-40% of patients need this), building a new breast, called reconstruction, offers a natural looking breast replacement.  Breast-conserving surgery (which removes only some of your breast) often works just as well as a mastectomy (which removes all of your breast). 

Mammograms can detect tumors in the earliest stages, however, a standard mammogram can miss 15-20% of cancerous tumors.  Heightened awareness of breast cancer risk in the past decades has led to an increase in the number of women undergoing mammography for screening, leading to detection of cancers in earlier stages and a resultant improvement in survival rates.

Research suggests that routine exercise may help prevent breast cancer.  No one knows the exact causes of breast cancer, but research has shown that women with certain risk factors are more likely than others to develop the disease.  Researchers at Stanford University and the National Institutes of Health, for example, found that high concentrations of the IGF-1 hormone stimulate cancer cell growth.  

Up to 10 percent of breast cancer patients eventually suffer a recurrence in the other breast.  Simple mammograms often miss small tumors, the researchers from the American College of Radiology Imaging Network found, while MRIs rarely miss them. 

The cause of breast cancer is unknown.  Early detection of breast cancer is therefore vital as it increases the chances of successful treatment.  The chance of a woman in her 40s developing breast cancer is about one in 70, whereas the risk of a woman in her 80s developing breast cancer is one in 25.  When breast cancer is confined to the breast the five year survival rate is over 95%.  For women aged 40-49, the evidence that screening mammography reduces mortality from breast cancer is weaker, and the absolute benefit of mammography is smaller, than it is for older women.

The good news is that breast cancer is a disease that can be treated and cured.  More than 90 out of 100 women whose breast cancer is found early will be cured.  Cancer found at a later stage, however, may be less likely to be cured.  While there is still no cure for the disease, the experts and leading organizations such as the American Cancer Society, Susan G.  Doctors and scientists are working on finding cures for all types of breast cancer.  Finding and treating breast cancer early is the best way to increase your chances of survival and cure.