Regular physical examinations and maintaining an accurate medical history are important for maintaining good health, especially when screening for cancer before symptoms are present. In this way, physicians are more likely to detect and be able to treat cancer in its earliest stages. When breast cancer is caught in its earliest stages, the survival rates are dramatically increased and the adjuvant therapies may be more tolerable.

Mammography is the single most effective way to detect early breast cancer because it can often identify the disease several years before the appearance of symptoms. Mammograms are x-ray pictures of the breast that can show a tumor before it is large enough to be felt. Mammograms, which use minute amounts of radiation, can also pick up abnormal microcalcifications, which are minute deposits of calcium. Most calcification deposits are not cancer.

Digital mammography, a new, more accurate type of mammography is being examined as another form of breast cancer detection. This methods appears to provide a more detailed image of breast tissue and may be particularly useful for women with dense breasts. Digital mammography continues to be studied for its use in breast cancer screening.

The National Cancer Institute (NCI) and American Cancer Society (ACS) recommend that all women age 40 or older receive mammograms every one to two years. Women who are at higher risk for breast cancer may be advised to receive mammograms more often or earlier in life. 

On average, mammography will detect approximately 80 to 90 percent of breast cancers in women without symptoms, according to the ACS. It is important for a woman to know that while mammograms offer the best way to detect breast cancer at its earliest stages, mammography is not a fail-safe way of detecting breast cancer. For example:

• A mammogram can give a false-negative result, which means that cancer is present but it does not show on the x-ray.
  
  
• A mammogram can give a false-positive result and areas of concern turn out not to be cancer.
  
  
• Certain breast cancers are fast-growing and can spread (metastasize) to other parts of the body before a regularly scheduled mammograms can detect their presence.

Women younger than 40 but who are at an elevated risk of developing breast cancer, such as those with a genetic predisposition, should discuss risk factors and additional screening with their physician.

In addition to mammograms, clinical breast exams (CBE) and breast self-examinations (BSE) are two more ways to screen for breast cancer. The clinical breast exam, which takes about 5 minutes, is performed carefully and systematically by a physician who feels the breasts with the pads of the fingers. Using this method, the physician will check the entire breast area, including under the arms, around the collarbone area and nearby lymph nodes. Ideally, the CBE should be a part of a regular health examination and should be scheduled shortly before a woman's mammogram.

Many women perform a breast self examination every month checking for possible changes in their breasts. While some changes can be the result of pregnancy, menstrual cycle, aging, menopause, birth control pills or other hormones, any unusual changes should be discussed with a physician. Breast self examinations are not intended to replace clinical exams or mammograms.

If a mammogram returns results that prove to be inconclusive, a physician may send the patient for a breast ultrasonography. The ultrasound test works by sending and receiving harmless high-frequency sound waves to create images of internal organs or tissues. Sound waves pass through the tissues of the area being examined. These sound waves are recorded and displayed on a computer screen or television-type monitor or printed out for a physician to review for any abnormalities.

If the clinical breast exam, mammogram or ultrasound shows an area of possible concern, a biopsy is usually the next step. A biopsy is the removal of cells or tissues of concern so that they can be viewed under a microscope and further tested by a pathologist. The pathologist will determine whether or not the cells are cancerous.

Biopsies are conducted using various methods and can be performed in a physician’s office, outpatient clinic or hospital. The four most common types of biopsy include excisional, incisional, core and needle.

Another technique used to diagnose breast cancer is ductal lavage. With this procedure, the physician inserts a small catheter into a duct within the breast since this is where the majority of breast cancers develop. Through the catheter, a sample of cells is removed and examined for precancerous changes that take place long before tumors can be detected by a mammogram.

Most breast biopsies are benign (noncancerous). However, if the biopsy turns out to be malignant (cancerous), other tests may be recommended to further determine the course of treatment and whether or not the cancer has spread beyond the breast. Further tests also help to follow the course of therapy, such as a test for tumor markers. Some tests also help determine changes in the state of the tumor.

These tests may help determine the best treatment options for the individual patient. Reactivity for two female hormones, estrogen and progesterone, is tested within the cancer cells. The result will give the estrogen-receptor status and the progesterone-receptor status. These results have impact on the type of treatment for the cancer.

For those breast cancer patients with an invasive form of breast cancer, the tumor should also be tested for another receptor called HER2/neu. When cancer cells overexpress the HER2/neu oncogene, they grow more rapidly and respond better to specific combinations of adjuvant therapy.

Other tests include the following:

• Chest x-ray. The purpose of the chest x-ray is to determine if the breast cancer has spread to the lungs. This is normally done before any breast cancer surgery takes place.
  
  
• Bone scan. A common place for breast cancer to spread is to the bones. A bone scan is often done with breast cancer patients to assure there is no detectable metastasis to the bones. The bone scan involves a small amount of a radioactive substance injected into a vein. The substance is attracted to areas of the bone that may be abnormal, which would appear on the films.
  
  
• Computerized axial tomography (CAT) scan. If metastasis to other organs is suspected or needs to be ruled out for any reason, the physician may order a CAT scan. This is normally used for more advanced or later stages of breast cancer.

• Magnetic resonance imaging (MRI). Powerful magnets linked to a computer are used to create detailed pictures of the breast tissue for use with the mammogram.  MRI may be used to detect breast cancer in some women at higher risk, although it should not replace mammography. MRI can also be used before surgery to identify areas of the breast affected by the tumor.
  
  
• Positron emission tomography (PET) scan. A noninvasive test that takes a three–dimensional image of tissue using relatively harmless radioactive tracers injected into the body. A camera inside the machine detects any sign of radioactivity.
  
  
• Blood tests. A complete blood count (CBC), as well as blood chemical and enzyme tests are normally requested prior to any surgery to determine if the blood has the correct number of blood cells and to give a quick glimpse into the patient’s overall health.
  

None of these tests is foolproof or 100 percent accurate, but the results give important information to treating physicians about the stage of the cancer and its response to therapy.