Breast Cancer Screening

by Specialist

Tests can screen for different types of cancer when a person is asymptomatic.

Scientists have studied various screening methods to find the least harmful and most beneficial screening method. The purpose of cancer screening tests also includes clarifying whether early detection (finding cancer before it causes symptoms) can help extend life or reduce the chance of dying from the disease. For some types of cancer, the chances of recovery are greater if detected and treated at an early stage.

Mammography is the most common screening test for breast cancer.

Mammography is able to detect non-palpable tumors by taking x-rays of the breast. This method can also detect ductal carcinoma in situ (DCIS). In ductal carcinoma in situ, the tumor cells are confined to the ducts of the breast. Some patients with ductal carcinoma in situ will develop invasive carcinoma.

Mammography has difficulty detecting tumors in dense breast tissue. It is difficult to distinguish between breast tumors and dense breast tissue because both appear as “white” dense shadows on mammograms. In young women, the mammary glands tend to be dense.

Mammography. The mammogram is taken by placing the subject’s breast between two splints and obtaining an image of the breast by radiography.

The ability to detect (find) breast cancer on mammography is influenced by a number of factors.

  • The patient’s age and weight
  • Size and type of tumor
  • The location of the tumor
  • The sensitivity of the breast tissue to hormones
  • The degree of denseness of the breast tissue
  • Menstrual cycle at the time of mammography
  • The quality of the mammogram
  • Radiologist’s technical level of film reading

    For women aged 50-69 years, breast cancer mortality can be reduced by screening mammography.

    Fewer women are dying from breast cancer in the United States, and whether this is because of the benefit of early detection with screening or because of better treatment outcomes is unclear.

    Magnetic resonance imaging (MRI) can be used to screen for breast cancer in women at high risk.

    MRI uses magnetic fields and radio waves and is processed by a computer to obtain images. MRI does not use x-ray exposure, so women who are tested are not exposed to radiation damage.

    MRI can be used as a screening method for women at high risk for breast cancer. Risk factors for breast cancer in women include:

  • Gene mutations, such as the BRCA1 or BRCA2 genes.
  • Family history of breast cancer (a first-degree relative, such as a mother, daughter, or sister with breast cancer).
  • Some genetic syndromes, such as #Lee-Vermini syndrome or #Cowden syndrome.

    MRI is more likely to detect a non-malignant breast mass than a mammogram.

    Whether to perform breast cancer screening and which screening method to choose depends on a variety of factors.

    Women with risk factors for breast cancer (such as mutations in the BRCA1 or BRCA2 genes, or certain genetic syndromes) can be screened multiple times at a younger age.

    Younger women who have had chest radiotherapy may be screened for routine breast cancer earlier. The pros and cons of performing mammography and magnetic resonance imaging in this population are not known.

    There is no evidence of benefit from screening for breast cancer in the following population:

  • Older women. This population usually dies from other diseases after breast cancer is diagnosed. For women aged 66-79 years who are screened for breast cancer, mammograms detect only a small proportion of breast cancer patients, and most of the tumors found are low-grade malignant.
  • For women at average risk, screening with mammography before age 40 does not benefit.
  • For women with shorter life expectancy and other diseases, detection and treatment of early breast cancer may reduce their quality of life and do not contribute to longer life expectancy.

    Clinical trials have been or are being conducted for other screening methods.

    To clarify whether different screening methods help detect breast cancer or prolong life, researchers have studied the following methods.

    Breast palpation

    Clinical breast palpation is a visual palpation of the breast performed by a physician. The doctor will carefully palpate the breast and underarm to look for lumps or other abnormalities. It is not known whether clinical breast palpation reduces breast cancer mortality.

    Breast self-examination is a self-examination to detect a lump or abnormal change in the breast. If you find an abnormality, consult your doctor. Regular breast self-examination does not reduce breast cancer mortality.

    Thermography

    Thermography uses special cameras that can sense temperature to record the temperature of the breast skin. Tumors can cause changes in body temperature that may be captured by thermography.

    There are no randomized clinical trials of thermography, and the pros and cons of this method are unknown.

    Tissue sampling

    Breast tissue sampling is the removal of cells from breast tissue for microscopic examination. It is not known whether breast tissue sampling, as a method of breast cancer screening, reduces the risk of death from breast cancer.

    Breast cancer screening methods are being studied through clinical trials

    The NCI Clinical Trials website retrieves information about clinical trials supported by the NCI. The Clinical trials.gov website retrieves information about clinical trials supported by other organizations.