Screening Guidelines: Breast Cancer

In 2008, approximately 184,450 new cases of breast cancer will be diagnosed in the US, with approximately 41,000 individuals dying from the disease. The average American woman has a one in seven chance of developing breast cancer during her lifetime.

Studies have shown that regular screening of women with no symptoms has decreased the number of women who die from breast cancer by approximately 45 percent.

In the past, recommendations for breast cancer screening have been the same for women from different cancer-risk groups. However, due to the results of recent studies, Memorial Sloan-Kettering investigators have developed separate breast cancer screening guidelines for women at average risk and for those at increased risk because of familial and genetic predisposition.

In the sections below, we include a discussion of different screening tests and our doctors' breast cancer screening guidelines, separated into four distinct risk categories.

Breast Cancer Risk Types

Average-risk women have:

• No symptoms
• No history of invasive breast cancer (breast cancers that have spread beyond the milk ducts, or lobules), ductal or lobular carcinoma in situ (cancers that are confined to the milk duct or lobule), or atypia, which is also known as atypical hyperplasia (a form of benign breast disease)
• No family history of breast cancer in a first degree relative (parent or sibling), or no suggestion/evidence of a hereditary syndrome
• No history of mantle radiation (a radiation therapy used to treat Hodgkin disease)

Above-average-risk women have any of the following:

• Family history of breast cancer (i.e. one first-degree relative — a parent or sibling — who had breast cancer)
• Diagnosis of atypia, also known as atypical hyperplasia (a form of benign breast disease), or lobular carcinoma in situ (cancers that are confined to the milk duct or lobule)
• History of having been treated with mantle radiation (a radiation therapy used to treat Hodgkin disease) before the age of 32

Breast Cancer Screening Tests

Breast cancer screening can involve a number of different types of examinations, which include breast self examination (BSE), clinical breast examination (CBE), mammography, magnetic resonance imaging (MRI), and ultrasound.

Breast Self-Examination

During a breast self-examination (BSE), a women checks her own breasts for any irregularities, which may include lumps, changes in breast size or shape, nipple discharge, or irregular tissue thickening. Despite attempts by investigators to demonstrate the impact of BSE on reducing breast cancer deaths, no study has been able to show a statistically significant reduction. As a result, our doctors and a number of national organizations no longer aggressively encourage women to perform BSE. However, because BSE is easy and free, and may detect some cancers, women are not discouraged from performing regular BSE.

Clinical Breast Examination

A clinical breast examination (CBE) is a physical examination of the breast performed by a health professional. In clinical studies where CBE was performed along with mammography, the reduction in deaths from breast cancer was similar to the reduction in those women who had received mammography alone. This suggests that CBE adds little to mammography in reducing breast cancer deaths.

Mammography

Mammography is the diagnostic examination of the breast using low-dose x-rays. Annual mammogram screenings have been shown to reduce significantly the number of women dying from breast cancer in the age group 40 years and older. Until fairly recently, all mammograms used the conventional film-based technique, which utilizes x-rays to produce an image of the breast on film. Introduced in the US in 2001, digital mammography also uses x-rays but captures the image on a computer, where it can be viewed and manipulated for contrast. While finding no significant difference between the two techniques when applied to the general population and for most women over 50, studies have shown that digital mammograms detected more tumors in three specific groups: women under 50, women with dense breasts, and women not yet in menopause.

Ultrasound

Ultrasound, also known as ultrasonography, is an imaging method in which high-frequency sound waves are used to create images of blood vessels, tissues, and organs including the breast. Breast ultrasound is often used to evaluate breast abnormalities that are found during mammography or a clinical breast exam. The accuracy of breast ultrasound is highly dependent on the skill level and training of the ultrasound technician. This creates an increased risk of false positives, requiring follow-up exams and biopsy — which can be expensive and lead to unnecessary anxiety for the patient.

Magnetic Resonance Imaging

Magnetic resonance imaging (MRI) is a diagnostic procedure that uses a magnetic field to provide three-dimensional images of internal body structures, including the breast. MRI is expensive and requires the injection of intravenous contrast dyes. Recent studies of women with an inherited risk of breast cancer have shown that MRI has a higher sensitivity in detecting breast cancers than other screening methods. However, there are no study data showing that MRI screening reduces the number of breast cancer deaths.

Our Breast Cancer Screening Guidelines

Our doctors recommend different breast cancer screening guidelines based on four distinct risk categories: women of average risk; women with at least one first-degree relative (i.e. parent or sibling) affected by breast cancer; women who have received a diagnosis of atypical hyperplasia (a form of benign breast disease) or lobular carcinoma in situ (cancers that are confined to the milk duct or lobule); and women with a history of mantle radiation (radiation received during treatment for Hodgkin disease).

Average Risk Women

• Annual clinical breast examination (CBE) beginning at age 25
• Annual mammography beginning at age 40
• Women should be aware of any changes in their breasts. Monthly breast self-examination beginning at 20 years old is optional.

Women with a Family History of Breast Cancer — i.e., One or More First-Degree Relative (Parent or Sibling)

• CBE every three to six months starting no later than ten years earlier than the age at which the youngest family member was diagnosed with breast cancer
• Annual mammography starting ten years prior to the age of the youngest family member with breast cancer (but not earlier than age 25 and not later than age 40)
• Consider annual MRI (consult with your physician)
• Women should be aware of any changes in their breasts. Monthly breast self-examination beginning at 20 years old is optional.

Women with a Diagnosis of Atypical Hyperplasia or Lobular Carcinoma In Situ

• CBE every three to six months beginning at time of diagnosis
• Annual mammography beginning at the time of diagnosis
• Consider annual MRI (consult with your physician).
• Women should be aware of any changes in their breasts. Monthly breast self-examination beginning at 20 years old is optional.

Women with a History of Mantle Radiation (Radiation Received during Earlier Hodgkin's Disease Treatment)

• CBE every three to six months beginning no later than five years post-treatment
• Annual mammography starting eight years after radiation treatment
• Consider annual MRI (consult with your physician)
• Women should be aware of any changes in their breasts. Monthly breast self-examination beginning at 20 years old is optional.