Updated 24 August 2009
About one in nine women living to age ninety will eventually be diagnosed as having breast cancer. Mammography for screening should be directed towards women at high risk. Risk increases with advancing age and the following screening procedures are recommended for women over forty years of age. The criteria to estimate the level of risk for women under age forty are described in below. These women require individualized assessment of risk and benefit from Hereditary Cancer Program.
High Risk Groups in Women Under Age Forty
A woman with two or more first-degree relatives with premenopausal or bilateral breast cancer is at particularly high risk and should be referred for genetic counselling and assessment for hereditary cancer. The Hereditary Cancer Program is a joint activity of the B.C. Cancer Agency and the Provincial Medical Genetics Program. Some families, accounting for perhaps up to 10% of breast cancers, may be carriers of specific genetic mutations. Testing is available for families at risk of mutations in BRCA1 or BRCA2. These women are candidates for programs of special surveillance. Women at high risk should be referred to the Hereditary Cancer Program.
A woman with a sister or mother with bilateral breast cancer would be at four-fold risk of breast cancer, if the case were postmenopausal or nine-fold if the case were premenopausal. This person would be at even higher risk if, in addition to the family history, she met any of the following criteria:
- There was also a family history of ovarian cancer or male breast cancer.
- Ashkenazi Jewish heritage.
3.1 Breast Self-examination
Women may be encouraged to do regular breast self-examination (BSE). For premenopausal women this is best done in the week following the menstrual period. For postmenopausal women a specific day of the month should be chosen. The examination should include inspection of the breast and palpation of the breast and axilla. To perform adequate BSE the patient needs instruction in the technique and the manner in which she is carrying this out. This should be checked at subsequent examinations by her family physician.There is no evidence that BSE improves survival, but regular self-examination does allow a woman to know her own body and therefore she may recognize changes early.
3.2 Family Physician
The combination of physical examination by a physician and mammographic screening has been shown to reduce mortality from breast cancer. The relative importance of the physical examination vis-a-vis the mammogram remains unclear. It is recommended that all women over the age of 20 years receive an annual physical examination of the breasts by their family physician both as a screening procedure and as an opportunity to teach breast self-examination. Ten percent of breast cancers will not show up on a mammogram in older women, but as many as 25-30% of breast cancers are not seen on screening mammograms in women age 40 to 49.
3.3 Screening Mammography
Screening Mammography Program of B.C. (SMPBC) Recruitment & Recall Policies Basic Eligibility Criteria:
- 40-79 years of age
- resident of B.C.
- no breast problems
- no mammogram in last 12 months
- has a family doctor
- no previous history of breast cancer
- no breast implants
- not pregnant or breast feeding
SMPBC Recommendations:
|
AGE |
SELF-REFERRAL |
SMPBC WILL SEND YOU A RECALL LETTER |
|
40-49 |
yes |
every 12- 18 months |
|
50-79 |
yes |
every 2 years* |
|
|
|
|
|
80+ |
no |
will accept with family physician referral |
*a reminder letter will be sent if no visit/appointment is made 4-6 weeks after the recall letter is sent.
Age<40
Family physicians may wish to refer women age <40 with a strong family history of breast cancer (i.e. two or more family members), to be screened at the SMPBC. These women may also benefit from discussion of breast cancer risks including genetic counseling and testing. Screening mammography is only one component of care for these higher risk families. The SMPBC asks that each screening exam for women age <40 be arranged by family physicians with a radiologist at the SMPBC centre of choice.
Age 40-49
Women ages 40 -49 are eligible for screening. There has been discussion about the risks and benefits, including the decreased sensitivity of mammography in women this age with dense breasts but the recommendations from the Breast Tumour Group and the SMPBC is that there are benefits to screening. Although the sojourn time (the time during which a breast cancer is potentially detectable), may be shorter in women between 40 – 49, there is not clear evidence at this time for annual screening, so women are encouraged to attend at least every 24 months.
Age 50-79
Research studies show that 25-40% fewer breast cancer deaths can be expected in women if they have regular screening mammograms over the age of 50. To achieve this, at least 70% of eligible women in this age group must have regular screening mammography. The SMPBC recommends that women age 50-79 have a screening mammogram at least every 24 months and will actively re-invite women to attend.
Age 80+
Family physicians may wish to refer women age 80+ in good general health for screening at the SMPBC. The possible benefits of screening mammography in light of other potential health concerns at this age should be discussed with the women. Therefore, the SMPBC asks that each screening exam for women age 80+ be referred by family physicians to the SMPBC centre of choice.
Other High Risk Groups
There is evidence that women with dense breasts have a higher risk of breast cancer and it is not clear if annual mammography is warranted in this group. The SMPBC is proposing a provincial system for rating density according to the BIRADS system, with the intention of identifying and recalling women with dense breasts who may be at increased risk for annual screens. Similarly, it is not clear if women on hormone replacement therapy or women with a family history of breast cancer should have more frequent screens and this is being assessed, but some of these women, particularly if they also have dense breasts, may benefit from annual screening.
For women who had radiation for Hodgkin's disease or other childhood cancers, screening may be indicated earlier due to the high risk of breast cancer, particularly if the radiation occured in teens or early 20s (annual mammography for women beginning 10 years after diagnosis of Hodgkin's lymphoma or at age 40 years, whichever comes first).
3.4 Other Methods
There has been considerable interest in methods of detection of non-palpable abnormalities in the breast that do not use ionizing radiation. Such methods include thermography, U/S (ultrasound) and diaphanography, but in the screening of asymptomatic women none of these techniques approach the sensitivity or the specificity of mammography and cannot be recommended at the present time as the sole screening method. Ultrasound may be very useful, in conjunction with mammogram, for diagnosis of (to assess) breast lesions, and in that situation is part of the workup of a mass. However, in the absence of any abnormality on physical examination or mammogram, U/S is not required, is not a validated screening method, and is not funded by MSP.
MRI (magnetic resonance imaging) is being studied in high-risk women with identified genetic mutations to see if it can add to their screening. At this time there are no studies showing a survival benefit using MRI screening, but there are studies suggesting its value in women with identified mutations as an additional study.See clinical guidelines for MRI.