Breast cancer screening - High risk women

Personal history of breast biopsy

Many women perceive higher risk due to prior biopsies.
Many authors have cited that prior breast biopsies put one at higher risk for breast cancer.
Yet, there is an important distinction regarding the nature of the tissue removed.
IF the biopsy revealed typical cells, then one's risk is not increased.
IF the biopsy revealed atypical cells, then one's risk is modestly increased (Fletcher, 2004).

What is the clinical implication? Order a copy of the final pathology report so clinician and patient can discuss risk status more thoroughly.

Family history of breast cancer

To clarify, the family history factors that put one at greater risk are:

Closer the relative (especially 1st degree: mother, sister, daughter, father, brother)
Earlier age of relative's diagnosis (e.g., premenopausal)
Number of close maternal relatives who have had breast cancer

BRCA 1 and 2 gene mutations This increased risk is usually due to a genetic defect such as in the breast cancer susceptibility genes, BRCA 1 or BRCA 2.

Most experts recommend that health care providers tailor their screening based on family history.

If women have a first degree family relative with breast cancer then they should get mammograms earlier, especially if the family member had pre-menopausal breast cancer.

Experts recommend starting screening five years prior to the age of family member developing breast cancer.

The USPSTF recently issued recommendations on BRCA testing and genetic counseling:

Women whose family history is associated with an increased risk for mutations in BRCA 1 or 2 genes, should be referred for genetic counseling and evaluation for BRCA testing (B recommendation).
Routine referral for BRCA 1 and 2 testing or genetic counseling is not recommended for women whose family history is not associated with an increased risk for these genetic mutations (AHRQ, 2005).

And, we need to remember that most women--about 2/3--who develop breast cancer do not have a family history of it!!

If women do not have a close family history of breast cancer, then follow guidelines for women of average risk.

Breast cancer screening in women with known BRCA mutation

Most cancer diagnosed in this group is more aggressive with a higher frequency of positive lymph nodes at diagnosis.
Recommendations based on expert opinions. No evidence to support.
Start annual screening with mammogram and/or ultrasound at age 25-35 or at least five years before the age of diagnosis of the youngest or consider using MRI for screening (Levavi, 2003).

A recent small study found that half of all breast cancers diagnosed in women scheduled for close surveillance (due to their known genetic abnormality) were diagnosed in between annual screening (Komenada, 2004). This raises the possibility of new recommendations in the future for more frequent screening. Studies on the use of the MRI to screen women with a high genetic risk for breast cancer have shown that the MRI is more sensitive for detecting breast cancer than mammography but it is not known if this contributes to a reduction in mortality from breast cancer. Research is ongoing to improve current technologies and develop new technologies to further increase the sensitivity and specificity of breast cancer screening (NCI, 2005).

Screening in women on hormone replacement therapy (HRT)

Taking HRT for over five years is associated with a relative risk of developing breast cancer of 1.3 (a 30% increased risk of developing breast cancer).
No difference in mortality has been shown--so either the cancers are less aggressive to start with or are found earlier and therefore have a better prognosis.
HRT is associated with increased breast density which can make reading mammograms more difficult (Persson, 1997).
Continuous combined HRT is associated with the highest increases in mammographic density.
HRT is associated with higher recall rates for minimally abnormal mammograms. In the Women's Health Initiative, abnormal mammogram recall rates, overall: Placebo 21%, HRT 31.5%, p<0.001
No special screening recommendations are available yet for women on HRT, so they should be treated as average risk.

Relative risk - the risk of an event occurring under circumstances compared to the risk under other circumstances. So, in this case the risk of a woman developing breast cancer if she is taking HRT compared to her risk if she were not taking HRT.

Breast cancer screening in high-risk women