Breast Center at St. Anthony's Cancer Center

In 2007, St. Anthony's (SAH) opened a dedicated breast cancer diagnostic center which includes digital mammography, breast MRI and mammotome biopsy procedures using both ultrasound and MRI.

The number of cancers diagnosed  has increased dramatically compared to older data as noted below. The percent of patients with a biopsy positive for cancer (28%) is actually somewhat lower than in the previous period (32%). In a recent study looking at computer assisted mamography (CAD) (NEJM 2007;356:1399) the percent of positive biopsies was 28-33% without CAD and fell to 24% after the use of CAD. In a large study comparing film with digital mammography (NEJM 2005;353:1773) the rate of positive biopsies was related to the BIRADS score (1-3% for BIRADS 1-3 and 42-47% for BIRADS 4 and 78-88% for BIRADS 5) and overall 24%. The optimal percent of positive biopsies has not been determined, but the rates at SAH appear comparable to what is expected from the literature.
  Biopsies Benign Malignant Atypical
July 2007 59 39 19 1
August 2007 61 48 11 2
September 2007 51 36 13 1
October 2007 53 37 15 1
November 2007 54 34 18 2
December 2007 41 29 9 3
January 2008 56 34 21 1
February 2008 57 46 10 1
March 2008 56 34 19 3
Total for 9 Months 488 337 (69%) 135 (28%) 15 (3%)

Mammography at St. Anthony's Hospital 1987 - 1997
Year Studies Cancers Ca/Studies Biopsies Ca/Biopsy
1987 757 5 0.7% 16 31%
1988 5175 29 0.6% 70 41%
1989 8185 42 0.5% 85 49%
1992 6751 31 0.5% 100 31%
1993 5663 31 0.5% 81 38%
1994 2672 51 1.9% 144 35%
1995 3844 34 0.9% 160 21%
1996 4430 34 0.8% 141 24%
1997 3881 25 0.6% 80 31%
Total 41,358 282 0.7% 877 32%

Discussion.

Studies have shown that in certain groups of women, digital mammography and breast MRI are more sensitive in identifying breast cancer. One consequence of increased sensitivity may be lowered specificity or more false positive studies as demonstrated in the trial using computer assisted mammography cited above. In 2007 the American Cancer Society modified their screening recommendations for breast cancer to include breast MRI in high risk women (CA Cancer J Clin 2007; 57:75-89). As more centers introduce these new, more sensitive imaging technologies it will be important to track the results to better identify the women most likely to benefit from more intense screening. The breast imaging center at St. Anthony’s will continue to monitor their experience as these modalities are increasingly utilized at the community level.