Increase in the cost of breast cancer screening results in no benefit for older women

Killelea et al in their paper published by the JNat Cancer Inst report that cost for breast cancer screening have increased dramatically since the introduction of newer imaging technologies such as digital mammography, computer aided detection, MRI and image guided biopsies, but the outcomes remain undefined, particularly among older women.

The authors used the Surveillance, Epidemiology, and End Results-Medicare linked database, and constructed two cohorts of women without a history of breast cancer, which they followed for 2 years. They compared the use and cost of screening mammography including digital mammography, CAD, and adjunct procedures such as CAD, breast ultrasound, MRI, and biopsies between the period of 2001 and 2002 and the period of 2008 and 2009.

There were 137150 women (mean age = 76.0 years) in the early cohort (2001-2002) and 133097 women (mean age = 77.3 years) in the later cohort (2008-2009). The use of digital image acquisition for screening mammography increased from 2.0% in 2001 and 2002 to 29.8% in 2008 and 2009 (P < .001). CAD use increased from 3.2% to 33.1% (P < .001). Average screening-related cost per capita increased from $76 to $112 (P < .001), with annual national fee-for-service Medicare spending increasing from $666 million to $962 million. There was no statistically significant change in detection rates of early-stage tumors (2.45 vs 2.57 per 1000 person-years; P = .41).

The authors concluded that although breast cancer screening-related costs increased substantially from 2001 through 2009 among Medicare beneficiaries, a clinically significant change in stage at diagnosis was not observed.

Radiologists perform better at screening if they follow up with diagnostic mammograms

Buist et al in their Radiology article analyzed the performance of 96 radiologists at screening mammograms (651 671).  They looked at the effect the number of diagnostic work-ups performed after abnormal findings were found at screening had if the same or a different radiologist interpreted them.

Annually, 38% of radiologists performed the diagnostic work-up for 25 or fewer of their own recalled screening mammograms, 24% for 0–50, and 39% for more than 50. For the work-up of recalled screening mammograms from other radiologists, 24% of radiologists performed the work-up for 0–50 mammograms, 32% performed the work-up for 51–125, and 44% performed the work-up for more than 125.

With increasing numbers of radiologist work-ups for their own recalled mammograms, the sensitivity of screening mammography increased, yielding a stepped increase in women recalled per cancer detected from 17.4 for 25 or fewer mammograms to 24.6 for more than 50 mammograms. Increases in work-ups for any radiologist yielded significant increases in false positive rate and cancer detection rate and a non-significant increase in sensitivity. Radiologists with a lower annual volume of any work-ups had consistently lower false positive rate, sensitivity, and cancer detection rate at all annual interpretive volumes.

They conclude that radiologists may improve their screening accuracy by performing diagnostic work-up for their own recalled screening mammograms.  They recommend arranging for radiologists to work up a minimum number of their own recalled cases in order to improve their accuracy in screening.