Proponents of screening mammography have been quick to criticize a study published this week by Norwegian and Danish scientists that claims there's no evidence that mammography screening for breast cancer has any effect on death rates.
In a study published online March 24 in the British Medical Journal, researchers from the Nordic Cochrane Centre in Copenhagen and the Norwegian Institute of Public Health in Oslo said reductions in breast cancer death rates in regions with screening were the same or actually smaller than in areas where no women were screened.
The BMJ published a response from Professor Elsebeth Lynge in the Institute of Public Health at the University of Copenhagen March 25.
"Jørgensen et al claim that mammography screening in Denmark had no impact on breast cancer mortality," she wrote. "This claim is unsubstantiated, firstly because the authors used very crude data, and secondly because the analysis was not geared to answer the question."
Breast cancer screening can only have an effect on women not already diagnosed with breast cancer prior to screening, Lynge wrote. Therefore, "refined mortality" should be used to evaluate the benefit of mammography screening, and Jørgensen's team did not do so.
"They merge data from three screening areas starting screening at different points in time, and used age groups instead of cohorts. Together this gave quite 'polluted' data," she wrote.
The measured impact of mammography screening on breast cancer mortality is highly dependent on the dataset used for the analysis, according to Lynge.
"Using cohort-based refined mortality, we found a 25% decrease in breast cancer mortality in the municipality of Copenhagen during the first 10 years following the introduction of mammography screening," Lynge wrote.
Jørgensen's study data are inconsistent, according to Dr. Peter Dean, professor of radiology at the University of Turku in Finland.
"[Jørgensen's team] did not determine whether or not the breast cancer deaths were from cancers diagnosed before or after screening was offered, and whether or not the women had actually attended screening," Dean wrote AuntMinnie.com in an e-mail. "Their inability to find a difference in breast cancer mortality is most likely a result of the dilution of the effect caused by including so many breast cancer deaths from women who had not attended screening."
By Kate Madden Yee
AuntMinnie.com staff writer
March 26, 2010
Related Reading
Breast cancer screens don't save lives: Nordic study, March 25, 2010
Study: Less breast screening leads to more palpable cancers, March 16, 2010
USPSTF guidelines influencing doctors, poll finds, February 16, 2010
Editorial: Research flaws make USPSTF guidelines obsolete, February 8, 2010
ACR, SBI: Breast cancer screening should begin at 40, January 4, 2010
Copyright © 2010 AuntMinnie.com
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![Examples of ultrasound findings and techniques. (A) Images in a 39-year-old male patient with a mass in the left thigh. The mass is heterogeneous on the B-mode US image (compared with the patient in D) and showed increased microvascularity (superb microvascular imaging [SMI]) and shear-wave elastography (SWE) values. Undifferentiated pleomorphic sarcoma was diagnosed at biopsy (with pleomorphic rhabdomyosarcoma in surgical specimen). (B) Images in an 18-year-old male patient with a mass in the left leg. The mass is hypoechoic on the B-mode image, with no other findings suggestive of malignancy. The lesion is in contact with the cortex of the tibia, which is slightly irregular. CT revealed a doubtful anteromedial tibial erosion. The microvascular study demonstrated high vascularization, suggestive of malignancy. Periosteal Ewing sarcoma was diagnosed with both histologic and immunohistochemical confirmation. (C) Images in a 69-year-old female patient with a lump growing on the outside of the left leg. Multiple SWE examinations were performed (please note the high values obtained in the measurements, whereas the color map highlights the stiffness relative to adjacent tissues). SMI showed areas of increased vascularization to target for sampling. Undifferentiated spindle cell sarcoma was diagnosed at biopsy, with residual leiomyosarcoma in the surgical specimen after neoadjuvant therapy. (D) Images in a 56-year-old female patient with a mass in the right thigh. The mass is heterogeneous at both B-mode ultrasound (similar to patient A) and MRI (coronal T2-weighted spectral attenuated inversion recovery [SPAIR]; T1-weighted pre-contrast and postcontrast imaging), which even shows uptake after the administration of paramagnetic contrast material, which is traditionally suggestive of malignancy. Low values at SMI and elastography are suggestive of benignity. Spindle cell lipoma was diagnosed at biopsy, with atypical spindle cell lipomatous tumor in the surgical specimen.](https://img.auntminnieeurope.com/mindful/smg/workspaces/default/uploads/2026/08/images-radiol250278fig2.APCFLSvX6p.jpg?auto=format%2Ccompress&dpr=2&fit=crop&h=167&q=70&w=250)
