Annual Screening with Breast Ultrasound or MRI Could Benefit Some Women

Results of a large-scale clinical trial presented presented at the 95th Scientific Assembly and Annual Meeting of the Radiological Society of North America (RSNA) provide the first strong evidence of the benefit of annual screening ultrasound for women with dense breasts who are at elevated risk for breast cancer. In addition, the study confirmed that MRI is highly sensitive in depicting early breast cancer.

"We found that annual screening with ultrasound in addition to mammography significantly improves the detection of early breast cancer," said lead researcher Wendie A. Berg, M.D., Ph.D., breast imaging specialist at American Radiology Services, Johns Hopkins — Green Spring Station in Lutherville, Md., "and that significantly more early breast cancer can be found when MRI is performed, even after combined screening with both ultrasound and mammography. However, both ultrasound and MRI increase the risk of false-positive findings."

Women who are at high risk for breast cancer need to begin screening at a younger age, because they often develop cancer earlier than women at average risk. However, women below age 50 are more likely to have dense breast tissue, which can limit the effectiveness of mammography as a screening tool.

Multicenter trials have shown that MRI enables radiologists to accurately identify tumors missed by mammography and ultrasound. The American Cancer Society recommends that some groups of women with a high risk of developing breast cancer should be screened with MRI in addition to their yearly mammogram beginning at age 30. However, MRI is not for everyone.

"Because MRI is a very expensive test and requires intravenous contrast, it is something we only recommend for screening the approximately 2% of women who are known or likely carriers of BRCA1 or BRCA2 gene mutations or have other unusual circumstances that put them at very high risk for breast cancer," Dr. Berg said.

"There are another 10 to 15% of women who are at some increased risk because of personal history of breast cancer, family history of breast cancer and/or dense breast tissue," she added. "For many of these women, MRI is not currently justified, but annual ultrasound would be appropriate in addition to mammography."

Fig 1. This breast MRI showing focus of enhancement in left breast, negative on mammography and screening ultrasound. Pathology proven infiltrating ductal carcinoma

The researchers studied 612 women, mean age 55 years, at elevated risk of breast cancer enrolled at 14 sites in the American College of Radiology Imaging Network (ACRIN) 6666 trial funded by the Avon Foundation and the National Cancer Institute. Women underwent baseline screening mammography and ultrasound with follow-up exams at 12 and 24 months and then a single, contrast-enhanced MRI at 24 months.

Sixteen women were diagnosed with breast cancer. Twelve of the cancers were invasive, and four were ductal carcinoma in situ (DCIS). Over the course of the study, 50 to 56 percent of cancers were shown on mammography. Adding ultrasound allowed detection of 70 to 94% of cancers. Adding MRI allowed for detection of additional cancers at their earliest stage.

Fig 2. Ultrasound showing 9-mm benign mass (arrows) in upper inner quadrant

The study also found that supplemental screening with ultrasound or MRI significantly increased the risk of false-positive findings, leading to unnecessary biopsies in some women.

"It is important that women are advised of the increased potential of undergoing an unnecessary biopsy as a result of screening with ultrasound or MRI," Dr. Berg said, "but we hope this study motivates women and their doctors to learn more about their risk factors and to consider supplemental screening in addition to mammography where indicated."

Also see Abstracts:
Supplemental Yield and Performance Characteristics of Screening MRI after Combined Ultrasound and Mammography: ACRIN* 6666 *American College of Radiology Imaging Network.

Ultrasound can Predict Tumor Burden and Survival in Melanoma Patients, Sparing Unnecessary Surgery

Ultrasound can predict tumor burden and survival in melanoma patients. Researchers have shown for the first time that patterns of ultrasound signals can be used to identify whether or not cancer has started to spread in melanoma patients, and to what extent. The discovery enables doctors to decide on how much surgery, if any, is required and to predict the patient’s probable survival.

Dr Christiane Voit told Europe’s largest cancer congress, the joint 15th European CanCer Organisation (ECCO) and 34th European Society for Medical Oncology (ESMO) Multidisciplinary Congress, September 20 – 24 in Berlin, Germany: “We have identified two ultrasound patterns of lymph node metastasis in melanoma patients which can identify correctly any amount of tumor cells in the sentinel lymph nodes in 75-90% of cases before proceeding to surgery on the sentinel lymph nodes.”

Voit, who is a dermatologist and head of the diagnostic unit at the Skin Cancer Centre at Charité – Universitätsmedizin Berlin, the Medical University of Berlin, said that although her research needs to be confirmed in multi-centre, randomized clinical trials, it had the potential to spare patients unnecessary surgery, especially if it was combined with ultrasound-guided fine needle biopsy of lymph nodes rather than conventional surgery.

Since 2001 Dr Voit and her colleagues in Germany and The Netherlands have included 850 melanoma patients in a prospective study to investigate the use of ultrasound in diagnosis and treatment planning. They have already demonstrated that ultrasound-guided fine needle biopsy of sentinel nodes before conventional sentinel node surgery can identify up to 65% of patients in whom the cancer has started to spread. The study presented today shows how far ultrasound patterns correlate with disease progression, tumor burden, survival and prognosis in the first 400 of these patients with stage I/II melanoma and with the longest follow-up.

Before having sentinel node surgery the patients were investigated using ultrasound, and these results were checked against the results of the subsequent surgery. The researchers found that two ultrasound patterns together could correctly identify the amount of cancer cells in the lymph nodes in 80% of cases.

A balloon shape ultrasound pattern with or without loss of central echoes (where the lymph node has lost central echoes or still has some residual central echoes, but these are wandering toward the rim, giving an asymmetrical shape to the centre) was an indicator in up to 83% of cases of a large amount of cancer cells in the sentinel node. “This ultrasound pattern was a late sign, only occurring in cases of advanced metastasis,” said Voit.

A pattern of peripheral perfusion (where small blood vessels start to surround the lymph node) was an early sign of a small number of cancer cells present. “The early signs are signs of first disruption of the normal lymph node architecture by an early stage metastasis. The most important one is peripheral perfusion, which shows angiogenesis (the formation of new blood vessels) is occurring,” she explained.

The researchers found that these two ultrasound patterns could predict overall survival. Estimates for overall survival after five years for patients with stage I/II is between 50-90% depending on the state of the tumour. Dr Voit found that 93% of patients with neither of these ultrasound patterns, 87% of patients with peripheral perfusion, and 56% of patients with balloon shapes with or without loss of central echoes, survived for at least five years; survival without cancer spreading to other parts of the body was 74%, 60% and 26% respectively.

Dr Voit said: “For the first time we have established that ultrasound patterns can be used as criteria for diagnosing disease progression and tumor burden. Balloon shaped lymph nodes with or without loss of central echoes and peripheral perfusion are independent prognostic factors for survival.”

Discovering if cancer has spread to the lymph nodes is the most important factor influencing the prognosis and treatment of melanoma patients. Doctors usually cut out one or two key lymph nodes, called sentinel nodes, and use these as an indicator of whether or not the cancer has spread to the other lymph nodes. If the sentinel node is free of cancer, patients don’t need to have more extensive lymph node removal.

However, only 20% of patients who have a sentinel node biopsy have cancer that has spread there, and so the operation, which can be accompanied by side effects such as chronic swelling and seroma, is unnecessary for 80% of patients. Using ultrasound first to detect the presence or not of sentinel node metastases could be a non-invasive way of limiting the numbers of patients who require subsequent surgery or simply watchful follow-up care.

For more information:

• Abstract no: 9303. Melanoma session, Wednesday 14.45-17.00 hrs CEST (Hall 7)

Also read these PubMed abstracts:

• Voit C, Kron M, Schäfer G, Schoengen A, Audring H, Lukowsky A, Schwürzer-Voit M, Sterry W, Winter H, Rademaker J. Ultrasound-guided fine needle aspiration cytology prior to sentinel lymph node biopsy in melanoma patients. Ann Surg Oncol. 2006 Dec;13(12):1682-9.
• Voit CA, Schäfer-Hesterberg G, Kron M, van Akkooi AC, Rademaker J, Lukowsky A, Schoengen A, Schwürzer-Voit M, Sterry W, Krause M, Röwert-Huber J, Eggermont AM.
  Impact of molecular staging methods in primary melanoma: reverse-transcriptase polymerase chain reaction (RT-PCR) of ultrasound-guided aspirate of the sentinel node does not improve diagnostic accuracy, but RT-PCR of peripheral blood does predict survival. J Clin Oncol. 2008 Dec 10;26(35):5742-7. Epub 2008 Nov 3.

Images courtesy American Society of Clinical oncology (ASCO).