Breast cancer is the second leading cause of cancer-related death for women in the United States. Every year approximately 180,000 new cases of breast cancer occur, and it is estimated that 12% of women in the U.S. will at some point be diagnosed with the disease [1]. Early detection and treatment improve prognosis and survival rate [2-5], motivating the implementation of screening tests and improved methods of staging therapy.
If screening (usually by x-ray mammography) detects a possible tumor, further diagnosis is often obtained by biopsy. Biopsy can determine whether the structure is cancerous, and if so, can also determine the type of cancer and thereby aid in treatment selection. However, biopsy is time consuming for the physician, often uncomfortable for the patient, and can increase the patient's radiation exposure. Of the some 700,000 biopsies performed every year, only 25% find cancer, leading many breast cancer experts to conclude that better diagnostic imaging techniques are needed.
If biopsy confirms a malignant tumor, it is desirable to know before
treatment begins whether the cancer has spread to the axillary nodes, as this
affects the surgery, treatment selection, and prognosis. Biopsy tissue
characterization and axillary lymph node status are the most important
prognostic factors [6, 7], and 60-90% of those patients without nodal
involvement have no further breast cancers detected in their lifetimes [8].
Surgical dissection of the axillary nodes is of major importance in therapeutic
staging (particularly for patients with favorable primary biopsy findings) but
is a procedure of contemporary controversy [9]. Those patients whose primary
biopsy examination yields favorable signs of no nodal involvement are expected
to be nevertheless at 10% risk for that involvement [10, 11]. Presently, there
is no established noninvasive test for axillary node status.
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[3] J.L. Kelsey and M.D. Gammon, "The epidemiology of breast cancer," Cancer, vol. 41, pp. 146-165, 1985.
[4] M.Moskowitz and P.S. Gartside, "Evidence of breast cancer mortality reduction: aggressive screening in women under age 30," Am J Roentgenology, vol. 138, pp. 911-916, 1982.
[5] J.D.F. Habbema, G.V.v. Oortmarssen, D.J.v. Putten, et al., "Age-specific reduction in breast cancer mortality by screen: an anlysis of the results of Health Insurance Plan of greater New York study," J Nat Cancer Inst, vol. 77, pp.317-320, 1986.
[6] B. Fisher, M. Bauer, L. Wickerham, et al., "Relation of number of positivie axillary nodes to the prognosis of patients with primary breast cancer," Cancer, vol. 52, pp. 1551-1557, 1983.
[7] P.J. Morris and R.A. Malt, In Oxfort textbook of surgery,, pp. 815, Oxford Medical Publications, Oxford, 1994.
[8] "Strategies for Managing the Breast Cancer Research Program," National Academy of Sciences Institute of Medicine Report to the U.S. Army Medical Research and Development Command, 1993.
[9] W.K. Ruffin, A. Stacey-Clear, J. Younger, et al., "Rationale for routine axillary dissection in carcinoma of the breast," Journal of the American College of Surgeons, vol. 180, pp. 245-251, 1995.
[10] M. Morrow, "Role of axillary dissection in breast cancer management," Annals of Surgical Oncology, vol. 3, pp. 233-234, 1996.
[11] P. Ravidin, M. DeLaurentes, T. Vondely, et al., "Prediction of axillary node status in breast cancer patients by use of prognostic indicators," J Natl Cancer Inst, vol. 86, pp. 1171-1175, 1994.