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ASCO publishes new guidelines for use of tumor marker tests to diagnose, manage breast cancer

Monday, November 12 2007 | Comments

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What's This? The American Society of Clinical Oncology published updated guidelines for using tumor marker tests in the prevention, screening, treatment, and surveillance of breast cancer.

ASCO recommended that estrogen receptor and progesterone receptor should be measured on every primary invasive breast cancer and may be measured on metastatic lesions if the results would influence treatment planning. Steroid hormone receptor status should be used to identify patients who are likely to benefit from endocrine therapy in early breast cancer and metastatic disease, regardless of menopausal status. However, there is not enough data to support routine measurement of these receptors in patients with ductal carcinoma in situ who are candidates for hormonal therapy.

Similarly, human epidermal growth factor receptor 2 (HER2) status should be evaluated in every primary invasive breast cancer, either at the time of diagnosis or at the time of recurrence. This information is primarily used to identify patients who are suitable for trastuzumab (Herceptin, Genentech Inc.) therapy in the adjuvant or metastatic settings. Additionally, data from prospective therapeutic trials with marker utility as a secondary objective have suggested that HER2 overexpression (3+ by protein or >2.0 fluorescence in situ hybridization [FISH] ratio by gene amplification) may identify patients who are likely to derive greater benefit from anthracycline-based adjuvant therapy.

ASCO recommended that uPA and PAI-1, as measured by enzyme-linked immunosorbant assay (ELISA) on >=300 mg of fresh or frozen breast cancer tissue, may be used to determine prognosis in patients with newly diagnosed, node-negative breast cancer. Low levels of both markers are associated with a low enough risk of recurrence that chemotherapy will add minimal additional benefit, whereas high levels identify patients who are likely to derive substantial benefit from adjuvant chemotherapy.

The organization suggested that current data are insufficient to recommend measurement of immunohistochemically based markers, including proliferation marker Ki67, cyclins D and E, p27, p21, thymidine kinase, topoisomerase II, and other markers of proliferation, to assign patients to prognostic groups. Likewise, present data are insufficient to recommend the use of whole-length or fragment measurements of cyclin E, bone marrow micrometastases, or proteomic patterns to manage patients.

Although the Food and Drug Administration recently cleared a test to measure circulating tumor cells (CTCs), ASCO recommended against using this or similar CTC-based tests to make diagnoses or treatment decisions in patients with breast cancer until further validation confirms the clinical value of the tests.

In a topic new to the guidelines, ASCO recommended using the Oncotype DX multiparameter gene expression analysis assay (Genomic Health Inc.) to predict the risk of recurrence among patients with node-negative, ER+ breast cancer who are being treated with tamoxifen. The test can be used to identify patients who are most likely to benefit from adjuvant tamoxifen and may not require adjuvant chemotherapy or, conversely, those who will benefit more from adjuvant chemotherapy. Other multiparameter assays are being investigated.

All other recommendations were unchanged from the guidelines published in 2000.

These guidelines were published online by Harris L, et al. on Oct. 22 ahead of print in the Journal of Clinical Oncology.

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