Memorial Sloan-Kettering Cancer Center researchers and colleagues have developed a prediction tool to help newly diagnosed breast cancer patients assess the likelihood that the disease has spread beyond the original tumor to a sentinel lymph node. Called nomograms, several of these statistical models have already been developed by Memorial Sloan-Kettering investigators to help predict outcomes for other cancers. They take various clinical and pathological features into account, including a patient's age, tumor size, and tumor type.
Using this newest nomogram -- which will soon be available on Memorial Sloan-Kettering's Web site -- patients enter answers to a series of questions and the software program calculates the probability that an individual's cancer has spread to a sentinel node in advance of the results obtained from a lymph node biopsy. The sentinel node, usually under the arm, is the first to which cancer is likely to spread from a primary tumor, and its status is an important prognostic factor in patients with invasive breast cancer.
To develop the tool, researchers collected data from 3,786 patients who had sentinel node biopsies performed at Memorial Sloan-Kettering between 1996 and 2002. They then analyzed the information, developed the predictive model, and validated their findings against data gathered from 1,545 patients who had eligible biopsies at Memorial Sloan-Kettering between 2002 and 2004.
According to their study, published in the August 20 issue of the Journal of Clinical Oncology, the nomogram is roughly as accurate for predicting positive sentinel nodes as mammograms are for detecting breast cancer. [PubMed Abstract]
"Everyone should still have a sentinel node biopsy," emphasized the study's lead author, Memorial Sloan-Kettering breast surgeon Kimberly J. Van Zee. "This nomogram is for informational purposes only. Newly diagnosed patients often ask, 'What are my chances of having a positive node?' We can now provide a numerical answer to that question."
The nomogram will be available at www.mskcc.org/nomograms.
