Researchers discover promising prognostic marker for aggressive breast cancer
Andrey Nailor, M.D.·Published 24 January 2013·11 min read
Key points
A team of researchers led by Goutham Narla, MD, PhD, at Case Western Reserve University School of Medicine and University Hospitals Case Medical Center, and collaborators at the Mount Sinai School of Medicine and Erasmus Medical Center, have discovered a gene variant that drives the spread of breast cancer.
Tumor markers are proteins found in blood or urine when cancer is present.
Either test may be used as long as it is performed by an accredited laboratory.
Founded in 1843, Case Western Reserve University School of Medicine is the largest medical research institution in Ohio and is among the nation's top medical schools for research funding from the National Institutes of Health.
A team of researchers led by Goutham Narla, MD, PhD, at Case Western Reserve University School of Medicine and University Hospitals Case Medical Center, and collaborators at the Mount Sinai School of Medicine and Erasmus Medical Center, have discovered a gene variant that drives the spread of breast cancer. Published in Science Translational Medicine (embargoed Jan. 23 at 2:00 pm ET), the study lays the early foundation for predicting which breast cancer patients may develop more aggressive disease and for designing more effective treatments.
"Breast cancer is a genetically complex disease and it remains a challenge to predict disease outcomes and which patients may benefit from more aggressive treatment," says Dr. Narla, assistant professor at Case Western Reserve University School of Medicine and medical geneticist at UH Case Medical Center Seidman Cancer Center. "Our research has uncovered a promising gene marker that will not only help us better identify tumors that behave badly but provide a basis for developing and 'personalizing' therapies to better treat our patients."
The research team discovered that a mutant gene, KLF6-SV1, was linked to the recurrence and metastasis in women with breast cancer. The incorrect splicing of the KLF6 gene essentially creates a protein that causes cancer cells to spread or metastasize. The researchers examined the tumors of 671 breast cancer patients in a tumor bank at Erasmus University Medical Center (Rotterdam, The Netherlands) and found that those whose tumors expressed high levels of the gene variant were 50 percent more likely to die. Since recurrence and metastasis are the major causes of death in breast cancer, this finding will provide a new direction of research to both identify women at risk and to develop targeted drugs that block the process of metastasis.
"This study presents biological proof that this splice variant can potentially be a marker for determining which early stage breast cancer patients will have disease progression," adds Dr. Narla. "More studies need to be done, but this could provide an important prognostic marker to determine which patients need to be treated more aggressively or watched more closely."
Dr. Narla came to UH Case Medical Center and Case Western Reserve in spring, 2012, from Mt. Sinai and is the first Harrington Distinguished Scholar (Early Career Award). This inaugural award provides physician-scientists with the ability to tap into grant funding and a peer network of innovators and mentors within the infrastructure of the Harrington Discovery Institute at UH Case Medical Center. The Institute is part of the $250 million Harrington Project for Discovery & Development, which was launched in February, 2012, with a $50 million gift to UH from the Harrington family of Hudson, OH.
Dr. Narla's laboratory focuses on the identification and characterization of the genes and pathways involved in cancer metastasis. By studying the functional role of the KLF6 tumor suppressor gene, Dr. Narla and his team have identified new signaling pathways regulated by this gene family thus providing new insight into cancer diagnosis and treatment. The team's research found that KLF6 and FOXO1, both tumor suppressor genes, are turned off as cancer spreads through the body. Since first discovering the KLF6 gene 13 years ago as a medical student at Mount Sinai School of Medicine in the laboratory of Dr. Scott Friedman, Dr. Narla has been involved in the identification and characterization of the gene and its role in cancer development.
Written and revised by
Andrey Nailor, M.D.
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Breast cancer is the second most lethal cancer in women. (Lung cancer is the leading cancer killer in women.) The good news is that early detection and new treatments have improved survival rates. The 5-year survival rate for women diagnosed with cancer is 80%. About Unfortunately, women in lower social and economic groups still have significantly lower survival rates than women in higher groups.
Several factors are used to determine the risk for recurrence and the likelihood of successful treatment. They include:
Location of the tumor and how far it has spread Whether the tumor is hormone receptor-positive or -negative Tumor markers Gene expression Tumor size and shape Rate of cell division
The good news is that women are living longer with breast cancer. Due to better treatment options, breast cancer mortality rates declined by about 25% since 1990. However, survivors must live with the uncertainties of possible recurrent cancer and some risk for complications from the treatment itself.
Recurrences of cancer usually develop within 5 years of treatment. About 25% of recurrences and half of new cancers in the opposite breast occur after 5 years.
"In this new research as well as previous studies, Goutham and his team have uncovered important and previously unrecognized genetic markers in cancer," said Stanton Gerson, MD, Director of the Case Comprehensive Cancer Center and the UH Case Medical Center Seidman Cancer Center. "This work highlights how understanding the basic mechanisms regulating cancer development and progression can lead to significant advances in the treatment of cancer. We are so pleased to have a physician-scientist of his caliber at our cancer center and are excited about the impact of this important work."
Dr. Narla will work with the breast cancer team, led by Lyndsay Harris, MD, to study further KLF6-SV1's potential as a prognostic marker for patients with poor outcomes. The group also will work to develop novel therapeutics that can turn the protein off and cause the cells to become less aggressive.
Breast Cancer Markers
Tumor markers are proteins found in blood or urine when cancer is present. Although they are not used to diagnose cancer, the presence of certain markers can help predict how aggressive a patient’s cancer may be and how well the cancer may respond to certain types of drugs.
Tumor markers relevant for breast cancer prognosis include:
HER2 . The American Cancer Society recommends that all women newly diagnosed with breast cancer get a biopsy test for a growth-promoting protein called HER2/neu. HER2-positive cancer usually occurs in younger women and is more quickly-growing and aggressive than other types of breast cancer. The HER2 marker is present in about 20% of cases of invasive breast cancer. Two types of tests are used to detect HER2:
Either test may be used as long as it is performed by an accredited laboratory. Tests that are not clearly positive or negative should be repeated.
Treatment with trastuzumab (Herceptin) or lapatinib (Tykerb) may help women who test positive for HER2. In 2008, the FDA approved a new genetic test (Spot-Light) that can help determine which patients with HER2-positive breast cancer may be good candidates for trastuzumab treatment.
Other Markers . Other markers that may be evaluated include CA 15-3, CA 27.29, CEA, ER, PgR, uPA, and PAI-1.
"We look forward to continuing this work to further define the role of this gene variance and improve our understanding of the molecular basis for tumor progression and metastasis," says Dr. Harris, Director of the Breast Cancer Program at UH Case Medical Center and Professor, Medicine-Hematology/Oncology at the Case Western Reserve School of Medicine. "These findings provide us with an important new tool to be able to distinguish between indolent and lethal early stage disease. This will potentially enable us to develop more "personalized" treatments for patients and thereby reduce breast cancer mortality."
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This work was supported by the Howard Hughes Medical Institute (HHMI). Additional support for Dr. Narla's research comes from the Case Comprehensive Cancer Center, Case Western Reserve University School of Medicine, Case Western Reserve University Institute for Transformative Molecular Medicine, and the Mount Sinai School of Medicine. Dr. Narla is also supported by an early physician scientist career award from the HHMI.
About Case Western Reserve University School of Medicine
Founded in 1843, Case Western Reserve University School of Medicine is the largest medical research institution in Ohio and is among the nation's top medical schools for research funding from the National Institutes of Health. The School of Medicine is recognized throughout the international medical community for outstanding achievements in teaching. The School's innovative and pioneering Western Reserve2 curriculum interweaves four themes - research and scholarship, clinical mastery, leadership, and civic professionalism - to prepare students for the practice of evidence-based medicine in the rapidly changing health care environment of the 21st century. Nine Nobel Laureates have been affiliated with the School of Medicine.
The importance of tumor size as a prognostic variable in cases of invasive carcinoma is robust enough to survivemeasurements derived variously from clinical estimates, mammograms, and gross and histologic sections. In many analyses it is second only to axillary node status as an independent prognostic factor. Tumor size is directly related to an increasing probability of regional metastasis, an increasing average number of involved axillary lymph nodes, and an increasing probability of recurrence and death.
The favorable prognosis of nonpalpable invasive carcinomas relative to palpable ones and of screening-detectedversus nonscreening-detected cancers is easily explained by their smaller size. In one report cancers 0.1 to 5 mm and 6 to 10 mm in diameter produced axillary metastasis in only 7.7 and 12.5 percent of cases, respectively.However, the incidence of positive nodes can range up to 21 percent for both of these size groups.15 Tumors of equal size are prognostically similar whether they are palpable or not and regardless of how they are detected.
The influence of primary tumor size on prognosis can be appreciated in both node-negative and node-positive cases. This relationship probably reflects increasing vascular and lymphatic dissemination with progressive tumor growth. Of particular interest are node-negative cases, where tumor size provides a readily available means foridentifying patients at low and high risk for recurrence.
Tumors 1.0 cm or less in diameter have an especially low risk of recurrence. The five-year disease-free survival of node-negative patients with tumors 1.0 cm or less in diameter is 92 to 96 percent. A large study at Memorial Sloan-Kettering Cancer Center found a 10-year relapse-free survival of 91 percent.
These and other studies support the contention that patients with the combination of node-negative disease and a tumor diameter of 1 cm or less represent a favorable subset of patients who would not benefit significantly from systemic adjuvant therapy.88 As failure rates are high enough in any case with macrometastasis to axillary lymphnodes to justify systemic adjuvant therapy, investigations have largely focused on the ability of other biologicvariables to further define the prognosis of node-negative individuals, a group that is increasing due to more widespread use of screening mammography.
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Traditional pathologic features (i.e., nodal status, tumor size, and tumor differentiation) continue to provide guides for prognosis and are information that is routinely available. ER and PR are also important, but are more important for guiding selection of hormone treatment than for determining prognosis. Newer prognostic indicators relating to the proliferative rates of tumors are increasingly available and are potentially helpful, but for the most part their role is uncertain.
ER and PR are the prime examples of prognostic indicators capable of identifying patients likely to respond to aparticular form of therapy (i.e., hormone therapy). Poor histologic grade may indicate a higher potential for response to chemotherapy. The overexpression of c-ERBB2 may be a potential indicator of resistance to chemotherapy and hormone therapy. It is possible that reliable markers for resistance or sensitivity to specific chemotherapeutic agents will be forthcoming, information that could have a constructive influence on treatment planning.
Patients with an excellent prognosis include women with DCIS and women with negative axillary nodes whose invasive carcinomas are less than 1.0 cm in diameter or who have special histologic types of carcinoma less than 3.0 cm in diameter. On the other hand, patients with any number of metastases to regional lymph nodes and node-negative patients with tumors more than 2.0 cm in maximum diameter have recurrence rates high enough to derive a substantial benefit from systemic therapy.
Node-negative patients with tumors 1.0 to 2.0 cm in diameter have an intermediate prognosis with average five-year disease-free survivals of about 85 percent. It is in this group that measures of proliferation such as histologic or nuclear grade, SPF, and ER status may have the most value in deciding for or against systemic therapy.
Annually, the School of Medicine trains more than 800 MD and MD/PhD students and ranks in the top 25 among U.S. research-oriented medical schools as designated by U.S. News & World Report's "Guide to Graduate Education."
The School of Medicine's primary affiliate is University Hospitals Case Medical Center and is additionally affiliated with MetroHealth Medical Center, the Louis Stokes Cleveland Department of Veterans Affairs Medical Center, and the Cleveland Clinic, with which it established the Cleveland Clinic Lerner College of Medicine of Case Western Reserve University in 2002.
About Case Comprehensive Cancer Center Case Comprehensive Cancer Center is an NCI-designated Comprehensive Cancer Center located at Case Western Reserve University. The center, now in its 22nd year of funding, integrates the cancer research activities of the largest biomedical research and health care institutions in Ohio – Case Western Reserve, University Hospitals (UH) Case Medical Center and the Cleveland Clinic. NCI-designated cancer centers are characterized by scientific excellence and the capability to integrate a diversity of research approaches to focus on the problem of cancer. It is led by Stanton Gerson, MD, Asa and Patricia Shiverick- Jane Shiverick (Tripp) Professor of Hematological Oncology, director of the National Center for Regenerative Medicine, Case Western Reserve, and director of the Seidman Cancer Center at UH Case Medical Center.
About University Hospitals
University Hospitals serves the needs of patients through an integrated network of hospitals, outpatient centers and primary care physicians. At the core of our health system is University Hospitals Case Medical Center. The primary affiliate of Case Western Reserve University School of Medicine, University Hospitals Case Medical Center is home to some of the most prestigious clinical and research centers of excellence in the nation and the world, including cancer, pediatrics, women's health, orthopedics and spine, radiology and radiation oncology, neurosurgery and neuroscience, cardiology and cardiovascular surgery, organ transplantation and human genetics. Its main campus includes the internationally celebrated UH Rainbow Babies & Children's Hospital, ranked among the top children's hospitals in the nation; UH MacDonald Women's Hospital, Ohio's only hospital for women; and UH Seidman Cancer Center, part of the NCI-designated Case Comprehensive Cancer Center at Case Western Reserve University. University Hospitals Case Medical Center is the 2012 recipient of the American Hospital Association – McKesson Quest for Quality Prize for its leadership and innovation in quality improvement and safety.
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Alicia Reale
alicia.reale@uhhospitals.org University Hospitals Case Medical Center