The phosphoinositide-3-kinase (PI3-kinase)-Akt-mTOR pathway is a central signal transduction pathway that regulates many critical aspects of normal and cancer physiology, including cell proliferation, apoptosis, cell morphology and migration, protein synthesis, and integration of metabolism. In breast cancer, somatic mutations that activate the pathway occur in more than 50% of tumors, underscoring the potentially broad impact of targeting the pathway for therapy. A vast body of preclinical data demonstrates the efficacy of pathway inhibition on tumor growth, and evidence also shows that activation of the pathway occurs in models of acquired resistance to hormonal therapy. This preclinical work led to the investigation of allosteric mTOR inhibitors, everolimus and temsirolimus, in metastatic hormone receptor-positive breast cancer. The recent BOLERO-2 trial comparing everolimus plus exemestane versus placebo plus exemestane in women with resistance to nonsteroidal aromatase inhibitors demonstrated a 6-month improvement in progression-free survival and led to FDA approval of everolimus for this indication in the United States. This landmark trial is the first demonstration of significant clinical benefit using drugs targeting this pathway in breast cancer. Many questions remain about the role of everolimus and other pathway-targeting drugs in clinical development in breast cancer treatment. This article reviews the role of the PI3-kinase-Akt-mTOR pathway in breast cancer biology and the clinical trial evidence available to date.
Josh Lauring, Ben Ho Park, and Antonio C. Wolff
D. Craig Allred, Robert W. Carlson, Donald A. Berry, Harold J. Burstein, Stephen B. Edge, Lori J. Goldstein, Allen Gown, M. Elizabeth Hammond, James Dirk Iglehart, Susan Moench, Lori J. Pierce, Peter Ravdin, Stuart J. Schnitt, and Antonio C. Wolff
The NCCN Task Force on Estrogen Receptor and Progesterone Receptor Testing in Breast Cancer by Immunohistochemistry was convened to critically evaluate the extent to which the presence of the estrogen receptor (ER) and progesterone receptor (PgR) biomarkers in breast cancer serve as prognostic and predictive factors in the adjuvant and metastatic settings, and the ability of immunohistochemical (IHC) detection of ER and PgR to provide an accurate assessment of the expression of these biomarkers in breast cancer tumor tissue. The task force is a multidisciplinary panel of 13 experts in breast cancer who are affiliated with NCCN member institutions and represent the disciplines of pathology, medical oncology, radiation oncology, surgical oncology, and biostatistics. The main overall conclusions of the task force are ER is a strong predictor of response to endocrine therapy; ER status of all samples of invasive breast cancer or ductal carcinoma in situ (DCIS) should be evaluated by IHC; IHC measurements of PgR, although not as important clinically as ER, can provide useful information and should also be performed on all samples of invasive breast cancer or DCIS; IHC is the main testing strategy for evaluating ER and PgR in breast cancer and priority should be given to improve the quality of IHC testing methodologies; all laboratories performing IHC assays of ER and PgR should undertake formal validation studies to show both technical and clinical validation of the assay in use; and all laboratories performing IHC assays of hormone receptors in breast cancer should follow additional quality control and assurance measures as outlined in the upcoming guidelines from the American Society of Clinical Oncology and College of American Pathologists.
Jennifer Barsky Reese, Lauren A. Zimmaro, Sharon L. Bober, Kristen Sorice, Elizabeth Handorf, Elaine Wittenberg, Areej El-Jawahri, Mary Catherine Beach, Antonio C. Wolff, Mary B. Daly, Brynna Izquierdo, and Stephen J. Lepore
Background: Most breast cancer clinicians lack training to counsel patients about sexual concerns. The purpose of this study was to assess the feasibility, acceptability, and preliminary effects of a mobile learning (mLearning) intervention (improving Sexual Health and Augmenting Relationships through Education [iSHARE]) aimed at enhancing breast cancer clinicians’ knowledge of, beliefs about, and comfort with discussing patients’ sexual health concerns. Methods: Clinicians listened to a 2-part educational podcast series offering information on breast cancer–related sexual health concerns and effective communication on the topic, which consisted of interviews with expert guests. Intervention feasibility was assessed through rates of enrollment, retention, and intervention completion, with benchmarks of 40%, 70%, and 60%, respectively. Acceptability was assessed through program evaluations, with 75% of clinicians rating the intervention favorably (eg, relevance, satisfaction) signifying acceptability. Clinicians self-reported their knowledge about breast cancer–related sexual health concerns, beliefs (ie, self-efficacy for discussing sexual health concerns), and comfort with discussing sexual concerns measured at preintervention and postintervention. Qualitative analysis examined clinicians’ perceptions of lessons learned from the intervention. Results: A total of 32 breast cancer clinicians enrolled (46% of those invited; 97% of those who responded and screened eligible), 30 (94%) completed both the intervention and study surveys, and 80% rated the intervention favorably, demonstrating feasibility and acceptability. Results showed positive trends for improvement in clinician knowledge, beliefs, and comfort with discussing sexual health concerns. Clinicians reported key lessons learned, including taking a proactive approach to discussing sexual health concerns, normalizing the topic, addressing vaginal health, sending the message that help is available, and assessing sexual health concerns with patients from different backgrounds. Conclusions: Breast cancer clinicians were amenable to participating in the iSHARE intervention and found it useful. iSHARE showed promise for improving clinician’s knowledge and comfort discussing patients’ sexual health concerns. A larger trial is required to demonstrate efficacy. Future studies should also examine whether iSHARE can improve patient–clinician communication and address patients’ sexual concerns.
Sarah Asad, Carlos H. Barcenas, Richard J. Bleicher, Adam L. Cohen, Sara H. Javid, Ellis G. Levine, Nancy U. Lin, Beverly Moy, Joyce Niland, Antonio C. Wolff, Michael J. Hassett, and Daniel G. Stover
Background: Triple-negative breast cancer (TNBC) accounts for disproportionately poor outcomes in breast cancer, driven by a subset of rapid-relapse TNBC (rrTNBC) with marked chemoresistance, rapid metastatic spread, and poor survival. Our objective was to evaluate clinicopathologic and sociodemographic features associated with rrTNBC. Methods: We included patients diagnosed with stage I–III TNBC in 1996 through 2012 who received chemotherapy at 1 of 10 academic cancer centers. rrTNBC was defined as a distant metastatic recurrence event or death ≤24 months after diagnosis. Features associated with rrTNBC were included in a multivariable logistic model upon which backward elimination was performed with a P<.10 criterion, with a final multivariable model applied to training (70%) and independent validation (30%) cohorts. Results: Among all patients with breast cancer treated at these centers, 3,016 fit the inclusion criteria. Training cohort (n=2,112) bivariable analyses identified disease stage, insurance type, age, body mass index, race, and income as being associated with rrTNBC (P<.10). In the final multivariable model, rrTNBC was significantly associated with higher disease stage (adjusted odds ratio for stage III vs I, 16.0; 95% CI, 9.8–26.2; P<.0001), Medicaid/indigent insurance, lower income (by 2000 US Census tract), and younger age at diagnosis. Model performance was consistent between the training and validation cohorts. In sensitivity analyses, insurance type, low income, and young age were associated with rrTNBC among patients with stage I/II but not stage III disease. When comparing rrTNBC versus late relapse (>24 months), we found that insurance type and young age remained significant. Conclusions: Timing of relapse in TNBC is associated with stage of disease and distinct sociodemographic features, including insurance type, income, and age at diagnosis.
Robert W. Carlson, Elizabeth Brown, Harold J. Burstein, William J. Gradishar, Clifford A. Hudis, Charles Loprinzi, Eleftherios Paul Mamounas, Edith A. Perez, Kathleen Pritchard, Peter Ravdin, Abram Recht, George Somlo, Richard L. Theriault, Eric P. Winer, Antonio C. Wolff, and for the NCCN Adjuvant Therapy for Breast Cancer Task Force
The National Comprehensive Cancer Network (NCCN) first published the NCCN Breast Cancer Treatment Guidelines in 1996. The Guidelines address the treatment of all stages of breast cancer across the spectrum of patient care and have been updated yearly. Adjuvant therapy for breast cancer has undergone an especially rapid evolution over the past few years. Therefore, the NCCN Breast Cancer Guidelines Panel was supplemented by additional experts to form the Adjuvant Therapy Task Force to provide a forum for an extended discussion and expanded input to the adjuvant therapy recommendations for the Breast Cancer Treatment Guidelines. Issues discussed included methods of risk-stratification for recurrence; how biologic markers such as HER2 status, quantitative estrogen receptor, or genetic markers can be incorporated as prognostic or predictive factors; and how age, menopausal status, and estrogen receptor levels impact benefits from chemotherapy and endocrine therapy. Additionally, the task force discussed the strategies for use of aromatase inhibitors in postmenopausal women and the potential incorporation of trastuzumab into adjuvant therapy of women with HER2/neu positive breast cancer. This supplement summarizes the background data and ensuing discussion from the Adjvuant Task Force meeting. (JNCCN 2006;4[suppl 1]:S-1–S-26)
Robert W. Carlson, Susan J. Moench, M. Elizabeth H. Hammond, Edith A. Perez, Harold J. Burstein, D. Craig Allred, Charles L. Vogel, Lori J. Goldstein, George Somlo, William J. Gradishar, Clifford A. Hudis, Mohammad Jahanzeb, Azadeh Stark, Antonio C. Wolff, Michael F. Press, Eric P. Winer, Soonmyung Paik, Britt-Marie Ljung, and for the NCCN HER2 Testing in Breast Cancer Task Force
The NCCN HER2 Testing in Breast Cancer Task Force was convened to critically evaluate the ability of the level of HER2 expression or gene amplification in breast cancer tumors to serve as a prognostic and a predictive factor in the metastatic and adjuvant settings, to assess the reliability of the methods of measuring HER2 expression or gene amplification in the laboratory, and to make recommendations regarding the interpretation of test results. The Task Force is a multidisciplinary panel of 24 experts in breast cancer representing the disciplines of medical oncology, pathology, radiation oncology, surgical oncology, epidemiology, and patient advocacy. Invited members included members of the NCCN Breast Cancer Panel and other needed experts selected solely by the NCCN. During a 2-day meeting, individual task force members provided didactic presentations critically evaluating important aspects of HER2 biology and epidemiology: HER2 as a prognostic and predictive factor; results from clinical trials in which trastuzumab was used as a targeted therapy against HER2 in the adjuvant and metastatic settings; the available testing methodologies for HER2, including sensitivity, specificity, and ability to provide prognostic and predictive information; and the principles on which HER2 testing should be based. Each task force member was charged with identifying evidence relevant to their specific expertise and presentation. Following the presentations, an evidence-based consensus approach was used to formulate recommendations relating to the pathologic and clinical application of the evidence to breast cancer patient evaluation and care. In areas of controversy, this process extended beyond the meeting to achieve consensus. The Task Force concluded that accurate assignment of the HER2 status of invasive breast cancer is essential to clinical decision making in the treatment of breast cancer in both adjuvant and metastatic settings. Formal validation and concordance testing should be performed and reported by laboratories performing HER2 testing for clinical purposes. If appropriate quality control/ assurance procedures are in place, either immunohistochemistry (IHC) or fluorescence in situ hybridization (FISH) methods may be used. A tumor with an IHC score of 0 or1+, an average HER2 gene/chromosome 17 ratio of less than 1.8, or an average number of HER2 gene copies/cell of 4 or less as determined by FISH is considered to be HER2 negative. A tumor with an IHC score of 3+, an average HER2 gene/chromosome 17 ratio of greater than 2.2 by FISH, or an average number of HER2 gene copies/cell of 6 or greater is considered HER2 positive. A tumor with an IHC score of 2+ should be further tested using FISH, with HER2 status determined by the FISH result. Tumor samples with an average HER2 gene/chromosome ratio of 1.8 to 2.2 or average number of HER2 gene copies/cell in the range of greater than 4 to less than 6 are considered to be borderline, and strategies to assign the HER2 status of such samples are proposed. (JNCCN 2006;4(Suppl 3):S1–S22)