Either microsatellite instability testing or immunohistochemical staining for the 4 mismatch repair proteins (MLH1, MSH2, MSH6, and PMS2) should be performed on all newly diagnosed colorectal cancers. This testing will identify tumors that are microsatellite unstable, which has implications for patient prognosis and possibly treatment. In addition, it will identify patients who are more likely to have Lynch syndrome. Of every 35 colorectal cancer patients, 1 has Lynch syndrome, the most common hereditary cause of colorectal and endometrial cancers. Diagnosis of Lynch syndrome affects the medical management of the patient and their relatives, with potentially life-saving ramifications. Although screening only a subset of patients with colorectal cancer based on age at diagnosis, family history, or histologic criteria will reduce the number of screening tests necessary, it will miss a significant proportion of patients with microsatellite unstable colorectal cancer and many patients with Lynch syndrome. Given that universal screening of all patients with newly diagnosed colorectal cancer using immunohistochemistry as the initial test was recently shown to be cost-effective and comparable with other widely accepted preventive services, it is not necessary to try to reduce costs by restricting screening to a subset of patients, which leads to a reduction in the efficacy of the screening program.
Sofia D. Merajver and Kara Milliron
Breast cancer, a complex and heterogeneous disease, is the most common malignancy diagnosed in women in the United States, with over 180,000 new cases and approximately 44,000 deaths per year. Breast cancer risk is influenced by a large number of factors, including age, family history, reproductive and hormonal history, proliferative breast conditions, physical activity, diet, and environmental exposures. These factors all interact in a complex manner to contribute to the risk of developing breast cancer. Because the interactions between risk factors are poorly understood at the molecular level, it is difficult to accurately evaluate the breast cancer risk of a given person presenting with an individual constellation of factors. To better define the population at increased risk that may warrant specific intervention, several models exist to estimate a woman's risk for developing breast cancer and for harboring a germline mutation in a cancer susceptibility gene. This article summarizes these models and gives brief guidelines about which model may be preferable given a specific family history.
Christina Rybak and Michael J. Hall
Colorectal cancer (CRC) risk assessment involves the evaluation of an individual's personal and family history for characteristics of an inherited susceptibility to develop CRC. Lynch syndrome (LS), or hereditary nonpolyposis colorectal cancer, is the most common cause of hereditary CRC, underlying 2% to 3% of patients with newly diagnosed (incident) CRC. Risk assessment for LS is complex, and the interpretation of the many available tests can be challenging even for the genetics specialist. A move toward universal (reflex) LS screening for mismatch repair in all patients with incident CRC supports the importance of improving the awareness and understanding of LS testing, teaching rational testing approaches, and honing interpretive skills among cancer care providers. This article reviews important clinical features of LS genetic evaluation using 3 pedigree-based case examples from the Fox Chase Cancer Center Gastrointestinal Risk Assessment Clinic.
Mary E. Freivogel and Stephanie A. Cohen
Rishi Jain, Michelle J. Savage, Andrea D. Forman, Reetu Mukherji and Michael J. Hall
Through tumor genomic profiling (TGP), existing and novel treatments can be selected to better target the specific dysregulated molecular pathways that drive growth and spread of a patient's tumor. Although the primary purpose of TGP is to detect targetable somatic mutations for treatment, TGP may also uncover germline mutations with important implications for patients and family members. Oncology care providers should be aware of the hereditary cancer risks associated with genes commonly tested by TGP. Further, patients should be informed about the possible discovery of hereditary cancer risk information and the relevance of this information to their health and that of family members, and should have their preferences toward further evaluation of hereditary risk information that could be revealed by TGP documented in the medical record and followed.
Mary B. Daly, Robert Pilarski, Jennifer E. Axilbund, Saundra S. Buys, Beth Crawford, Susan Friedman, Judy E. Garber, Carolyn Horton, Virginia Kaklamani, Catherine Klein, Wendy Kohlmann, Allison Kurian, Jennifer Litton, Lisa Madlensky, P. Kelly Marcom, Sofia D. Merajver, Kenneth Offit, Tuya Pal, Boris Pasche, Gwen Reiser, Kristen Mahoney Shannon, Elizabeth Swisher, Nicoleta C. Voian, Jeffrey N. Weitzel, Alison Whelan, Georgia L. Wiesner, Mary A. Dwyer and Rashmi Kumar
During the past few years, several genetic aberrations that may contribute to increased risks for development of breast and/or ovarian cancers have been identified. The NCCN Guidelines for Genetic/Familial High-Risk Assessment: Breast and Ovarian focus specifically on the assessment of genetic mutations in BRCA1/BRCA2, TP53, and PTEN, and recommend approaches to genetic testing/counseling and management strategies in individuals with these mutations. This portion of the NCCN Guidelines includes recommendations regarding diagnostic criteria and management of patients with Cowden Syndrome/PTEN hamartoma tumor syndrome.
Mary B. Daly, Jennifer E. Axilbund, Saundra Buys, Beth Crawford, Carolyn D. Farrell, Susan Friedman, Judy E. Garber, Salil Goorha, Stephen B. Gruber, Heather Hampel, Virginia Kaklamani, Wendy Kohlmann, Allison Kurian, Jennifer Litton, P. Kelly Marcom, Robert Nussbaum, Kenneth Offit, Tuya Pal, Boris Pasche, Robert Pilarski, Gwen Reiser, Kristen Mahoney Shannon, Jeffrey R. Smith, Elizabeth Swisher and Jeffrey N. Weitzel
Susan M. Domchek, Jill E. Stopfer and Timothy R. Rebbeck
Bilateral risk-reducing oophorectomy (BRRO) is widely used for cancer risk reduction in women with BRCA1 and BRCA2 (BRCA1/2) mutations. BRRO significantly reduces breast cancer risk by approximately 50% and ovarian cancer risk by 85% to 95%, but it may be accompanied by menopausal symptoms, impaired quality of life, and accelerated bone loss. Therefore, decisions regarding the timing of BRRO, the risks and benefits of a simultaneous hysterectomy, and the use of hormone replacement therapy (HRT) must be made in concert with the patient and individualized to their circumstances. However, recent data demonstrate that HRT after BRRO in unaffected premenopausal women does not negate the breast cancer risk reduction that BRRO provides. This article reviews the studies regarding BRRO in BRCA1/2 mutation carriers, with particular focus on the use of HRT.
Caiqian Cropper, Ashley Woodson, Banu Arun, Carlos Barcenas, Jennifer Litton, Sarah Noblin, Diane Liu, Minjeong Park and Molly Daniels
Background: Mutations in the BRCA1 and BRCA2 genes predispose individuals to a significantly elevated risk for breast and ovarian cancers. Identification of these individuals allows for proper screening, management, and testing of at-risk relatives. NCCN has established clinical criteria for recommending BRCA1/2 testing. Patients and Methods: A retrospective chart review of 1,123 patients with breast cancer was performed to evaluate the positive predictive values (PPVs) of 14 individual criteria for predicting BRCA1/2 mutations. Results: Two criteria had PPVs significantly below 10%. Only 2 of 115 patients who were recommended for testing based solely on the criterion of “diagnosed with breast cancer at ≤45 years of age” had pathogenic mutations at a PPV of 1.6% (95% CI, 0.2%–6.0%). Additionally, 0 of 37 individuals who underwent testing based on the criterion, “diagnosed with breast cancer at any age with ≥2 close blood relatives with breast cancer at any age” tested positive (95% CI, 0%–9%). Overall, meeting >1 criterion has a PPV of 12%, whereas meeting only 1 criterion has a PPV of 3.2% (95% CI, 1.6%–5.7%), significantly below 10% (P<.0001) for predicting BRCA1/2 positivity. Conclusions: Patients with breast cancer meeting >1 criterion constitute a population significantly enriched for BRCA1/2 mutations, whereas those meeting only 1 criterion test positive at a rate similar to unselected patients with breast cancer. These data will inform ongoing discussions regarding how to best implement BRCA1/2 genetic testing.
Deborah J. MacDonald, Kathleen R. Blazer and Jeffrey N. Weitzel
Rapidly evolving genetic and genomic technologies for genetic cancer risk assessment (GCRA) are revolutionizing the approach to targeted therapy and cancer screening and prevention, heralding the era of personalized medicine. Although many academic medical centers provide GCRA services, most people receive their medical care in the community setting. However, few community clinicians have the knowledge or time needed to adequately select, apply, and interpret genetic/genomic tests. This article describes alternative approaches to the delivery of GCRA services, profiling the City of Hope Cancer Screening & Prevention Program Network (CSPPN) academic and community-based health center partnership as a model for the delivery of the highest-quality evidence-based GCRA services while promoting research participation in the community setting. Growth of the CSPPN was enabled by information technology, with videoconferencing for telemedicine and Web conferencing for remote participation in interdisciplinary genetics tumor boards. Grant support facilitated the establishment of an underserved minority outreach clinic in the regional County hospital. Innovative clinician education, technology, and collaboration are powerful tools to extend GCRA expertise from a National Cancer Institute–designated Comprehensive Cancer Center, enabling diffusion of evidenced-base genetic/genomic information and best practice into the community setting.