Advances in molecular testing have enabled families of those with thyroid cancers to determine whether or not they may be at increased risk for developing thyroid cancer.
Nicoleta C. Voian, MD, MPH
Advances in molecular testing have enabled families of those with thyroid cancers to determine whether or not they may be at increased risk for developing thyroid cancer and, if appropriate, to take preventive measures that can minimize that risk.
The Roswell Park Cancer Institute in Buffalo, New York, has developed programs specifically geared toward addressing issues related to genetic testing in cancer.1
Targeted Oncologyasked Nicoleta C. Voian, MD, MPH, assistant professor of oncology and director, clinical genetics service, department of medicine at Roswell Park, about genetic testing for thyroid cancer.
Voian’s clinical interests include hereditary cancer syndromes, providers’ awareness, patients’ accessibility, health insurance coverage, ethics in genetics, and preventative medicine.Voian:It’s very important to know your personal medical and family history and establish your risk profile, because there are interventions we can take to reduce your cancer risk or detect cancer at an early stage.
There are important differentiations between the medullary and nonmedullary types of thyroid carcinoma. Nonmedullary thyroid cancer includes the papillary, follicular, and anaplastic types. The vast majority of thyroid cancers, about 70% to 80% of them, are papillary thyroid cancer, usually a nonaggressive and highly treatable form of the disease. Because most of these cases are sporadic, or not connected to any apparent genetic pattern, we would not recommend genetic counseling or testing for someone with a personal or family history of a singular case of papillary thyroid cancer. There is an exception with the cribriform-morular variant of papillary thyroid carcinoma; every individual with this type of cancer should have genetic evaluation, [because] this form of cancer is usually associated with familial adenomatous polyposis.
There are hereditary cancer syndromes associated with increased risk for nonmedullary thyroid cancer, including, but not limited to, Cowden syndrome, familial adenomatous polyposis, and the Carney complex. To detect thyroid cancer early, individuals with these conditions are offered periodic screening with thyroid ultrasound. Individuals who have a family with multiple close relatives with a history of papillary thyroid cancer may also benefit from thyroid cancer screening with ultrasound.
One hereditary condition is multiple endocrine neoplasia type 2 (MEN2), which is associated with medullary thyroid cancer. All individuals with this type of thyroid cancer should be referred for genetic counseling and offered genetic testing. If a mutation in theRETgene is identified in a family, it will be important to diagnose other relatives with this condition so they can benefit from preventive surgery (thyroidectomy). The good news is that people can live long, happy, active, and fulfilling lives after their thyroid is removed, with proper medication and follow-up.
Charis Eng, MD, PhD, is founding chairwoman of the Genomic Medicine Institute at the Cleveland Clinic and founding director of its Center for Personalized Genetic Healthcare. Eng is a global leader in cancer genetics and cancer genomic medicine.
According to Eng, there is a growing list of genes that may play an important role in thyroid cancer, and that certain ‘red flags’ may point to an increased risk for the disease, such as family history of thyroid cancer, developing thyroid cancer at an early age, or diagnosis of the patient with specific forms of thyroid cancer, such as medullary thyroid cancer, which is an aggressive form of thyroid cancer.
Eng emphasized the high survival rate, 100%, if thyroid cancer is diagnosed early. She has developed several online resources listed below, which are easy to understand, and written for a broad readership, that families of patients with thyroid cancer can use in deciding if genetic testing is right for them; these resources may also be useful in addressing patient fears or anxieties regarding genetic testing.
When we’re interviewing someone to determine whether or not they’re a good candidate for genetic counseling and perhaps genetic testing, we try to establish the specific type of thyroid cancer that occurred in their personal or family history. We look for patterns of cancer occurrence to tell us whether or not someone falls within a higher risk profile based on their personal and family histories of cancer. If their family history includes multiple individuals with the same or related cancers (on the same side of the family); if they or a close relative have been diagnosed with a certain type of cancer; or if they themselves have been diagnosed with 2 or more separate, primary cancers, then that person would qualify for genetic counseling, with or without testing. If genetic testing is appropriate, it would typically be covered by health insurance.Voian:You can ask your primary care physician or oncologist for a referral, or use online resources to identify genetic counselors in your area. The National Society of Genetic Counselors has a great search tool on its web site, www.NSGC.org. And many comprehensive cancer centers offer public information and prescreening to help people determine whether they’re a good candidate for genetic counseling, with or without genetic testing. At Roswell Park Cancer Institute, people can complete an intake questionnaire over the phone by calling 1-877-ASK-RPCI (1-877-275-7724).
The first consultation will typically take 1 to 2 hours, and will primarily be focused on building a detailed personal and family medical history. If genetic testing is appropriate based on your risk factors, pretest counseling is offered to explain the test, the benefits and limitations, and the impact on personal and family medical management.
A blood sample will be collected and sent to a specialized laboratory. The second visit is a follow-up appointment where we will discuss and interpret the results.Voian:If there is concern about a possible increased risk for thyroid cancer based on personal or family history, talk to your medical providers to discuss your options or contact specialized cancer centers or genetic counseling services. Genetic counseling and genetic testing are essential for cancer risk assessment and should be offered by providers with expertise and experience in genetics. Screening with thyroid ultrasound or prophylactic surgery are recommended on a case-by-case basis for individuals deemed to have an increased risk.