15th International Thyroid Congress, 85th Annual Meeting of the American Thyroid Association:
Thyroid Cancer Previvors Face Unique Concerns and Ethical Issues
Presented at the meeting by Peter Angelos, MD, PhD
Cancer previvors face a unique set of emotional, medical, and privacy concerns as well as many of the same fears as cancer survivors, even though they have not had cancer, explained Peter Angelos, MD, PhD, at the 15th International Thyroid Congress and 85th Annual Meeting of the American Thyroid Association (ITC/ATA).
The term previvor was developed to describe women with the BRCA1 mutation who have a genetic predisposition for breast cancer, and is relevant to patients at risk for thyroid cancer, particularly with respect to medullary thyroid cancer, said Dr. Angelos, who is Professor and Chief of Endocrine Surgery at the University of Chicago.
Patients with hereditary medullary thyroid cancer—multiple endocrine neoplasia (MEN) 2a, MEN 2b, and familial medullary thyroid cancer—have a germline mutation in the RET proto-oncogene that leads to thyroid cancer in nearly 100% of patients unless the thyroid is removed.
“Hereditary medullary thyroid cancer is in some ways the poster child for the promise of genetics; early diagnosis and treatment absolutely prevents the development of this disease,” Dr. Angelos said. “In that sense, it is much more predictive than the BRCA1 mutation in most patient populations,” Dr. Angelos continued.
Barriers to the Elimination of Hereditary Medullary Thyroid Cancer
Barriers to elimination of hereditary medullary thyroid cancer include a lack of knowledge of the importance of genetic testing and a lack of access to genetic testing or genetic counselors across the globe, Dr. Angelos said.
In addition, a positive genetic test may make it difficult to obtain health insurance in the future. “Based on that worry about future insurability, people take the don’t ask don’t tell approach: I won’t get genetic testing because then no one will know if I have the genetic mutation, and it won’t affect my ability to get health insurance,” Dr. Angelos said.
“In resource-poor countries, it is really hard to emphasize surgery to prevent a disease when there are so many other diseases already present; thus, to some extent, this discussion has to be framed in the context of the health system that one is practicing in,” Dr. Angelos noted.
Dr. Angelos noted that the following questions remain unanswered on this topic and warrant further investigation:
- Are there socioeconomic and social implications for thyroid cancer previvors?
- Does prophylactic thyroidectomy improve the quality of life for previvors?
- How does quality of life of thyroid cancer previvors compare to that of thyroid cancer survivors?
- Should clinicians treat thyroid cancer previvors as a group that is distinct from thyroid cancer survivors?
- Are the stresses on parents to choose to make their children cancer previvors significantly different from the stresses on parents of thyroid cancer survivors?
- Is it better to become a thyroid cancer previvor as a young adult or adolescent, as opposed to as a young child?
- Is it better for parents to make the decision to undergo prophylactic surgery for their children, or for children to be involved in that decision-making themselves?
“It is not surprising that given the little we know about thyroid cancer survivors’ quality of life, we will have difficulty understanding the quality of life of thyroid cancer previvors,” Dr. Angelos said. Initial data from the North American Thyroid Cancer Survivorship Study suggests that the quality of life “is not as good as many of us had thought,” Dr. Angelos noted.1 “Again, I would suggest that we may have our own assumptions of what a patient’s quality of life would be following prophylactic total thyroidectomy; however, until we actually gather that data, we really don’t know,” he said.
He added that there are more degrees of variability in decision-making when a patient doesn’t have cancer, but rather has a predisposition for cancer.
“All surgery on previvors is, by definition, prophylactic surgery. The question then is: are there differences in operating on a patient with thyroid cancer compared to a patient who has a risk of thyroid cancer?,” Dr. Angelos asked. While there is little data on this topic, Dr. Angelos suggested that informed consent differs when performing prophylactic surgery versus cancer surgery.
“No one ever wants complication, but it is easier to accept it if the complication occurs in the course of cancer surgery, as opposed to occurring during prophylactic surgery,” Dr. Angelos said. “Complications in prophylactic surgery raise concerns about whether the risks of cancer justify the complication,” Dr. Angelos said.
“In the context of prophylactic surgery, I think it may be particularly valuable to think about not just informed consent, but also shared decision-making, and the idea that really patients (or parents often) need to actively engage in this decision-making,” Dr. Angelos said. “It is valuable to discuss with the parents whether, if there is a complication, is prophylactic surgery still going to be considered the right thing to do? The concept of shared decision-making may be even more important in prophylactic surgery than in cancer surgery,” Dr. Angelos said.
“Genetic testing for thyroid cancer will increase the numbers of thyroid cancer previvors in the years to come,” Dr. Angelos concluded. “There are many unanswered questions that remain regarding the long-term outcomes of thyroid cancer previvors. It remains to be seen if the identification of this group—thyroid cancer previvors—will be a valuable label in the years to come,” Dr. Angelos added.