Prof. Hyein Kim received an M.D. degree from Sungkyunkwan University and completed his Masters degree at the same university. Professor Kim started his career at Sungkyunkwan University and Samsung Changwon Hospital in 2018, and he has produced numerous publications regarding thyroid dysfunction.
questionThank you for joining us for the interview. For our readers, would you briefly introduce yourself and your key research interest? Or, you might want to introduce us to your most recent research and what it includes.
I'm a relatively young practitioner who obtained a certificate of internal medicine in 2016, and I graduated and received my master's degree from Sungkyunkwan University School of Medicine. After completing the training courses at Samsung Medical Center, I went on to work at Samsung Changwon Hospital as a specialist of Endocrinology, and I've been doing so since 2018. In particular, I have been interested in how the thyroid functions have an impact on other diseases in our bodies and how to improve the treatment of thyroid cancer.
Studying thyroid dysfunction could be a boring subject for some doctors. This is because the medicine and examinations for thyroid dysfunction are quite basic and simplified. However, studying thyroid dysfunction has led to an interesting research topic when it is associated with immunotherapy, which is currently in the spotlight as a promising therapy for metastatic cancer. It is noteworthy that thyroid dysfunction, which is one of the most common immune-related adverse events of immunotherapy, is associated with the mechanism of the antitumor effect of immunotherapy, and it can easily be monitored with a thyroid function test. This led me to ask, "How about using thyroid dysfunction as an easy indicator of antitumor effect by immunotherapy?"
Actually, my cohort and I recently demonstrated that the treatment efficacy of PD-1 blockade (the most promising immunotherapy) was associated with thyroid dysfunction in a severity-dependent manner in metastatic non-small cell lung cancer patients (ONCOIMMUNOLOGY 2018, VOL. 7, NO. 1, e1375642). A total of 58 patients with stage IV NSCLC treated with PD-1 blockade were categorized into thyroid dysfunction and euthyroid groups and the overall survival (OS), progression-free survival (PFS), and durable control rate of the two groups were compared: OS and PFS were significantly longer in the thyroid dysfunction group even after adjusting for other factors. And the severity of thyroid dysfunction was associated with a durable control rate.
questionWhat initiated you to focus on this research subject? Also, can you share with us what obstacles you had to overcome while you carried on your research?
This research was facilitated not by any grand plan. Rather, it was a trial clinical experience which led me here. Several patients with PD-1 blockade treatment who were referred to the endocrinology outpatient clinic for thyroid dysfunction showed better oncologic outcomes than we expected. The prior studies that thyroid dysfunction after IL-2 treatment is associated with a good prognosis lent credence to the possibility that thyroid dysfunction after PD-1 inhibitor could be also associated with a good oncologic outcome.
Unfortunately, there were too few patients who used PD-1 inhibitor to perform a significant analysis for study as it was an early stage of immunotherapy. To overcome this obstacle, we asked for help from many other clinicians to enroll more patients for study. Therefore, in concluding this research, I owe many thanks to many colleagues in other departments and other hospitals.
questionWhat research are you planning, and do you have any significant objectives on future research?
At first, we were focusing on a follow-up study of the study mentioned before. In the previous data, there were only 7 patients that had a PD-L1 IHC measurement, which is a biomarker predicting response before treatment begins. We weren't convinced that thyroid dysfunction was a predictive factor for a good prognosis independent to a PD-L1 IHC measurement. So, we had been preparing the study from that point with a larger sample size of patients with a PD-L1 IHC measurement.
We are now focusing our efforts on finding an association of thyroid function and fatty liver. Thyroid functions are known to be related with metabolic diseases, such as diabetes, dyslipidemia, and fatty liver. Among them, fatty liver is an important and emerging metabolic disease. Interestingly, there are a few reports that levothyroxine is a possible treatment for fatty liver. With health exam data provided by Samsung Changwon Hospital, we have been preparing to set-up data for analysis which has been collected in the past 2 years.
The study of the thyroid hormone is not old-fashioned, but it is an area for study which still has much to be revealed. By not only studying thyroid disease itself - but also the association of thyroid hormones and other diseases, I would like to broaden the scope of study about the thyroid hormone.