Hosu Kim

Development of thyroid dysfunction is associated with clinical response to PD-1 blockade treatment in patients with advanced non-small cell lung cancer

ABSTRACT Purpose: Drugs that blockade interaction between programmed cell-death protein 1 (PD-1) and its ligand (PD-L1) are promising. Immune-related adverse events (irAEs) might be associated with favorable clinical outcomes, and thyroid dysfunction is one of the most common irAE. We evaluated the association of thyroid dysfunction during PD-1 blockade with the treatment efficacy in patients with non-small cell lung cancer (NSCLC). Experimental Design: A total 58 patients with stage IV NSCLC treated with PD-1 blockade were enrolled. Patients were categorized into thyroid dysfunction and euthyroid groups. Overall survival (OS) and progression-free survival (PFS) of the two groups were compared. Patients, tumor, and medication factors were adjusted using Cox proportional hazard modeling. Objective response rate (RR) and durable control rate were assessed according to the severity of thyroid dysfunction. Results: OS [median 118.0 (73.0-267.0) vs. 71.0 (28.0-160.0) days, log-rank P = 0.025] and PFS [118.0 (73.0-267.0) vs. 61.0 (28.0-130.0), log-rank P = 0.014] were longer in the thyroid dysfunction group. After adjustment, thyroid dysfunction was an independent predictive factor for favorable outcome [adjusted HR = 0.11 (95% CI) 0.01-0.92 for overall death; 0.38 (0.17-0.85) for disease progression]. The severity of thyroid dysfunction was associated with durable control rate (P for trend = 0.008). Conclusions: Thyroid dysfunction during PD-1 blockade is associated with treatment response and could provide supplementary information for immune monitoring in patients with advanced NSCLC.

Subclinical thyroid dysfunction and risk of carotid atherosclerosis

Background The effect of subclinical thyroid dysfunction on vascular atherosclerosis remains uncertain. The objective of this study was to elucidate the association between sustained subclinical thyroid dysfunction and carotid plaques, which are an early surrogate marker of systemic atherosclerosis. Methods The study included 21,342 adults with consistent thyroid hormonal status on serial thyroid function tests (TFTs) and carotid artery duplex ultrasonography at a health screening center between 2007 and 2014. The effect of subclinical thyroid dysfunction on baseline carotid plaques and newly developed carotid plaques during 5-year follow-up was determined by logistic regression analyses and GEE (Generalized Estimating Equations), respectively. Results Carotid plaques were more common in the subclinical hypothyroidism (55.6%) than the euthyroidism (47.8%) at baseline. However, in multivariable analysis, thyroid status was not a significant risk for the carotid plaques at baseline. Instead, traditional cardiovascular risk factors, such as age (P <0.001), systolic blood pressure (P = 0.023), fasting blood glucose (P = 0.030), and creatinine (P = 0.012) were associated with baseline carotid plaques in subclinical hypothyroidism. In longitudinal analyses of subjects who were followed up for more than 5 years, there was no significant difference in the cumulative incidence of new carotid plaques according to time between subjects with subclinical hypothyroidism and those with euthyroidism (P = 0.392). Conclusions Sustained subclinical thyroid dysfunction did not affect the baseline or development of carotid plaques in healthy individuals.

Delayed TSH recovery after dose adjustment during TSH-suppressive levothyroxine therapy of thyroid cancer

Delayed thyroid‐stimulating hormone (TSH) recovery during treatment of Graves’ disease is caused by long‐term excessive thyroid hormone, which results in downregulation of pituitary thyrotrophs. However, it is unknown whether delayed TSH recovery exists after levothyroxine (LT4) dose reduction in patients with differentiated thyroid cancer (DTC) after long‐term TSH suppression.

Restratification of survival prognosis of N1b papillary thyroid cancer by lateral lymph node ratio and largest lymph node size

The current 7th TNM staging stratifies N1b papillary thyroid cancer (PTC) patients without distant metastasis into either stage I or stage IV merely by an age threshold (45 years). To date, no studies have adequately quantified the mortality risk of PTC patients with N1b disease. We hypothesized that incorporating lymph node (LN) factors into the staging system would better predict cancer‐specific mortality (CSM). A total of 745 nonmetastatic PTC patients with N1b disease were enrolled. We identified factors related to LNs and cut‐points using Cox regression and time‐dependent ROC analysis. New prognostic groupings were derived based on minimal hazard differences for CSM among the groups stratified by LN risk and age, and prediction of CSM was assessed. Lateral lymph node ratio (LNR) and largest LN size were significant prognostic LN factors at cut‐points of 0.3 and 3 cm. Without LN risk (lateral LNR >0.3 or largest LN size >3 cm), stage IV patients had prognosis [adjusted HR 1.10 (98% CI 0.19–6.20); P = 0.906] similar to stage I patients with LN risk. Patients were restratified into three prognostic groups: Group 1, <45 years without LN risk; Group 2, <45 years with LN risk or ≥45 years without LN risk; and Group 3, ≥45 with LN risk. This system had a lower log‐rank P‐value (<0.001 vs. 0.002) and higher C‐statistics (0.80 vs. 0.71) than the 7th TNM. New prognostic grouping using lateral LNR and largest LN size predicts CSM accurately and distinguishes N1b patients with different prognosis.

Eighth edition of tumor-node-metastasis staging system improve survival predictability for papillary, but not follicular thyroid carcinoma: A multicenter cohort study

OBJECTIVES This study aimed to evaluate the proposed changes in the eighth edition of the tumor-node-metastasis staging system (TNM-8) compared with the seventh edition (TNM-7) in terms of pathologic subtypes, using a large multicenter thyroid cancer cohort. MATERIALS AND METHODS We retrospectively reviewed 7717 patients with papillary (PTC) and 273 with follicular thyroid carcinoma (FTC) who underwent thyroid surgery between 1996 and 2005. We assessed the proportion of variation explained (PVE) to compare the predictive accuracy of disease-specific survival (DSS). RESULTS During a median 11.3 years of follow-up, 169 (2%) disease-specific deaths were recorded. In patients with PTC, the 10-year DSS rates of stages I, II, III, and IV disease in TNM-8 were 99.6%, 95.7%, 81.5%, and 54.8%, respectively; the corresponding rates in TNM-7 were 99.6%, 98.4%, 98.4%, and 90.1%, respectively. In patients with FTC, the 10-year DSS rates of stages I, II, III, and IV disease in TNM-8 were 97.2%, 69.8%, 50.0%, and 45.5%, respectively; the corresponding rates in TNM-7 were 98.3%, 90.0%, 92.3%, and 42.1%, respectively. Comparing TNM-7 and TNM-8, the PVE values increased from 3.4% to 4.7% in the PTC group, whereas they decreased from 17.5% to 14.5% in the FTC group. CONCLUSION Our study suggests that the changes in TNM-8 have improved the clinical usefulness of the TNM staging system in terms of predicting DSS in patients with PTC but not FTC. Further studies to establish a more predictable TNM staging system that focuses on patients with FTC are necessary.

Modification of the eight-edition tumor-node-metastasis staging system with N1b for papillary thyroid carcinoma: A multi-institutional cohort study

OBJECTIVES Based on the tumor-node-metastasis staging system, eighth edition (TNM-8), N1b is no longer used as a variable to determine final stage in papillary thyroid carcinoma (PTC). We aimed to evaluate the predictability of a simple modification of the TNM staging with N1b classification in a large multicenter thyroid cancer cohort. MATERIALS AND METHODS This study included 7717 patients with PTC who underwent thyroid surgery between 1996 and 2005 from six tertiary hospitals. We classified patients with stage II into stage IIA and IIB with modified-TNM: older patients with N1b disease were classified as stage IIB, while remaining patients were classified as stage IIA. RESULTS The mean age was 46.2 years, and 24% were aged ≥55 years. In older patients, the 10-year disease-specific survival (DSS) rate of N1b disease (86.3%) was approximately 10% lower than that of N1a disease, and patients with N1b had significantly poorer DSS than those with N1a (HR = 3.3, p < 0.001). When the modified-TNM was applied, DSS curves between stage groups significantly differed (p < 0.001), and the relative risk of DSS in stage IIB patients was 2.3 times higher than in stage IIA patients (p < 0.001). The proportion of variation explained value of the modified-TNM was 4.9% and that of the TNM-8 was 4.7%. CONCLUSION This multicenter study reveals that the presence of lateral lymph node metastasis affects disease mortality in PTC, especially in older patients. The sub-classification of stage II in older patients improves DSS predictability. This simple modification of TNM-8 provides better prognostic information for patients with PTC.

Preoperative serum thyroglobulin predicts initial distant metastasis in patients with differentiated thyroid cancer

Differentiated thyroid cancer (DTC) generally has a favorable prognosis. However, a small percentage of patients suffer from initial distant metastasis (DM). To date, there is no effective predictor for the presence of initial DM. The aim of this study was to determine if preoperative serum thyroglobulin (Tg) level could predict initial DM in DTC. We reviewed an institutional thyroid cancer database from October 1994 to February 2016. To determine the Tg cutoff for predicting initial DM, 4,735 patients who were diagnosed with DTC were included in this study. Fifty-seven patients (1.2%) were identified as having DTC with initial DM. Median preoperative Tg level was 328.4 ng/ml in the initial DM group and 10.0 ng/ml in the non-DM group. Initial DM was the most important factor affecting serum Tg level (β = 2,049.32 ± 103.40; P < 0.001). The Tg cutoff level that distinguished overall DM with the greatest accuracy was 63.4 ng/ml [area under the ROC curve 0.914, sensitivity 84.2%, specificity 90.6%, negative likelihood ratio (LR) 0.17, and positive LR 8.97]. Preoperative Tg levels were useful for predicting initial DM of DTC. Measurement of serum Tg in patients with DTC may guide preoperative staging evaluation and initial treatment.

Effect of Rifampin on Thyroid Function Test in Patients on Levothyroxine Medication

Background Levothyroxine (LT4) and rifampin (RIF) are sometimes used together; however, no clinical studies have assessed the effects of these drugs on thyroid function or the need to adjust LT4 dose. Methods We retrospectively reviewed the records of 71 Korean patients who started RIF during LT4 treatment. Clinically relevant cases that required dose adjustment according to the American Thyroid Association (ATA)/American Association of Clinical Endocrinologists (AACE) guidelines were identified, and risk factors of increased LT4 dose were analyzed. Results After administering RIF, median serum thyroid-stimulating hormone (TSH) level (2.58 mIU/L, interquartile range [IQR] 0.21–7.44) was significantly higher than that before RIF (0.25 mIU/L, IQR, 0.03–2.62; P < 0.001). An increased LT4 dose was required for 50% of patients in the TSH suppression group for thyroid cancer and 26% of patients in the replacement group for hypothyroidism. Risk factor analysis showed that remaining thyroid gland (odds ratio [OR] 9.207, P = 0.002), the time interval between starting RIF and TSH measurement (OR 1.043, P = 0.019), and baseline LT4 dose per kg body weight (OR 0.364, P = 0.011) were clinically relevant variables. Conclusions In patients receiving LT4, serum thyroid function test should be performed after starting RIF treatment. For patients with no remnant thyroid gland and those receiving a lower LT4 dose, close observation is needed when starting RIF and TB medication.

Disease-Specific Mortality of Differentiated Thyroid Cancer Patients in Korea: A Multicenter Cohort Study

Background Little is known regarding disease-specific mortality of differentiated thyroid cancer (DTC) patients and its risk factors in Korea. Methods We retrospectively reviewed a large multi-center cohort of thyroid cancer from six Korean hospitals and included 8,058 DTC patients who underwent initial surgery between 1996 and 2005. Results Mean age of patients at diagnosis was 46.2±12.3 years; 87% were females. Most patients had papillary thyroid cancer (PTC; 97%) and underwent total thyroidectomy (85%). Mean size of the primary tumor was 1.6±1.0 cm. Approximately 40% of patients had cervical lymph node (LN) metastases and 1.3% had synchronous distant metastases. During 11.3 years of follow-up, 150 disease-specific mortalities (1.9%) occurred; the 10-year disease-specific survival (DSS) rate was 98%. According to the year of diagnosis, the number of disease-specific mortality was not different. However, the rate of disease-specific mortality decreased during the study period (from 7.7% to 0.7%). Older age (≥45 years) at diagnosis, male, follicular thyroid cancer (FTC) versus PTC, larger tumor size (>2 cm), presence of extrathyroidal extension (ETE), lateral cervical LN metastasis, distant metastasis and tumor node metastasis (TNM) stage were independent risk factors of disease-specific mortality of DTC patients. Conclusion The rate of disease-specific mortality of Korean DTC patients was 1.9%; the 10-year DSS rate was 98% during 1996 to 2005. Older age at diagnosis, male, FTC, larger tumor size, presence of ETE, lateral cervical LN metastasis, distant metastasis, and TNM stages were significant risk factors of disease-specific mortality of Korean DTC patients.