Benefits of Surgeon-Performed Office-Based Ultrasonography / 대한이비인후과학회지

Background and Objectives@#The purpose of this study was to examine the benefits of ultrasonography performed by a surgeon rather than a radiologist.Subjects and Method This retrospective study enrolled 122 cases of ultrasonography performed by a head and neck surgeon and 116 cases of the same examination performed by a radiologist before surgery. The time intervals between the first visit and surgery were compared in both groups. @*Results@#The average waiting time for surgery after the first hospital visit was significantly reduced when a surgeon performed the ultrasound examination. Furthermore, there was no significant difference in sampling inadequacy rate on thyroid fine needle aspiration (FNA) between FNA performed by a head and neck surgeon and a radiologist. @*Conclusion@#Surgeons can utilize ultrasound as a diagnostic and therapeutic tool in an office-based setting. For patients, diagnosis and treatment provided by a single doctor will lead to more efficient outcomes.

The Influence of Non-Linear Frequency Compression on the Perception of Speech and Music in Patients with High Frequency Hearing Loss

Background and Objectives@#Non-linear frequency compression (NLFC) technology compresses and shifts higher frequencies into a lower frequency area that has better residual hearing. Because consonants are uttered in the high-frequency area, NLFC could provide better speech understanding. The aim of this study was to investigate the clinical effectiveness of NLFC technology on the perception of speech and music in patients with high-frequency hearing loss. @*Subjects and Methods@#Twelve participants with high-frequency hearing loss were tested in a counter-balanced order, and had two weeks of daily experience with NLFC set on/off prior to testing. Performance was repeatedly evaluated with consonant tests in quiet and noise environments, speech perception in noise, music perception and acceptableness of sound quality rating tasks. Additionally, two questionnaires (the Abbreviated Profile of Hearing Aid Benefit and the Korean version of the International Outcome Inventory-Hearing Aids) were administered. @*Results@#Consonant and speech perception improved with hearing aids (NLFC on/off conditions), but there was no significant difference between NLFC on and off states. Music perception performances revealed no notable difference among unaided and NLFC on and off states. The benefits and satisfaction ratings between NLFC on and off conditions were also not significantly different, based on questionnaires, however great individual variability preferences were noted. @*Conclusions@#Speech perception as well as music perception both in quiet and noise environments was similar between NLFC on and off states, indicating that real world benefits from NLFC technology may be limited in Korean adult hearing aid users.

Comparative Analysis About Clinical Manifestation and Prognostic Factors of Thyroid Follicular and Hurthle Cell Carcinoma / 대한이비인후과학회지

Background and Objectives@#Follicular thyroid carcinoma (FTC) is the second common thyroid cancer which comprises about 10% of differentiated thyroid carcinoma. Hurthle cell carcinoma (HCC) is a relatively rare disease that has been classified as a subtype of FTC. However, there have been insufficient reports about these two similar thyroid cancers in South Korea due to low incidences. This study aims to present clinical features and evaluate prognostic factors of FTC and HCC.Subjects and Method We reviewed data of 189 FTC and 12 HCC patients who underwent surgery in our center from January 2000 to December 2020. Variables such as clinical characteristics, surgical method, pathologic result, post-operative treatment, survival rate and prognostic factors were included in our study. @*Results@#As for age, 67.2% of patients in FTC group and 33.3% of patients in HCC group were older than 55 years-old (p=0.017). The average tumor sizes of FTC and HCC were 2.98 and 3.1 cm, respectively. The 10-year overall survival rates of FTC and HCC were 96.5% and 100%, respectively. The 10-year disease free survival rates of FTC and HCC were 89.1% and 91.7%, respectively. Subclassification (widely invasive: p=0.036) and initial distant metastasis (p<0.001) were significant prognostic factors in FTC. @*Conclusion@#This study will be helpful for diagnosis and treatment of FTC and HCC, which are relatively rare.

Age and Tumor Size is a Prognostic Factor in Pediatric/Adolescent Differentiated Thyroid Carcinoma / 대한두경부종양학회지

Background/Objectives@#To analyze the clinical characteristics of differentiated thyroid cancer (DTC) in children and adolescents.Materials & Methods: Medical records of 31 DTC cases that were diagnosed and treated at Korea Cancer Center Hospital between 2002 and 2018 were retrospectively reviewed. @*Results@#Most cases were papillary carcinoma (n=26), with female predominance (n=25). Median age was 16.4 years (range, 11.9-18.6 years). Extrathyroidal extension was present in 24 cases. Twenty cases had tumor involvement at cervical lymph nodes and three had lung metastasis. Twenty-two patients received radioactive iodide treatment with a median cumulative dose of 300 mCi (range, 100-920 mCi). During a median follow-up of 68.2 months (range, 2.3-191.4 months), serum thyroglobulin level was elevated in 15 patients. Among them, two cases had remnant thyroid tissue, 4 had recurrence at cervical lymph nodes, and the remaining 9 did not have any detectable lesion. All were alive, and 5-year event-free survival (EFS) was 45.2±10.1%. Age £15 years, tumor size, lymph node status (N1b), and distant metastasis had negative effects on EFS. On multivariate analysis, age and tumor size had prognostic significance. @*Conclusion@#For DTC of children and adolescents (£18 years old), age ≤15 years and tumor size were prognostic factor. Therefore, patients in this age group need meticulous follow-up. Further studies are necessary to answer the potential influence of age on the incidence and behavior of DTC.

Age and Tumor Size is a Prognostic Factor in Pediatric/Adolescent Differentiated Thyroid Carcinoma / 대한두경부종양학회지

Background/Objectives@#To analyze the clinical characteristics of differentiated thyroid cancer (DTC) in children and adolescents.Materials & Methods: Medical records of 31 DTC cases that were diagnosed and treated at Korea Cancer Center Hospital between 2002 and 2018 were retrospectively reviewed. @*Results@#Most cases were papillary carcinoma (n=26), with female predominance (n=25). Median age was 16.4 years (range, 11.9-18.6 years). Extrathyroidal extension was present in 24 cases. Twenty cases had tumor involvement at cervical lymph nodes and three had lung metastasis. Twenty-two patients received radioactive iodide treatment with a median cumulative dose of 300 mCi (range, 100-920 mCi). During a median follow-up of 68.2 months (range, 2.3-191.4 months), serum thyroglobulin level was elevated in 15 patients. Among them, two cases had remnant thyroid tissue, 4 had recurrence at cervical lymph nodes, and the remaining 9 did not have any detectable lesion. All were alive, and 5-year event-free survival (EFS) was 45.2±10.1%. Age £15 years, tumor size, lymph node status (N1b), and distant metastasis had negative effects on EFS. On multivariate analysis, age and tumor size had prognostic significance. @*Conclusion@#For DTC of children and adolescents (£18 years old), age ≤15 years and tumor size were prognostic factor. Therefore, patients in this age group need meticulous follow-up. Further studies are necessary to answer the potential influence of age on the incidence and behavior of DTC.

Evaluation of Surgical Completeness in Endoscopic Total Thyroidectomy with Central Neck Dissection via a Unilateral Axillo-Breast Approach Compared with Bilateral Axillo-Breast and Open Approach / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: The aim of this study was to evaluate surgical completeness in endoscopic total thyroidectomy with central neck dissection via unilateral axillo-breast approach (UABA) compared with bilateral axillo-breast (BABA) and open approach (OA) by means of the radioactive iodine uptake (RAIU) ratio and thyroglobulin (Tg) of remnant thyroid. SUBJECTS AND METHOD: From July 2010 to March 2013, 82 patients who had underwent total thyroidectomy with central neck dissection and postoperative radioactive iodine (RAI) ablation for papillary thyroid carcinoma were enrolled. Of these patients, 27 patients underwent UABA, 24 patients BABA, and 31 patients OA. Clinicopathologic data, surgical outcome, stimulated Tg and RAIU ratio on the first postoperative RAI ablation scan were compared among 3 groups. RESULTS: Patients in the endoscopic surgery groups (UABA, BABA) were younger than those in the OA groups. Invasiveness such as operation time, postoperative pain, and drain amount in UABA was less than that in BABA and severer than that in OA. Other variables regarding clinicopathologic and surgical data were not significantly different. Stimulated Tg and RAIU ratio did not show significant differences among 3 groups (p=0.659 and p=0.664). CONCLUSION: The completeness of UABA was comparable with that of BABA and OA. The UABA may be a safe option for patients who need endoscopic thyroidectomy for papillary thyroid carcinoma.

Falsely increased bispectral index values by convective air warming system during kidney transplantation

Bispectral index [BIS] is a reliable parameter for measuring depth of hypnotic level during anesthesia. Convective air warming system is an effective equipment to maintain normothermia during operation. We report falsely elevated BIS value due to convective air warming system while undergoing kidney transplantation

Cardiac arrest after sugammadex administration in a patient with variant angina: a case report / 대한마취과학회지

A 76-year-old man with no notable medical history was scheduled for a robot-assisted radical prostatectomy. After the operation, he was given sugammadex. Two minutes later, ventricular premature contraction bigeminy began, followed by cardiac arrest. Cardiac arrest occurred three times and cardiopulmonary resuscitation was done. The patient recovered after the third cardiopulmonary resuscitation and was transferred to the intensive care unit. Coronary angiography was done on postoperative day 1. The patient was diagnosed with variant angina and discharged uneventfully on postoperative day 8.

Comparative Study of Unilateral Axillo-Breast Approach with Gas Insufflation Versus Gasless Transaxillary Approach for Endoscopic Thyroidectomy in a Single Institute / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: There have been various approaches introduced for endoscopic thyroidectomy. This study evaluates and compares the surgical outcomes of two such approaches: the unilateral axillo-breast approach (UABA) with gas and the gasless transaxillary approach (TA). SUBJECTS AND METHOD: We retrospectively analyzed 279 patients who underwent endoscopic thyroidectomy via UABA with gas or gasless TA from March 2008 to August 2012. Studied variables were clinicopathologic data, surgical outcomes, complications, and cosmetic satisfactions. RESULTS: Of the 279 patients, 195 (69.9%) underwent UABA with gas and 84 (30.1%) underwent gasless TA. All of the variables related to clinicopathologic characteristics showed no significant differences between the two groups. The mean operation time was significantly shorter in the UABA with gas group (131.76±44.37 min) than in the gasless TA group (191.01±55.90 min) (p<0.001). The mean postoperative pain Visual Analogue Scale scores in the UABA with gas group were 2.61±0.96 and 1.85±0.79, respectively, and those in the gasless TA group were 3.12±1.02 and 2.17±0.76, respectively, at 1 and 3 days after surgery. Incidences of postoperative complications were similar except for the higher rate of seroma in the gasless TA group. Cosmetic satisfaction scores of UABA with gas were higher than those of the gasless TA. CONCLUSION: UABA with gas may be a good option for endoscopic thyroidectomy because this approach is less invasive than the gasless TA is.

Clinical Features and Outcomes of Papillary Thyroid Carcinoma in Patients Aged under 20 / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Thyroid carcinoma rarely occurs in children and adolescents, whose clinical features are diverse, and treatment outcomes are still controversial. The aim of this study was to evaluate the clinical features and the treatment outcomes of papillary thyroid carcinoma (PTC) patients younger than 20 years old. SUBJECTS AND METHOD: This is a retrospective study for patients younger than 20 years old, who were diagnosed as PTC from January 1992 to February 2009. Clinical features, size, pathologic type, extrathyroidal extension, recurrence, multiplicity, extent of surgery, and lymph node metastasis were retrospectively evaluated. RESULTS: Forty patients, of 6 malse and 34 females, were enrolled, with their mean age being 16 years old. The initial operations were total thyroidectomy for 9 patients, unilateral lobectomy for 15 patients, and total thyroidectomy and lateral neck dissection for 16 patients. Cervical lymph node metastases were diagnosed in 25 patients. Extrathyroidal extensions were observed in 30 patients. Postoperative radioactive iodine therapy was performed in 35 patients. During the follow-up period, 8 patients had recurred. All patients were alive at the last follow-up. CONCLUSION: PTC in children and adolescents aged under 20 is a rare disease and tends to present as an advanced disease with low mortality compared to adult PTC. Recurrence had no effect on survival. Aggressive treatment with total thyroidectomy, central neck dissection, and radioiodine therapy may prevent recurrence.

Analysis of Treatment Results after Thyroid Lobectomy with Prophylactic Ipsilateral Central Neck Lymph Node Dissection for Low-Risk Papillary Thyroid Carcinoma: A Single Institute Experience / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Surgical options for low-risk papillary thyroid carcinoma (PTC) have been in debate. The purpose of this study was to analyze the treatment results of lobectomy and prophylactic ipsilateral central lymph node dissection (cND) for low-risk PTC. SUBJECTS AND METHOD: We retrospectively analyzed 906 patients who were diagnosed as PTC pre- or post-operatively and underwent lobectomy and/or prophylactic ipsilateral cND from 2001 to 2010. Studied variables were clinicopathologic data, complications, sites of recurrence, overall survival, and recurrence free survival rates. RESULTS: Fifty two (5.7%) patients showed recurrence during follow-up. Of the 52 recurrent cases, 32 (61.5%) cases recurred in a remnant thyroid only, 11 (21.2%) cases in a lymph node (LN) only, and 9 (17.3%) cases in a remnant thyroid and the LN. One (0.1%) patient showed permanent vocal cord palsy. Overall survival rate at 10 years was 99.6%. Overall recurrence free survival rates at 5 and 10 years were 97.1% and 81.0%, respectively. Risk factors for recurrences were old age (>45), contralateral nodule(s) at initial surgery, large tumor, no prophylactic cND, and pathological LN metastasis. CONCLUSION: Lobectomy with prophylactic ipsilateral cND may be a good option for low risk PTC patients due to excellent overall survival rates, recurrence rates, and minimal complication rates.

Clinical Characteristics of Diffuse Sclerosing Variant of Papillary Thyroid Carcinoma / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Diffuse sclerosing variant (DSV) is a rare variant of papillary thyroid carcinoma (PTC) and has been adopted as a histologic variant. Due to the limited number of cases and the heterogeneity of the tumor's clinical behavior, there is no consensus for DSV's optimal treatment and post-operative follow-up. The purpose of this study is to evaluate the clinical manifestation, recurrence and prognosis of 10 patients with DSV. SUBJECTS AND METHOD: We retrospectively reviewed ten consecutive patients in whom DSV was first observed between 2000 and 2012. All patients are presently under active follow-up at Korea Cancer Center Hospital. Patients underwent a total thyroidectomy with central compartment and laterocervical lymph node dissection only when this involvement was documented by pre-surgery ultrasound examination with fine needle aspiration biopsy. RESULTS: The mean observation interval was 41.6 months. The ratio of male to female was 1 : 9, and the age of incidence was 34.2+/-11.4. The average size of mass was measured 2.9+/-1.9 cm. Upon the diagnosis, eight cases had central and lateral neck lymph nodal metastasis, which was confirmed during the operation. There was no distant metastasis, but one case was confirmed with lung metastasis during the follow-up period. There was no mortality during the follow-up periods in all ten cases. CONCLUSION: DSV of PTC has high risk characteristics of large tumor size, extrathyroidal extension, and multiple lymph nodes metastasis. We may expect comparable outcome with classical PTC by proper surgical treatment and postoperative radioactiveiodine ablation.

Follicular Variant of Papillary Thyroid Carcinoma: Clinical Manifestation and Prognosis / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Despite relatively high incidences of follicular variant of papillary thyroid carcinoma (FV-PTC), there is a continuous debate regarding the clinical behavior, treatment outcome, prognostic variables and survival of this disease. We performed this study for the purpose of getting further understanding and more supporting ideas for the treatment of FV-PTC. SUBJECTS AND METHOD: A clinicopathologic analysis of 116 patients who underwent a thyroidectomy with a final diagnosis of FV-PTC divided the patients into three groups: the FV-PTC only group (group A, n=78), the FV-PTC group who developed classical papillary thyroid carcinoma (C-PTC) (group B, n=38) and the C-PTC only (group C, n=320, 2003, Korea Cancer Center Hospital). The three groups were compared with respect to the following various clinicopathological characteristics: age at diagnosis, tumor size, stage of tumor, capsular invasion, age, metastasis, extent, size score, multifocality of tumor, LN metastasis, treatment, and recurrence. RESULTS: The mean tumor sizes, disease stage, and type of initial surgery were similar in three groups. However, the prevalence of nodal disease and capsular invasion were significantly higher in the groups B and C compared to the patients of group A. The 8-year disease-free survival rate was 93.7% in the patients with FV-PTC only, 90.4% in the patients with C-PTC only and 88.2% in the patients with FV-PTC group, who developed C-PTC (p>0.05). CONCLUSION: The clinical behavior and prognosis of PTC and FV-PTC groups did not differ significantly. In treating FV-PTC, we find that it is desirable to choose a similar strategy as that used to treat C-PTC.

The Clinical Importance of Minimal Extrathyroid Extension on Tumor Recurrence in Patients with Papillary Thyroid Carcinoma

BACKGROUND: We wanted to evaluate whether a minimal extrathyroid extension (METE) is associated with the clinicopathological parameters that are indicative of a poor prognosis, including lymph node metastasis, distant metastasis at the time of the initial diagnosis and tumor recurrence, in patients with papillary thyroid carcinoma (PTC), and especially in the patients with papillary thyroid microcarcinoma (PTMC). METHODS: We retrospectively evaluated the medical records of patients with PTC and who had undergone total thyroidectomy with/without subsequent 131I remnant ablation at the Korea Cancer Center Hospital from January 1998 through December 2005. A total of 557 patients with PTC were enrolled in the study. We excluded 13 patients with an unknown status of extension and 29 patients with massive ETE. RESULTS: Of the 515 patients, 401 were found to have a METE. We analyzed the 464 patients who were without distant metastasis at the time of the initial diagnosis and who had a follow-up duration of more than 6 months. METE was not significantly associated with tumor recurrence during the follow-up period (median follow-up period: 122 months, range: 6-142 months): 8% vs. 15% of the patients with and without METE had tumor recurrence, respectively (P = 0.069 by the log-rank test). We analyzed the effect of tumor size in the patients with METE. Size was not significantly associated with tumor recurrence (P = 0.374 by the log-rank test). CONCLUSION: These findings suggest that METE might not be a prognostic factor to predict tumor recurrence in patients with PTC, including PTMC.

Sclerosing Mucoepidermoid Carcinoma of the Parotid Gland / 대한이비인후과학회지

Sclerosing mucoepidermoid carcinoma of salivary gland is a rare variant of mucoepidermoid carcinoma and can be confused with benign condition on clinical, radiological, and pathologic examination. A 34-year old female was found to have a parotid mass with a long history. Preoperative evaluation including computed tomography and fine needle aspiration cytology were nondiagnostic. Intraoperatively, frozen section specimens showed only low grade tubular lesion with severe background inflammatory infiltration. Final pathological examination demonstrated multiple cystic nests composed of mucinous and squamoid intermediate cells within the background of central dense, sclerotic, collagenized stroma and peripheral inflammatory infiltrate, consistent with a low grade sclerosing mucoepidermoid carcinoma. Sclerosing mucoepidermoid carcinoma is a very rare salivary gland tumor with an uncertain clinical behavior. Complete surgical excision with tumor-free margins is recommended. Postoperative radiation therapy is suggested for positive or close margins, and close follow-up of the patients is mandatory.

Clinical Assessment and Management of Papillary Thyroid Carcinoma with Coexistent Hashimoto's Thyroiditis / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: The frequency of co-occurence of Hashimoto's thyroiditis and papillary thyroid carcinoma has been variously reported to range from 0.3% to 38%, and the association of these two diseases is still controversial. The aim of our study is to determine the relationship between these two entities, and in this paper, we compare the clinical characteristics of patients with and without histopathological evidence of Hashimoto's thyroiditis. SUBJECTS AND METHOD: Among 366 patients treated for thyroid nodules (including benign nodules and thyroid cancers) during the period of July 2004-June 2005, 278 patients (male versus female=1 : 7.9) with papillary thyroid carcinoma were included in this study. RESULTS: Hashimoto's thyroiditis co-occurred with papillary thyroid carcinoma in 68 of 278 patients (24.5%), compared with 0 of 21 patients (0%) with other thyroid malignancies. The age at presentation (median, 43.9 years), tumor size (median, 1.31 cm), methods of diagnostic evaluation, and the extent of surgery had not influenced by the presence of Hashimoto's thyroiditis. However, TNM stage, AMES stage, MACIS score were slightly lower and the proportion of female patients (1 : 67) was higher in patients with Hashimoto's thyroiditis. CONCLUSION: These results suggest that patients who have papillary thyroid carcinoma may have more favorable prognosis in the co-ocurring Hashimoto's thyroiditis. Further studies are required to confirm the long-term prognostic association between these two diseases.

Two Cases of Synovial Sarcoma Arising in the Anterior Neck / 대한이비인후과학회지

Synovial sarcomas is a mesenchymal tumor that usually occurs in the extremities. Fewer than 100 cases of synovial sarcoma have been reported in the head and neck lesion. We experienced 2 cases of synovial sarcoma of neck, and so reported with a review of literature.

SUV Analysis of PET Scan for Prognostic Factor of Head and Neck Cancer / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Previous studies have shown that uptake of 18Fluoro-2-deoxy-glucose in head and neck cancer, as determined by the standardized uptake value (SUV) on positron emission tomography scan (PET scan), is associated with the biology of tumor. The aims of this study were to confirm the association with the biology of tumor and to establish whether a high SUV had prognostic significance. MATERIALS AND METHOD: Thirty patients with the head and neck cancer diagnosed as squamous cell carcinoma underwent a PET scan before treatment. SUVs were analyzed for possibility correlated with diseasefree survival. RESULTS: In univariate survival analysis, when patients were divided into two groups based on the SUV cut-off value of 8, the group whose SUV was greater than 8 in the pre-treatment PET scan showed significantly worse outcome (p=0.029). Correlation analysis demonstrated that SUV provided prognostic information independent of the tumor size, pathologic differentiation and stage. CONCLUSION: We conclude that high FDG uptake on PET (SUV >8 in pre-treatment PET scan) is an important prognostic indicator for poor outcome. Identified patients are thought to require intensive treatment protocol and more careful follow up.

A Clinical Analysis of Recurrence in Differentiated Thyroid Carcinoma / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Differentiated thyroid carcinoma (DTC) is a known malignant tumor arising from the follicular epithelium in thyroid gland. Although the prognosis for patients with DTC is generally good, appropriate surgical management can further reduce recurrence and cancer death rates significantly. The therapeutic methods performed are total thyroidectomy plus radioactive iodine (131I) therapy and life-long thyroid-stimulating hormone (TSH) suppression. Histopathologically, DTC contains papillary and follicular adenocarcinoma. In numerous studies, staging systems-AMES, AGES, MACIS, etc-have been created to evaluate prognostic outcome. By applying staging systems, we have treated 394 patients with DTC since 1998. The purpose of our study was to analyze characteristics of recurrent cases and evaluate remission rates of recurrent cases according to diagnostic methods. MATERIALS AND METHOD: From January 1998 to December 2001, we performed 630 thyroidectomies and 487 malignant tumors (421 papillary, 28 follicular, 20 medullary, 12 undifferentiated carcinoma and 6 other malignant tumors). We analyzed 394 DTC cases; excluding other malignancy, 65 cases were recurrent cancer (58 papillary and 7 follicular carcinoma). The medical records of 394 patients with DTC treated at our hospital were reviewed retrospectively. We analyzed impact of primary surgery on recurrence in 65 recurrent patients and compared the remission rates of those patients using physical examination with those using laboratory tests and imaging studies. RESULTS: 347 patients with DTC were treated initially in our hospital and 18 patients showed recurrence. Among them, lobectomy was performed as a primary surgery in 69 patients of whom one (1.4%) had recurrence. Forty-seven patients with DTC treated initially in other hospitals were referred to our hospital. Lobectomy was performed as a primary surgery in 23 patients (54.7%). Recurrence of 32 patients was detected by palpation. Of these patients, the remission rate was 25.0%, whereas patients diagnosed by laboratory tests and imaging systems showed 53.3% remission rate (p=0.056). CONCLUSION: The extent of primary thyroid resection appeared to have significant impact on the recurrence of DTC. In view of this, we should apply staging system strictly in treating DTC-total thyroidectomy and central neck dissection in high-risk groups. In following up patients, we should check the thyroglobulin level and use image tests like computed tomography and positron emission tomography to detect recurrence earlier.

Effects of the Genetic Polymorphisms of CYP1A1 and GSTP1 on the Risk of Laryngeal Cancer in Koreans / 대한이비인후과학회지

BACKGROUND AND ackground and Objectives: Smoking has been reported as an important risk factor of laryngeal cancer. Cytochrome P450 1A1 (CYP1A1) and glutathione S-transferase P1 (GSTP1) are genes that encode enzymes which are involved in the metabolism of carcinogens in cigarette smoke. In this study, we statistically tested the significances of smoking and genotypes of CYP1A1 and GSTP1 as risk factors of laryngeal cancer. MATERIALS AND METHOD: In this case-control study, 84 pathologically proven laryngeal cancer patients and 168 age- and sex-matched controls were included as the study subjects. Information on smoking habit was collected using a self-administered questionnaire, and CYP1A1 and GSTP1 genotypes were analyzed using PCR-RFLP method. Chi-square test, Student's t-test and conditional logistic analysis were used to test statistical significance. RESULTS: Smoking was turned out to be a significant risk factor of laryngeal cancer both in univariate and multivariate analyses. The CYP1A1 Ile/Ile genotype was significant in the univariate test, but the statistical significance disappeared in the multivariate conditional logistic model including smoking. The odds ratio (95% confidence interval) of GSTP1 A/A genotype for laryngeal cancer was 0.71 (0.38, 1.33), which was not statistically significant. CONCLUSION: Smoking is the most potent risk factor among the three factors, and the genotypes of CYP1A1 and GSTP1 would not be major risk factors for laryngeal cancer in Koreans.