Mijin Kim1, Hee Kyung Kim2, Hye In Kim3, Eun Heui Kim1, Min Ji Jeon4, Hyon-Seung Yi5, Eun Sook Kim6, Hosu Kim7, Tae Hyuk Kim8, Bo Hyun Kim1, Tae Yong Kim4, Ho-Cheol Kang2, Won Bae Kim4, Jae Hoon Chung8, Young Kee Shong4, Sun Wook Kim9, Won Gu Kim10. 1. Division of Endocrinology and Metabolism, Department of Internal Medicine, Biomedical Research Institute, Pusan National University Hospital, Busan, Republic of Korea. 2. Department of Internal Medicine, Chonnam National University Medical School, Gwangju, Republic of Korea. 3. Division of Endocrinology and Metabolism, Department of Medicine, Samsung Changwon Hospital, Sungkyunkwan University School of Medicine, Changwon, Republic of Korea. 4. Division of Endocrinology and Metabolism, Department of Internal Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea. 5. Department of Internal Medicine, Chungnam National University Hospital, Chungnam National University School of Medicine, Daejeon, Republic of Korea. 6. Department of Internal Medicine, Ulsan University Hospital, University of Ulsan College of Medicine, Ulsan, Republic of Korea. 7. Division of Endocrinology, Department of Medicine, Gyeongsang National University Changwon Hospital, Gyeongsang National University School of Medicine, Changwon, Republic of Korea. 8. Division of Endocrinology and Metabolism, Department of Medicine, Thyroid Cancer, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea. 9. Division of Endocrinology and Metabolism, Department of Medicine, Thyroid Cancer, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea. Electronic address: swkimmd@skku.edu. 10. Division of Endocrinology and Metabolism, Department of Internal Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea. Electronic address: wongukim@amc.seoul.kr.
Abstract
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.
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.
Authors: Mijin Kim; Won Gu Kim; Min Ji Jeon; Hee Kyung Kim; Hyon Seung Yi; Eun Sook Kim; Bo Hyun Kim; Won Bae Kim; Young Kee Shong; Ho Cheol Kang; Tae Yong Kim Journal: Endocrinol Metab (Seoul) Date: 2020-03