Different View on Tumor Size Dilemma in Tumor-Node-Metastasis Staging System for Thymoma

Abstract

Background Although tumor size is included in the definition of T descriptor in the tumor-node-metastasis (TNM) classification of many solid tumors, it is not considered for thymomas. This study aimed to assess the relationship of tumor diameters (the largest tumor diameter [LTD] and the mean tumor diameter [MTD]) with survival in thymoma patients undergoing surgical resection in a single center.

Methods The study included 127 thymoma patients (age, 49.2 ± 15.2 years; 65 males), who were evaluated based on pathological tumor sizes according to the LTD and MTD ([largest diameter + shortest diameter] / 2) and divided into three subgroups for each parameter as: patients with an LTD of ≤5 cm, 5.1 to 10 cm, and >10 cm and patients with an MTD of ≤5, 5.1 to 10, and >10 cm.

Results In thymoma patients, survival significantly differed according to the presence of myasthenia gravis (p = 0.018), resection status (R0 or R1; p = 0.001), T status (p = 0.015), and the Masaoka–Koga stage (p = 0.003). In the LTD subgroups, the overall survival of those with R0 resection was lower in those with an LTD of 5.1 to 10 cm than in those with an LTD of ≤5 cm (p = 0.051) and significantly lower in those with an MTD of 5.1 to 10 cm than in those with an MTD of ≤5 cm (p = 0.027). In the MTD subgroups, survival decreased as the tumor size increased.

Conclusion Both smaller tumor size and complete resection are associated with better survival in thymoma patients. Therefore, the largest or the mean tumor size might be considered as a criterion in the TNM staging for thymoma.

Keywords

thymoma - tumor staging - tumor size - thymic epithelial tumors

Note

It was presented as a poster at the 20th World Lung Cancer Conference in Barcelona-Spain.

Publikationsverlauf

Eingereicht: 30. April 2020

Angenommen: 24. Juni 2020

Artikel online veröffentlicht:
08. September 2020

• References

• 1 National Comprehensive Cancer Network. NCCN guidelines in oncology: thymomas and thymic carcinomas. Accessed February 3, 2020 at: https://www.nccn.org/professionals/physician_gls/pdf/thymic.pdf
• 2 Dai CY, Lin CY, Tsai PC. et al. Impact of tumor size on the prognosis of hepatocellular carcinoma in patients who underwent liver resection. J Chin Med Assoc 2018; 81 (02) 155-163
• 3 Anderson KR, Heidinger BH, Chen Y, Bankier AA, VanderLaan PA. Measurement bias of gross pathologic compared with radiologic tumor size of resected lung adenocarcinomas: implications for the T-stage revisions in the eighth edition of the American Joint Committee on Cancer Staging Manual. Am J Clin Pathol 2017; 147 (06) 641-648
• 4 Bhindi B, Lohse CM, Mason RJ. et al. Are we using the best tumor size cut-points for renal cell carcinoma staging?. Urology 2017; 109: 121-126
• 5 Suzuki S, Sakurai H, Masai K. et al. A proposal for definition of minimally invasive adenocarcinoma of the lung regardless of tumor size. Ann Thorac Surg 2017; 104 (03) 1027-1032
• 6 Cong L, Liu Q, Zhang R. et al. Tumor size classification of the 8th edition of TNM staging system is superior to that of the 7th edition in predicting the survival outcome of pancreatic cancer patients after radical resection and adjuvant chemotherapy. Sci Rep 2018; 8: 10383
• 7 National Comprehensive Cancer Network. NCCN guidelines in oncology: thyroid carcinoma. Accessed February 3, 2020 at: https://www.nccn.org/professionals/physician_gls/pdf/thyroid.pdf
• 8 National Comprehensive Cancer Network. NCCN guidelines in oncology: breast cancer. Accessed February 3, 2020 at: https://www.nccn.org/professionals/physician_gls/pdf/breast-screening.pdf
• 9 National Comprehensive Cancer Network. NCCN guidelines in oncology: non-small cell lung cancer. Accessed February 3, 2020 at: https://www.nccn.org/professionals/physician_gls/pdf/nscl.pdf
• 10 National Comprehensive Cancer Network. NCCN guidelines in oncology: hepatobiliary cancers. Accessed February 3, 2020 at: https://www.nccn.org/professionals/physician_gls/pdf/hepatobiliary.pdf
• 11 National Comprehensive Cancer Network. NCCN guidelines in oncology: kidney cancer. Accessed February 3, 2020 at: https://www.nccn.org/professionals/physician_gls/pdf/nscl.pdf
• 12 National Comprehensive Cancer Network. NCCN Guidelines : pancreatic adenocarcinoma. Accessed February 3, 2020 at: https://www.nccn.org/professionals/physician_gls/pdf/hepatobiliary.pdf
• 13 Detterbeck FC, Nicholson AG, Kondo K, Van Schil P, Moran C. The Masaoka-Koga stage classification for thymic malignancies: clarification and definition of terms. J Thorac Oncol 2011; 6 (07) (Suppl. 03) S1710-S1716
• 14 Detterbeck FC, Stratton K, Giroux D. et al; Staging and Prognostic Factors Committee; Members of the Advisory Boards; Participating Institutions of the Thymic Domain. The IASLC/ITMIG Thymic Epithelial Tumors Staging Project: proposal for an evidence-based stage classification system for the forthcoming (8th) edition of the TNM classification of malignant tumors. J Thorac Oncol 2014; 9 (09) (Suppl. 02) S65-S72
• 15 Filosso PL, Ruffini E, Lausi PO, Lucchi M, Oliaro A, Detterbeck F. Historical perspectives: the evolution of the thymic epithelial tumors staging system. Lung Cancer 2014; 83 (02) 126-132
• 16 Nicholson AG, Detterbeck FC, Marino M. et al; Staging and Prognostic Factors Committee; Members of the Advisory Boards; Participating Institutions of the Thymic Domain. The IASLC/ITMIG Thymic Epithelial Tumors Staging Project: proposals for the T Component for the forthcoming (8th) edition of the TNM classification of malignant tumors. J Thorac Oncol 2014; 9 (09) (Suppl. 02) S73-S80
• 17 Masaoka A, Monden Y, Nakahara K, Tanioka T. Follow-up study of thymomas with special reference to their clinical stages. Cancer 1981; 48 (11) 2485-2492
• 18 Koga K, Matsuno Y, Noguchi M. et al. A review of 79 thymomas: modification of staging system and reappraisal of conventional division into invasive and non-invasive thymoma. Pathol Int 1994; 44 (05) 359-367
• 19 Fukui T, Fukumoto K, Okasaka T. et al. Prognostic impact of tumour size in completely resected thymic epithelial tumours. Eur J Cardiothorac Surg 2016; 50 (06) 1068-1074
• 20 Bian D, Zhou F, Yang W. et al. Thymoma size significantly affects the survival, metastasis and effectiveness of adjuvant therapies: a population based study. Oncotarget 2018; 9 (15) 12273-12283
• 21 Okumura M, Yoshino I, Yano M. et al. Tumour size determines both recurrence-free survival and disease-specific survival after surgical treatment for thymoma. Eur J Cardiothorac Surg 2019; 56 (01) 174-181
• 22 Marx A, Chan JK, Coindre JM. et al. The 2015 World Health Organization classification of tumors of the thymus: continuity and changes. J Thorac Oncol 2015; 10 (10) 1383-1395
• 23 Fukui T, Fukumoto K, Okasaka T. et al. Clinical evaluation of a new tumour-node-metastasis staging system for thymic malignancies proposed by the International Association for the Study of Lung Cancer Staging and Prognostic Factors Committee and the International Thymic Malignancy Interest Group. Eur J Cardiothorac Surg 2016; 49 (02) 574-579
• 24 Roden AC, Yi ES, Jenkins SM. et al. Reproducibility of 3 histologic classifications and 3 staging systems for thymic epithelial neoplasms and its effect on prognosis. Am J Surg Pathol 2015; 39 (04) 427-441
• 25 Ruffini E, Detterbeck F, Van Raemdonck D. et al; European Association of Thoracic Surgeons (ESTS) Thymic Working Group. Tumours of the thymus: a cohort study of prognostic factors from the European Society of Thoracic Surgeons database. Eur J Cardiothorac Surg 2014; 46 (03) 361-368
• 26 Wright CD, Wain JC, Wong DR. et al. Predictors of recurrence in thymic tumors: importance of invasion, World Health Organization histology, and size. J Thorac Cardiovasc Surg 2005; 130 (05) 1413-1421
• 27 Nakagawa K, Asamura H, Matsuno Y. et al. Thymoma: a clinicopathologic study based on the new World Health Organization classification. J Thorac Cardiovasc Surg 2003; 126 (04) 1134-1140
• 28 Blumberg D, Port JL, Weksler B. et al. Thymoma: a multivariate analysis of factors predicting survival. Ann Thorac Surg 1995; 60 (04) 908-913 , discussion 914
• 29 Van Raemdonck D, Ruffini E. Thymic malignancies: does size matter?. Eur J Cardiothorac Surg 2016; 50 (06) 1075-1076