T1aN0M0 and T1bN0M0 Non–Small Cell Lung Cancer: A Retrospective Study of the Prognosis

Abstract

Background Stage IA of non–small cell lung cancer (NSCLC) is divided into two subgroups, T1aN0M0 (d ≤ 2 cm) and T1bN0M0 (2 < d ≤ 3 cm), in the International Association for the Study of Lung Cancer, seventh edition of TNM Classification of Malignant Tumors.

Objective The purpose of this study was the identification of independent clinicopathological predictors of prognosis of these two subgroups of NSCLC.

Methods Between 1986 and 2005, a cohort of 1,929 cases of stage IA NSCLC in Tian Jin Medical University Cancer Institute and Hospital were retrospectively analyzed. The impact of clinicopathological characteristics on patients' survival was investigated.

Results The overall 5-year survival rate was 71.07%. Patients with T1aN0M0 NSCLC had a better 5-year survival than those with T1bN0M0 (73.98 vs. 68.18%, p = 0.0135). The Cox proportional hazard model revealed that the prognostic factors of T1aN0M0 were intratumoral vessel invasion (p = 0.035) and histologic differentiation (p = 0.004). In patients with T1bN0M0 NSCLC, the prognostic factors were histologic differentiation (p < 0.01), intratumoral vessel invasion (p < 0.01), removal of 6 or more lymph node stations (p < 0.01), and removal of lymph node station 7 (p < 0.01).

Conclusion Prognostic factors of T1aN0M0 and T1bN0M0 NSCLC are different. In patients with T1bN0M0 NSCLC, 6 or more lymph node stations and lymph node station 7 should be removed.

Keywords

T1aN0M0 - T1bN0M0 - non–small cell lung cancer - prognosis

• References

• 1 López-Encuentra A, Duque-Medina JL, Rami-Porta R, de la Cámara AG, Ferrando P. Bronchogenic Carcinoma Co-operative Group of the Spanish Society of Pneumology and Thoracic Surgery. Staging in lung cancer: is 3 cm a prognostic threshold in pathologic stage I non-small cell lung cancer? A multicenter study of 1,020 patients. Chest 2002; 121 (5) 1515-1520
• 2 Wisnivesky JP, Yankelevitz D, Henschke CI. The effect of tumor size on curability of stage I non-small cell lung cancers. Chest 2004; 126 (3) 761-765
• 3 Mery CM, Pappas AN, Burt BM , et al. Diameter of non-small cell lung cancer correlates with long-term survival: implications for T stage. Chest 2005; 128 (5) 3255-3260
• 4 Agarwal M, Brahmanday G, Chmielewski GW, Welsh RJ, Ravikrishnan KP. Age, tumor size, type of surgery, and gender predict survival in early stage (stage I and II) non-small cell lung cancer after surgical resection. Lung Cancer 2010; 68 (3) 398-402
• 5 UICC International Union Against Cancer. Lung and pleural tumors. In: Sobin LH, Gospodarowicz MK, Wittekind C, , eds. TNM Classification of Malignant Tumors. 7th ed. Oxford, England: Wiley-Blackwell; 2009: 138-146
• 6 Goldstraw P. The 7th edition of TNM in lung cancer: what now?. J Thorac Oncol 2009; 4 (6) 671-673
• 7 Patz Jr EF, Rossi S, Harpole Jr DH, Herndon JE, Goodman PC. Correlation of tumor size and survival in patients with stage IA non-small cell lung cancer. Chest 2000; 117 (6) 1568-1571
• 8 Yanagi S, Sugiura H, Morikawa T , et al. Tumor size does not have prognostic significance in stage IA NSCLC. Anticancer Res 2000; 20 (2B) 1155-1158
• 9 Ye C, Masterman JR, Huberman MS , et al. Subdivision of the T1 size descriptor for stage I non-small cell lung cancer has prognostic value: a single institution experience. Chest 2009; 136 (3) 710-715
• 10 Rusch VW, Asamura H, Watanabe H, Giroux DJ, Rami-Porta R, Goldstraw P. Members of IASLC Staging Committee. The IASLC Lung Cancer Staging Project: A proposal for a new international lymph node map in the forthcoming seventh edition of the TNM classification for lung cancer. J Thorac Oncol 2009; 4: 568-577
• 11 Zhang Z, Xu F, Wang S, Li N, Wang C. Influence of smoking on histologic type and the efficacy of adjuvant chemotherapy in resected non-small cell lung cancer. Lung Cancer 2008; 60 (3) 434-440
• 12 Mountain CF, Carr DT, Anderson WAD. A system for the clinical staging of lung cancer. Am J Roentgenol Radium Ther Nucl Med 1974; 120 (1) 130-138
• 13 Flieder DB, Port JL, Korst RJ , et al. Tumor size is a determinant of stage distribution in T1 non-small cell lung cancer. Chest 2005; 128 (4) 2304-2308
• 14 Chang MY, Mentzer SJ, Colson YL , et al. Factors predicting poor survival after resection of stage IA non-small cell lung cancer. J Thorac Cardiovasc Surg 2007; 134 (4) 850-856
• 15 Christian C, Erica S, Morandi U. The prognostic impact of tumor size in resected stage I non-small cell lung cancer: evidence for a two thresholds tumor diameters classification. Lung Cancer 2006; 54 (2) 185-191
• 16 Goldstraw P, Crowley J, Chansky K , et al; International Association for the Study of Lung Cancer International Staging Committee; Participating Institutions. The IASLC Lung Cancer Staging Project: proposals for the revision of the TNM stage groupings in the forthcoming (seventh) edition of the TNM classification of malignant tumours. J Thorac Oncol 2007; 2 (8) 706-714
• 17 Rami-Porta R, Ball D, Crowley JJ , et al; International Staging Committee; Cancer Research and Biostatistics; Observers to the Committee; Participating Institutions. The IASLC Lung Cancer Staging Project: proposals for the revision of the T descriptors in the forthcoming (seventh) edition of the TNM classification for lung cancer. J Thorac Oncol 2007; 2 (7) 593-602
• 18 Postmus PE, Brambilla E, Chansky K , et al; International Association for the Study of Lung Cancer International Staging Committee; Cancer Research and Biostatistics; Observers to the Committee; Participating Institutions. The IASLC Lung Cancer Staging Project: proposals for revision of the M descriptors in the forthcoming (seventh) edition of the TNM classification of lung cancer. J Thorac Oncol 2007; 2 (8) 686-693
• 19 Maeda R, Yoshida J, Ishii G , et al. Long-term survival and risk factors for recurrence in stage I non-small cell lung cancer patients with tumors up to 3 cm in maximum dimension. Chest 2010; 138 (2) 357-362
• 20 Suzuki K, Nagai K, Yoshida J. Conventional clinicopathologic prognostic factors in surgically resected nonsmall cell lung carcinoma. A comparison of prognostic factors for each pathologic TNM stage based on multivariate analyses. Cancer 1999; 86 (10) 1976-1984
• 21 Miyoshi K, Moriyama S, Kunitomo T, Nawa S. Prognostic impact of intratumoral vessel invasion in completely resected pathologic stage I non-small cell lung cancer. J Thorac Cardiovasc Surg 2009; 137 (2) 429-434
• 22 Naruke T. Significance of lymph node metastases in lung cancer. Semin Thorac Cardiovasc Surg 1993; 5 (3) 210-218
• 23 Izbicki JR, Passlick B, Pantel K , et al. Effectiveness of radical systematic mediastinal lymphadenectomy in patients with resectable non-small cell lung cancer: results of a prospective randomized trial. Ann Surg 1998; 227 (1) 138-144
• 24 Gajra A, Newman N, Gamble GP, Kohman LJ, Graziano SL. Effect of number of lymph nodes sampled on outcome in patients with stage I non-small-cell lung cancer. J Clin Oncol 2003; 21 (6) 1029-1034
• 25 Wu YC, Lin C-FJ, Hsu WH, Huang BS, Huang MH, Wang LS. Long-term results of pathological stage I non-small cell lung cancer: validation of using the number of totally removed lymph nodes as a staging control. Eur J Cardiothorac Surg 2003; 24 (6) 994-1001
• 26 Ou SH, Zell JA. Prognostic significance of the number of lymph nodes removed at lobectomy in stage IA non-small cell lung cancer. J Thorac Oncol 2008; 3 (8) 880-886
• 27 Izbicki JR, Passlick B, Hosch SB , et al. Mode of spread in the early phase of lymphatic metastasis in non-small-cell lung cancer: significance of nodal micrometastasis. J Thorac Cardiovasc Surg 1996; 112 (3) 623-630
• 28 Gu CD, Osaki T, Oyama T , et al. Detection of micrometastatic tumor cells in pN0 lymph nodes of patients with completely resected nonsmall cell lung cancer: impact on recurrence and Survival. Ann Surg 2002; 235 (1) 133-139