“Validation” of the Proposed IASLC/ITMIG Staging Revisions of

Thymic Carcinomas Using Data from 287 Patients

Yang Zhao; Heng ZhaoDivision of Thoracic Surgery

Shanghai Chest Hospital

AATS ， Seattle, April 27th 2015

Disclosure

No conflicts related to this presentation;

Not a true validation study, only evaluation process;

Some statistic flaw amended by professional statistic personnel with resultant new results and conclusions;

BACKGROUND

• Thymic carcinoma ： A relatively rare neoplasm;• With distinct pathologic and clinical characteristics

(overt cytological atypia;lack of organotypical features);

• First reported by Shimosato

(Am J Surg Pathol 1977;1:109–21);• Nomenclature: 1982, Snover, Levine, Rosai

(Am J Surg Pathol 1982;6:451-70);• 2004 WHO classification: 13 histological subtypes;

• No official stage classification for thymic malignancies has been defined by the UICC and AJCC;

• From 2010, ITMIG recommended Masaoka-Koga stage classification system;

(James Huang. JCO 2010;5:2017-2023)

1981, Masaoka, based on 93 patients;

1994, Koga, based on 79 patients;

Has many ambiguities that have not been clearly defined

• The Masaoka system is limited to thymomas and does not seem to properly predict the outcome of TC.

• Masaoka stage did not have any statistical impact on survival.

(Pier Luigi Filosso.Lung cacer 2014;83;205-210) (40cases) (Yang Zhao. Ann Thorac Surg 2013;96:1019–24) (105 cases) (Yusuke Okuma. Lung Cancer 2014;84:175-181) (68 cases) (Usman Ahmad. JTCVS 2015;149:95-101)

(ITMIG&ESTS,1042cases) (Motoki Yano. JTO 2008;3:265-269) (30 cases)

But not in the SEER cohort (Benny Weksler ATS2013;95:299-304)

In 2014, the IASLC/ITMIG launched a worldwide

TNM staging proposal to inform the next edition

of thymic tumors.

Recommended that this proposed staging system is also applicable to thymic carcinomas.

• The rationale of this study is that a solidly staging system should been subjected to an intense evaluation process before officially published and widely accepted.

METHODS

• A retrospective review, single institution, consecutive patients,

Pathologically confirmed thymic carcinoma;

Carcinoid tumors were excluded ；

• Treated from February 2003 to April 2014;

• The last general follow-up of survivors was done at the end of October 2014;

• 287 patients was enrolled and 263 (91.6%) of them had complete follow-up data.

• Follow-up data was completed with a median of 32.0 months (range, 1 - 149 months).

Patients Characteristics

Survival

• OS: 5-years = 63.0%; 10-years = 46.5%; the median survival time = 101.0 ± 19.1 months;• DFS: 5-years = 43.4%; 10-years = 23.5%; the median recurrence time = 40.0 ± 7.4 months;

• At the conclusion of the study: 127 patients (48.3%) were alive with no evidence of disease progression; 57 were alive with the disease (21.7%); 72 died with the disease (27.4%);

• Seven patients (2.7%) died from disease-unrelated causes postoperatively.

A migration of stage distribution between these two system

OS of our 263 TC patientsIASLC & ITMIG

ITMIG & IASLC OS of our 263 TC patients

Masaoka-Koga system Proposed TNM system

Overall Survival

Masaoka-Koga system Proposed TNM system

Disease-free Survival

Masaoka-Koga system Proposed TNM system

Limitations:• Inherent biases associated with the retrospective study design;• Experience of a single center ；

Strengths:• An international classification system must be reproducible in the

diverse setting in which it is applied. In our 287 patients, 9.4% (27/287) managed nonsurgically, thus making this findings more generalizable.

• The prognostic ability of the staging system was verified by a multivariate analysis that considers other prognostic factors, i.e., sex, age, completeness of resection, yielding statistically valid analyses.

Summary

• The proposed TNM staging system shows priority on predicting clinical course compared with the conventional Masaoka-Koga system in thymic carcinoma patients for its capability of predicting both OS and DFS efficiently, compared failure of Masaoka-Koga system on OS predicting.

• We advocate this new system to be an official one on our clinical practice.

Thank you! Welcome to Shanghai!