Prognostic Significance and Reproducibility of Two Histological Classifications for Thymic Epithelial Tumors
AC Roden, ES Yi, SC Bryant, JL Donovan, JE Lewis, RS Marks, SD Cassivi, YI Garces, MC Aubry. Mayo Clinic, Rochester, MN
Background: Thymomas can be complicated by invasion, recurrence, metastases and death. Several histological classifications have been proposed, however, their prognostic significance, ability to guide further treatment and reproducibility have been controversial.
Design: Medical records from 100 pts with thymoma (19421981) were reviewed. Two pts were classified having carcinoma and removed from analyses (N=98). Two pathologists blinded to outcome independently classified all cases. If more than one subtype, a predominant and a worst type were determined. Statistical analyses were performed.
Results: 50 men & 48 women had a median age of 53yrs. The median FU was 9.5yrs. In 13 pts recurrence and/or metastasis occurred. 11 died of disease.
|WHO||# of pts|
|Mixed epithelial & lymphocytic||41|
Patients were staged according to Masaoka: I in 24, II in 48, III in 20, IVa in 5, IVb in1.
Results of Univariate Analyses*p-values
|Recurrence free survival (RFS)*||Overall survival (OS)*||Death to disease survival (DDS)*|
|Sup. vena cava (SVC) syndrome||<0.001||0.018||<0.001|
In multiple variable survival analysis, after adjusting for resection and neo-adjuvant therapy, only Bernatz classification (p=0.02) was an independent prognostic feature. Interobserver agreements were: WHO, 0.475; Bernatz 0.425, Invasion 0.293.
Conclusions: SVC syndrome, complete resection and neo-adjuvant radiation are strongest survival predictors. WHO and Bernatz classifications predicted RFS and OS but not DDS. Invasion into capsule predicts RFS, however not OS and DDS. After adjusting for resection and radiation, Bernatz classification was an independent factor. The interobserver agreement was only moderate in both classifications and poor for determining invasion into capsule.
Monday, March 9, 2009 9:30 AM
Poster Session I Stowell-Orbison/Autopsy Award # 233, Monday Morning