[631] Validation of a Topographic-Anatomic Subclassification for Adenocarcinoma of the GE Junction (GEJ)

EG Demicco, AB Farris, B Agbor-Etang, J Fukuoka, D Daives, M Snimizu, HA Gaissert, M Mino-Kenudson. Massachusetts General Hospital, Boston; Emory University, Atlanta; Toyama University Hospital, Toyama, Japan; Saitama Medical University, Saitama, Japan

Background: The incidence of adenocarcinoma of the GEJ is increasing more rapidly than any other cancer in the US. Due to the location, staging and treatment for GEJ tumors varies among institutions. The Siewert classification system differentiates between adenocarcinoma of the esophagus (type 1) and that of "cardia" (type 2). The aim of this study was to evaluate whether there was a difference in biologic properties between the 2 types.
Design: We evaluated 149 untreated GEJ type 1 (n=49) and type 2 (n=100) tumors consecutively resected between 2000 and 2008. Demographic data, clinical and/or pathologic evidence of BE, tumor stage, tumor histology (adenosquamous cell carcinoma [AdSq], conventional adenocarcinoma [Ad], mucinous/signet ring cells [muc], medullary/undifferentiated [med], heterogenous [mix]) and outcome were compared between the 2 types. A subset of cases with available blocks (type 1: 40, type 2: 74) was examined by immunohistochemistry using tissue microarray and classified into 4 mucin phenotypes (intestinal [I], gastric [G], combined intestinal and gastric [M], and null [N]).
Results: Type 1 was more likely associated with male gender (p = 0.060), BE background (p = 0.00072) and mixed mucin phenotype (p = 0.028) (Table 1).

Table 1
Type 1 (n=49)Type 2 (n=100)
Age (yrs)65.7 +/- 11.166.0 +/- 10.7
BE42 (89%)b58 (58%)b
Tumor size (cm)4.2 +/- 2.13.9 +/- 2.2
a: p=0.06, b: p < 0.001, c: p < 0.05

While the 5 year survival rate was better in type 1 (27.3% vs. 11.1%), the difference was not statistically significant (p = 0.11). On multivariate analysis, cardiac location (type 2) trended to independently predict poor survival (p = 0.0783), as did older age (p = 0.0419), advanced T stage (p = 0.027), LN metastasis (p = 0.005), and tumor size (p = 0.027).
Conclusions: Although type 1 and type 2 tumors are morphologically similar, type 2 tumors are associated with a lower incidence of BE background and mucin phenotypes different from those of type 1, and appear to predict poor prognosis. Our results suggest that type 1 and type 2 tumors have different biologic properties.
Category: Gastrointestinal

Wednesday, March 24, 2010 9:30 AM

Poster Session V # 71, Wednesday Morning


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