[619] Measurement of Depth of Invasion, Submucosal and Lymphovascular Invasion (LVI) Predicts Lymph Node (LN) Involvement in T1 Esophageal Adenocarcinoma (EAC). Invasion of Duplicated Muscularis Mucosae (MM) Has Similar Risk of LN Involvement as Mucosal Invasion.

Jeannelyn S Estrella, Wayne Hofstetter, Arlene M Correa, Jaffer Ajani, Stephen Swisher, Asif Rashid, Dipen Maru. U.T. M.D. Anderson Cancer Center, Houston, TX

Background: The major challenge in treatment of T1 EAC is to decide who should be treated by endoscopic mucosal resection or limited esophagectomy. Measurement of depth of invasion has prognostic value in other tumor sites but has not been assessed in EAC. Recent studies have shown duplicated MM in EAC but potential for LN metastasis in tumors invading the duplicated MM space is yet to be addressed.
Design: H&E from esophagectomy from 91 patients (M/F 84/7, average age 63 yrs.) with T1 EAC were evaluated for tumor differentiation, tumor configuration (exophytic or ulcerated), depth of invasion (mucosa, duplicated MM or submucosa), LVI and depth of invasion in millimeter (from the top of the tumor to deepest focus of invasion). Depth of invasion in millimeter and invasion into three layers were reviewed by second pathologist for interobserver variability. Both pathologists were blinded from LN status. Interobserver variability was assessed by kappa statistics/Pearson coefficient and logistic regression was used to correlate parameters with LN metastases in univariate model.
Results: LN metastases were observed with mucosal invasion (n=2), with submucosal invasion (n=9), and LVI (n=7), none with tumors in duplicated MM space.

Correlation of Pathologic Parameters with LN Status

	N	p	Odds Ratio	95% CI*
Depth of Invasion	91	0.006	1.04	1.01-1.07
Differentiation		0.07
Well (reference)	35
Moderate	42	0.17	4.60	0.51-41.34
Poor	14	0.03	13.60	1.36-135.91
LVI
No (reference)	71
Yes	20	<0.001	23.00	4.35-121.73
pT		0.15
Mucosa (LP or Inner MM)* (reference)	27
Duplicated MM*	37	1.00	0.00	0.00-N/A
Submucosa	27	0.05	5.26	1.00-27.69
pT
Mucosa* and Duplicated MM* (reference)	64
Submucosa	27	0.002	13.05	2.55-66.79

*CI-confidence interval; LP-lamina propria

Depth of invasion in millimeter, LVI and submucosal invasion were significantly associated with LN metastases while tumor configuration was not. Agreement in depth of invasion in millimeter and invasion into three layers between pathologists were good (k=1, pearson coefficient=0.81 respectively).
Conclusions: Measurement of depth of invasion, submucosal invasion and LVI are predictors of LN metastases in T1 EAC. Patients with invasion into duplicated MM space has similar risk of LN metastasis as those with mucosal invasion.
Category: Gastrointestinal

Tuesday, March 1, 2011 9:00 AM

Platform Session: Section E, Tuesday Morning