[1127] Predictors of Lymph Node Metastasis or Extrauterine Disease in Low Grade Endometrial Carcinoma, a Multi Institutional Study

Elizabeth Euscher, Patricia Fox, Roland Bassett, Hayma Al-Ghawi, Rouba Ali-Fehmi, Denise Barbuto, Bojana Djordjevic, Elizabeth Frauenhoffer, Sun Rang Hong, Insun Kim, Delia Montiel, Elizabeth Moschiano, Andres Roma, Elvio Silva, Anais Malpica. MD Anderson, Houston, TX

Background: Lymph node metastases (LNM) and extrauterine disease (ED) are infrequent in low grade (FIGO grades 1/2) endometrioid carcinoma (LGEC). This study evaluates predictors of LNM or ED in a large multi institutional study.
Design: For LGEC with and without LNM and ED, each of the 9 participating institutions evaluated pt age,tumor (tu) size, myometrial invasion (MI), FIGO grade, % solid component, % papillary architecture (PA) and presence of microcystic elongated and fragmented glands (MELF), single cell invasion (SCI), lymphovascular invasion (LVI), lower uterine segment (LUS) and cervix (CX) involvement and numbers of pelvic (PLN) and paraaortic (PALN) LNs sampled.
Results: Pt ages ranged from 23-91yrs (median 61). Table 1 summarizes the histopathologic variables. Table 2 provides univariate logistic regression results modeling LNM or ED. There was no evidence of a difference in the number of pelvic or para aortic LNs sampled between groups (p=0.10, 0.64, respectively).

Summary of Histopathologic Variables

	LN+ or ED+ (n=96)	LN-/ED- (n=206)
Variable	Count (%)	Count (%)
Tu≥2cm	93 (97)	149 (72)
MI >50%	54 (56)	56 (27)
MELF	61 (64)	68 (33)
SCI	28 (29)	16 (8)
LVI	77 (80)	52 (25)
>20% solid	31 (32)	44 (21)
PA	58 (60)	100 (49)
LUS involved	64 (67)	75 (36)
CX involved	40 (42)	23 (11)

Univariate Logistic Regression Results Modeling LNM or ED

Variable	Odds Ratio	Confidence Interval	p-value
Tu>2 cm	13.95	3.31-58.89	0.0003
%solid >20%	1.72	0.99-2.93	0.0527
PA	1.59	0.97-2.60	0.0658
%PA *	1.02	1.01-1.03	0.0058
MELF	3.54	2.13-5.87	<0.0001
SCI	4.58	2.36-8.89	<0.0001
LVI	12.00	6.64-21.7	<0.0001
LUS Involved	3.31	1.91-5.75	<0.0001
CX Involved	5.93	3.28-10.73	<0.0001
MI >50%	3.44	2.075-5.717	<0.0001
# PALN sampled	1.09	1.03-1.15	0.0048

*Several cutoffs were statistically significant with the lowest p-value at 0.001 for >30%PA


Conclusions: Tu size ≥2 cm, %PA, MELF, SCI, LVI, LUS and CX involvement, MI>50% and number of PALNs sampled were found to be significant predictors of the odds of LNM or ED.Presence of PA and %solid >20% also suggest increased odds (p=0.0658, 0.0527 respectively). Age, FIGO grade 2 vs 1 and number of PLNs sampled were not significant predictors. This multi institutional study validates MI and LVI as predictors of LNM and ED. Additionally, MELF and SCI invasion patterns as predictors of LNM and ED. Attention to pattern of invasion during frozen section may identify pts who could benefit from LND. Further study is required to determine a multivariate model to predict advanced stage and to study whether these features could also be predictors of recurrence.
Category: Gynecologic & Obstetrics

Monday, March 19, 2012 8:00 AM

Platform Session: Section E, Monday Morning