[1119] Low Grade, Low Stage Endometrioid Adenocarcinoma of the Endometrium: Clinical Implications of the Pattern of Myoinvasion.

Charles M Quick, Taymaa May, Neil S Horowitz, Marisa R Nucci. Brigham and Women's Hospital, Boston, MA

Background: Endometrioid adenocarcinoma of the endometrium (EEC) is the most common histologic type of endometrial cancer with stage being the most important prognostic factor. While the majority of patients with low grade, low stage disease have a favorable prognosis (95% Stage 1, 70% Stage II, 5 year disease free survival), a subset of patients have a risk of recurrence and death. We were interested in evaluating patterns of myometrial invasion and correlating it with clinical outcome in order to potentially identify patients at increased risk.
Design: 230 cases of low grade EEC, from November 1998 to June 2004 were identified from our archives and reviewed to collect cases of low grade, low stage ECC with myoinvasion with at least 2 years of clinical followup. The myoinvasive cases were subclassified based on the type of invasion present: infiltrating glands, broad front, adenomyosis-like, microcystic elongated and fragmented glands (MELF), and adenoma-malignum. The depth of invasion and presence or absence of lymphovascular invasion were confirmed, and clinical follow up data was obtained.
Results: 71 (31%) cases of invasive low grade EEC were identified of which 55 had greater than 2 years of followup and formed the basis of this study. Of these, 24 (45%) were superficially invasive (<10% myoinvasion), 27 (48%) invaded 10-49%, and 4 (7%) invaded >50% into the myometrium. 6 (10%) cases contained cervical stromal invasion. The invasive patterns consisted of infiltrative glands (34; 56%), broad front (14; 32%), MELF (4; 6%), adenomyosis-like (2; 4%), and adenoma malignum like (1 case with 90% invasion). Lymphovascular invasion was noted in 3 cases (7%). Twenty-seven (48%) patients had a hysterectomy and bilateral salpingo-oophorectomy while 28 (52%) also underwent a lymphadenectomy. Twenty percent (13 patients) received adjuvant therapy which consisted of chemotherapy, radiation therapy, or vaginal brachytherapy. None of the cases with myoinvasion recurred (follow-up from 24-141 months; mean 83 months).
Conclusions: In this series, only a small percentage of patients with low grade, low stage EEC had myometrial invasion (71/230; 31%). Pattern of myoinvasion does not appear to impact the rate of recurrence. Regardless of the pattern of myoinvasion, overall prognosis for women with low grade EEC remains excellent.
Category: Gynecologic & Obstetrics

Wednesday, March 2, 2011 1:00 PM

Poster Session VI # 152, Wednesday Afternoon


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