[1114] The Significance of the Pattern of Invasion in High Grade Serous Carcinoma of the Ovary.

Devki M Patel, Elvio G Silva, Christine Walsh. Cedars-Sinai Medical Center, Los Angeles, CA

Background: Most high grade serous carcinomas (HGSCa) of the ovaries are advanced stage tumors, which respond to chemotherapy but frequently recur quickly with fatal outcomes. However, there are some unusual cases that do not recur and have excellent survival. In this study, we compared cases that showed rapid recurrences with cases that did not recur.
Design: Out of a group of 216 cases of high stage (HGSCa), 45 cases did not recur. From this group, we studied 16 cases that had clinical and pathological material available and a minimum follow-up of 60 months. These cases were compared to 17 cases matched for comparable amounts of residual tumor and treatment that recurred in less than 18 months. A pattern of invasion characterized by small groups of cells in clefts or non-epithelial lined spaces (NELS) was evaluated in the primary and metastatic tumors. The volume of invasive tumor cells present within NELS was quantified as greater than or less than 50%. In addition, ER, PR, and p53 immunostains were performed in 29 cases. Significant p53 staining was defined as p53 staining greater than or equal to 90% of tumor cells or complete negativity (mutation without protein expression).
Results: Greater than 50% of tumor in NELS was identified in 14 of 17 cases (82%) that recurred, compared to only 4 of 16 cases (25%) that did not recur (p = 0.0016). ER was positive and PR was negative in most cases in both groups. Significant p53 staining was found in 12 of 15 cases (80%) that recurred and in 7 of 14 cases (50%) that did not recur (p = 0.128). Of the 10 cases that had greater than 50% of tumor in NELS and significant p53 staining, 9 cases (90%) recurred. Of the 4 cases that had less than 50% of tumor in NELS and p53 staining of less than 90%, all 4 cases (100%) did not recur. Of the 15 cases with discordant results, less than 50% of tumor in NELS but significant p53 staining or greater than 50% of tumor in NELS but p53 staining less than 90%, the pattern of invasion was more predictive than p53 staining (60% vs 40%).
Conclusions: 1. HGSCa with greater than 50% of tumor in NELS recur in a short time.
2. Significant p53 staining is found in cases that recur but without statistical significance.
3. When the amount of tumor in NELS and p53 expression agree, there is at least a 90% predictive value.
4. In cases that lack agreement between the amount of tumor in NELS and p53 expression, there is a slightly increased predictive value of the amount of tumor in NELS.
Category: Gynecologic & Obstetrics

Monday, February 28, 2011 8:45 AM

Platform Session: Section D, Monday Morning


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