[1256] A Population-Based Study of Ovarian Serous Borderline Tumors (SBTs) with Uniform Pathology Review and Long-Term Follow-Up

Russell Vang, Charlotte G Hannibal, Susanne K Kjaer, Jette Junge, Kirsten Frederiksen, Anette Kjaerbye-Thygesen, Robert J Kurman. The Johns Hopkins Hospital, Baltimore; Danish Cancer Society, Copenhagen, Denmark; Hvidovre Hospital, Hvidovre, Denmark

Background: The behavior of SBTs and their relation to low-grade (micropapillary) serous carcinoma remain uncertain. We undertook a population-based study involving the entire country of Denmark, with uniform pathology review, no patients lost, and long-term follow-up.
Design: 2 nationwide registries, which cover 100% of the female population in Denmark, were searched for all cases with a diagnosis of SBT over a 25-year period (n=1,516). In order to find SBTs misclassified as carcinoma, cases with a diagnosis of “well-differentiated serous carcinoma” from 1997 to 2002 were also retrieved (n=114), resulting in an additional 64 SBTs. Slides of the ovarian tumors and implants from all cases were re-reviewed, and 1,009 SBTs were confirmed. The cohort was followed for up to 31 years (mean, 12.7 yrs). We subdivided SBTs into atypical proliferative serous tumor (APST) and non-invasive micropapillary serous carcinomas (MPSC) based on the amount of micropapillary (MP) growth. Because the threshold amount of MP growth that correlates with aggressive behavior has not been firmly established, we compared survival using a cut-point of at least 5 mm of MP growth vs. a cut-point of 1 mm as the criterion for a diagnosis of MPSC.
Results: Overall survival for patients with APST was significantly lower than the general female population using either the 1 mm or 5 mm cut-point to distinguish APST from MPSC (p=0.001, 0.003, respectively). Similarly, the overall survival for MPSC using the 1 mm cut-point was significantly lower than that of APST (p=0.007), but survival using the 5 mm cut-point, although lower, was not significant (p=0.15). Using both the 1 mm and 5 mm cut-points, MPSC compared to APST had a higher frequency of advanced stage disease (p<0.0001, 0.001, respectively), invasive implants (p<0.0001, 0.0001, respectively), and microinvasion (p<0.0001, 0.003, respectively).
Conclusions: The mortality of patients with APST with <1 mm of MP growth is lower than that of the general population in Denmark. Mortality for tumors with 1-5 mm of MP growth was significantly increased compared to APST. Based on these findings, consideration should be given to reducing the threshold for the diagnosis of MPSC from 5 mm to 1 mm.
Category: Gynecologic & Obstetrics

Tuesday, March 20, 2012 8:00 AM

Platform Session: Section E, Tuesday Morning


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