Diagnosis of Ovarian Carcinoma Histotype Based on Limited Sampling: A Prospective Study Comparing Cytology, Frozen Section, and Core Biopsies to Full Pathologic Examination

Growing insights into the biological features and molecular underpinnings of ovarian cancer has prompted a shift toward histotype-specific treatments and clinical trials. As a result, the preoperative diagnosis of ovarian carcinomas based on small tissue sampling is rapidly gaining importance. The data on the accuracy of ovarian carcinoma histotype-specific diagnosis based on small tissue samples, however, remains very limited in the literature. Herein, we describe a prospective series of 30 ovarian tumors diagnosed using cytology, frozen section, core needle biopsy, and immunohistochemistry (p53, p16, WT1, HNF-1β, ARID1A, TFF3, vimentin, and PR). The accuracy of histotype diagnosis using each of these modalities was 52%, 81%, 85%, and 84% respectively, using the final pathology report as the reference standard. The accuracy of histotype diagnosis using the Calculator for Ovarian Subtype Prediction (COSP), which evaluates immunohistochemical stains independent of histopathologic features, was 85%. Diagnostic accuracy varied across histotype and was lowest for endometrioid carcinoma across all diagnostic modalities (54%). High-grade serous carcinomas were the most overdiagnosed on core needle biopsy (accounting for 45% of misdiagnoses) and clear cell carcinomas the most overdiagnosed on frozen section (accounting for 36% of misdiagnoses). On core needle biopsy, 2/30 (7%) cases had a higher grade lesion missed due to sampling limitations. In this study, we identify several challenges in the diagnosis of ovarian tumors based on limited tissue sampling. Recognition of these scenarios can help improve diagnostic accuracy as we move forward with histotype-specific therapeutic strategies.

Impact of Surgical Staging in Stage I Clear Cell Adenocarcinoma of the Ovary

Aim

The aim of this study was to evaluate the impact of surgical staging in stage I clear cell adenocarcinoma of the ovary (CCC).

Methods

We performed a retrospective review of 165 patients with stage I CCC treated with optimal or nonoptimal staging surgery.

Results

The median follow-up period in this study was 67 months. No significant difference was detected in recurrence-free survival (RFS) or overall survival (OS) between patients optimally and nonoptimally staged (RFS: P = 0.434; OS: P = 0.759). The estimated 5-year RFS and OS rates were 92.1% and 95.3% in patients with stages IA/IC1 and 81.0% and 83.7% in stages IC2/IC3, respectively. The multivariate analysis indicated that stages IC2/IC3 predicted worse RFS and OS than stages IA/IC1 in stage I CCC patients (RFS: P = 0.011; OS: P = 0.011). Subsequently, we investigated the impact of surgical staging, respectively, in stages IA/IC1 and stages IC2/IC3. Significant differences were observed in PFS and OS between patients optimally and nonoptimally staged with stages IA/IC1 (RFS: P = 0.021; OS: P = 0.024), but no significant difference was found in those with stages IC2/IC3. The multivariate analysis indicated that nonoptimal staging surgery predicted worse RFS than the optimal staging surgery in stages IA/IC1 CCC patients (P = 0.033). In addition, we investigated the impact of surgical staging for stages IA/IC1 in the adjuvant chemotherapy group. The 5-year RFS and OS rates in patients optimally and nonoptimally staged with stages IA/IC1 in the adjuvant chemotherapy group were 97.8% and 100%, and 85.2% and 89.4%, respectively. The multivariate analysis indicated that nonoptimal staging surgery predicted worse RFS than the optimal staging surgery for stages IA/IC1 patients in the adjuvant chemotherapy group (P = 0.019).

Conclusions

The prognosis for women with stage 1A/IC1 is very good. Surgical staging category was the only independent prognostic factor for RFS in stages IA/IC1 CCC.