Medizinische Universität Graz Austria/Österreich - Forschungsportal - Medical University of Graz
Gewählte Publikation:
Hatzl, S.
Accordance between frozen section and paraffin section diagnosis in renal cell carcinoma a single center analysis of 3140 renal cell carcinoma patients
Humanmedizin; [ Diplomarbeit ] Graz Medical University; 2015. pp.
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- Autor*innen der Med Uni Graz:
- Betreuer*innen:
- Chromecki Thomas
- Zigeuner Richard
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- Abstract:
- Purpose: One of the basic principles in partial nephrectomy is the resection of the tumor with negative margins verified by frozen section analysis. In cases of positive tumor margins the surgeon is committed to complete the local resection or to perform radical nephrectomy. In this study I retrospectively evaluated the accordance between the yields of frozen section analysis performed during partial nephrectomy and the yields of final pathologic reports, with regard to the compatibility of histological tumor types and positive surgical margins. Material and Methods: I retrospectively re-evaluated567pathology report of patients undergoing partial nephrectomy with localized renal cell carcinoma from 1994-2013. I stratified the patients into a “frozen section analysis”-group (FSA) and “non - frozen section analysis” –group (non FSA). In 442 patients (78%) frozen section was performed during partial nephrectomy and in125 patients (22%) no frozen section analysis was done. These two groups were compared using ¿²-test, ANOVA, log-rank test and Mann–Whitney U test regarding paraffin embedded pathology, local recurrence and cancer specific survival. I further investigated the histological tumor types, which have been misinterpreted by the pathologist in the “frozen section analysis” group using the ¿²-test and ANOVA. Results: A total of 567 patients (mean age 60.8 years ± 17.7 years, 66.6% male) underwent intended partial nephrectomy (mean tumor size 3.3cm ± 1.8 cm) from 1994 to 2013.Comparing tumor characteristics between FSA and non-FSA groups, no differences with regard to histological types, tumor grade (Fuhrman), tumor stage, vascular invasion, sarcomatoid differentiation and tumor size were observed between groups. Frozen section margins were positive in 103 patients (23.3%) in the “FSA”-group. Final margins were positive overall in 54/567 (9.5%), including 7 /125 patients (5.6%) in the “nonFSA”-group compared to 47/442patients (10.6%) in the “FSA”-group (p = 0.09).75 patients underwent immediate radical nephrectomy for positive margins in the FSA group. Final pathology revealed residual tumor in 22/75(29%) and no tumor in 53/75 (71%) kidneys. Thus, FSA altered surgical management in 75/442 (17%) operations, in 22/442 (5%) with potential benefit for the patient whereas in 53/442 (12%) cases FSA resulted in overtreatment. Frozen section analysis regarding margin status yielded a sensitivity of 74.5%, a specificity of 82.8%, positive predictive value was 34% and negative predictive value was 96.5%. Overall, 20/492 (4%) patients developed local recurrence after partial nephrectomy, including 17/367(4.6%) in the “FSA”-group and 3 (2.4%) in the “nonFSA”-group (p=0.33).4patients with a local recurrence had PSM and 13 a negative surgical margin in the final pathology. Cancer specific survival rates were comparable between FSA and non-FSA-groups. Regarding tumor entities, frozen section and final pathology diagnosis were concordant in 88% (400/442) of the cases in which frozen section was performed. Of the 42 (10%) discordant cases, 4 (10 %) were over diagnosed and 38 (90%) were under diagnosed. Univariable analysis did not reveal any correlation with the accuracy of frozen section diagnosis and patient age, tumor size, presence or absence of sarcomatoid differentiation, the side of tumor localization, grading or staging. Conclusion: Partial nephrectomy for treatment of RCC can be safely performed with sufficient parenchymal excision without frozen section. Due to its low positive predictive value regarding margin status we cannot recommend routinely frozen section in the treatment of renal lesion, since it does not seem to impact on oncological outcomes and may even result unnecessary nephrectomies.