OBJECTIVE: Discrepancies may exist between an original pathology report and formal pathology review, with subsequent implications for treatment. We conducted a study of pathology review in endometrial cancer from a population-based study to identify areas of discrepancy and effect on treatment.
METHODS: This was a retrospective cohort study in Ontario, Canada from 1996 to 2000. We identified hysterectomy cases from patients with endometrial cancer that were subject to formal pathology review by a gynecologic pathologist at one of six tertiary care centers. Sarcomas and other rare histologic subtypes with fewer than five cases were excluded. We evaluated discrepancy between original pathology and review by demographics, stage, grade, and risk group. Four risk groups were defined: 1) low (stage I), 2) intermediate (stage I and II), 3) high-risk (stage I and II), and 4) advanced stage (all stage III and IV). Reclassification from one risk group to another upon pathology review represented a potential change in treatment. Factors associated with significant discrepancy were identified by a multivariable logistic regression model.
RESULTS: Formal pathology review was available on 450 cases. There were no differences by age, year, or hospital type. The overall discrepancy rate was 42.7% (95% confidence interval 38.2–47.3%). The intermediate-risk group had the highest rate of reclassification into another group (33.1%). The most significant rates of discrepancy were associated with endometrioid grades 2 and 3 tumors and stage IIA disease (39.8%, 50.9%, and 79.6%, respectively).
CONCLUSION: There was significant discrepancy between original pathology and formal review in endometrial cancer, with implications for guidelines on pathology review at a population level.
LEVEL OF EVIDENCE: III
There is significant discrepancy between original pathology and formal pathology review in endometrial cancer that has implications for guidelines at a population level.
From the 1Department of Gynecologic Oncology, M.D. Anderson Cancer Center, Houston, Texas; 2Division of Gynecologic Oncology, University of Western Ontario, London, Ontario, Canada; 3Department of Programming and Biostatistics, Institute for Clinical Evaluative Sciences, Toronto, Ontario, Canada; and 4Department of Pathology, London Health Sciences and University of Western Ontario, London, Ontario, Canada.
See related editorial on page 1222.
Supported by a junior scientist award from the Mitchell Family, National Ovarian Cancer Association, and Cancer Care Ontario to Dr. Kwon.
Corresponding author: Janice S. Kwon, MD, MPH, FRCSC, Department of Gynecologic Oncology, M.D. Anderson Cancer Center, PO Box 301439, Unit 1362, Houston, TX, 77230-1439; e-mail: firstname.lastname@example.org.
Financial Disclosure The authors have no potential conflicts of interest to disclose.