Low Rate of Cancer Events After Partial Nephrectomy for Renal Cell Carcinoma: Clinicopathologic Analysis of 1994 Cases with Emphasis on Definition of "Recurrence".

Systematic pathology reviews in patients who experienced a clinical "recurrence" after partial nephrectomy for renal cell carcinoma (RCC) are anecdotal; therefore, definitions of "recurrence" varies considerably. We aimed to better define local recurrence by re-evaluation of surgical specimens of patients who experienced "recurrences" after partial nephrectomy at our institution.

Retrospective analysis of our institutional partial nephrectomy data set was performed. Patients who were clinically diagnosed with a local recurrence during the oncological follow-up after primary intervention for RCC were considered (January 2007 to December 2017, institutional review board number 5065, 15-1593). Re-evaluation of specimens coming from either primary treatment or management of the diagnosed recurrent disease was performed by 2 dedicated urologic pathologists. According to the findings of the pathology review, patients were assigned to 3 groups of disease event: (1) local recurrence of RCC; (2) new occurrence of RCC; and (3) micrometastatic RCC. Patient demographic characteristics, tumor pathological characteristics, oncological outcomes, disease treatment, and follow-up were reported for each patient. Cancer-specific survival was compared using the Kaplan-Meier method.

Of 1994 cases recorded in the institutional database, data on 30 patients who were clinically diagnosed with a local recurrence were extracted. After pathology review, 9 patients were found who truly developed a local recurrence (group 1). Positive surgical margin status was poorly related to the likelihood of a true local recurrence as defined herein. Twelve patients were assessed with a new occurrence of RCC (group 2). Nine were diagnosed with micrometastatic RCC (group 3). With comparable follow-up lengths among the groups (39 [interquartile range (IQR), 32-45] versus 51.5 [IQR, 35-90.5] versus 42 [IQR, 13-65], group 1 versus 2 versus 3, respectively; P = .4), patients classified in group 1 and 3 had comparable cancer-specific survival (P = .5). Conversely, patients in group 2 were less likely to die of disease compared with group 1 and 3 patients (P = .02).

Careful pathologic classification of RCC disease events after partial nephrectomy has important prognostic implications and allows more precise study of the clinical significance of margin status.

Clinical genitourinary cancer. 2019 Mar 23 [Epub ahead of print]

Riccardo Bertolo, Marlo Nicolas, Juan Garisto, Cristina Magi-Galluzzi, Jesse K McKenney, Jihad Kaouk

Glickman Urological and Kidney Institute, Department of Urology, Cleveland Clinic, Cleveland, OH., Robert J. Tomsich Pathology and Laboratory Medicine Institute, Department of Anatomic Pathology, Cleveland Clinic, Cleveland, OH., Glickman Urological and Kidney Institute, Department of Urology, Cleveland Clinic, Cleveland, OH. Electronic address: .