Differentiation between penile squamous cell carcinoma patients who can benefit from limited organ-sparing surgery and those at significant risk of lymph node metastasis is based on histopathological prognostic factors including histological grade and tumor histological subtype. We examined levels of interobserver and intraobserver agreement in assessment of histological subtype and grade in 207 patients with penile squamous cell carcinoma. The cases were assessed by seven pathologists from three hospitals located in Sweden and Italy. There was poor to moderate concordance in assessing both histological subtype and grade, with Fleiss kappas of 0.25 (range: 0.02-0.48) and 0.23 (range: 0.07-0.55), respectively. When choosing HPV-associated and non-HPV-associated subtypes, interobserver concordance ranged from poor to good, with a Fleiss kappa value of 0.36 (range: 0.02-0.79). A re-review of the slides by two of the pathologists showed very good intraobserver concordance in assessing histological grade and subtype, with Cohen's kappa values of 0.94 and 0.91 for grade and 0.95 and 0.84 for subtype. Low interobserver concordance could lead to undertreatment and overtreatment of many patients with penile cancer, and brings into question the utility of tumor histological subtype and tumor grade in determining patient treatment in pT1 tumors.
Virchows Archiv : an international journal of pathology. 2021 Dec 10 [Epub ahead of print]
Luiza Dorofte, Diane Grélaud, Michelangelo Fiorentino, Francesca Giunchi, Costantino Ricci, Tania Franceschini, Mattia Riefolo, Sabina Davidsson, Jessica Carlsson, Gabriella Lillsunde Larsson, Mats G Karlsson
Department of Laboratory Medicine, Faculty of Medicine and Health, Örebro University, Örebro, Sweden. ., Department of Clinical Genetics and Pathology, Skåne University Hospital and Regional Laboratories, Malmö, Sweden., Department of Experimental, Diagnostic and Specialty Medicine, Alma Mater Studiorum, University of Bologna, Bologna, Italy., Pathology, Istituto Di Ricovero E Cure a Carattere Scientifico, Azienda Ospedaliero-Universitaria Policlinico Sant'Orsola-Malpighi, Bologna, Italy., Pathology Unit, Maggiore Hospital, AUSL Bologna, Bologna, Italy., Department of Urology, Faculty of Medicine and Health, Örebro University, Örebro, Sweden., Department of Laboratory Medicine, Faculty of Medicine and Health, Örebro University, Örebro, Sweden.