An Audit And Review Of Histopathological Reporting Of Prostate Cancer On Prostatic Tissue Specimens In Kenyatta National Hospital

Abstract

Background Cancer of the prostate is the second most frequent cancer in males globally and commonest in Kenya. The gold standard of diagnosis is histopathology. A complete report is required for patient management. Auditing of histopathology reporting is a key element of the quality assurance programme to ensure the generation of a reliable report. Studies have established that there have been significant changes in patient grading using the new modification of Gleason system and that there is observer variability in grading using this system. This study evaluated the completeness of prostate cancer reporting using the College of American Pathologists prostate cancer reporting protocol, to identify changes in grading with the 2014 modifications and to assess the level of inter-observer variability in grading. Objective: The main objective was to audit and review histopathological reporting of prostate cancer on prostatic tissue specimens in Kenyatta National Hospital. Study Design: A retrospective descriptive study. Study Area: KNH/University of Nairobi (UoN) histopathology laboratory. Study Population: A total of 137 prostatic tissue specimens previously reported as prostatic adenocarcinoma were audited. Method: All consecutive request forms, reports and blocks for cases previously reported as prostate cancer were retrieved. Information from the request form and reports was then entered into the data collection tool which incorporated the CAP reporting protocol. Histological sections were prepared and stained using Hematoxylin and Eosin. The diagnosis and grading were reviewed using the International Society of Urological Pathologists 2014 Gleason system by the principal investigator and two consultant pathologists. The initial Gleason grades and grade groups were compared with the review findings. Results: Age was indicated in 84.7% of all cases. The patient name and hospital number were xii the only parameters provide in all cases. Other request form details including date of procedure, type of procedure, date specimen received in the laboratory, PSA level, clinician’s details, clinical history and diagnosis were inconsistently indicated. Few macroscopic features were also inconsistently mentioned. The histological type in all cases was prostate adenocarcinoma not otherwise specified. In the initial report, 97.1% of cases were completely graded. Tumour volume was provided in 48.2% of cases. The other microscopic features were inconsistently reported. In the review, 94.2% of cases were graded. The predominant Gleason score sum was 9 while the grade group was 5. Gleason scores were upgraded in 51.8% of cases in the review whereas grade groups were upgraded in 43.1% of cases. The level of agreement was fair for the primary pattern (k 0.25), poor for the secondary pattern (k -0.31) and slight for the Gleason score sum (k 0.20). Conclusions: Histopathologic request forms for histopathology of prostatic tissue specimens are not adequately filled. Completeness of reporting of tumour characteristics compares well with other studies done elsewhere. The presence and use of a standard reporting protocol that is inclusive of all required features ensures complete capture of all these essential parameters. There was an upward shift in Gleason grades and grade groups with the use of the ISUP 2014 modified Gleason system. The strength of agreement between the initial and review Gleason grades and scores ranged from poor to fair. Recommendations: Sensitization of the clinicians on the importance of providing adequate information on the request forms. This can be done through continuous medical education sessions and clinico-pathological conferences. Use of the CAP cancer reporting protocol to enable the generation of a concise report with all the necessary features. There is need for institution of measures aimed at reducing observer variability in grading using the Gleason system. These include consensus grading of difficult cases, use of reference images and continuous training on any new changes in the system.