Reporting trends, practices, and resource utilization in neuroendocrine tumors of the prostate gland: A survey of genitourinary (GU) pathologists
Dhillon J, Williamson S, Desai S, Menon S, Shah R, Sirohi D, Balzer B, Varma M, Luthringer D, Nigam L, Roy P, Kaushal S, Midha D, Aron M, Jain K, Naik S, Baisakh M, Kini L, Sharma S, Sable M, Jain E, Samra S, Ro J, Osunkoya AO, Vankalakunti M, Parwani A, Gopalan A, Magi-Galluzzi C, and Mohanty S. Reporting trends, practices, and resource utilization in neuroendocrine tumors of the prostate gland: A survey of genitourinary (GU) pathologists. Modern Pathology 2020; 33(3):880.
Background: Neuroendocrine tumors of the prostate gland were recently classified in the WHO. Despite increasing experience in this area, the specifics and the new clinical and molecular emerging data from prostate cancers treated by contemporary androgen deprivation therapies, as well as primary lesions, need refinement of the diagnostic terminology to encompass the full spectrum of neuroendocrine differentiation. Use of immunohistochemistry (IHC) as a diagnostic, prognostic, and/or predictive tool remains unclear. This study aims at questionnaire- and scenario-based survey among the GU pathologists. Although some of the questions may appear superfluous, this topic based on discussions at multiple levels has evoked surprisingly passionate responses from some who have adopted a "more objective approach" using IHC, citing that recommendations imply that IHC is necessary to be certain. Design: An online survey containing 35 questions was undertaken by 39 GU pathologists (with 5 to 10 years, >10 years and >20 years experience) from four continents, focusing on ascertaining practice patterns in this area. Specific questions included whether, when, and how the respondents classify neuroendocrine differentiation/mixed carcinomas/Paneth cell change/neuroendocrine carcinoma (small, SCC/large cell, LCNEC) of the prostate gland. Additionally questions were posed regarding frequency and indications of IHC with respect to these issues. Some therapy and biomarker-related questions were added as well. De-identified respondent data was tabulated and analyzed by routine statistics. The responses were scored in percentage for each question. Results: 70% and 63% of the responders correctly diagnosed a SCC and mixed acinar adenocarcinoma-SCC, respectively. 37% pathologists felt the need of IHC in a SCC, even if the morphology is classical. A majority (87%) of the responders have the correct idea about the immunopanel and therapeutic options for a SCC. Most importantly, pathologists (85%) correctly mentioned that there is no role of TTF1 indifferentiating pulmonary from prostatic SCC, and determination of site of origin of a high-grade neuroendocrine carcinoma has no importance, as these are treated similarly. In the mixed carcinoma cases, exact quantitation of both the elements, grading of the acinar component as the therapy includes both androgen deprivation and platinum-based chemotherapy, and importance of androgen receptor immunoreactivity have been voted by 85% responders. 49% failed to diagnose Paneth cell-like differentiation, nor were they clear about its prognostic implications. Conclusions: 1. Awareness on morphological features and management of SCC across the pathologists was consistent and IHC work up was necessary for a subset of pathologists for confirmation. 2. Majority failed to recognize Paneth cell-like differentiation, nor were they clear about its prognostic implications, while a small subset failed to identify small cell-like PIN. 3. There still lies some confusion in recognizing Gleason 10 acinar adenocarcinoma and large cell neuroendocrine carcinoma. 4. In the mixed carcinoma cases, there seems to have a legitimate call for appropriate IHC work up, including prostatic and neuroendocrine markers and exact quantitation and grading of the acinar component as the therapy includes both androgen deprivation and platinum-based chemotherapy. 5. Based on the responses, practising trends are different between North America and Asia. Further study and consensus on best practice guidelines based on NCCN parameters are needed to provide guidance with regards to the appropriate indications for IHC use in the various scenarios and patterns of neuroendocrine features in the prostate gland.