Matthieu Tihy, Jean-Yves Scoazec, Serge Guyétant, Mohamed-Amine Bani, Céline Bazille, Geneviève Belleannée, Christian Boissy, Camille Boulagnon-Rombi, Aurélie Cazes, Aurélie Charissoux, Marie-Pierrette Chenard, Marie Danjoux, Camille Darcha, Laurent Doucet, Charlotte Dufour, Antonin Fattori, Anne Guyot, Valérie Hervieu, Marie-Françoise Heymann, Catherine Julié, Thibault Kervarrec, Cosmin Lazaroiu, Emmanuelle Leteurtre, Laurent Martin, Stéphanie Patouraux, Flora Poizat, Nicolas Poté, Agathe Régnier, Benjamin Rivière, Magali Svrcek, Benoît Terris, Jérôme Cros, Anne Couvelard
The ENDOCAN-TENpath third-reading process yields a high rate of clinically actionable diagnostic decisions directly altering treatment strategy, while identifying unmet needs and providing a framework for reducing diagnostic variability in complex NEN cases.
PURPOSE: In some situations, the pathological diagnosis of neuroendocrine neoplasms (NEN) remains challenging, with direct consequences for treatment decisions. ENDOCAN-TENpath, the French national expert network for NEN pathology, established monthly virtual "third-reading" sessions for collegial review of difficult cases. We evaluated the diagnostic outcomes and clinical impact of this process.
METHODS: All cases submitted to third-reading sessions from March 2022 to December 2023 were retrospectively reviewed. We analyzed diagnostic difficulties, diagnostic modifications, and their expected therapeutic impact.
RESULTS: Of 3239 cases received by ENDOCAN-TENpath, 126 (3.9%) were submitted to third-reading by 22 of 33 network pathologists (median turnaround: 20 days). Diagnostic difficulties fell into four categories: high-grade NEN classification (33.3%), mixed neuroendocrine/non-neuroendocrine neoplasm diagnosis (36.5%), incomplete neuroendocrine phenotypes (23.0%), and unfamiliar entities (7.1%). Consensus or majority diagnosis was reached in 102 cases (81%). Unresolved cases were due to lack of consensus (n = 13) or insufficient material (n = 10). Critically, the process yielded decisions with major therapeutic consequences: 20/46 presumed NENs were reclassified as non-neuroendocrine malignancies and 5/25 presumed adenocarcinomas as NENs, fundamentally altering treatment strategy. Furthermore, 32/42 ambiguous high-grade NENs were definitively classified as tumor or carcinoma, directly determining first-line chemotherapy regimen. These findings also prompted internal guidelines to reduce diagnostic variability.
CONCLUSION: The ENDOCAN-TENpath third-reading process yields a high rate of clinically actionable diagnostic decisions directly altering treatment strategy, while identifying unmet needs and providing a framework for reducing diagnostic variability in complex NEN cases.