Moving Forward on Tumor Pathology Research Reporting: A Guide for Pathologists From the World Health Organization Classification of Tumors Living Evidence Gap Map by Tumour Type Group.

Evidence-based medicine (EBM) can be an unfamiliar territory for those working in tumor pathology research, and there is a great deal of uncertainty about how to undertake an EBM approach to planning and reporting histopathology-based studies. In this article, reviewed and endorsed by the Word Health Organization International Agency for Research on Cancer's International Collaboration for Cancer Classification and Research, we aim to help pathologists and researchers understand the basics of planning an evidence-based tumor pathology research study, as well as our recommendations on how to report the findings from these. We introduce some basic EBM concepts, a framework for research questions, and thoughts on study design and emphasize the concept of reporting standards. There are many study-specific reporting guidelines available, and we provide an overview of these. However, existing reporting guidelines perhaps do not always fit tumor pathology research papers, and hence, here, we collate the key reporting data set together into one generic checklist that we think will simplify the task for pathologists. The article aims to complement our recent hierarchy of evidence for tumor pathology and glossary of evidence (study) types in tumor pathology. Together, these articles should help any researcher get to grips with the basics of EBM for planning and publishing research in tumor pathology, as well as encourage an improved standard of the reports available to us all in the literature.

A New Hierarchy of Research Evidence for Tumor Pathology: A Delphi Study to Define Levels of Evidence in Tumor Pathology.

The hierarchy of evidence is a fundamental concept in evidence-based medicine, but existing models can be challenging to apply in laboratory-based health care disciplines, such as pathology, where the types of evidence and contexts are significantly different from interventional medicine. This project aimed to define a comprehensive and complementary framework of new levels of evidence for evaluating research in tumor pathology-introducing a novel Hierarchy of Research Evidence for Tumor Pathology collaboratively designed by pathologists with help from epidemiologists, public health professionals, oncologists, and scientists, specifically tailored for use by pathologists-and to aid in the production of the World Health Organization Classification of Tumors (WCT) evidence gap maps. To achieve this, we adopted a modified Delphi approach, encompassing iterative online surveys, expert oversight, and external peer review, to establish the criteria for evidence in tumor pathology, determine the optimal structure for the new hierarchy, and ascertain the levels of confidence for each type of evidence. Over a span of 4 months and 3 survey rounds, we collected 1104 survey responses, culminating in a 3-day hybrid meeting in 2023, where a new hierarchy was unanimously agreed upon. The hierarchy is organized into 5 research theme groupings closely aligned with the subheadings of the WCT, and it consists of 5 levels of evidence-level P1 representing evidence types that merit the greatest level of confidence and level P5 reflecting the greatest risk of bias. For the first time, an international collaboration of pathology experts, supported by the International Agency for Research on Cancer, has successfully united to establish a standardized approach for evaluating evidence in tumor pathology. We intend to implement this novel Hierarchy of Research Evidence for Tumor Pathology to map the available evidence, thereby enriching and informing the WCT effectively.

Induced sarcoid-like reactions in patients with metastatic melanoma treated with dabrafenib and trametinib: a monocentric retrospective study.

Combined BRAF and MEK inhibition is one of the first-line treatment strategies for patients with advanced BRAF-mutant melanoma. Sarcoid-like reactions (SLRs) have occasionally been described with melanoma systemic treatments such as immunotherapy or the BRAF inhibitor vemurafenib, but very few cases have been reported with dabrafenib and trametinib. Our aim was to better characterize SLR induced by this combination. We conducted a monocentric retrospective observational study among patients treated with dabrafenib and trametinib for BRAF-mutant advanced melanoma from January 2015 to March 2019. Patients presenting with histologically proven SLR were included. We also searched Medline database for all reported cases of SLR induced by targeted therapy. Of 63 patients on dabrafenib/trametinib combination, seven were diagnosed with a SLR. They all had specific cutaneous involvement, and one also displayed mediastinal and salivary glands involvement. None required systemic corticosteroids or dabrafenib/trametinib discontinuation. Three of them (43%) reached melanoma complete remission and are still on targeted therapy; and four patients progressed and died. A literature review yielded 22 additional cases of SLR induced by targeted therapy: the main affected organ was the skin, 11 patients (50%) had systemic involvement, five patients (23%) required systemic corticosteroids to reach partial or complete remission of SLR, 12 (55%) reached partial or complete response of melanoma while six (27%) progressed. BRAF and MEK inhibitors are potential triggers of SLR, although pathological mechanisms remain unclear. The mainstay of treatment is systemic or topical corticotherapy; targeted therapy discontinuation is usually not necessary.

[Basal cell carcinoma with matrical differentiation]. / Carcinome basocellulaire à différenciation matricielle.

Basal cell carcinoma with matrical differentiation is a very rare variant of basal cell carcinoma. To our knowledge, less than 30 cases have been reported. This tumor is composed of basaloid lobules showing a differentiation toward the pilar matrix cells. Recently, it has been demonstrated that beta-catenin would interfer with physiopathogenesis of matrical tumors, in particular pilomatricomas, but also basal cell carcinomas with matrical differentiation. This is a new case, with immunohistochemical and molecular analysis of beta-catenin, in order to explain its histogenesis.