Precision oncology relies on precision diagnostics, and histopathological diagnosis, along with biomarker evaluation, currently represents the cornerstone for personalized treatment. In gastrointestinal neoplasms, diagnostic assessment and molecular profiling are often performed on biopsy tissue, which may be quantitatively/qualitatively limited. Therefore, appropriate sample management is essential to avoid unnecessary waste and to obtain all the information necessary for treatment planning. Several factors may significantly impact biomarker testing: (i) pre-analytical issues; (ii) heterogeneity in biomarker expression; (iii) lack of standardization in biomarker testing and evaluation. Moreover, in the metastatic setting, inadequate/incomplete clinical information can lead to inappropriate sample handling, with negative implications. The application of appropriate guidelines in testing and reporting biomarker status according to clinical context is, therefore, strongly encouraged. In this position paper, the Italian Group of Gastrointestinal Pathologists (GIPAD), a section of the Italian Society of Pathological Anatomy and Cytology (SIAPeC-IAP), aims to summarize all the clinical and pathological requirements for adequate assessment of prognostic and predictive biomarkers in the gastrointestinal oncology patient, from biopsy acquisition to diagnostic reporting.

The NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines) for Genetic/Familial High-Risk Assessment: Breast, Ovarian, Pancreatic, and Prostate are intended to serve as a resource for health care providers to identify individuals who may benefit from cancer risk assessment and genetic counseling and testing; help guide decisions related to genetic testing; and facilitate a multidisciplinary approach in the comprehensive care of individuals at increased risk for hereditary breast, ovarian, pancreatic, and prostate cancer. The current guidelines focus primarily on assessment of pathogenic and likely pathogenic (P/LP) variants associated with increased risk of breast, ovarian, pancreatic, and prostate cancer and recommended approaches to genetic counseling/testing and care strategies in individuals with these P/LP variants associated with increased risk of these cancers. These NCCN Guidelines Insights summarize the panel's most recent recommendations regarding screening for prostate cancer and pancreas cancer, as well as testing criteria for nonepithelial ovarian cancer.

Cancer predisposition syndromes (CPSs), including genetic tumour risk syndromes (genturis), are a heterogeneous group of genetic disorders characterised by an increased risk of developing tumours compared to the general population. CPSs raise reproductive issues for affected individuals because of the risk of passing the disease-causing genetic alterations on to offspring. The demand for reproductive counselling is often unmet due to the lack of sufficient healthcare professionals with the specialised knowledge, experience and skill. Based on a comprehensive literature review of 851 publications and expert consensus (multidisciplinary medical experts and patient representatives), the European Reference Network on genetic tumour risk syndromes (ERN GENTURIS) developed a guideline providing 16 recommendations for reproductive counselling in CPSs. The central recommendation is to offer reproductive counselling proactively to all individuals with a CPS and their relevant family members, together with psychological support and in multidisciplinary collaborations. This guideline aims to standardize the offer of reproductive counselling for individuals with a CPS across Europe, empowers healthcare professionals for their specific tasks, and helps patients dealing with their own challenges.

Unresectable stage III non-small cell lung cancer (NSCLC) exhibits substantial heterogeneity and complexity. The landmark LAURA and POLESTAR studies have established a standard therapeutic model involving targeted consolidation therapy with osimertinib or aumolertinib after definitive chemoradiotherapy for NSCLC patients harboring EGFR-sensitive mutations. However, treatment strategies for patients with other driver gene mutations (e.g., ALK fusions, ROS1 rearrangement) still lack robust support from high-level evidence-based medical study. To enhance the standardization of diagnosis and treatment for unresectable stage III driver-positive NSCLC patients, the Radiotherapy Committee of the Chinese Society of Clinical Oncology convened an expert working group. This group identified common clinical practice issues and conducted an in-depth, problem-oriented analysis of domestic and international guidelines alongside evidence-based medical data. Through multiple rounds of comprehensive discussion and expert voting, this consensus was jointly developed. It provides evidence-based recommendations addressing frequently encountered clinical questions regarding unresectable stage III driver-positive NSCLC, aiming to serve as a key reference for clinical practice.

Measurable residual disease (MRD) monitoring has become a critical component in the management of acute myeloid leukemia (AML), to inform prognosis, guide therapy, and serve as a key end point in clinical trials. The 2025 update of the MRD guideline provides a comprehensive and refined framework for MRD assessment, aligned with the European LeukemiaNet (ELN) 2022 genetic risk classification. Developed by members of the ELN AML MRD Working Party, the guidelines incorporate expert consensus determined through a 2-stage Delphi round. They address the clinical implementation of MRD methodologies, technical considerations, integration into clinical trials, and future directions. Importantly, MRD recommendations are tailored to individual prognostic and genetic subgroups. A new qualitative MRD response category, designated as optimal, warning, or high risk of treatment failure, has been introduced to facilitate contextual interpretation of the MRD burden and its clinical relevance. Notably, ultrahigh-sensitivity next-generation sequencing-based MRD assessment is now recommended for FLT3 internal tandem duplication-mutated AML after intensive chemotherapy and before allogeneic hematopoietic cell transplantation. A total of 56 recommendations were formulated, with 53 achieving a high level of consensus (≥90%). These updated guidelines represent a major step forward toward harmonizing MRD assessments in AML and enhancing its clinical utility across diverse treatment settings.

Waldenström's macroglobulinemia (WM) is a rare, indolent B-cell lymphoma that predominantly affects older adults. In recent years, significant progress has been made in understanding its pathogenesis, identifying relevant biomarkers, and developing novel therapeutic approaches to complement traditional chemoimmunotherapy-collectively reshaping the management landscape of WM. In this article, we provide comprehensive, evidence-based recommendations for the diagnosis, molecular evaluation, and treatment of WM, including strategies for both frontline and relapsed disease. These guidelines are informed by the latest clinical research, expert consensus, and current practice standards, with the goal of equipping clinicians with a practical and effective framework for delivering optimal care to patients with WM.

It has been five years since the last version of the clinical practice guidelines for the management of adult diffuse gliomas was published by the Asian Glioma Genome Atlas (AGGA). Significant progress and revisions have occurred in the diagnosis and treatment of adult diffuse gliomas in recent years. In response to these updates, the joint guideline committee of the Chinese Glioma Cooperative Group (CGCG), the Society for Neuro-Oncology of China (SNO-China), and the Chinese Brain Cancer Association (CBCA) has revised the clinical practice guidelines. This updated guideline emphasizes molecular and pathological diagnostics, as well as the primary treatment modalities of surgery, radiotherapy, chemotherapy, and targeted therapy. Additionally, we have incorporated findings from recent clinical trials of new therapies to align with cutting-edge treatment strategies. This guideline is designed to serve as a practical resource for all professionals involved in managing adult diffuse glioma patients, while also providing valuable information for insurance companies and other institutions responsible for regulating cancer care costs in China and beyond.

Approximately 5% of all colorectal cancers have a strong genetic component and are classified as hereditary colorectal cancer (HCRC). Some of the unique features commonly seen in HCRC cases include early age of onset, synchronous/metachronous cancer occurrence, and multiple cancers in other organs. These characteristics require different management approaches, including diagnosis, treatment or surveillance, from those used in the management of sporadic colorectal cancer. Accurate diagnosis of HCRC is essential because it enables targeted surveillance and risk reduction strategies that improve patient outcomes. Recent genetic advances revealed several causative genes for polyposis and non-polyposis syndromes. The Japanese Society for Cancer of the Colon and Rectum (JSCCR) first published guidelines for the management of HCRC in 2012, with subsequent revisions every 4 years. The 2024 update to the JSCCR guidelines for HCRC was developed by meticulously reviewing evidence from systematic reviews and the consensus of the JSCCR HCRC Guidelines Committee, which includes representatives from patient advocacy groups for FAP and Lynch syndrome. These guidelines provide an up-to-date summary of HCRC, along with clinical recommendations for managing FAP and Lynch syndrome.

RAD51C, RAD51D, and BRIP1 germline pathogenic variants (GPVs) are associated with increased lifetime risks of tubo-ovarian cancer. Resources for managing RAD51C, RAD51D, and BRIP1 heterozygotes in clinical practice are limited.

The Italian Society of Pathology's Molecular Pathology and Precision Medicine Study Group (PMMP/SIAPeC) has released a three-part set of best practice guidelines to stan-dardize and enhance molecular testing in solid tumors. Part I focuses on the pre-analytical phase, emphasizing proper tissue handling and quality control to preserve nucleic acid integrity. Part II addresses the analytical phase, outlining workflows for next-generation sequencing (NGS), from extraction to variant interpretation, with recommendations on choice of platform, gene panels, and bioinformatics. Part III covers the post-analytical phase, offering guidance on structured, clinically meaningful reporting to support thera-peutic decisions, including standards for both tissue and liquid biopsies. Together, these documents aim to harmonize molecular diagnostics, ensuring reliable, high-quality results that support precision oncology.

The NCCN Guidelines for Non-Small Cell Lung Cancer (NSCLC) provide recommendations for the treatment of NSCLC. These NCCN Guidelines Insights discuss recent updates to the NCCN Guidelines, with a focus on systemic therapy options for the treatment of patients with nonmetastatic NSCLC and the corresponding molecular testing considerations.

UK Guidelines for the management of uveal melanoma (UM) were first published in 2015 using an evidence-based systematic approach. The primary aim of this guideline was to optimise patient care by providing recommendations based on the best available scientific evidence. The resulting guideline reflected the strengths and weaknesses of the available evidence, made recommendations that were clinically impactful around prognostication, surveillance, and treatment for patients with primary lesions and metastatic disease. The guideline development process and content met the standards required by NICE and were ultimately NICE accredited. Here, we present an update to these guidelines, highlighting where practice or treatment has changed to such an extent that the original recommendations are now out of date. Presented here are updated guidelines on molecular and genetic testing, management of metastatic disease and clinical surveillance.

Microsatellite instability (MSI) is the accumulation of insertion and deletion variants (instability) in short tandem repeat DNA sequences (microsatellites). High levels of MSI occur following loss of function of the DNA mismatch repair system (MMR). MMR deficiency is an increasingly important cancer biomarker that is associated with chemotherapy resistance and response to immune checkpoint blockade, as well as one of the commonest hereditary cancer syndromes, Lynch syndrome. Since its discovery over two decades ago, our biological understanding, the testing methods, and the clinical implications of MSI analysis have expanded rapidly and up-to-date best practice guidelines are needed. An expert working group reviewed the literature and devised 15 best practice recommendations that were finalised following consultation with clinical and laboratory scientists partnered with EMQN. These include seven recommendations on key technical aspects of MSI testing and eight recommendations on the clinical interpretation and reporting of results. The latter focuses on Lynch syndrome screening and immune checkpoint blockade therapy. Example report wording is provided to assist implementation and standardisation. Common terminology and MSI analysis methods are also discussed. These guidelines are aimed primarily at genomic scientists working in diagnostic testing laboratories, but will provide a useful review of MSI for clinicians, academics, and other related professionals.

To provide diagnostic guidance for individuals with lateralized overgrowth (LO) and implement appropriate screening protocols. LO without a syndromic presentation is considered idiopathic isolated lateralized overgrowth (ILO).

Cutaneous angiosarcoma is a rare aggressive malignancy with poor prognosis. Due to its rarity, high-level evidence from randomized controlled trials is limited, and treatment strategies have historically been adapted from other sarcomas. These guidelines aim to provide updated recommendations based on newly available evidence to standardize clinical practice in Japan. The 2024 revision was conducted under the Japanese Dermatological Association's commission, incorporating expert reviews and public comments. Given the lack of an established staging system, recommendations were formulated through systematic literature reviews and a structured consensus process. Five clinical questions were addressed, covering first-line chemoradiotherapy (CRT), management of residual lesions post-CRT, second-line treatment options, the role of pembrolizumab in tumor mutational burden-high cases, and treatment strategies for nonhead-and-neck angiosarcomas. Key recommendations include weakly recommending CRT for large (≥ 5 cm) nonmetastatic tumors, preferring drug modification over excision for residual lesions after CRT, and equally considering docetaxel, pazopanib, or eribulin for paclitaxel-resistant cases. Pembrolizumab was weakly recommended for tumor mutational burden-high cases. For radiation-associated angiosarcoma, surgical treatment was favored over CRT, while Stewart-Treves syndrome cases were treated similarly to head-and-neck angiosarcoma. Future directions emphasize the need for multicenter registry studies and prospective trials to refine treatment strategies. As advances in genomic medicine and immunotherapy evolve, guideline updates will be essential to ensure optimal patient care.

Living guidelines are developed for selected topic areas with rapidly evolving evidence that drives frequent change in recommended clinical practice. Living guidelines are updated on a regular schedule by a standing expert panel that systematically reviews the health literature on a continuous basis, as described in theASCO Guidelines Methodology Manual. ASCO Living Guidelines follow theASCO Conflict of Interest Policy Implementation for Clinical Practice Guidelines. Living Guidelines and updates are not intended to substitute for independent professional judgment of the treating clinician and do not account for individual variation among patients. See appendix for disclaimers and other important information (Appendix 1 and Appendix 2). Updates are published regularly and can be found athttps://ascopubs.org/nsclc-da-living-guideline.

Uveal melanoma (UM) is a rare malignancy originating from uveal melanocytes. Despite effective control of the primary tumour, metastatic uveal melanoma (MUM) occurs in approximately 20-30% of patients, primarily affecting the liver, with a poor prognosis and overall survival (OS). The unique molecular profile of UM, lacking BRAF, NRAS, and KIT mutations, limits targeted therapy efficacy. Chemotherapy and immune checkpoint inhibitors (ICIs) also show limited benefits, while tebentafusp has emerged as the first drug to improve OS, but this systemic treatment can be used only in HLA-A*02:01-positive patients. A French multidisciplinary panel developed evidence-based guidelines for MUM management presented in this review. Recommendations emphasise on comprehensive diagnosis, including liver biopsy and imaging, circulating tumour DNA (ctDNA) analysis, and high-definition HLA typing for HLA-A*02:01. Local therapies are proposed for patients with limited hepatic metastases, from liver surgery to isolated hepatic perfusion and chemoembolisation for patients with more extensive hepatic involvement. Systemic therapy with tebentafusp is the standard of care for HLA-A*02:01-positive patients. For HLA-A*02:01-negative patients with extensive disease, treatment options are limited. They are encouraged to participate in a clinical trial, alternatively, percutaneous hepatic perfusion, ICI alone or in combination can be proposed. Treatment efficacy assessment includes response evaluation criteria in solid tumours (RECIST), tumour growth rate (TGR) analysis, and ctDNA dynamics. This consensus provides practical guidelines for French oncologists to optimise MUM management, integrating locoregional interventions, systemic therapies, and biomarkers to enhance patient outcomes.

Hereditary endocrine neoplasia syndromes comprise multiple entities associated with an increased risk for the development of endocrine and nonendocrine neoplasms and other systemic manifestations. These syndromes typically demonstrate autosomal dominant inheritance, and each syndrome is associated with a unique genetic predisposition to a distinct spectrum of tumor susceptibility. Moreover, genotype-phenotype associations within each syndrome may affect the spectrum, penetrance, and age of onset of associated tumors. As many endocrine tumors are benign and/or indolent, a careful approach to monitoring is necessary, wherein the nature, timing of initiation, and frequency of presymptomatic surveillance balance the goal of detecting tumors at a point in which intervention would limit tumor-associated morbidity against the physical, emotional, and financial burdens of surveillance. In this study, we summarize changes in knowledge and practice recommendations related to children with multiple endocrine neoplasia syndromes (types 1, 2A, 2B, 4, and 5), hyperparathyroidism-jaw tumor syndrome, and Carney complex since an initial summary in 2017. These updates reflect the evolving understanding of these complex genetic disorders and aim to improve patient care and outcomes.

With widening therapeutic indications, germline genetic testing is offered to an increasing proportion of patients with breast cancer (BC) via mainstream oncology services. However, the gene set tested varies widely from just BRCA1/BRCA2 through to 'pan-cancer' panels of nearly 100 genes. If a germline pathogenic variant (GPV) is detected, the BC proband and other family GPV-carriers may be offered interventions such as risk-reducing surgery and intensive surveillance over decades for the various cancers linked to that gene.

Despite significant improvements in survival of patients with multiple myeloma (MM), outcomes remain heterogeneous, and a significant proportion of patients experience suboptimal outcomes. Importantly, traditional prognostic factors based on data from patients treated with older therapies no longer capture prognosis accurately in the contemporary era of novel triplet or quadruplet therapies. Therefore, risk stratification requires refinement in the context of available and investigational treatment options in routine practice and clinical trials, respectively. The current identification of high-risk MM (HRMM) in routine practice is based on the Revised International Staging System, which stratifies patients using a combination of widely available serum biomarkers and chromosomal abnormalities assessed via fluorescence in situ hybridization. In recent years, a substantial body of evidence concerning additional clinical, biological, and molecular/genomic prognostic factors has accumulated, along with new MM risk stratification tools and consensus reports. The International Myeloma Society, along with the International Myeloma Working Group, convened an Expert Panel with the primary aim of revisiting the definition of HRMM and formulating a practical and data-driven consensus definition, based on new evidence from molecular/genomic assays, updated clinical data, and contemporary risk stratification concepts. The Panel proposes the following Consensus Genomic Staging (CGS) of HRMM which relies upon the presence of at least one of these abnormalities: (1) del(17p), with a cutoff of >20% clonal fraction, and/or TP53 mutation; (2) an IgH translocation including t(4;14), t(14;16), or t(14;20) along with 1q+ and/or del(1p32); (3) monoallelic del(1p32) along with 1q+ or biallelic del(1p32); or (4) β2 microglobulin ≥5.5 mg/L with normal creatinine (<1.2 mg/dL).