Origins of lymphatic and distant metastases in human colorectal cancer

Emerging roles for fatty acid oxidation in cancer

Fatty acid oxidation (FAO) denotes the mitochondrial aerobic process responsible for breaking down fatty acids (FAs) into acetyl-CoA units. This process holds a central position in the cancer metabolic landscape, with certain tumor cells relying primarily on FAO for energy production. Over the past decade, mounting evidence has underscored the critical role of FAO in various cellular processes such as cell growth, epigenetic modifications, tissue-immune homeostasis, cell signal transduction, and more. FAO is tightly regulated by multiple evolutionarily conserved mechanisms, and any dysregulation can predispose to cancer development. In this view, we summarize recent findings to provide an updated understanding of the multifaceted roles of FAO in tumor development, metastasis, and the response to cancer therapy. Additionally, we explore the regulatory mechanisms of FAO, laying the groundwork for potential therapeutic interventions targeting FAO in cancers within the metabolic landscape.

PERK+ Macrophages Drive Immunotherapy Resistance in Lymph Node Metastases of Oral Squamous Cell Carcinoma

PURPOSE

Neoadjuvant anti-PD-1 immunotherapy combined with chemotherapy has shown promising pathologic responses in various cancers, including oral squamous cell carcinoma (OSCC). However, the pathologic response of lymph node (LN) metastases remains poorly understood. This study aims to systematically evaluate the pathologic response rates (pRR) of LN metastases in patients with OSCC and identify potential targets to improve therapeutic outcomes.

PATIENTS AND METHODS

We assessed the pRRs of LN metastases and matched primary tumors (PT) in patients with OSCC enrolled in a randomized, two-arm, phase II clinical trial (NCT04649476). Single-cell and spatial transcriptomics and multiplex IHC were performed to analyze the tumor microenvironment and identify potential therapeutic targets in LN metastases. A neoadjuvant orthotopic OSCC mouse model was established to evaluate the therapeutic potential of these targets.

RESULTS

We observed significant heterogeneity in pathologic regression of LN metastases, with lower pRRs compared with PTs. pRRs in LN metastases were correlated with overall and disease-free survival in patients with OSCC. We identified an abundance of macrophages in LN metastases exhibiting an unfolded protein response and activated protein kinase RNA-like endoplasmic reticulum kinase (PERK) signaling. These macrophages contributed to an extracellular matrix-enriched microenvironment through interactions with fibroblasts, which hindered T cell-mediated cytotoxicity. Pharmacologic inhibition of the PERK pathway significantly enhanced anti-PD-1 therapy in LN metastases and PTs in the mouse model.

CONCLUSIONS

Our study confirms that the pathologic response of LN metastases in patients with OSCC undergoing neoadjuvant immunotherapy or immunochemotherapy is inferior to that of PTs. It suggests that targeting the PERK pathway in macrophages could be a potential strategy to enhance treatment outcomes.

Prognostic Implications of Node Status in Colon Adenocarcinoma With Synchronous Liver Metastasis

INTRODUCTION

In patients with metastatic colon cancer undergoing curative resection, lymph node status does not change management or staging as per current guidelines. The aim of this project is to assess the prognostic value of lymph node status and yield in clinical stage IV-A colon adenocarcinoma undergoing curative resection.

METHODS

This is a retrospective cohort study from the National Cancer Database from 2010 to 2018 that examines adults with colon adenocarcinoma with synchronous liver metastasis who underwent primary colectomy, hepatic metastasectomy, and systemic therapy. Survival analysis of subgroups with node-positive and node-negative was performed by Kaplan-Meier analysis and the Cox proportional hazards model.

RESULTS

Of 2071 patients with clinical stage IV-A colon adenocarcinoma, 25.6% had negative lymph nodes (N-LNs). Patients with N-LNs had higher median survival compared to patients with positive lymph nodes (62.03 versus 48.69 mo, P < 0.001) and lower mortality risk (hazard ratio 0.75, P < 0.001). Resection of ≥12 lymph nodes was associated with longer median survival compared to patients with <12 lymph nodes in patients with positive lymph nodes (49.64 versus 28.09 mo, P < 0.001) but not in patients with N-LNs (63.01 versus 55.46 mo, P = 0.09). This relationship remained regardless of chemotherapy sequence.

CONCLUSIONS

In the setting of hepatic metastases in clinical stage IV colon adenocarcinoma, lymph node status is prognostic as N-LNs are associated with increased overall survival. Further research is necessary to delineate underlying differences in tumor biology and to help predict nodal status preoperatively.

Snord67 promotes breast cancer metastasis by guiding U6 modification and modulating the splicing landscape

Previously considered "housekeeping" genes, small nucleolar RNAs (snoRNAs) are increasingly understood to have wide-ranging functions in cancer, yet their role in metastasis has been less well studied. Here, we identify the snoRNA Snord67 as a regulator of lymph node (LN) metastasis in breast cancer. Snord67 expression is enriched in LN metastases in an immune-competent mouse model of female breast cancer. In an orthotopic breast cancer model, loss of Snord67 decreases LN metastasis. In a model of lymphatic metastasis, Snord67 loss decreases LN tumor growth and distant metastases. In breast cancer cell lines, Snord67 knockout results in loss of targeted 2'-O-methylation on U6 small nuclear RNA, as well as widespread changes in splicing. Together, these results demonstrate that Snord67 regulates splicing and promotes the growth of LN metastases and subsequent spread to distant metastases. SnoRNA-guided modifications of the spliceosome and regulation of splicing may represent a potentially targetable pathway in cancer.

Monoclonal antibodies as adjuvant therapies for resected melanoma

INTRODUCTION

Systemic adjuvant therapy is indicated in patients with high-risk, resected melanoma to reduce recurrence risk and potentially improve survival rates. Monoclonal antibodies (mAbs) target immune checkpoints and have made significant advances as systemic adjuvant therapies.

AREAS COVERED

This review discusses the main clinical trials that tested adjuvant mAbs in resected high-risk melanoma, including anti-cytotoxic T-lymphocyte antigen-4 (CTLA-4) and anti-programmed cell death-1 (PD-1); in addition to newer immunotherapies being tested in the adjuvant setting, including anti-lymphocyte activation gene 3 (LAG-3). We also briefly discuss targeted therapies as an alternative choice. Moreover, we highlight the pros and cons of using mAbs in the adjuvant setting, the reported adverse events (AEs), and the quality of life impact. Finally, we report data related to biomarker studies tested in the context of these clinical trials.

EXPERT OPINION

Immune checkpoint inhibitors (ICIs) have been shown to significantly improve relapse-free survival (RFS) as adjuvant therapy for high-risk melanoma. The long-term impact on overall survival (OS) was demonstrated in two trials that tested ipilimumab as compared to placebo (EORTC18071) and interferon-α (ECOG-ACRIN E1609). Furthermore, emerging data with neoadjuvant therapy followed by surgery and adjuvant therapy utilizing ICIs have demonstrated improved outcomes in the management of locoregionally advanced disease when compared to upfront surgery followed by adjuvant therapy alone.

Evolutionary paths towards metastasis

The evolution of metastasis in humans is considerably less well understood than the biology of early carcinogenesis. For over a century, clinicians and scientists have been debating whether metastatic potential is the intrinsic property of a cancer, pre-determined by the molecular characteristics of the tumour founder cell, or whether metastatic capacity evolves in a stepwise fashion as the tumour grows, akin to the multistage accumulation of oncogenic alterations that give rise to the first cancer cell. In this Perspective, I examine how genetic analyses of primary tumours and matched metastases can distinguish between these two competing metastasis evolution models, with particular emphasis on the utility of metastatic randomness - a quantitative measure that reflects whether metastases arise from a random selection of primary tumour subclones or whether they are enriched for descendants of privileged lineages that have acquired pro-metastatic traits. Probable metastasis evolution trajectories in tumours with high and low baseline metastatic capacity are discussed, along with the role of seeding rates and selection at different metastatic host sites. Finally, I argue that trailblazing insights into human metastasis biology are immediately possible if we make a concerted effort to apply existing experimental and theoretical tools to the right patient cohorts.

Immune microenvironment of tumor-draining lymph nodes: insights for immunotherapy

Tumor-draining lymph nodes (TDLNs) play a crucial role in modulating tumor immune responses and influencing the efficacy of immunotherapy. However, our current understanding of the microenvironment within these lymph nodes remains limited. Tumors not only impair the anti-tumor activity of CD8+ T cells by creating an immunosuppressive microenvironment, but they also facilitate immune evasion and promote metastasis by altering the structure and function of TDLNs. Research has shown that tumor-specific memory CD8+ T cells (TTSM) within TDLNs are essential for the efficacy of immune checkpoint inhibitors, such as PD-1/PD-L1 blockers. Moreover, the abnormal structure of TDLNs, along with the presence of immunosuppressive cells-such as regulatory T cells (Tregs), regulatory B cells (Bregs), and immunosuppressive dendritic cells (DCs)-contributes to tumor-mediated immune evasion. Therefore, gaining a deeper understanding of the immune microenvironment within TDLNs is essential for improving the effectiveness of immunotherapies and developing novel therapeutic strategies. This review explores various TDLN-based therapeutic strategies, addressing the controversies surrounding lymph node dissection, the use of TDLNs as a source of tumor-infiltrating lymphocytes (TILs) for therapy, targeting immunosuppressive cells within TDLNs, and methods to reverse the structural abnormalities of TDLNs. These strategies offer valuable insights and potential directions for advancing tumor immunotherapy.

A Network Based Model for Predicting Spatial Progression of Metastasis

Metastatic cancer is reported to have a mortality rate of 90%. Understanding the underlying principles of metastasis and quantifying them through mathematical modelling provides insights into potential treatment regimes. This work presents a partial differential equation based mathematical model embedded on a network, representing the organs and the blood vessels between them, with the aim of predicting likely secondary metastatic sites. Through this framework the relationship between metastasis and blood flow and between metastasis and the diffusive behaviour of cancer is explored. An analysis of the model predictions showed a good correlation with clinical data for some cancer types, particularly for cancers originating in the gut and liver. The model also predicts an inverse relationship between blood velocity and the concentration of cancer cells in secondary organs. Finally, for anisotropic diffusive behaviour, where the cancer experiences greater diffusivity in one direction, metastatic efficiency decreased. This is aligned with the clinical observation that gliomas of the brain, which typically show anisotropic diffusive behaviour, exhibit fewer metastases. The investigation yields some valuable results for clinical practitioners and researchers-as it clarifies some aspects of cancer that have hitherto been difficult to study, such as the impact of differing diffusive behaviours and blood flow rates on the global spread of cancer. The model provides a good framework for studying cancer progression using cancer-specific information when simulating metastasis.

Cytogenetic signatures favoring metastatic organotropism in colorectal cancer

Colorectal carcinoma (CRC) exhibits metastatic organotropism, primarily targeting liver, lung, and rarely the brain. Here, we study chromosomal imbalances (CIs) in cohorts of primary CRCs and metastases. Brain metastases show the highest burden of CIs, including aneuploidies and focal CIs, with enrichment of +12p encoding KRAS. Compared to liver and lung metastases, brain metastases present with increased co-occurrence of KRAS mutation and amplification. CRCs with concurrent KRAS mutation and amplification display significant metabolic reprogramming with upregulation of glycolysis, alongside upregulation of cell cycle pathways, including copy number gains of MDM2 and CDK4. Evolutionary modeling suggests early acquisition of many organotropic CIs enriched in both liver and brain metastases, while brain-enriched CIs preferentially emerge later. Collectively, this study supports a model where cytogenetic events in CRCs favor site-specific metastatic colonization. These site-enriched CI patterns may serve as biomarkers for metastatic potential in precision oncology.

Premetastatic niche mechanics and organotropism in breast cancer

Numerous physical and mechanical changes occur in the premetastatic niche. Here, we review the mechanics of the premetastatic niche and how the altered extracellular matrix and cancer cell mechanics may play a role in organotropism in breast cancer. Future research into premetastatic niche development and organotropic cell behavior should address physical alterations and biomechanical effects to the same rigor that biochemical alterations are studied.

A Highly Sensitive Tissue-specific qRT-PCR-based Assay for Detection of Melanoma Cells in Tumor-Draining Lymph Nodes

Melanoma invasion of regional lymph nodes, a critical event in the progression of this disease, is well documented as a poor prognostic factor for patients with melanoma. Assessing lymph node involvement is therefore a routine part of the diagnostic workup for patients presenting with melanoma at a T stage of ≥T2a. In clinical settings, the status and degree of melanoma lymph node involvement is traditionally characterized by histopathological analysis of tissue obtained during a sentinel lymph node biopsy, a labor-intensive and costly approach that requires technically challenging sample preparation and interpretation by a trained pathologist. Alternative approaches that might reduce the financial burden and turnaround time of a sentinel lymph node biopsy workup are therefore desirable. Likewise, the ability to accurately assess lymph node invasion by melanoma in experimental settings is necessary to gain new insights into mechanisms of distant metastasis and tumor-associated immune suppression. With these applications in mind, we recently developed, and describe herein, a tissue-specific qRT-PCR-based protocol for detecting melanoma cells within tumor-draining lymph nodes. Using murine models of lymph-node-invasive and lymph-node-noninvasive melanoma cell lines and a melanin-biosynthesis-pathway-specific Trp2 gene expression assay, we validated this method as a highly sensitive strategy for assessing lymph node involvement by melanoma. © 2025 Wiley Periodicals LLC. Basic Protocol 1: Growth and maintenance of murine melanoma cell cultures Basic Protocol 2: Extraction and quantification of RNA from murine melanoma cultures Basic Protocol 3: cDNA synthesis via reverse transcription Basic Protocol 4: Probe and primer design for TaqMan-based qPCR Basic Protocol 5: qPCR analysis of tissue-specific Trp2 gene expression Basic Protocol 6: In vitro validation of qRT-PCR Trp2 gene expression assay for detection of melanoma cells in murine whole lymph node preparations Basic Protocol 7: In vivo validation of qRT-PCR Trp2 gene expression assay for detection of melanoma cells in murine tumor-draining lymph nodes.

The significance of microscopically positive lymph node margins (R1) following surgical resection for Stage III colon cancer-A retrospective, observational study

AIM

Microscopically positive resection margins (R1) are associated with poorer outcomes in colon cancer. While the sequalae of a positive margin related to the primary tumour (R1Tumour) are relatively well known, comparatively less is known when the positive margin pertains to a metastatic lymph node (R1LNM). The aim of this study is to confirm the significance and impact of R1LNM margins in colon cancer patients.

METHOD

A retrospective, observational study of patients treated for American Joint Committee on Cancer Stage 3 colon cancer with potentially curative surgical intervention during a 10-year study period was performed. Patients were stratified into three groups (R0, R1Tumour, R1LNM). Outcomes measured were disease-specific survival (DSS), local recurrence-free survival (LRFS) and systemic recurrence-free survival (SRFS). Cox multivariable analysis and sensitivity analyses (time-stratified, competing-risk and propensity-matched analyses) were performed to determine the independent importance of R1LNM.

RESULTS

A total of 801 patients were included. The R1 resection rate was 6.6% and the R1LNM resection rate was 4.7%. Compared with R0 resection, R1LNM margins had significantly lower 5-year DSS [R1LNM 53.8% (95% CI 37.4%-77.3%) vs. R0 74.2%], LRFS [R1LNM 61% (95% CI 41.7%-89.1%) vs. R0 80.5%] and SRFS [R1LNM 39.5% (95% CI 24.2%-63.8%) vs. R0 70%]. R1LNM was not independently associated with the above outcomes following traditional, time-stratified and competing-risk multivariable analyses, nor following propensity matching.

CONCLUSION

R1LNM positivity may reflect other poor-prognosis variables, which themselves play a more substantial role in determining disease outcomes.

Impact of lymph node metastasis on immune microenvironment and prognosis in colorectal cancer liver metastasis: insights from multiomics profiling

BACKGROUND

This study aimed to investigate the prognostic impact of lymph node metastasis (LNM) on patients with colorectal cancer liver metastasis (CRLM) and elucidate the underlying immune mechanisms using multiomics profiling.

METHODS

We enrolled patients with CRLM from the US Surveillance, Epidemiology, and End Results (SEER) cohort and a multicenter Chinese cohort, integrating bulk RNA sequencing, single-cell RNA sequencing and proteomics data. The cancer-specific survival (CSS) and immune profiles of the tumor-draining lymph nodes (TDLNs), primary tumors and liver metastasis were compared between patients with and without LNM. Pathological evaluations were used to assess immune cell infiltration and histological features.

RESULTS

The CRLM patients with LNM had significantly shorter CSS than patients without LNM in two large cohorts. Our results showed that nonmetastatic TDLNs exhibited a greater abundance of immune cells, including CD4+ T cells, CD8+ T cells, and CD19+ B cells, whereas metastatic TDLNs were enriched with fibroblasts, endothelial cells, and macrophages. Immunohistochemical analysis confirmed elevated levels of CD3+ T cells, CD8+ T cells, and CD19+ B cells in nonmetastatic TDLNs. The presence of nonmetastatic TDLNs was associated with enhanced antitumor immune responses in primary tumors, characterized by a higher Klintrup-Makinen (KM) grade and the presence of tertiary lymphoid structures. Furthermore, liver metastasis in patients with nonmetastatic TDLNs were predominantly of the desmoplastic growth pattern (dHGP), while those with metastatic TDLNs were predominantly of the replacement growth pattern (rHGP).

CONCLUSIONS

This research highlights the adverse prognostic impact of LNM on patients with CRLM and reveals potential related mechanisms through multiomics analysis. Our research paves the way for further refinement of the AJCC TNM staging system for CRLM in clinical practice.

Neck Dissection and Survival Among Head and Neck Cancer Patients Undergoing Adjuvant Immunotherapy

Background

Some studies suggest that neck dissection (ND) should be avoided in candidates for immunotherapy because lymph nodes are primary sites for immunotherapy activation. Our study investigates ND utilization and associated differences in overall survival (OS) among patients with head and neck cancer (HNC) undergoing adjuvant immunotherapy.

Methods

The 2013-2018 National Cancer Database was retrospectively reviewed for patients with HNC undergoing surgery with curative intent, and adjuvant immunotherapy. Multivariable binary logistic and Cox regression models adjusted for patient demographics, clinicopathologic features, and treatment.

Results

Of 1335 patients satisfying inclusion criteria, 679 (50.9%) patients underwent ND: 94 (13.8%) had pN0, 109 (16.1%) had pN1, 411 (60.5%) had pN2, 60 (8.8%) had pN3, and 5 (0.7%) had pNx classification. On multivariable binary logistic regression, academic treatment facility, cT4, and cN1-3 classification were associated with higher odds of undergoing ND (p < 0.05); salivary, sinonasal, oropharyngeal, hypopharyngeal, and laryngeal primary sites were associated with decreased odds (p < 0.05). Compared with those undergoing neck observation, patients undergoing ND had worse OS (49.4% vs. 61.5%, p < 0.001) on Kaplan-Meier but not multivariable Cox (adjusted hazard ratio [aHR] 1.00, 95% confidence interval [CI] 0.82-1.24, p = 0.968) regression. Compared with adjuvant immunotherapy alone, the addition of radiotherapy (aHR 0.64, 95% CI 0.44-0.93) and chemoradiotherapy (aHR 0.56, 95% CI 0.37-0.86) were associated with higher OS (p < 0.025).

Conclusion

ND was utilized in approximately 51% of patients with HNC undergoing adjuvant immunotherapy. ND was not associated with worse OS, possibly related to the high rate of pN1-3 classification.

Level of Evidence

4.

Intratumoral heterogeneity and drug resistance in cancer

Intratumoral heterogeneity is the main cause of tumor treatment failure, varying across disease sites (spatial heterogeneity) and polyclonal properties of tumors that evolve over time (temporal heterogeneity). As our understanding of intratumoral heterogeneity, the formation of which is mainly related to the genomic instability, epigenetic modifications, plastic gene expression, and different microenvironments, plays a substantial role in drug-resistant as far as tumor metastasis and recurrence. Understanding the role of intratumoral heterogeneity, it becomes clear that a single therapeutic agent or regimen may only be effective for subsets of cells with certain features, but not for others. This necessitates a shift from our current, unchanging treatment approach to one that is tailored against the killing patterns of cancer cells in different clones. In this review, we discuss recent evidence concerning global perturbations of intratumoral heterogeneity, associations of specific intratumoral heterogeneity in lung cancer, the underlying mechanisms of intratumoral heterogeneity potentially leading to formation, and how it drives drug resistance. Our findings highlight the most up-to-date progress in intratumoral heterogeneity and its role in mediating tumor drug resistance, which could support the development of future treatment strategies.

Deciphering lung adenocarcinoma evolution and the role of LINE-1 retrotransposition

Understanding lung cancer evolution can identify tools for intercepting its growth. In a landscape analysis of 1024 lung adenocarcinomas (LUAD) with deep whole-genome sequencing integrated with multiomic data, we identified 542 LUAD that displayed diverse clonal architecture. In this group, we observed an interplay between mobile elements, endogenous and exogenous mutational processes, distinct driver genes, and epidemiological features. Our results revealed divergent evolutionary trajectories based on tobacco smoking exposure, ancestry, and sex. LUAD from smokers showed an abundance of tobacco-related C:G>A:T driver mutations in KRAS plus short subclonal diversification. LUAD in never smokers showed early occurrence of copy number alterations and EGFR mutations associated with SBS5 and SBS40a mutational signatures. Tumors harboring EGFR mutations exhibited long latency, particularly in females of European-ancestry (EU_N). In EU_N, EGFR mutations preceded the occurrence of other driver genes, including TP53 and RBM10. Tumors from Asian never smokers showed a short clonal evolution and presented with heterogeneous repetitive patterns for the inferred mutational order. Importantly, we found that the mutational signature ID2 is a marker of a previously unrecognized mechanism for LUAD evolution. Tumors with ID2 showed short latency and high L1 retrotransposon activity linked to L1 promoter demethylation. These tumors exhibited an aggressive phenotype, characterized by increased genomic instability, elevated hypoxia scores, low burden of neoantigens, propensity to develop metastasis, and poor overall survival. Reactivated L1 retrotransposition-induced mutagenesis can contribute to the origin of the mutational signature ID2, including through the regulation of the transcriptional factor ZNF695, a member of the KZFP family. The complex nature of LUAD evolution creates both challenges and opportunities for screening and treatment plans.

Lymphatic system is the mainstream for breast cancer dissemination and metastasis revealed by single-cell lineage tracing

Cancer metastasis is the primary cause of cancer-related death, yet the forces that drive cancer cells through various steps and different routes to distinct target organs/tissues remain elusive. In this study, we applied a barcoding system based single-cell lineage tracing approach to study the metastasis rate and route of breast cancer cells and their interactions with the tumor microenvironment (TME) during metastasis. The results indicate that only a small fraction of cells, accounting for fewer than 3% of total barcodes, can intravasate from the primary site into the blood circulation, whereas more cells disseminate through the lymphatic system to different organs. Tumor cells derived from the same progenitor cell exhibit different gene expression patterns in different soils, and the cancer cell-TME communication paradigm varies significantly between primary and metastatic tumors. Furthermore, metastable cells require a prewired particular cytokine expression ability which may be specific for lymph metastasis route although the underlying mechanism requires further investigation. In summary, leveraging a single-cell lineage tracing system, we demonstrate that the crosstalk between tumor cells and the TME is the driving force controlling the preferential metastatic fate of cancer cells through the lymphatic system.

Enhancing the role of MRI in rectal cancer: advances from staging to prognosis prediction

Rectal cancer (RC) is one of the major health challenges worldwide. Accurate staging, restaging, invasiveness assessment, and treatment efficacy evaluation are crucial for its clinical management. Magnetic resonance imaging (MRI) plays a significant role in these processes. However, standard MRI techniques, including T2-weighted and diffusion-weighted imaging, have uncertainties in identifying early-stage tumors, high-risk nodules, extramural vascular invasion, and treatment efficacy, potentially leading to inappropriate treatment. Recent advances suggest that the integration of traditional MRI methods, including diffusion-weighted imaging, opposed-phase or contrast-enhanced T1-weighted imaging, as well as emerging synthetic MRI, could address these challenges. Additionally, improvements in imaging technology have spurred research into advanced functional MRI techniques such as diffusion kurtosis imaging and amide proton transfer weighted MRI, yielding promising results in RC assessment. Total neoadjuvant therapy has emerged as a new treatment paradigm for locally advanced RC, with neoadjuvant immunotherapy and chemotherapy offering viable alternatives to neoadjuvant chemoradiotherapy. However, the lack of standards for the early prediction of patient survival and tumor response to neoadjuvant therapy highlights a critical unmet need in matching therapies to suitable patients. Furthermore, organ preservation strategies after neoadjuvant therapy provide personalized options based on tumor response and patient preferences, yet traditional MRI assessments show significant variability. Radiomics and artificial intelligence hold promise for revealing complex patterns in MRI images associated with patient prognosis and treatment response. This review provides an overview of current MRI advancements in RC assessment and emphasizes how future research can refine tailored treatment strategies to improve patient outcomes. KEY POINTS: Question The accurate diagnosis of early-stage rectal tumors, high-risk nodules, treatment responses, and the early prediction of patient survival and therapeutic outcomes remain an unmet need. Findings Visual MRI has improved staging, restaging, and invasiveness evaluation. Advanced MRI, radiomics and artificial intelligence provide significant potential for tumor characterization and outcome prediction. Clinical relevance Advances in visual MRI are improving routine imaging protocols and radiomics and artificial intelligence show promise in enhancing treatment decisions through precise tumor characterization and outcome prediction.

Lymphatic transport in anti-tumor immunity and metastasis

Although lymphatic vessels (LVs) are present in many tumors, their importance in cancer has long been underestimated. In contrast to the well-studied tumor-associated blood vessels, LVs were previously considered to function as passive conduits for tumor metastasis. However, emerging evidence over the last two decades has shed light on their critical role in locally shaping the tumor microenvironment (TME). Here we review the involvement of LVs in tumor progression, metastasis, and modulation of anti-tumor immune response.

Quantifying cell divisions along evolutionary lineages in cancer

Cell division drives somatic evolution but is challenging to quantify. We developed a framework to count cell divisions with DNA replication-related mutations in polyguanine homopolymers. Analyzing 505 samples from 37 patients, we studied the milestones of colorectal cancer evolution. Primary tumors diversify at ~250 divisions from the founder cell, while distant metastasis divergence occurs significantly later, at ~500 divisions. Notably, distant but not lymph node metastases originate from primary tumor regions that have undergone surplus divisions, tying subclonal expansion to metastatic capacity. Then, we analyzed a cohort of 73 multifocal lung cancers and showed that the cell division burden of the tumors' common ancestor distinguishes independent primary tumors from intrapulmonary metastases and correlates with patient survival. In lung cancer too, metastatic capacity is tied to more extensive proliferation. The cell division history of human cancers is easily accessible using our simple framework and contains valuable biological and clinical information.

Lymph node metastatic patterns of gastric carcinoma with a combination of adenocarcinoma and neuroendocrine carcinoma components

BACKGROUND

Gastric mixed-adenoneuroendocrine carcinoma (G-MANEC) is a subtype of gastric cancer. Building upon prior research findings, we propose that tumours containing both neuroendocrine carcinoma (NEC) and adenocarcinoma (AC) components, with each component ranging from 1% to 99% of the tumour, be classified as a distinct entity. We hereby term this adenoneuroendocrine mixed gastric cancer (G-ANEC). Research on lymph node (LN) involvement in G-MANEC has focused mainly on metastasis status, with limited studies on metastatic composition.

AIM

To investigate the LN metastasis patterns of G-ANEC, the clinicopathological features associated with these metastasis patterns, and to explore adjuvant chemotherapy regimens for G-ANEC.

METHODS

We analyzed 68 G-ANEC cases treated with radical surgery and confirmed LN metastasis at Peking University Cancer Hospital between August 2012 and June 2022. Utilizing χ 2 tests in IBM statistical product and service solutions statistics and R software.

RESULTS

We identified three distinct LN metastasis patterns in G-ANEC that were significantly associated with the NEC proportion, tumour invasion depth, Lauren classification, and tumour location (P values: 0.008, 0.015, 0.01, and 0.004, respectively). When the SOX/XELOX regimen was applied for adjuvant chemotherapy, patients with LN metastasis comprising only AC exhibited better overall survival (OS) (94.25 ± 11.07 months vs 54.36 ± 11.36 months) than did those with NEC. When LN metastasis components contained NEC, there was a trend towards improved OS (64 ± 10.77 months vs 54.35 ± 11.36 months) and disease-free survival (71.28 ± 9.92 months vs 66.28 ± 11.93 months) in patients treated with the etoposide and cisplatin compared to those receiving the SOX/XELOX regimen.

CONCLUSION

We found a significant correlation between the NEC percentage, tumour invasion depth, Lauren classification, and tumour location and LN metastasis patterns in G-ANEC. For G-ANEC, a lower proportion of NEC or AC in the primary lesion does not preclude the possibility of these components metastasizing to the LNs. Different adjuvant chemotherapy regimens should be administered on the basis of the varying components of LN metastasis in patients with G-ANEC.

Invasion and metastasis in cancer: molecular insights and therapeutic targets

The progression of malignant tumors leads to the development of secondary tumors in various organs, including bones, the brain, liver, and lungs. This metastatic process severely impacts the prognosis of patients, significantly affecting their quality of life and survival rates. Research efforts have consistently focused on the intricate mechanisms underlying this process and the corresponding clinical management strategies. Consequently, a comprehensive understanding of the biological foundations of tumor metastasis, identification of pivotal signaling pathways, and systematic evaluation of existing and emerging therapeutic strategies are paramount to enhancing the overall diagnostic and treatment capabilities for metastatic tumors. However, current research is primarily focused on metastasis within specific cancer types, leaving significant gaps in our understanding of the complex metastatic cascade, organ-specific tropism mechanisms, and the development of targeted treatments. In this study, we examine the sequential processes of tumor metastasis, elucidate the underlying mechanisms driving organ-tropic metastasis, and systematically analyze therapeutic strategies for metastatic tumors, including those tailored to specific organ involvement. Subsequently, we synthesize the most recent advances in emerging therapeutic technologies for tumor metastasis and analyze the challenges and opportunities encountered in clinical research pertaining to bone metastasis. Our objective is to offer insights that can inform future research and clinical practice in this crucial field.

Inferring cancer type-specific patterns of metastatic spread using Metient

Cancers differ in how they establish metastases. These differences can be studied by reconstructing the metastatic spread of a cancer from sequencing data of multiple tumors. Current methods to do so are limited by computational scalability and rely on technical assumptions that do not reflect current clinical knowledge. Metient overcomes these limitations using gradient-based, multi-objective optimization to generate multiple hypotheses of metastatic spread and rescores these hypotheses using independent data on genetic distance and organotropism. Unlike current methods, Metient can be used with both clinical sequencing data and barcode-based lineage tracing in preclinical models, enhancing its translatability across systems. In a reanalysis of metastasis in 169 patients and 490 tumors, Metient automatically identifies cancer type-specific trends of metastatic dissemination in melanoma, high-risk neuroblastoma, and non-small cell lung cancer. Its reconstructions often align with expert analyses but frequently reveal more plausible migration histories, including those with more metastasis-to-metastasis seeding and higher polyclonal seeding, offering new avenues for targeting metastatic cells. Metient's findings challenge existing assumptions about metastatic spread, enhance our understanding of cancer type-specific metastasis, and offer insights that inform future clinical treatment strategies of metastasis.

Progress in personalized immunotherapy for patients with brain metastasis

Brain metastasis leads to poor outcomes and CNS injury, significantly reducing quality of life and survival rates. Advances in understanding the tumor immune microenvironment have revealed the promise of immunotherapies, which, alongside surgery, chemotherapy, and radiation, offer improved survival for some patients. However, resistance to immunotherapy remains a critical challenge. This review explores the immune landscape of brain metastases, current therapies, clinical trials, and the need for personalized, biomarker-driven approaches to optimize outcomes.

The ending is not the end: Lymph node metastasis in oral squamous cell carcinoma

Lymph node metastasis is an important biological feature of oral squamous cell carcinoma, bearing poorly prognostic implications. However, the role of lymph node metastasis in cancer progression remains inconclusive. On the one hand, lymph nodes are pivotal sites for initiating specific immunity, which is crucial for maintaining antitumor immune response. On the other hand, they also serve as primary conduits for tumor metastasis, with lymph node colonization potentially inducing systemic immune dysfunction, thereby further promoting tumor progression. Considering this paradoxical role of lymph nodes, comprehending their impact on the primary tumor and immunity becomes paramount. Furthermore, leveraging these distinctive attributes of lymph nodes presents novel avenues for enhancing current therapeutic strategies against oral squamous cell carcinoma. This review summarizes the anatomical and molecular profiles of lymph node metastasis in oral squamous cell carcinoma, elucidating how lymphatic involvement compromises antitumor immunity, thus facilitating primary tumor and distant metastases. Additionally, it explores avenues for harnessing these mechanisms to optimize clinical interventions.

Applicability of the Scottish screen-detected polyp cancer study (SSPoCS) algorithm in a multicentric cohort in the management of malignant colorectal polyps

BACKGROUND/OBJECTIVES

Robust evidence regarding the management after endoscopic resection of malignant colorectal polyps (MCP) is lacking. Inconsistencies in reporting on potential prognostic factors hinder the decision process. To address these issues, the Scottish Screen-detected Polyp Cancer Study (SSPoCS) introduced an algorithm based in two easily obtainable variables: resection margin and lymphovascular invasion. This study aims to assess the applicability of the SSPoCS algorithm in a Portuguese multicentric cohort.

METHODS

Endoscopically resected MCP in five centers were included. The main outcome was residual/recurrent malignancy (RRM), defined as any of the following: (1) residual intramural or lymph node malignancy in the surgical specimen after completion surgery; (2) local or systemic recurrent disease in conservatively managed patients.

RESULTS

Two-hundred and eleven patients were included (mean age: 68.6 ± 10.4 years; male participants: 65.4%); 121 underwent completion surgery while 90 remained in surveillance. Thirty-two patients (15.2%) experienced RRM: 27 displayed residual malignancy in the surgical specimen and five developed recurrent disease. According to the SSPoCS algorithm: 120 patients were classified as having low-risk of residual disease, six of whom displayed RRM (5.0%); 10 as medium-risk, with one having RRM (10.0%); and 81 as high-risk, 25 of whom experienced RRM (30.9%). Lesions classified as low risk showed a negative predictive value (NPV) of 95.0% to exclude RRM. The algorithm demonstrated good accuracy in predicting RRM in a Receiver Operating Characteristic curve analysis (AUC: 0.74; 95% CI: 0.65-0.83; p < 0.001).

CONCLUSIONS

The SSPoCS algorithm revealed good accuracy in predicting residual/recurrent malignancy with a NPV of 95.0% to exclude RRM in low-risk lesions.

VEGF-C propagates 'onward' colorectal cancer metastasis from liver to lung

BACKGROUND

The formation of lung metastasis as part of the progression of colon cancer is a poorly understood process. Theoretically, liver metastases could seed lung metastases.

METHODS

To assess the contribution of the liver lymphatic vasculature to metastatic spread to the lungs, we generated murine liver-metastasis-derived organoids overexpressing vascular endothelial growth factor (VEGF)-C. The organoids were reimplanted into the mouse liver for tumour generation and onward metastasis.

RESULTS

Liver metastases from patients with concomitant lung metastases showed higher expression of VEGF-C, lymphatic vessel hyperplasia, and tumour cell invasion into lymphatic vessels when compared to those without lung metastases. Reimplantation of VEGF-C overexpressing organoids into the mouse liver showed that VEGF-C caused peritumoral lymphatic vessel hyperplasia, lymphatic tumour cell invasion, and lung metastasis formation. This change in metastatic organotropism was accompanied by reduced expression of WNT-driven adult stem cell markers, and increased expression of fetal stem cell markers and NOTCH pathway genes. Further NOTCH pathway inhibition with γ-secretase inhibitor (DAPT) in vivo results in a slight reduction in lung metastases and a decrease in lymphatic hyperplasia and invasion in VEGF-C-overexpressing tumours.

CONCLUSION

Collectively, these data indicate that VEGF-C can drive onward metastasis from the liver to the lung and suggest that targeting VEGF-C/NOTCH pathways may impair the progression of colorectal cancer.

Delivery of imiquimod to intestinal lymph nodes following oral administration

Intestinal lymph nodes are involved in the progression of colorectal cancer (CRC). Tumours suppress the activation of dendritic cells (DCs) in draining lymph nodes, diminishing anti-cancer immune response. Imiquimod (IMQ) facilitates DCs activation via toll-like receptor 7, suggesting that targeted delivery of IMQ to intestinal lymph nodes can improve the treatment of CRC. This study aims to enhance the delivery of IMQ to intestinal lymph nodes by a highly lipophilic prodrug approach. Amide prodrugs were synthesised by conjugating IMQ with saturated and unsaturated medium- to long-chain fatty acids. Their potential for intestinal lymphatic transport was assessed by their affinity to chylomicrons and solubility in long-chain triglycerides. Further selection of prodrug candidates was determined by resistance to enzymatic hydrolysis in intestinal lumen and release of IMQ in the lymphatics using fasting state simulated intestinal fluid supplemented with esterases, brush border enzyme vesicles and plasma. Key pharmacokinetic parameters and biodistribution in rats were assessed for the most promising compounds, prodrugs 5 and 8. The plasma concentration-time profile of IMQ following oral administration of the prodrugs was less erratic in comparison to the administration of unmodified IMQ. The lymph-to-plasma ratios of IMQ concentration increased 1.9- and 1.7-fold using prodrugs 5 and 8 in comparison to administration of unmodified IMQ, respectively. Importantly, the average concentration of IMQ in mesenteric lymph nodes (MLN) was 11.2- and 7.6-fold higher than in plasma following the administration of prodrugs 5 and 8, respectively. Additionally, the non-specific wide distribution of IMQ into various organs and tissues was reduced with prodrugs. This work suggests that the highly lipophilic prodrug approach can efficiently deliver IMQ to intestinal lymphatics. In addition, this study demonstrates the feasibility of an amide prodrug approach for intestinal lymphatic targeting.

Genetic dysregulation of EP300 in cancers in light of cancer epigenome control - targeting of p300-proficient and -deficient cancers

Some cancer types including bladder, cervical, and uterine cancers are characterized by frequent mutations in EP300 that encode histone acetyltransferase p300. This enzyme can act both as a tumor suppressor and oncogene. In this review, we describe the role of p300 in cancer initiation and progression regarding EP300 aberrations that have been identified in TGCA Pan-Cancer Atlas studies and we also discuss possible anticancer strategies that target EP300 mutated cancers. Copy number alterations, truncating mutations, and abnormal EP300 transcriptions that affect p300 abundance and activity are associated with several pathological features such as tumor grading, metastases, and patient survival. Elevated EP300 correlates with a higher mRNA level of other epigenetic factors and chromatin remodeling enzymes that co-operate with p300 in creating permissive conditions for malignant transformation, tumor growth and metastases. The status of EP300 expression can be considered as a prognostic marker for anticancer immunotherapy efficacy, as EP300 mutations are followed by an increased expression of PDL-1.HAT activators such as CTB or YF2 can be applied for p300-deficient patients, whereas the natural and synthetic inhibitors of p300 activity, as well as dual HAT/bromodomain inhibitors and the PROTAC degradation of p300, may serve as strategies in the fight against p300-fueled cancers.

Assessing the clinical utility of tumor invasion proportion of lymph nodes for enhanced risk stratification in N1 colorectal cancer

N staging systems are paramount clinical features for colorectal cancer (CRC). In N1 stage (N1) CRC, patients present with a limited number of metastatic lymph nodes, yet their prognoses vary widely. The tumor invasion proportion of lymph nodes (TIPLN) has gained attention, but its prognostic value in N1 CRC remains unclear. We retrospectively analyzed 416 N1 CRC patients who underwent radical surgery from January 2014 to December 2018, reviewing 713 hematoxylin and eosin (H&E)-stained slides to assess TIPLN. Overall survival was the primary outcome in our study. Using restricted cubic splines, we explored the relationship between TIPLN and prognosis, with Cox regression and subgroup analyses adjusting for potential confounders. We found that increased TIPLN was associated with an unfavorable prognosis. At a cut-off value of 50%, patients with high-TIPLN exhibiting poorer outcomes than their low-TIPLN counterparts (hazard ratio: 3.77, P < 0.001). Furthermore, high-TIPLN was confirmed as an independent risk factor for overall survival (hazard ratio: 3.12, P < 0.001) after adjusting for clinical confounders. Notably, TIPLN could also enhance risk stratification within the T and N stages, where patients with low-risk (T1-3 stage) and high-TIPLN demonstrated poorer overall survival compared to those with high-risk (T4 stage) and low-TIPLN (hazard ratio: 2.54, P = 0.021). In conclusion, TIPLN is a promising prognostic indicator for N1 CRC patients that complements traditional N staging system for a more comprehensive evaluation. Integrating TIPLN into the TNM staging system could enhance risk stratification and guide treatment decisions.

Lymphadenectomy in the treatment of sarcomas - indications and technique

Sarcomas are a rare type of malignancy with limited treatment options so far. This analysis aimed to describe the impact of lymphadenectomy on treating sarcoma patients. Sarcomas characterized by lymphatic spread are rare. For this reason, lymphadenectomy is not a procedure that is performed frequently. However, there are histological subtypes that spread more frequently through lymphatic vessels, such as rhabdomyosarcoma (RMS), epithelioid sarcoma (ES), clear cell sarcoma (CCS), and angiosarcoma. On the other hand, synovial sarcoma (SS) is not characterized by an increased tendency to lymphogenous metastases. In our study, we focus on these subtypes of sarcomas. The relationship between lymphadenectomy results and the subsequent prognosis of the patients was investigated. Metastases in the lymph nodes are diagnosed synchronously with distant metastases or when the primary tumor is detected. At the same time, despite lymphadenectomy, sarcoma patients developed further distant metastases. Currently, lymphadenectomy is not a routinely recommended method of treatment for patients with sarcomas. Most often, its potential use is indicated in the case of epithelioid sarcoma, clear cell sarcoma, and rhabdomyosarcoma after a previous positive sentinel lymph node biopsy (SLNB) result. Multicenter randomized prospective clinical trials on the role of lymphadenectomy in the treatment of sarcomas are needed.

Lymph node metastasis in cancer: Clearing the clouds to see the dawn

Lymph node metastasis (LNM) is often regarded as an indicator of poor prognosis in various cancers. Despite over three centuries of exploration since its discovery, the molecular mechanisms underlying LNM remain inconclusive. This review summarizes the molecular mechanisms of LNM, using the "PUMP+" principle for clarification. Pathological examination remains the gold standard for LNM diagnosis, yet there is a need to explore early diagnostic strategies that can effectively improve patient outcomes. With the advent of immunotherapy, discussions on the fate of lymph nodes (LN) have emerged, emphasizing the importance of preserving LN integrity prior to immunotherapy. This, in turn, poses higher demands for diagnostic accuracy and precision treatment of LNM. This review comprehensively discusses the molecular mechanisms, diagnostic methods, and treatment strategies for cancer lymph node metastasis, along with current bottlenecks and future directions in this field.

The roles of PD-L1 in the various stages of tumor metastasis

The interaction between tumor programmed death ligand 1 (PD-L1) and T-cell programmed cell death 1 (PD-1) has long been acknowledged as a mechanism for evading immune surveillance. Recent studies, however, have unveiled a more nuanced role of tumor-intrinsic PD-L1 in reprograming tumoral phenotypes. Preclinical models emphasize the synchronized effects of both intracellular and extracellular PD-L1 in promoting metastasis, with intricate interactions with the immune system. This review aims to summarize recent findings to elucidate the spatiotemporal heterogeneity of PD-L1 expression and the pro-metastatic roles of PD-L1 in the entire process of tumor metastasis. For example, PD-L1 regulates the epithelial-to-mesenchymal transition (EMT) process, facilitates the survival of circulating tumor cells, and induces the formation of immunosuppressive environments at pre-metastatic niches and metastatic sites. And the complexed and dynamic regulation process of PD-L1 for tumor metastasis is related to the spatiotemporal heterogeneity of PD-L1 expression and functions from tumor primary sites to various metastatic sites. This review extends the current understandings for the roles of PD-L1 in mediating tumor metastasis and provides new insights into therapeutic decisions in clinical practice.

Linking spatial drug heterogeneity to microbial growth dynamics in theory and experiment

Diffusion and migration play pivotal roles in microbial communities - shaping, for example, colonization in new environments and the maintenance of spatial structures of biodiversity. While previous research has extensively studied free diffusion, such as range expansion, there remains a gap in understanding the effects of biologically or physically deleterious confined environments. In this study, we examine the interplay between migration and spatial drug heterogeneity within an experimental meta-community of E. faecalis, a Gram-positive opportunistic pathogen. When the community is confined to spatially-extended habitats ('islands') bordered by deleterious conditions, we find that the population level response depends on the trade-off between the growth rate within the island and the rate of transfer into regions with harsher conditions, a phenomenon we explore by modulating antibiotic concentration within the island. In heterogeneous islands, composed of spatially patterned patches that support varying levels of growth, the population's fate depends critically on the specific spatial arrangement of these patches - the same spatially averaged growth rate leads to diverging responses. These results are qualitatively captured by simple simulations, and analytical expressions which we derive using first-order perturbation approximations to reaction-diffusion models with explicit spatial dependence. Among all possible spatial arrangements, our theoretical and experimental findings reveal that the arrangement with the highest growth rates at the center most effectively mitigates population decline, while the arrangement with the lowest growth rates at the center is the least effective. Extending this approach to more complex experimental communities with varied spatial structures, such as a ring-structured community, further validates the impact of spatial drug arrangement. Our findings suggest new approaches to interpreting diverging clinical outcomes when applying identical drug doses and inform the possible optimization of spatially-explicit dosing strategies.

Prognostic and Predictive Determinants of Colorectal Cancer: A Comprehensive Review

Colorectal cancer (CRC) remains a significant global health burden, necessitating a thorough understanding of prognostic and predictive factors to enhance patient outcomes. This systematic review aims to comprehensively evaluate prognostic and predictive determinants in CRC, encompassing both traditional and emerging biomarkers. A systematic search of major electronic databases was conducted to identify relevant studies published from 1995 up to 2024. Eligible articles were critically appraised, and data extraction was performed according to predefined criteria. The prognostic determinants examined included clinicopathological features such as tumor stage, grade, and lymph node involvement, as well as molecular biomarkers including RAS, BRAF, and MSI status. Predictive determinants encompassed biomarkers influencing response to targeted therapies and immunotherapy, such as HER2 and Immunoscore. The review also explores novel prognostic and predictive markers, including tumor microenvironment characteristics and liquid biopsy-based biomarkers. Synthesizing evidence from diverse studies, this review provides insights into the prognostic and predictive landscape of CRC, highlighting the potential clinical implications of identified determinants. Understanding the multifaceted nature of prognostic and predictive factors in CRC is imperative for the advancement of personalized treatment strategies and improvement of patient outcomes.

Characterization of the T-cell receptor repertoire associated with lymph node metastasis in colorectal cancer

Purpose

Colorectal cancer (CRC) is a leading cause of cancer-related mortality worldwide, with lymph node (LN) metastasis playing a pivotal role in disease progression. This study aimed to explore the T-cell receptor (TCR) repertoire among CRC patients, distinguishing those with LN metastasis from those without, in order to uncover potential biomarkers for predicting metastasis.

Methods

We analyzed the TCR repertoire in CRC patients with and without LN metastasis. A classification model utilizing random forest analysis was developed to assess the predictive potential of the TCR repertoire.

Results

The findings demonstrated a significant increase in the number of V-J combinations and immune CDR3 sequences in patients with LN metastasis compared to the control group. The classification model achieved high accuracy in differentiating patients with LN metastasis, with AUC values ranging from 0.514 to 0.794. Specific V-J combinations and CDR3 sequences were identified as significant predictors of the model's predictive accuracy.

Conclusion

These results suggest that the TCR repertoire is altered in CRC patients exhibiting LN metastasis, potentially influencing disease progression. This study highlights the importance of TCR repertoire analysis as a non-invasive biomarker for predicting LN metastasis in CRC patients.

Developmental mosaicism underlying EGFR-mutant lung cancer presenting with multiple primary tumors

Although the development of multiple primary tumors in smokers with lung cancer can be attributed to carcinogen-induced field cancerization, the occurrence of multiple tumors at presentation in individuals with EGFR-mutant lung cancer who lack known environmental exposures remains unexplained. In the present study, we identified ten patients with early stage, resectable, non-small cell lung cancer who presented with multiple, anatomically distinct, EGFR-mutant tumors. We analyzed the phylogenetic relationships among multiple tumors from each patient using whole-exome sequencing (WES) and hypermutable poly(guanine) (poly(G)) repeat genotyping as orthogonal methods for lineage tracing. In four patients, developmental mosaicism, assessed by WES and poly(G) lineage tracing, indicates a common non-germline cell of origin. In two other patients, we identified germline EGFR variants, which confer moderately enhanced signaling when modeled in vitro. Thus, in addition to germline variants, developmental mosaicism defines a distinct mechanism of genetic predisposition to multiple EGFR-mutant primary tumors, with implications for their etiology and clinical management.

The Molecular Evolution of Melanoma Distant Metastases

The evolution of primary melanoma to lymph node and distant metastasis is incompletely understood. We examined the genomic diversity in melanoma progression in matched primary melanomas and lymph node and distant metastases from 17 patients. FISH analysis revealed cancer cell fractions with monotonic copy number alterations, including PHIP gain and PTEN loss, in the metastatic cascade. By contrast, the cancer cell fraction with copy number alterations for BPTF and MITF was reduced in lymph node metastases but increased in distant metastases. Separately, the cancer cell fraction with NCOA3 copy number alteration was comparable between primary tumors and lymph node metastases yet increased in distant metastases. These results suggest enrichment of the phosphoinositide 3-kinase and MITF pathways in the transition through the metastatic cascade. By contrast, next-generation sequencing analysis did not identify a consistent pattern of changes in variant allele frequency while revealing several intriguing findings, including decreased variant allele frequency in distant metastases and distinct drivers in lymph node versus distant metastases. These results provide evidence that distant melanoma metastasis does not always emanate from lymph node metastasis. These results enhance our understanding of clonal patterns of melanoma metastasis, with possible implications for targeted therapy and metastasis competency.

Survival Benefits of Postoperative Chemotherapy in Patients With Colorectal Mucinous Adenocarcinoma: An Analysis Utilizing Propensity Score Matching From the Surveillance, Epidemiology, and End Results Database

OBJECTIVE

This study aimed to investigate the characteristics of patients with colorectal mucinous adenocarcinoma (MAC) who benefit from postoperative chemotherapy (POCT) and to develop effective postoperative survival nomograms for predicting overall survival (OS) in colorectal MAC patients.

METHODS

Data of colorectal MAC patients who underwent surgery from the Surveillance, Epidemiology, and End Results (SEER) database between 2010 and 2020 were collected. Patients were grouped based on POCT, and intergroup analysis was performed using 1:1 propensity score matching (PSM). Kaplan-Meier (K-M) curves were used to compare the prognosis between the 2 groups. Cox analysis was employed to identify factors associated with OS in patients with colorectal MAC who underwent POCT. The variance inflation factor (VIF) and bilateral stepwise regression were used to determine factors included in the model. Additionally, a nomogram was constructed to predict postoperative survival outcomes for patients. The discriminative ability of the nomograms was evaluated using the C-index and calibration curve analysis, the decision curve analysis (DCA) assessed the clinical utility of the nomogram, and the receiver operating characteristic (ROC) curve evaluated the nomograms' performance.

RESULTS

This study encompassed 6829 patients with colorectal MAC, among whom 2258 received POCT, and 4571 did not. Whether pre or post PSM, patients in the POCT group consistently exhibited a superior median OS compared to those in the postoperative non-chemotherapy group (P < .0001). For colorectal MAC patients undergoing POCT, OS was correlated with factors such as patient age, carcinoembryonic antigen levels, tumor deposits, perineural invasion (PNI), lymph node examination count, T staging, and Grade staging. Notably, a significant chemotherapy advantage was observed in patients without perineural invasion, those with lymph node examination counts exceeding 12, and patients with moderately differentiated tumors. The overall colorectal MAC patient postoperative OS predictive nomogram demonstrated a C-index of .74, with a calibration curve near the diagonal and a DCA curve indicating positive net benefits. In comparison to TNM staging, the ROC curves of the nomogram at 1 year, 3 years, and 5 years demonstrated superior predictive capabilities (AUC: .80 vs .71, .78 vs .71, .77 vs .70).

CONCLUSION

This study revealed the characteristics of colorectal MAC patients who benefit from POCT and established effective prognostic nomograms, which can aid clinicians in designing personalized treatment plans for individual patients and promote precision medicine.

The role of PIK3CA gene mutations in colorectal cancer and the selection of treatment strategies

PIK3CA gene encodes the p110α catalytic subunit of PI3K, which regulates the PI3K/AKT/mTOR signaling pathway. PIK3CA gene mutation is one of the most common mutations in colorectal cancer (CRC), affecting about 15%-20% of CRC patients. PIK3CA gene mutation leads to the persistent activation of the PI3K/AKT/mTOR signaling pathway, which promotes the proliferation, invasion, metastasis, and drug resistance of CRC. This article provides a summary of the key detection methods for PIK3CA gene mutation, and provides an introduction to the existing colorectal cancer treatments and their practical applications in the clinic. Besides, this article summarizes the role and mechanism of PIK3CA gene mutation in the occurrence and development of CRC. It also explores the relationship between PIK3CA gene mutation and the clinical features and prognosis of CRC. This article focuses on the influence and mechanism of PIK3CA gene mutation on the targeted therapy and immunotherapy of CRC, and discusses the potential value and future direction of PIK3CA gene mutation in the personalized therapy of CRC. We aim to provide new perspectives and ideas for the precise diagnosis and treatment of CRC.

Clonal Lineage Tracing with Somatic Delivery of Recordable Barcodes Reveals Migration Histories of Metastatic Prostate Cancer

The patterns by which primary tumors spread to metastatic sites remain poorly understood. Here, we define patterns of metastatic seeding in prostate cancer using a novel injection-based mouse model-EvoCaP (Evolution in Cancer of the Prostate), featuring aggressive metastatic cancer to bone, liver, lungs, and lymph nodes. To define migration histories between primary and metastatic sites, we used our EvoTraceR pipeline to track distinct tumor clones containing recordable barcodes. We detected widespread intratumoral heterogeneity from the primary tumor in metastatic seeding, with few clonal populations instigating most migration. Metastasis-to-metastasis seeding was uncommon, as most cells remained confined within the tissue. Migration patterns in our model were congruent with human prostate cancer seeding topologies. Our findings support the view of metastatic prostate cancer as a systemic disease driven by waves of aggressive clones expanding their niche, infrequently overcoming constraints that otherwise keep them confined in the primary or metastatic site. Significance: Defining the kinetics of prostate cancer metastasis is critical for developing novel therapeutic strategies. This study uses CRISPR/Cas9-based barcoding technology to accurately define tumor clonal patterns and routes of migration in a novel somatically engineered mouse model (EvoCaP) that recapitulates human prostate cancer using an in-house developed analytical pipeline (EvoTraceR).

The prognostic and therapeutic potential of vimentin in colorectal cancer

Several cells and molecules in the tumor microenvironment have been introduced as effective factors in the prognosis and progression of colorectal cancer. As a key element of the intermediate filament family, vimentin is expressed by mesenchymal cells in a ubiquitous manner and contributes significantly to cellular integrity and stress resistance in colorectal cancer. Recent studies have shown that alterations in the expression patterns of intermediate filaments are significantly related to cancer progression, especially in phenotypes associated with cellular migration and invasion. In addition to its multiple biological roles, vimentin also has a substantial function in mediating the epithelial-mesenchymal transition. Therefore, evaluating vimentin as an effective factor involved in the prognosis of colorectal cancer and targeting it as a novel approach to cancer therapy have become one of the main goals of many researchers worldwide. In this article, we will review the various biological functions of vimentin, as well as its relationship with colorectal cancer with the aim of providing novel insights into its clinical importance in the prognosis and treatment of colorectal cancer.

A unique interplay of access and selection shapes peritoneal metastasis evolution in colorectal cancer

Whether metastasis in humans can be accomplished by most primary tumor cells or requires the evolution of a specialized trait remains an open question. To evaluate whether metastases are founded by non-random subsets of primary tumor lineages requires extensive, difficult-to-implement sampling. We have realized an unusually dense multi-region sampling scheme in a cohort of 26 colorectal cancer patients with peritoneal metastases, reconstructing the evolutionary history of on average 28.8 tissue samples per patient with a microsatellite-based fingerprinting assay. To assess metastatic randomness, we evaluate inter- and intra-metastatic heterogeneity relative to the primary tumor and find that peritoneal metastases are more heterogeneous than liver metastases but less diverse than locoregional metastases. Metachronous peritoneal metastases exposed to systemic chemotherapy show significantly higher inter-lesion diversity than synchronous, untreated metastases. Projection of peritoneal metastasis origins onto a spatial map of the primary tumor reveals that they often originate at the deep-invading edge, in contrast to liver and lymph node metastases which exhibit no such preference. Furthermore, peritoneal metastases typically do not share a common subclonal origin with distant metastases in more remote organs. Synthesizing these insights into an evolutionary portrait of peritoneal metastases, we conclude that the peritoneal-metastatic process imposes milder selective pressures onto disseminating cancer cells than the liver-metastatic process. Peritoneal metastases' unique evolutionary features have potential implications for staging and treatment.

Single-cell exome sequencing reveals polyclonal seeding and TRPS1 mutations in colon cancer metastasis

Liver metastasis remains the primary cause of mortality in patients with colon cancer. Identifying specific driver gene mutations that contribute to metastasis may offer viable therapeutic targets. To explore clonal evolution and genetic heterogeneity within the metastasis, we conducted single-cell exome sequencing on 150 single cells isolated from the primary tumor, liver metastasis, and lymphatic metastasis from a stage IV colon cancer patient. The genetic landscape of the tumor samples revealed that both lymphatic and liver metastases originated from the same region of the primary tumor. Notably, the liver metastasis was derived directly from the primary tumor, bypassing the lymph nodes. Comparative analysis of the sequencing data for individual cell pairs within different tumors demonstrated that the genetic heterogeneity of both liver and lymphatic metastases was also greater than that of the primary tumor. This finding indicates that liver and lymphatic metastases arose from clusters of circulating tumor cell (CTC) of a polyclonal origin, rather than from a single cell from the primary tumor. Single-cell transcriptome analysis suggested that higher EMT score and CNV scores were associated with more polyclonal metastasis. Additionally, a mutation in the TRPS1 (Transcriptional repressor GATA binding 1) gene, TRPS1 R544Q, was enriched in the single cells from the liver metastasis. The mutation significantly increased CRC invasion and migration both in vitro and in vivo through the TRPS1R544Q/ZEB1 axis. Further TRPS1 mutations were detected in additional colon cancer cases, correlating with advanced-stage disease and inferior prognosis. These results reveal polyclonal seeding and TRPS1 mutation as potential mechanisms driving the development of liver metastases in colon cancer.

The SW480 cell line as a model of resident and migrating colon cancer stem cells

Intra-tumor heterogeneity, i.e., the presence of diverse cell types and subpopulations within tumors, presents a significant obstacle in cancer treatment due to its negative consequences for resistance to therapy and disease recurrence. However, the mechanisms that underlie intra-tumor heterogeneity and result in the plethora of different cancer cells within a single lesion remain poorly understood. Here, we leverage the SW480 cell line as a model system to investigate the molecular and functional diversity of colon cancer cells. Through a combination of fluorescence-activated cell sorting (FACS) analysis and transcriptomic profiling, we identified three distinct subpopulations, namely resident cancer stem cells (rCSCs), migratory CSCs (mCSCs), and high-relapse cells (HRCs). These subpopulations show varying Wnt signaling levels and gene expression profiles mirroring their stem-like and functional properties. Examination of publicly available spatial transcriptomic data confirms the presence of these subpopulations in patient-derived cancers and reveals their distinct spatial distribution relative to the tumor microenvironment.

Mechanisms of lymph node metastasis: An extracellular vesicle perspective

In several solid tumors such as breast cancer, prostate cancer, colorectal cancer or melanoma, tumor draining lymph nodes are the earliest tissues where colonization by tumor cells is detected. Lymph nodes act as sentinels of metastatic dissemination, the deadliest phase of tumor progression. Besides hematogenous dissemination, lymphatic spread of tumor cells has been demonstrated, adding more complexity to the mechanisms involved in metastasis. A network of blood and lymphatic vessels surrounds tumors providing routes for tumor soluble factors to mediate regional and long-distance effects. Additionally, extracellular vesicles (EVs), particularly small EVs/exosomes, have been shown to circulate through the blood and lymph, favoring the formation of pre-metastatic niches in the tumor-draining lymph nodes (TDLNs) and distant organs. In this review, we present an overview of the relevance of lymph node metastasis, the structural and immune changes occurring in TDLNs during tumor progression, and how extracellular vesicles contribute to modulating some of these alterations while promoting the formation of lymph node pre-metastatic niches.

T cell exhaustion in human cancers

T cell exhaustion refers to a progressive state in which T cells become functionally impaired due to sustained antigenic stimulation, which is characterized by increased expression of immune inhibitory receptors, but weakened effector functions, reduced self-renewal capacity, altered epigenetics, transcriptional programme and metabolism. T cell exhaustion is one of the major causes leading to immune escape of cancer, creating an environment that supports tumor development and metastatic spread. In addition, T cell exhaustion plays a pivotal role to the efficacy of current immunotherapies for cancer. This review aims to provide a comprehensive view of roles of T cell exhaustion in cancer development and progression. We summerized the regulatory mechanisms that involved in T cell exhaustion, including transcription factors, epigenetic and metabolic reprogramming events, and various microenvironmental factors such as cytokines, microorganisms, and tumor autocrine substances. The paper also discussed the challenges posed by T cell exhaustion to cancer immunotherapies, including immune checkpoint blockade (ICB) therapies and chimeric antigen receptor T cell (CAR-T) therapy, highlightsing the obstacles encountered in ICB therapies and CAR-T therapies due to T cell exhaustion. Finally, the article provides an overview of current therapeutic options aimed to reversing or alleviating T cell exhaustion in ICB and CAR-T therapies. These therapeutic approaches seek to overcome T cell exhaustion and enhance the effectiveness of immunotherapies in treating tumors.

Mechanisms of metastatic colorectal cancer

Despite extensive research and improvements in understanding colorectal cancer (CRC), its metastatic form continues to pose a substantial challenge, primarily owing to limited therapeutic options and a poor prognosis. This Review addresses the emerging focus on metastatic CRC (mCRC), which has historically been under-studied compared with primary CRC despite its lethality. We delve into two crucial aspects: the molecular and cellular determinants facilitating CRC metastasis and the principles guiding the evolution of metastatic disease. Initially, we examine the genetic alterations integral to CRC metastasis, connecting them to clinically marked characteristics of advanced CRC. Subsequently, we scrutinize the role of cellular heterogeneity and plasticity in metastatic spread and therapy resistance. Finally, we explore how the tumour microenvironment influences metastatic disease, emphasizing the effect of stromal gene programmes and the immune context. The ongoing research in these fields holds immense importance, as its future implications are projected to revolutionize the treatment of patients with mCRC, hopefully offering a promising outlook for their survival.

Does Adjuvant Chemotherapy Benefit Patients with T4 N0 Colon Cancer?

Background and Objectives: Colorectal cancer (CRC) poses a major global health challenge, with high incidence rates and ongoing treatment debates. Adjuvant chemotherapy benefits for high-risk subgroups, particularly stage II disease, remain controversial. This study seeks to clarify this issue by specifically examining the impact of adjuvant chemotherapy on disease-free survival (DFS) and overall survival (OS) in patients diagnosed with T4 colon cancer. Materials and Methods: This retrospective study analyzed patients undergoing radical surgery for T4 colon cancer between 2002 and 2023. Results: Our study of 184 pT4 pN0 colon cancer patients revealed that 79.3% received adjuvant chemotherapy. Multivariate analysis demonstrated significant DFS improvement: a 60% reduction in risk for those who received adjuvant therapy (0.40 95% CI: 0.25-0.62, p < 0.001). Lymphovascular invasion (LVI) and adjuvant treatment were also significantly associated with OS. Adjuvant treatment reduced mortality by 60% (HR: 0.40, 95% CI: 0.23-0.68, p = 0.001). Patients with LVI had a 1.9-fold increase in mortality (HR: 1.94, 95% CI: 1.17-3.20, p = 0.011). These findings underscore the potential value of adjuvant chemotherapy and highlight the importance of treatment completion in managing T4 colon cancer. Conclusions: Our study identifies LVI and adjuvant chemotherapy as key prognostic factors in T4 colon cancer patients. These results support the consideration of adjuvant chemotherapy in this patient population.