Integrated molecular subtyping defines a curable oligometastatic state in colorectal liver metastasis

Computed Tomography-Based Habitat Analysis for Prognostic Stratification in Colorectal Liver Metastases

Background

Colorectal liver metastasis (CRLM) has a poor prognosis, and traditional prognostic models have certain limitations in clinical application. This study aims to evaluate the prognostic value of CT-based habitat analysis in CRLM patients and compare it with existing traditional prognostic models to provide more evidence for individualized treatment of CRLM patients.

Methods

This retrospective study included 197 patients with CRLM whose preoperative contrast-enhanced CT images and corresponding DICOM Segmentation Objects (DSOs) were obtained from The Cancer Imaging Archive (TCIA). Tumor regions were segmented, and habitat features representing distinct subregions were extracted. An unsupervised K-means clustering algorithm classified the tumors into two clusters based on their habitat characteristics. Kaplan-Meier analysis was used to evaluate overall survival (OS), disease-free survival (DFS), and liver-specific DFS. The habitat model's predictive performance was compared with the Clinical Risk Score (CRS) and Tumor Burden Score (TBS) using the concordance index (C-index), Integrated Brier Score (IBS), and time-dependent area under the curve (AUC).

Results

The habitat model identified two distinct patient clusters with significant differences in OS, DFS, and liver-specific DFS (p < 0.01). Compared with CRS and TBS, the habitat model demonstrated superior predictive accuracy, particularly for DFS and liver-specific DFS, with higher time-dependent AUC values and improved model calibration (lower IBS).

Conclusions

CT-based habitat analysis captures spatial tumor heterogeneity and provides enhanced prognostic stratification in CRLM. The method outperforms conventional models and offers potential for more personalized treatment planning.

Therapeutic Potentials of MiRNA for Colorectal Cancer Liver Metastasis Treatment: A Narrative Review

Colorectal cancer (CRC) ranks among the most prevalent cancers worldwide and is the fourth leading cause of cancer-related deaths. Metastasis poses a significant obstacle in CRC treatment, as distant metastasis, particularly to the liver, remains the primary cause of mortality. Colorectal liver metastasis (CRLM) occurs frequently due to the liver's direct vascular connection to the colorectal region via the portal vein. Standard treatment approaches for CRLM are limited; only a few patients qualify for surgical intervention, resulting in a persistently low survival rate. Additionally, resistance to chemotherapy is common, emphasizing the need for more effective targeted therapies. Emerging evidence highlights the pivotal role of microRNAs (miRNAs) in modulating critical pathways associated with CRLM, including tumor invasion, epithelial-mesenchymal transition, and angiogenesis. MiRNAs exhibit dual functions as tumor suppressors and oncogenes by targeting multiple genes, thus playing a complex role in both the initiation and progression of metastasis. The regulatory mechanisms of miRNAs could help to identify novel biomarkers for early diagnosis and prognosis of CRLM, as well as promising therapeutic targets to overcome chemoresistance. Despite numerous studies on miRNA involvement in CRC metastasis, dedicated reviews focusing on miRNAs and CRLM remain scarce. This review aims to approach targeted therapies by examining the current understanding of miRNA involvement in CRLM and exploring their potential as diagnostic, prognostic, and therapeutic agents. Through an integrative approach, we aim to provide insights that could transform CRLM management and improve patient outcomes.

Long-term survival and undetectable circulating tumor DNA following comprehensive involved site radiotherapy for oligometastases

Distant metastases account for ~ 90% of cancer deaths and major responses with systemic therapy alone for metastatic cancers are so rare that the National Cancer Institute launched the Exceptional Responders Initiative. Comprehensive involved site radiotherapy (ISRT) is a promising treatment for oligometastases but the role of circulating tumor DNA to confirm durable molecular response following treatment remains unexplored. Among 597 consecutive patients with distant metastases treated with radiation therapy from 2014 to 2021, 133 (22%) were oligometastatic and 464 (78%) were polymetastatic. The 5-year overall survival was 38% for oligometastases vs. 3% for polymetastases (p < 0.001). At a median follow-up of 71 months for treated oligometastases, 37 (28%) exceptional responders (ER) remain alive and recurrence free at ≥ 2 year follow-up. Among ER, 49% underwent stereotactic radiotherapy (median 27 Gy in 3 fractions, EQD2 43 Gy), 65% underwent intensity-modulated radiation therapy (median 53 Gy in 24 fractions, EQD2 54 Gy), and 76% received additional systemic therapy. Although ctDNA testing was not possible in most ER due to patient refusal or tumor specimen quality, all 12 ER tested ctDNA-negative. Long-term complete responses, including molecular complete responses, are achievable with comprehensive ISRT in diverse clinical presentations.

Evolving Paradigms in the Treatment of Oligometastatic Pancreatic Ductal Adenocarcinoma

Multiple randomized trials have suggested that the addition of comprehensive metastasis-directed therapy to best systemic therapy improves disease control and survival among patients with oligometastatic disease, even for histologies with a high propensity for rapid spread. Here, we review the growing literature supporting the oligometastatic paradigm in pancreatic ductal adenocarcinoma. We summarize key details from nascent institutional series and reflect on the recently reported phase II randomized EXTEND trial. We discuss various strategies for enhancing the clinical and technical implementation of metastasis-directed therapy in this patient population. Lastly, we highlight multiple ongoing landmark trials seeking to optimize and validate the role of metastasis-directed therapy in oligometastatic pancreatic cancer. Ultimately, these and other continued clinical and translational research efforts will be critical to improve care and outcomes for patients with oligometastatic pancreatic ductal adenocarcinoma.

A Personalized Approach for Oligometastatic Prostate Cancer: Current Understanding and Future Directions

Oligometastatic prostate cancer (OMPC) represents an intermediate state in the progression from localized disease to widespread metastasis when the radiographically significant sites are limited in number and location. With no clear consensus on a definition, its diagnostic significance and associated optimal therapeutic approach remain controversial, posing a significant challenge for clinicians. The current standard of care for metastatic disease is to start systemic therapy; however, active surveillance and targeted radiotherapy have become attractive options to mitigate the long-term effects of androgen deprivation therapy (ADT). Furthermore, evolving biomarker methodologies may further define optimal treatment selection. In this review, we summarize the current understanding that guides the treatment of OMPC, with a focus on how host response can be an important contributing factor. Evolving scientific understanding and clinical development will continue to shape the landscape of treatment strategies for this distinct disease state.

Multi-institutional Analysis of Metastasis-directed Therapy with or Without Androgen Deprivation Therapy in Oligometastatic Castration-sensitive Prostate Cancer

BACKGROUND

Metastasis-directed therapy (MDT) is increasingly being used in oligometastatic castration-sensitive prostate cancer (omCSPC). However, it is currently unclear how to optimally integrate MDT with the standard of care of systemic hormonal therapy.

OBJECTIVE

To report long-term outcomes of MDT alone versus MDT and a defined course of androgen deprivation therapy (ADT) in omCSPC.

DESIGN, SETTING, AND PARTICIPANTS

Here, a multicenter, international retrospective cohort of omCSPC as defined by conventional imaging was reported.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Biochemical progression-free survival (bPFS), distant progression-free survival (dPFS), and combined biochemical or distant progression-free survival (cPFS) were evaluated with Kaplan-Meier and multivariable Cox proportional hazard regression models.

RESULTS AND LIMITATIONS

A total of 263 patients were included, 105 with MDT + ADT and 158 with MDT alone. The majority of patients had metachronous disease (90.5%). Five-year bPFS, dPFS, and cPFS were, respectively, 24%, 41%, and 19% in patients treated with MDT + ADT and 11% (hazard ratio [HR] 0.48, 95% confidence interval [CI] 0.36-0.64), 29% (HR 0.56, 95% CI 0.40-0.78), and 9% (HR 0.50, 95% CI 0.38-0.67) in patients treated with MDT alone. On a multivariable analysis adjusting for pretreatment variables, the use of ADT was associated with improved bPFS (HR 0.43, p < 0.001), dPFS (HR 0.45, p = 0.002), and cPFS (HR 0.44, p < 0.001).

CONCLUSIONS

In this large multi-institutional report, the addition of concurrent ADT to MDT appears to improve time to prostate-specific antigen progression and distant recurrence, noting that about 10% patients had durable control with MDT alone. Ongoing phase 3 studies will help further define treatment options for omCSPC.

PATIENT SUMMARY

Here, we report a large retrospective review evaluating the outcomes of metastasis-directed therapy with or without a limited course of androgen deprivation for patients with oligometastatic castration-sensitive prostate cancer. This international multi-institutional review demonstrates that the addition of androgen deprivation therapy to metastasis-directed therapy (MDT) improves progression-free survival. While a proportion of patients appear to have long-term disease control with MDT alone, further work in biomarker discovery is required to better identify which patients would be appropriate for de-escalated therapy.

Multi-stage mechanisms of tumor metastasis and therapeutic strategies

The cascade of metastasis in tumor cells, exhibiting organ-specific tendencies, may occur at numerous phases of the disease and progress under intense evolutionary pressures. Organ-specific metastasis relies on the formation of pre-metastatic niche (PMN), with diverse cell types and complex cell interactions contributing to this concept, adding a new dimension to the traditional metastasis cascade. Prior to metastatic dissemination, as orchestrators of PMN formation, primary tumor-derived extracellular vesicles prepare a fertile microenvironment for the settlement and colonization of circulating tumor cells at distant secondary sites, significantly impacting cancer progression and outcomes. Obviously, solely intervening in cancer metastatic sites passively after macrometastasis is often insufficient. Early prediction of metastasis and holistic, macro-level control represent the future directions in cancer therapy. This review emphasizes the dynamic and intricate systematic alterations that occur as cancer progresses, illustrates the immunological landscape of organ-specific PMN creation, and deepens understanding of treatment modalities pertinent to metastasis, thereby identifying some prognostic and predictive biomarkers favorable to early predict the occurrence of metastasis and design appropriate treatment combinations.

Patterns of initial ovarian cancer recurrence on niraparib maintenance monotherapy in patients with no baseline evidence of disease after first-line chemotherapy: An ad hoc subgroup analysis of PRIMA/ENGOT-OV26/GOG-3012

OBJECTIVES

Patterns of disease recurrence on poly(ADP-ribose) polymerase inhibitor maintenance therapy are unclear and may affect subsequent treatment. This ad hoc subgroup analysis of the phase 3 PRIMA/ENGOT-OV26/GOG-3012 study evaluated patterns of initial recurrence in patients with advanced ovarian cancer (AOC).

METHODS

PRIMA included participants at high risk for disease progression. This ad hoc analysis only evaluated participants randomized to niraparib maintenance without evidence of disease at baseline. The number and site(s) of initial recurrent lesions at investigator-assessed progressive disease (PD) were evaluated.

RESULTS

Of the 314 niraparib-treated patients analyzed, 190 developed ≥1 new lesion (median number of new lesions, 1.0; interquartile range, 1-2). In total, 93.2% (177/190) of patients developed 1-3 lesions at first disease progression. The most common sites of recurrence were the peritoneum (30.0% [57/190]), lymph nodes (26.3% [50/190]), and liver (20.5% [39/190]). Similar results were observed when patients with PD were stratified by biomarker status, disease stage at diagnosis, and type of debulking surgery. Patients with homologous recombination-proficient tumors, stage III disease, or a history of primary debulking developed a median of 2.0 new lesions at first progression; patients with homologous recombination-deficient tumors, stage IV disease, or a history of interval debulking developed a median of 1.0 new lesion.

CONCLUSIONS

Many patients with AOC without lesions at first-line maintenance treatment initiation develop oligometastatic disease at first recurrence. Prospective evaluation is required to determine whether these patients have improved outcomes when local therapies are combined with continuous, systemic, targeted maintenance therapy.

Transcriptomic subtyping of gastrointestinal malignancies

Gastrointestinal (GI) cancers are highly heterogeneous at multiple levels. Tumor heterogeneity can be captured by molecular profiling, such as genetic, epigenetic, proteomic, and transcriptomic classification. Transcriptomic subtyping has the advantage of combining genetic and epigenetic information, cancer cell-intrinsic properties, and the tumor microenvironment (TME). Unsupervised transcriptomic subtyping systems of different GI malignancies have gained interest because they reveal shared biological features across cancers and bear prognostic and predictive value. Importantly, transcriptomic subtypes accurately reflect complex phenotypic states varying not only per tumor region, but also throughout disease progression, with consequences for clinical management. Here, we discuss methodologies of transcriptomic subtyping, proposed taxonomies for GI malignancies, and the challenges posed to clinical implementation, highlighting opportunities for future transcriptomic profiling efforts to optimize clinical impact.

Beyond success: unveiling the hidden potential of radiotherapy and immunotherapy in solid tumors

Immunotherapy, particularly with immune checkpoint inhibitors, has significantly transformed cancer treatment. Despite its success, many patients struggle to respond adequately or sustain long-lasting clinical improvement. A growing consensus has emerged that radiotherapy (RT) enhances the response rate and overall efficacy of immunotherapy. Although combining RT and immunotherapy has been extensively investigated in preclinical models and has shown promising results, establishing itself as a dynamic and thriving area of research, clinical evidence for this combination strategy over the past five years has shown both positive and disappointing results, suggesting the need for a more nuanced understanding. This review provides a balanced and updated analysis of the combination of immunotherapy and RT. We summarized the preclinical mechanisms through which RT boosts antitumor immune responses and mainly focused on the outcomes of recently updated clinical trials, including those that may not have met expectations. We investigated the optimization of the therapeutic potential of this combined strategy, including key challenges, such as fractionation and scheduling, lymph node irradiation, and toxicity. Finally, we offered insights into the prospects and challenges associated with the clinical translation of this combination therapy, providing a realistic perspective on the current state of research and potential future directions.

Exploiting a subtype-specific mitochondrial vulnerability for successful treatment of colorectal peritoneal metastases

Peritoneal metastases (PMs) from colorectal cancer (CRC) respond poorly to treatment and are associated with unfavorable prognosis. For example, the addition of hyperthermic intraperitoneal chemotherapy (HIPEC) to cytoreductive surgery in resectable patients shows limited benefit, and novel treatments are urgently needed. The majority of CRC-PMs represent the CMS4 molecular subtype of CRC, and here we queried the vulnerabilities of this subtype in pharmacogenomic databases to identify novel therapies. This reveals the copper ionophore elesclomol (ES) as highly effective against CRC-PMs. ES exhibits rapid cytotoxicity against CMS4 cells by targeting mitochondria. We find that a markedly reduced mitochondrial content in CMS4 cells explains their vulnerability to ES. ES demonstrates efficacy in preclinical models of PMs, including CRC-PMs and ovarian cancer organoids, mouse models, and a HIPEC rat model of PMs. The above proposes ES as a promising candidate for the local treatment of CRC-PMs, with broader implications for other PM-prone cancers.

Molecular profiling and patient selection for the multimodal approaches for patients with resectable colorectal liver metastases

Colorectal cancer represents the third most common cancer and about 20% are diagnosed with synchronous metastatic disease. From a historical point of view, surgery remains the mainstream treatment for resectable colorectal liver metastases (CRLM). Furthermore, disease outcomes are improving due significant advances in systemic treatments and diagnostic methods. However, the optimal timing for neoadjuvant chemotherapy or upfront surgery for CRLM has not yet been established and remains an open question. Thus, patient selection combining image workouts, time of recurrence, positive lymph nodes, and molecular biomarkers can improve the decision-making process. Nevertheless, molecular profiling is rising as a promising field to be incorporated in the multimodal approach and guide patient selection and sequencing of treatment. Tumor biomakers, genetic profiling, and circulating tumor DNA have been used to offer as much personalized treatment as possible, based on the precision oncology concept of tailored care rather than a guideline-based therapy. This review article discusses the role of molecular pathology and biomarkers as prognostic and predictor factors in the diagnosis and treatment of resectable CRLM.

ICG-Fluorescence Imaging for Margin Assessment During Minimally Invasive Colorectal Liver Metastasis Resection

Importance

Unintended tumor-positive resection margins occur frequently during minimally invasive surgery for colorectal liver metastases and potentially negatively influence oncologic outcomes.

Objective

To assess whether indocyanine green (ICG)-fluorescence-guided surgery is associated with achieving a higher radical resection rate in minimally invasive colorectal liver metastasis surgery and to assess the accuracy of ICG fluorescence for predicting the resection margin status.

Design, Setting, and Participants

The MIMIC (Minimally Invasive, Indocyanine-Guided Metastasectomy in Patients With Colorectal Liver Metastases) trial was designed as a prospective single-arm multicenter cohort study in 8 Dutch liver surgery centers. Patients were scheduled to undergo minimally invasive (laparoscopic or robot-assisted) resections of colorectal liver metastases between September 1, 2018, and June 30, 2021.

Exposures

All patients received a single intravenous bolus of 10 mg of ICG 24 hours prior to surgery. During surgery, ICG-fluorescence imaging was used as an adjunct to ultrasonography and regular laparoscopy to guide and assess the resection margin in real time. The ICG-fluorescence imaging was performed during and after liver parenchymal transection to enable real-time assessment of the tumor margin. Absence of ICG fluorescence was favorable both during transection and in the tumor bed directly after resection.

Main Outcomes and Measures

The primary outcome measure was the radical (R0) resection rate, defined by the percentage of colorectal liver metastases resected with at least a 1 mm distance between the tumor and resection plane. Secondary outcomes were the accuracy of ICG fluorescence in detecting margin-positive (R1; <1 mm margin) resections and the change in surgical management.

Results

In total, 225 patients were enrolled, of whom 201 (116 [57.7%] male; median age, 65 [IQR, 57-72] years) with 316 histologically proven colorectal liver metastases were included in the final analysis. The overall R0 resection rate was 92.4%. Re-resection of ICG-fluorescent tissue in the resection cavity was associated with a 5.0% increase in the R0 percentage (from 87.4% to 92.4%; P < .001). The sensitivity and specificity for real-time resection margin assessment were 60% and 90%, respectively (area under the receiver operating characteristic curve, 0.751; 95% CI, 0.668-0.833), with a positive predictive value of 54% and a negative predictive value of 92%. After training and proctoring of the first procedures, participating centers that were new to the technique had a comparable false-positive rate for predicting R1 resections during the first 10 procedures (odds ratio, 1.36; 95% CI, 0.44-4.24). The ICG-fluorescence imaging was associated with changes in intraoperative surgical management in 56 (27.9%) of the patients.

Conclusions and Relevance

In this multicenter prospective cohort study, ICG-fluorescence imaging was associated with an increased rate of tumor margin-negative resection and changes in surgical management in more than one-quarter of the patients. The absence of ICG fluorescence during liver parenchymal transection predicted an R0 resection with 92% accuracy. These results suggest that use of ICG fluorescence may provide real-time feedback of the tumor margin and a higher rate of complete oncologic resection.

Stereotactic body radiation therapy for adrenal gland metastases: A multi-institutional outcome analysis

Aim

The adrenal gland is a common site of metastasis with a rate of up to 27% in autopsy series. The incidence of these metastases is increasing due to greater use of Positron Emission Tomography scans and improved overall survival of patients with metastatic cancers. Stereotactic body radiation therapy (SBRT) is a non-invasive treatment option for metastasis. The aim of this study is to assess prognostic factors influencing local control, progression-free and overall survival in oligometastatic patients treated with SBRT for an adrenal metastasis.

Methods

In this multicentric retrospective study, we included patients with adrenal metastases treated with SBRT between 2010 and 2021 in eleven french centers. All primary tumors were included.

Results

A total of 110 patients treated for 121 adrenal lesions were included. Non-small-cell lung cancer was the predominant histologic type (55.4 %). Eighty-two percent of patients had at least 2 metastatic sites. The median Planning Target Volume was 70 cm3 with a median prescription dose of 40 Gray (Gy). The mean Biologically Effective Dose (BED) 10 dose was 74.2 Gy. Local control at 1 and 2 years was 85.9 % and 72.5 % respectively. The median overall survival and progression-free survival were 31.6 and 8.5 months respectively. Local control was significantly improved by systemic treatment one month before or after SBRT (p = 0.009) and by a BED10 greater than or equal to 50 Gy (p = 0.003).In multivariate analysis, oligometastatic presentation (p = 0.009) and a metachronous metastatic presentation (p = 0.008) were independent factors for progression-free survival.Tolerance was excellent, no grade 3 and 4 toxicities were described due to SBRT.

Conclusion

Stereotactic radiotherapy of adrenal metastases makes possible a local control of more than 85% at one year and was well tolerated. The factors influencing survival in oligometastatic patients still need to be found in order to better select those who benefit the most from this type of treatment.

Patterns of Failure in Metastatic NSCLC Treated With First Line Pembrolizumab and Use of Local Therapy in Patients With Oligoprogression

INTRODUCTION

The patterns of failure (POF) for metastatic non-small-cell lung cancer (mNSCLC) treated with immunotherapy are not well established.

METHODS

We conducted a retrospective cohort study of mNSCLC that received first-line pembrolizumab with or without chemotherapy at a single academic center from 2015 to 2021. We defined POF with 2 classifications: 1) local, regional, or distant failure, or 2) failure in existing lesions, new lesions, or a combination. Oligoprogression was defined as disease progression (PD) in ≤3 sites of failure. Overall survival (OS) was measured via Kaplan-Meier and modelled with Cox regression.

RESULTS

Of 298 patients identified, 198 had PD. Using POF classification 1, most failures were distant (43.9%) or a combination of locoregional and distant (34.4%). For POF classification 2, failures occurred in a combination of new and existing lesions (45.0%), existing lesions alone (33.3%), or in new lesions only (21.7%). Oligoprogression occurred in 39.9% (n = 79) cases. Median OS was higher in the following: PD in existing lesions vs. new or new + existing lesions (28.7 vs. 20.2 vs. 13.9 months, P < .001) and oligoprogression vs. polyprogression (35.1 vs. 12.2 months, P < .001). In oligoprogression, median OS was better for those who received radiation to all sites of PD (62.2 months) than for those who changed systemic therapy (22.9 months, P = .007). On multivariable analysis, radiation for oligoprogression (HR 0.35, 95% CI: 0.20-0.62, P < .001) was associated with improved OS.

CONCLUSIONS

In mNSCLC treated with pembrolizumab, oligoprogression is relatively common. Randomized data are needed to define the benefits of radiation in oligoprogressive mNSCLC.

Optimizing Treatment Strategy for Oligometastases/Oligo-Recurrence of Colorectal Cancer

Colorectal cancer (CRC) is the third most common cancer, and nearly half of CRC patients experience metastases. Oligometastatic CRC represents a distinct clinical state characterized by limited metastatic involvement, demonstrating a less aggressive nature and potentially improved survival with multidisciplinary treatment. However, the varied clinical scenarios giving rise to oligometastases necessitate a precise definition, considering primary tumor status and oncological factors, to optimize treatment strategies. This review delineates the concepts of oligometastatic CRC, encompassing oligo-recurrence, where the primary tumor is under control, resulting in a more favorable prognosis. A comprehensive examination of multidisciplinary treatment with local treatments and systemic therapy is provided. The overarching objective in managing oligometastatic CRC is the complete eradication of metastases, offering prospects of a cure. Essential to this management approach are local treatments, with surgical resection serving as the standard of care. Percutaneous ablation and stereotactic body radiotherapy present less invasive alternatives for lesions unsuitable for surgery, demonstrating efficacy in select cases. Perioperative systemic therapy, aiming to control micrometastatic disease and enhance local treatment effectiveness, has shown improvements in progression-free survival through clinical trials. However, the extension of overall survival remains variable. The review emphasizes the need for further prospective trials to establish a cohesive definition and an optimized treatment strategy for oligometastatic CRC.

Oligometastatic Colorectal Cancer: A Review of Definitions and Patient Selection for Local Therapies

PURPOSE

Nearly one-third of patients diagnosed with colorectal cancer (CRC) will ultimately develop metastatic disease. While a small percentage of patients can be considered for curative resection, more patients have limited disease that can be considered for local therapy. Challenges remain in defining oligometastatic CRC as well as developing treatment strategies guided by high level evidence.

METHODS

In this review, we present the challenges in defining oligometastatic CRC and summarize the current literature on treatment and outcomes of local therapy in patients with metastatic CRC.

RESULTS

For patients with liver- and/or lung-confined CRC metastases, surgical resection is the standard of care given the potential for long-term progression-free and overall survival. For patients with liver- or lung-confined disease not amenable to surgical resection, non-surgical local therapies, such as thermal ablation, hepatic arterial infusion pump (HAIP), or stereotactic body radiation therapy (SBRT), should be considered. For patients with more advanced disease, such as lymph node or bony metastases, the role of metastasis-directed therapy is controversial. Emerging data suggests that SBRT to ablate all metastases can improve progression-free and overall survival.

CONCLUSION

Multidisciplinary management is critical for patients with metastatic CRC due to the complexity of their cases and the nuanced patient, tumor, biological, and anatomical factors that must be weighed when considering local therapy. High-quality prospective randomized data in CRC are needed to further clarify the role of local ablative therapy in patients with unresectable oligometastatic CRC with ongoing studies including the RESOLUTE trial (ACTRN12621001198819) and the upcoming NCTN ERASur trial (NCT05673148).

Oligo-Metastatic Disease in Oncology: Exploring the Limits and the Potential of Genetic Assessment

Oligo-metastatic disease (OMD) in the field of oncology denotes a distinct subset of metastatic tumors characterized by less aggressive biological behavior and extended survival times in comparison to their widely metastatic counterparts. While there is a general consensus regarding the existence of OMD, there remains a lack of widely accepted criteria for its a priori identification at the time of presentation. This review delves into the concept of OMD, placing a particular emphasis on the significance of understanding the limitations and potential of genetic assessments. It explores how these aspects are crucial in advancing our comprehension of this phenomenon. In a rapidly advancing era of precision medicine, understanding the intricacies of OMD opens up exciting possibilities for tailored treatment approaches. By elucidating the genetic underpinnings and dynamic nature of this condition, we stand to improve patient outcomes and potentially shift the paradigm of metastatic cancer management.

Chemotherapy and Targeted Therapy Strategies in Patients with Unresectable or Borderline Resectable Metastatic Colorectal Cancer: Evidence for a Lack of Focus on Resection Rates

BACKGROUND AND AIMS

Chemotherapy (CTx) with targeted therapy (TT) have increased the overall response rate (ORR) and improved survival in unresectable or borderline resectable metastatic colorectal cancer (mCRC). However, the resection rate is an endpoint with often suboptimal expert involvement. The aim was to investigate whether the improvements in ORR have translated to improved resection rates (RR).

STUDY DESIGN

A systematic literature search was performed using the PICO process.

STATISTICAL ANALYSIS

Odds ratios, and 95% confidence intervals (OR, 95% CI) were analyzed for ORR and RR using dichotomous values with the Mantel-Haenszel method. Progression-free survival (PFS) and overall survival (OS) were analyzed using the inverse-variance method and displayed as hazard ratios and 95% confidence intervals (HR, 95% CI).

RESULTS

The literature search returned 469 records. Sixteen articles with 5724 patients were selected for analysis. The qualitative analysis revealed low and moderate risk of bias endpoints. Higher ORR was observed with CTx + TT versus CTx only (OR: 0.62 [95% CI 0.45; 0.82], p = 0.002) and with triplet CTx + TT versus doublet CTx + TT (OR: 0.61 [95% CI 0.46; 0.81], p < 0.001). PFS and OS were improved by use of TT (HR: 0.68-0.84; p < 0.001 to 0.04). The overall RR was low (< 15%) and did not improve in the same way as the other endpoints.

CONCLUSION

The ORR and survival rates in unresectable and borderline resectable mCRC were improved by modern CTx and TT that did not translate into higher RR, mostly due to the lack of expert involvement.

Oligometastatic Disease (OMD): The Classification and Practical Review of Prospective Trials

Oligometastatic disease (OMD) is currently known as an intermediate state of cancer, characterized by a limited number of systemic metastatic lesions for which local ablative therapy could be curative. Indeed, data from multiple clinical trials have illustrated an increase in overall survival (OS) for cancer patients when local ablative therapy was included in the systemic adjuvant therapy. Given that no driver and somatic mutations specific to OMD are currently established, the diagnosis of OMD is mainly based on the results of X-ray studies. In 2020, 20 international experts from the European Society for Radiotherapy and Oncology (ESTRO) and the European Organization for Research and Treatment of Cancer (EORTC) developed a comprehensive system for the characterization and classification of OMD. They identified 17 OMD characteristics that needed to be assessed in all patients who underwent radical local treatment. These characteristics reflect the tumor biology and clinical features of the disease underlying the development of OMD independently of the primary tumor type and the number of metastatic lesions. In particular, the system involves the characteristics of the primary tumor (e.g., localization, histology, TNM stage, mutational status, specific tumor markers), clinical parameters (e.g., disease-free interval, treatment-free interval), therapies (e.g., local, radical or palliative treatment, the numbers of the therapeutic regimens), and type of OMD (e.g., invasive). Based on the aforementioned criteria, an algorithm was introduced into the clinic to classify OMDs collectively according to their nomenclature. A history of polymetastatic disease (PMD) prior to OMD is used as a criterion to delineate between induced OMD (previous history of PMD after successful therapy) and genuine OMD (no history of PMD). Genuine OMD is divided into two states: recurrent OMD (i.e., after a previous history of OMD) and de novo OMD (i.e., a first newly diagnosed oligometastatic disease). de novo OMD is differentiated into synchronous and metachronous forms depending on the length of time from the primary diagnosis to the first evidence of OMD. In the case of synchronous OMD, this period is less than 6 months. Lastly, metachronous and induced OMD are divided into oligorecurrence, oligoprogression, and oligopersistence, depending on whether OMD is firstly diagnosed during an absence (oligo recurrence) or presence (oligoprogression or oligopersistence) of active systemic therapy. This classification and nomenclature of OMD are evaluated prospectively in the OligoCare study. In this article, we present a practical review of the current concept of OMD and discuss the available prospective clinical trials and potential future directions.

Differential Perspectives by Specialty on Oligometastatic Colorectal Cancer: A Korean Oligometastasis Working Group's Comparative Survey Study

PURPOSE

Despite numerous studies on the optimal treatments for oligometastatic disease (OMD), there is no established interdisciplinary consensus on its diagnosis or classification. This survey-based study aimed to analyze the differential opinions of colorectal surgeons and radiation oncologists regarding the definition and treatment of OMD from the colorectal primary.

MATERIALS AND METHODS

A total of 141 participants were included in this study, consisting of 63 radiation oncologists (44.7%) and 78 colorectal surgeons (55.3%). The survey consisted of 19 questions related to OMD, and the responses were analyzed using the chi-square test to determine statistical differences between the specialties.

RESULTS

The radiation oncologists chose "bone" more frequently compared to the colorectal surgeons (19.2% vs. 36.5%, p=0.022), while colorectal surgeons favored "peritoneal seeding" (26.9% vs. 9.5%, p=0.009). Regarding the number of metastatic tumors, 48.3% of colorectal surgeons responded that "irrelevant, if all metastatic lesions are amendable to local therapy", while only 21.8% of radiation oncologist chose same answer. When asked about molecular diagnosis, most surgeons (74.8%) said it was important, but only 35.8% of radiation oncologists agreed.

CONCLUSION

This study demonstrates that although radiation oncologists and colorectal surgeons agreed on a majority of aspects such as diagnostic imaging, biomarker, systemic therapy, and optimal timing of OMD, they also had quite different perspectives on several aspects of OMD. Understanding these differences is crucial to achieving multidisciplinary consensus on the definition and optimal management of OMD.

Similarity network fusion to identify phenotypes of small-for-gestational-age fetuses

Fetal growth restriction (FGR) affects 5-10% of pregnancies, is the largest contributor to fetal death, and can have long-term consequences for the child. Implementation of a standard clinical classification system is hampered by the multiphenotypic spectrum of small fetuses with substantial differences in perinatal risks. Machine learning and multiomics data can potentially revolutionize clinical decision-making in FGR by identifying new phenotypes. Herein, we describe a cluster analysis of FGR based on an unbiased machine-learning method. Our results confirm the existence of two subtypes of human FGR with distinct molecular and clinical features based on multiomic analysis. In addition, we demonstrated that clusters generated by machine learning significantly outperform single data subtype analysis and biologically support the current clinical classification in predicting adverse maternal and neonatal outcomes. Our approach can aid in the refinement of clinical classification systems for FGR supported by molecular and clinical signatures.

Integrated Clinical-Molecular Classification of Colorectal Liver Metastases: A Biomarker Analysis of the Phase 3 New EPOC Randomized Clinical Trial

Importance

Personalized treatment approaches for patients with oligometastatic colorectal liver metastases are critically needed. We previously defined 3 biologically distinct molecular subtypes of colorectal liver metastases: (1) canonical, (2) immune, and (3) stromal.

Objective

To independently validate these molecular subtypes in the phase 3 New EPOC randomized clinical trial.

Design, Setting, and Participants

This retrospective secondary analysis of the phase 3 New EPOC randomized clinical trial included a bi-institutional discovery cohort and multi-institutional validation cohort. The discovery cohort comprised patients who underwent hepatic resection for limited colorectal liver metastases (98% received perioperative chemotherapy) from May 31, 1994, to August 14, 2012. The validation cohort comprised patients who underwent hepatic resection for liver metastases with perioperative chemotherapy (fluorouracil, oxaliplatin, and irinotecan based) with or without cetuximab from February 26, 2007, to November 1, 2012. Data were analyzed from January 18 to December 10, 2021.

Interventions

Resected metastases underwent RNA sequencing and microRNA (miRNA) profiling in the discovery cohort and messenger RNA and miRNA profiling with microarray in the validation cohort.

Main Outcomes and Measures

A 31-feature (24 messenger RNAs and 7 miRNAs) neural network classifier was trained to predict molecular subtypes in the discovery cohort and applied to the validation cohort. Integrated clinical-molecular risk groups were designated based on molecular subtypes and the clinical risk score. The unique biological phenotype of each molecular subtype was validated using gene set enrichment analyses and immune deconvolution. The primary clinical end points were progression-free survival (PFS) and overall survival (OS).

Results

A total of 240 patients were included (mean [range] age, 63.0 [56.3-68.0] years; 151 [63%] male), with 93 in the discovery cohort and 147 in the validation cohort. In the validation cohort, 73 (50%), 28 (19%), and 46 (31%) patients were classified as having canonical, immune, and stromal metastases, respectively. The biological phenotype of each subtype was concordant with the discovery cohort. The immune subtype (best prognosis) demonstrated 5-year PFS of 43% (95% CI, 25%-60%; hazard ratio [HR], 0.37; 95% CI, 0.20-0.68) and OS of 63% (95% CI, 40%-79%; HR, 0.38; 95% CI, 0.17-0.86), which was statistically significantly higher than the canonical subtype (worst prognosis) at 14% (95% CI, 7%-23%) and 43% (95% CI, 32%-55%), respectively. Adding molecular subtypes to the clinical risk score improved prediction (the Gönen and Heller K for discrimination) from 0.55 (95% CI, 0.49-0.61) to 0.62 (95% CI, 0.57-0.67) for PFS and 0.59 (95% CI, 0.52-0.66) to 0.63 (95% CI, 0.56-0.70) for OS. The low-risk integrated group demonstrated 5-year PFS of 44% (95% CI, 20%-66%; HR, 0.38; 95% CI, 0.19-0.76) and OS of 78% (95% CI, 44%-93%; HR, 0.26; 95% CI, 0.08-0.84), superior to the high-risk group at 16% (95% CI, 10%-24%) and 43% (95% CI, 32%-52%), respectively.

Conclusions and Relevance

In this prognostic study, biologically derived colorectal liver metastasis molecular subtypes and integrated clinical-molecular risk groups were highly prognostic. This novel molecular classification warrants further study as a possible predictive biomarker for personalized systemic treatment for colorectal liver metastases.

Trial Registration

isrctn.org Identifier: ISRCTN22944367.

Multisocietal European consensus on the terminology, diagnosis, and management of patients with synchronous colorectal cancer and liver metastases: an E-AHPBA consensus in partnership with ESSO, ESCP, ESGAR, and CIRSE

BACKGROUND

Contemporary management of patients with synchronous colorectal cancer and liver metastases is complex. The aim of this project was to provide a practical framework for care of patients with synchronous colorectal cancer and liver metastases, with a focus on terminology, diagnosis, and management.

METHODS

This project was a multiorganizational, multidisciplinary consensus. The consensus group produced statements which focused on terminology, diagnosis, and management. Statements were refined during an online Delphi process, and those with 70 per cent agreement or above were reviewed at a final meeting. Iterations of the report were shared by electronic mail to arrive at a final agreed document comprising 12 key statements.

RESULTS

Synchronous liver metastases are those detected at the time of presentation of the primary tumour. The term 'early metachronous metastases' applies to those absent at presentation but detected within 12 months of diagnosis of the primary tumour, the term 'late metachronous metastases' applies to those detected after 12 months. 'Disappearing metastases' applies to lesions that are no longer detectable on MRI after systemic chemotherapy. Guidance was provided on the recommended composition of tumour boards, and clinical assessment in emergency and elective settings. The consensus focused on treatment pathways, including systemic chemotherapy, synchronous surgery, and the staged approach with either colorectal or liver-directed surgery as first step. Management of pulmonary metastases and the role of minimally invasive surgery was discussed.

CONCLUSION

The recommendations of this contemporary consensus provide information of practical value to clinicians managing patients with synchronous colorectal cancer and liver metastases.

Multisocietal European consensus on the terminology, diagnosis, and management of patients with synchronous colorectal cancer and liver metastases: an E-AHPBA consensus in partnership with ESSO, ESCP, ESGAR, and CIRSE

BACKGROUND

Contemporary management of patients with synchronous colorectal cancer and liver metastases is complex. The aim of this project was to provide a practical framework for care of patients with synchronous colorectal cancer and liver metastases, with a focus on terminology, diagnosis, and management.

METHODS

This project was a multiorganizational, multidisciplinary consensus. The consensus group produced statements which focused on terminology, diagnosis, and management. Statements were refined during an online Delphi process, and those with 70 per cent agreement or above were reviewed at a final meeting. Iterations of the report were shared by electronic mail to arrive at a final agreed document comprising 12 key statements.

RESULTS

Synchronous liver metastases are those detected at the time of presentation of the primary tumour. The term 'early metachronous metastases' applies to those absent at presentation but detected within 12 months of diagnosis of the primary tumour, the term 'late metachronous metastases' applies to those detected after 12 months. 'Disappearing metastases' applies to lesions that are no longer detectable on MRI after systemic chemotherapy. Guidance was provided on the recommended composition of tumour boards, and clinical assessment in emergency and elective settings. The consensus focused on treatment pathways, including systemic chemotherapy, synchronous surgery, and the staged approach with either colorectal or liver-directed surgery as first step. Management of pulmonary metastases and the role of minimally invasive surgery was discussed.

CONCLUSION

The recommendations of this contemporary consensus provide information of practical value to clinicians managing patients with synchronous colorectal cancer and liver metastases.

Oligometastases: Characterizing the Role of Epigenetic Regulation of Epithelial-Mesenchymal Transition

The "oligometastasis" hypothesis proposes that metastases exist as a spectrum and are not always disseminated. According to this theory, a subset of patients with metastatic disease could benefit from aggressive local therapies. However, the identification of patients most likely to exhibit an oligometastatic phenotype remains challenging. Recent literature focusing on basic and translational studies has identified novel epigenetic regulators of epithelial-mesenchymal transition (EMT) and the emergence of a spectrum of metastatic behavior. Herein, we review these scientific advances and suggest that the spectrum of metastatic virulence produced by these epigenetic mechanisms broadly contributes to the emergence of clinically evident "oligometastases." Epigenetic regulation of EMT programs can result in a spectrum of cell trajectories (e.g., quasi-mesenchymal and highly mesenchymal states) with differential propensity to develop metastases. We propose that quasi-mesenchymal cell states may be associated with a polymetastatic phenotype, whereas highly mesenchymal cell states may be associated with a more oligometastatic phenotype. The mechanisms governing epigenetic regulation of EMT and its array of intermediate states are multifaceted and may contribute to the development of the metastatic spectrum observed clinically. Within this context, translational studies that support the role of EMT and its epigenetic regulation are discussed. Continued translation of these mechanistic discoveries into novel biomarkers may help optimally select patients most likely to exhibit an oligometastatic phenotype and benefit from aggressive local therapies, such as surgery, radiotherapy, and other ablative procedures.

Transcriptomic Maps of Colorectal Liver Metastasis: Machine Learning of Gene Activation Patterns and Epigenetic Trajectories in Support of Precision Medicine

The molecular mechanisms of the liver metastasis of colorectal cancer (CRLM) remain poorly understood. Here, we applied machine learning and bioinformatics trajectory inference to analyze a gene expression dataset of CRLM. We studied the co-regulation patterns at the gene level, the potential paths of tumor development, their functional context, and their prognostic relevance. Our analysis confirmed the subtyping of five liver metastasis subtypes (LMS). We provide gene-marker signatures for each LMS, and a comprehensive functional characterization that considers both the hallmarks of cancer and the tumor microenvironment. The ordering of CRLMs along a pseudotime-tree revealed a continuous shift in expression programs, suggesting a developmental relationship between the subtypes. Notably, trajectory inference and personalized analysis discovered a range of epigenetic states that shape and guide metastasis progression. By constructing prognostic maps that divided the expression landscape into regions associated with favorable and unfavorable prognoses, we derived a prognostic expression score. This was associated with critical processes such as epithelial-mesenchymal transition, treatment resistance, and immune evasion. These factors were associated with responses to neoadjuvant treatment and the formation of an immuno-suppressive, mesenchymal state. Our machine learning-based molecular profiling provides an in-depth characterization of CRLM heterogeneity with possible implications for treatment and personalized diagnostics.

The abscopal effect of immune-radiation therapy in recurrent and metastatic cervical cancer: a narrative review

Despite human papillomavirus vaccination and screening, in about 5% of cases, cervical cancer (CC) is discovered at an initial metastatic stage. Moreover, nearly one-third of patients with locally advanced CC (LACC) will have a recurrence of their disease during follow-up. At the stage of recurrent or metastatic CC, there are very few treatment options. They are considered incurable with a very poor prognosis. For many years, the standard of care was the combination of platinum-based drug and paclitaxel with the possible addition of bevacizumab. The most recent years have seen the development of the use of immune checkpoint inhibitors (ICIs) (pembrolizumab, cemiplimab and others) in patients with CC. They have shown long term responses with improved overall survival of patients in 1st line (in addition to chemotherapy) or 2nd line (as monotherapy) treatment. Another emerging drug is tisotumab vedotin, an antibody-drug conjugate targeting tissue factor. Radiation therapy (RT) often has a limited palliative indication in metastatic cancers. However, it has been observed that RT can induce tumor shrinkage both in distant metastatic tumors beyond the radiation field and in primary irradiated tumors. This is a rarely observed phenomenon, called abscopal effect, which is thought to be related to the immune system and allows a tumor response throughout the body. It would be the activation of the immune system induced by the irradiation of cancer cells that would lead to a specific type of apoptosis, the immunogenic cell death. Today, there is a growing consensus that combining RT with ICIs may boost abscopal response or cure rates for various cancers. Here we will review the potential abscopal effect of immune-radiation therapy in metastatic cervical cancer.

Local Therapies for Metastatic Sarcoma: Why, When, and How?

Management of patients with advanced sarcoma has been evolving in recent decades, from a one-fit-all perspective to a more refined, personalized, and multidisciplinary approach. In parallel, the evolution of local therapies (radiotherapy, surgical and interventional radiology techniques) has contributed to the improvement of survival of patients with advanced sarcoma. In this article, we review the evidence regarding local treatments in advanced sarcoma, as well as its integration with systemic therapies, to provide the reader a wider and deeper perspective on the management of patients with metastatic sarcoma.

Spatially Resolved Transcriptomics Deconvolutes Prognostic Histological Subgroups in Patients with Colorectal Cancer and Synchronous Liver Metastases

Strong immune responses in primary colorectal cancer correspond with better patient survival following surgery compared with tumors with predominantly stromal microenvironments. However, biomarkers to identify patients with colorectal cancer liver metastases (CRLM) with good prognosis following surgery for oligometastatic disease remain elusive. The aim of this study was to determine the practical application of a simple histological assessment of immune cell infiltration and stromal content in predicting outcome following synchronous resection of primary colorectal cancer and CRLM and to interrogate the underlying functional biology that drives disease progression. Samples from patients undergoing synchronous resection of primary colorectal cancer and CRLM were evaluated in detail through histological assessment, panel genomic and bulk transcriptomic assessment, IHC, and GeoMx spatial transcriptomics (ST) analysis. High immune infiltration of metastases was associated with improved cancer-specific survival. Bulk transcriptomic analysis was confounded by stromal content, but ST demonstrated that the invasive edge of the metastases of long-term survivors was characterized by adaptive immune cell populations enriched for type II IFN signaling and MHC-class II antigen presentation. In contrast, patients with poor prognosis demonstrated increased abundance of regulatory T cells and neutrophils with enrichment of Notch and TGFβ signaling pathways at the metastatic tumor center. In summary, histological assessment can stratify outcomes in patients undergoing synchronous resection of CRLM, suggesting that it has potential as a prognostic biomarker. Furthermore, ST analysis has revealed significant intratumoral and interlesional heterogeneity and identified the underlying transcriptomic programs driving each phenotype.

SIGNIFICANCE

Spatial transcriptomics uncovers heterogeneity between patients, between matched lesions in the same patient, and within individual lesions and identifies drivers of metastatic progression in colorectal cancer with reactive and suppressed immune microenvironments.

The Management of Oligometastatic Disease in Colorectal Cancer: Present Strategies and Future Perspectives

Oligometastatic disease has been described as an intermediate clinical state between localized cancer and systemically metastasized disease. Recent clinical studies have shown prolonged survival when aggressive locoregional approaches are added to systemic therapies in patients with oligometastases. The aim of this review is to outline the newest options to treat oligometastatic colorectal cancer (CRC), also considering its molecular patterns. We present an overview of the available local treatment strategies, including surgical procedures, stereotactic body radiation therapy (SBRT), thermal ablation, as well as trans-arterial chemoembolization (TACE) and selective internal radiotherapy (SIRT). Moreover, since imaging methods provide crucial information for the early diagnosis and management of oligometastatic CRC, we discuss the role of modern radiologic techniques in selecting patients that are amenable to potentially curative locoregional treatments.

Repeat stereotactic body radiotherapy for oligometastatic disease

BACKGROUND

Patients with oligometastatic disease (OMD) treated with metastasis-directed definitive local therapy such as stereotactic body radiotherapy (SBRT) are at risk of developing new metastases. Here, we compare characteristics and outcomes of patients treated with a single course and repeat SBRT.

MATERIALS/METHODS

OMD patients treated with SBRT to 1-5 metastases were included in this retrospective study, and classified as single course or repeat SBRT. Progression-free survival (PFS), widespread failure-free survival (WFFS), overall survival (OS), systemic therapy-free survival (STFS) and cumulative incidence of different first failures were analyzed. Patient and treatment characteristics predicting the use of repeat SBRT were investigated using univariable and multivariable logistic regression.

RESULTS

Among the 385 patients included, 129 and 256 received repeat or single course SBRT, respectively. The most common primary tumor and OMD state in both groups were lung cancer and metachronous oligorecurrence. Patients treated with repeat SBRT had shorter PFS (p<0.0001), while WFFS (p=0.47) and STFS (p=0.22) were comparable. Distant failure, particularly with a single metastasis, was more frequently observed in repeat SBRT patients. Repeat SBRT patients had longer median OS (p=0.01). On multivariable logistic regression, low distant metastases velocity and more previous lines of systemic therapy significantly predicted the use of repeat SBRT.

CONCLUSION

Despite shorter PFS and comparable WFFS and STFS, repeat SBRT patients had longer OS. The role of repeat SBRT for OMD patients warrants further prospective investigation, focussing on predictive factors to select patients that might derive a benefit.

Unravelling oligometastatic disease from the perspective of radiation and medical oncology. Part II: prostate cancer and colorectal cancer

Oligometastatic disease (OMD) defines a status of cancer that is intermediate between localized and widely spread metastatic disease, and can be treated with curative intent. While imaging diagnostic tools have considerably improved in recent years, unidentified micrometastases can still escape from current detection techniques allowing disease to progress. The variety of OMD scenarios are mainly defined by the number of metastases, the biological and molecular tumour profiles, and the timing of the development of metastases. Increasing knowledge has contributed to the earlier and improved detection of OMD, underlining the importance of an early disease control. Based on increasing detection rates of OMD in the current real clinical practice and the lack of standardized evidence-based guidelines to treat this cancer status, a board of experts from the Spanish Societies of Radiation Oncology (SEOR) and Medical Oncology (SEOM) organized a series of sessions to update the current state-of-the-art on OMD from a multidisciplinary perspective, and to discuss how results from clinical studies may translate into promising treatment options. This experts' review series summarizes what is known and what it is pending clarification in the context of OMD in the scenarios of Non-Small Cell Lung Cancer and Breast Cancer (Part I), and Prostate Cancer and Colorectal Cancer (Part II), aiming to offer specialists a pragmatic framework that might contribute to the improved management of patients.

The oligometastatic setting in HNSCC: A critical review by the Rete Oncologica Piemonte e Valle d'Aosta multidisciplinary team

INTRODUCTION

The oligometastatic disease is a low burden metastatic disease that might still benefit from curable treatment. Squamous cell carcinoma of the head and neck (HNSCC) is a complex group of malignancies, with high rates of loco-regional recurrences. Distant metastases are less frequent, and a single or few deposits are often observed (oligometastatic disease). The optimal management of oligometastatic HNSCC remains to be defined.

MATERIALS AND METHODS

Key references were derived from a PubMed query. Hand searching and clinicaltrials.gov were also used.

RESULTS

This paper contains a narrative report and a critical discussion of the available evidence on the management of oligometastatic HNSCC patients, with a focus on metastasis-directed therapy (MDT), particularly stereotactic ablative radiotherapy (SABR).

CONCLUSIONS

in line with literature data, the multidisciplinary evaluation emerged as the key element in the management of oligometastatic HNSCC patients.

Preoperative Mutational Analysis of Circulating Tumor Cells (CTCs) and Plasma-cfDNA Provides Complementary Information for Early Prediction of Relapse: A Pilot Study in Early-Stage Non-Small Cell Lung Cancer

PURPOSE

We assessed whether preoperativemutational analyses of circulating tumor cells (CTCs) and plasma-cfDNA could be used as minimally invasive biomarkers and as complimentary tools for early prediction of relapse in early-stage non-small -cell lung cancer (NSCLC).

EXPERIMENTAL DESIGN

Using ddPCR assays, hotspot mutations of BRAF, KRAS, EGFR and PIK3CA were identified in plasma-cfDNA samples and size-based enriched CTCs isolated from the same blood samples of 49 early-stage NSCLC patients before surgery and in a control group of healthy blood donors (n= 22). Direct concordance of the mutational spectrum was further evaluated in 27 patient-matched plasma-cfDNA and CTC-derived DNA in comparison to tissue-derived DNA.

RESULTS

The prevalence of detectable mutations of the four tested genes was higher in CTC-derived DNA than in the corresponding plasma-cfDNA (38.8% and 24.5%, respectively).The most commonly mutated gene was PIK3CA, in both CTCs and plasma-cfDNA at baseline and at the time of relapse. Direct comparison of the mutation status of selected drug-responsive genes in CTC-derived DNA, corresponding plasma-cfDNA and paired primary FFPE tissues clearly showed the impact of heterogeneity both within a sample type, as well as between different sample components. The incidence of relapse was higher when at least one mutation was detected in CTC-derived DNA or plasma-cfDNA compared with patients in whom no mutation was detected (p =0.023). Univariate analysis showed a significantly higher risk of progression (HR: 2.716; 95% CI, 1.030-7.165; p =0.043) in patients with detectable mutations in plasma-cfDNA compared with patients with undetectable mutations, whereas the hazard ratio was higher when at least one mutation was detected in CTC-derived DNA or plasma-cfDNA (HR: 3.375; 95% CI, 1.098-10.375; p =0.034).

CONCLUSIONS

Simultaneous mutational analyses of plasma-cfDNA and CTC-derived DNA provided complementary molecular information from the same blood sample and greater diversity in genomic information for cancer treatment and prognosis. The detection of specific mutations in ctDNA and CTCs in patients with early-stage NSCLC before surgery was independently associated with disease recurrence, which represents an important stratification factor for future trials.

Oligo-Metastatic Cancers: Putative Biomarkers, Emerging Challenges and New Perspectives

Some cancer patients display a less aggressive form of metastatic disease, characterized by a low tumor burden and involving a smaller number of sites, which is referred to as "oligometastatic disease" (OMD). This review discusses new biomarkers, as well as methodological challenges and perspectives characterizing OMD. Recent studies have revealed that specific microRNA profiles, chromosome patterns, driver gene mutations (ERBB2, PBRM1, SETD2, KRAS, PIK3CA, SMAD4), polymorphisms (TCF7L2), and levels of immune cell infiltration into metastases, depending on the tumor type, are associated with an oligometastatic behavior. This suggests that OMD could be a distinct disease with specific biological and molecular characteristics. Therefore, the heterogeneity of initial tumor burden and inclusion of OMD patients in clinical trials pose a crucial methodological question that requires responses in the near future. Additionally, a solid understanding of the molecular and biological features of OMD will be necessary to support and complete the clinical staging systems, enabling a better distinction of metastatic behavior and tailored treatments.

Colorectal Cancer Liver Metastases: Genomics and Biomarkers with Focus on Local Therapies

Molecular cancer biomarkers help personalize treatment, predict oncologic outcomes, and identify patients who can benefit from specific targeted therapies. Colorectal cancer (CRC) is the third-most common cancer, with the liver being the most frequent visceral metastatic site. KRAS, NRAS, BRAF V600E Mutations, DNA Mismatch Repair Deficiency/Microsatellite Instability Status, HER2 Amplification, and NTRK Fusions are NCCN approved and actionable molecular biomarkers for colorectal cancer. Additional biomarkers are also described and can be helpful in different image-guided hepatic directed therapies specifically for CRLM. For example, tumors maintaining the Ki-67 proliferation marker after thermal ablation was shown to be particularly resilient to ablation. Ablation margin was also shown to be an important factor in predicting local recurrence, with a ≥10 mm minimal ablation margin being required to attain local tumor control, especially for patients with mutant KRAS CRLM.

The molecular biology of peritoneal metastatic disease

Peritoneal metastases are a common form of tumor cell dissemination in gastrointestinal malignancies. Peritoneal metastatic disease (PMD) is associated with severe morbidity and resistance to currently employed therapies. Given the distinct route of dissemination compared with distant organ metastases, and the unique microenvironment of the peritoneal cavity, specific tumor cell characteristics are needed for the development of PMD. In this review, we provide an overview of the known histopathological, genomic, and transcriptomic features of PMD. We find that cancers representing the mesenchymal subtype are strongly associated with PMD in various malignancies. Furthermore, we discuss the peritoneal niche in which the metastatic cancer cells reside, including the critical role of the peritoneal immune system. Altogether, we show that PMD should be regarded as a distinct disease entity, that requires tailored treatment strategies.

Colorectal Cancer Metastases in the Liver Establish Immunosuppressive Spatial Networking between Tumor-Associated SPP1+ Macrophages and Fibroblasts

PURPOSE

The liver is the most frequent metastatic site for colorectal cancer. Its microenvironment is modified to provide a niche that is conducive for colorectal cancer cell growth. This study focused on characterizing the cellular changes in the metastatic colorectal cancer (mCRC) liver tumor microenvironment (TME).

EXPERIMENTAL DESIGN

We analyzed a series of microsatellite stable (MSS) mCRCs to the liver, paired normal liver tissue, and peripheral blood mononuclear cells using single-cell RNA sequencing (scRNA-seq). We validated our findings using multiplexed spatial imaging and bulk gene expression with cell deconvolution.

RESULTS

We identified TME-specific SPP1-expressing macrophages with altered metabolism features, foam cell characteristics, and increased activity in extracellular matrix (ECM) organization. SPP1+ macrophages and fibroblasts expressed complementary ligand-receptor pairs with the potential to mutually influence their gene-expression programs. TME lacked dysfunctional CD8 T cells and contained regulatory T cells, indicative of immunosuppression. Spatial imaging validated these cell states in the TME. Moreover, TME macrophages and fibroblasts had close spatial proximity, which is a requirement for intercellular communication and networking. In an independent cohort of mCRCs in the liver, we confirmed the presence of SPP1+ macrophages and fibroblasts using gene-expression data. An increased proportion of TME fibroblasts was associated with the worst prognosis in these patients.

CONCLUSIONS

We demonstrated that mCRC in the liver is characterized by transcriptional alterations of macrophages in the TME. Intercellular networking between macrophages and fibroblasts supports colorectal cancer growth in the immunosuppressed metastatic niche in the liver. These features can be used to target immune-checkpoint-resistant MSS tumors.

Association of comprehensive thyroid cancer molecular profiling with tumor phenotype and cancer-specific outcomes

BACKGROUND

Molecular testing improves the diagnostic accuracy of thyroid cancer. Whether specific molecular testing results are associated with tumor phenotype or provide prognostic information needs further delineation.

METHODS

Consecutive thyroid cancer patients after index thyroidectomy with ThyroSeq version 3 (Rye Brook, NY) molecular testing obtained on preoperative fine-needle aspiration or thyroidectomy specimens from patients with thyroid cancer were categorized into 3 molecular risk groups based on detected mutations, fusions, copy number alterations, and/or gene expression alterations and correlated with histopathology and recurrence, defined as biochemical or structural.

RESULTS

Of 578 patients, 49.9%, 37.5%, and 12.6% had molecular risk group-low, molecular risk group-intermediate, and molecular risk group-high cancers, respectively. With a median 19-month follow-up, 9.1% patients recurred. Compared with molecular risk group-low, molecular risk group-intermediate cancers were diagnosed in younger patients and more often had microscopic extrathyroidal extension, involved margins, and nodal disease. Compared with molecular risk group-intermediate, molecular risk group-high cancers were diagnosed in older patients and more often had gross extrathyroidal extension and vascular invasion. In multivariable analysis, recurrence was more likely in molecular risk group-high cancers than in molecular risk group-intermediate (hazard ratio = 4.0; 95% confidence interval, 1.9-8.6; P < .001) and more likely in molecular risk group-intermediate than in molecular risk group-low (hazard ratio = 5.0; 95% confidence interval, 2.0-12.5; P < .001).

CONCLUSION

Using modern comprehensive genotyping, the genetic profile of thyroid cancers can be categorized into 3 novel molecular risk groups that were associated with histopathologic phenotype and recurrence in short-term follow-up.

Delineating the molecular landscape of different histopathological growth patterns in colorectal cancer liver metastases

Background

Histopathological growth patterns (HGPs) have shown important prognostic values for patients with colorectal cancer liver metastases, but the potential molecular mechanisms remain largely unknown.

Methods

We performed an exploratory analysis by conducting the RNA sequencing of primary colorectal lesions, colorectal liver metastatic lesions and normal liver tissues.

Findings

We found that desmoplastic HGPs of the metastatic lesions were significantly enriched in EMT, angiogenesis, stroma, and immune signaling pathways, while replacement HGPs were enriched in metabolism, cell cycle, and DNA damage repair pathways. With the exception of immune-related genes, the differentially expressed genes of the two HGPs from colorectal liver metastases were mostly inherited from the primary tumor. Moreover, normal liver tissue in the desmoplastic HGP subgroup was markedly enriched in the fibrinous inflammation pathway.

Conclusions

We surmised that HGPs are observable morphological changes resulting from the regulation of molecular expressions, which is the combined effect of the heterogeneity and remodeling of primary tumors seeds and liver soils.

Clinical determinants impacting overall survival of patients with operable brain metastases from non-small cell lung cancer

Non-small cell lung cancer (NSCLC) is currently the leading cause of cancer-related death worldwide, and the incidence of brain metastases (BM) in NSCLC patients is continuously increasing. The recent improvements of systemic treatment in NSCLC necessitate continuous updates on prognostic subgroups and factors determining overall survival (OS). In order to improve clinical decision-making in tumor boards, we investigated the clinical determinants affecting survival in patients with resectable NSCLC BM. A retrospective analysis was conducted of NSCLC patients with surgically resectable BM treated in our institution between 01/2015 and 12/2020. The relevant clinical factors affecting survival identified by univariate analysis were included in a multivariate logistic regression model. Overall, 264 patients were identified, with a mean age of 62.39 ± 9.98 years at the initial diagnosis of NSCLC BM and OS of 23.22 ± 1.71 months. The factors that significantly affected OS from the time of primary tumor diagnosis included the systemic metastatic load (median: 28.40 ± 4.82 vs. 40.93 ± 11.18 months, p = 0.021) as well as a number of BM &lt;2 (median: 17.20 ± 2.52 vs. 32.53 ± 3.35 months, p = 0.014). When adjusted for survival time after neurosurgical intervention, a significant survival benefit was found in patients &lt;60 years (median 16.13 ± 3.85 vs. 9.20 ± 1.39 months, p = 0.011) and, among others, patients without any concurrent systemic metastases at time of NSCLC BM diagnosis. Our data shows that the number of BM (singular/solitary), the Karnofsky Performance Status, gender, and age but not localization (infra-/supratentorial), mass-edema index or time to BM occurrence impact OS, and postsurgical survival in NSCLC BM patients. Additionally, our study shows that patients in prognostically favorable clinical subgroups an OS, which differs significantly from current statements in literature. The described clinically relevant factors may improve the understanding of the risks and the course of this disease and Faid future clinical decision making in tumor boards.

Long-Term Outcomes and Genetic Predictors of Response to Metastasis-Directed Therapy Versus Observation in Oligometastatic Prostate Cancer: Analysis of STOMP and ORIOLE Trials

Clinical trials frequently include multiple end points that mature at different times. The initial report, typically based on the primary end point, may be published when key planned co-primary or secondary analyses are not yet available. Clinical Trial Updates provide an opportunity to disseminate additional results from studies, published in JCO or elsewhere, for which the primary end point has already been reported.The initial STOMP and ORIOLE trial reports suggested that metastasis-directed therapy (MDT) in oligometastatic castration-sensitive prostate cancer (omCSPC) was associated with improved treatment outcomes. Here, we present long-term outcomes of MDT in omCSPC by pooling STOMP and ORIOLE and assess the ability of a high-risk mutational signature to risk stratify outcomes after MDT. The primary end point was progression-free survival (PFS) calculated using the Kaplan-Meier method. High-risk mutations were defined as pathogenic somatic mutations within ATM, BRCA1/2, Rb1, or TP53. The median follow-up for the whole group was 52.5 months. Median PFS was prolonged with MDT compared with observation (pooled hazard ratio [HR], 0.44; 95% CI, 0.29 to 0.66; P value < .001), with the largest benefit of MDT in patients with a high-risk mutation (HR high-risk, 0.05; HR no high-risk, 0.42; P value for interaction: .12). Within the MDT cohort, the PFS was 13.4 months in those without a high-risk mutation, compared with 7.5 months in those with a high-risk mutation (HR, 0.53; 95% CI, 0.25 to 1.11; P = .09). Long-term outcomes from the only two randomized trials in omCSPC suggest a sustained clinical benefit to MDT over observation. A high-risk mutational signature may help risk stratify treatment outcomes after MDT.

Practical Implications of KRAS Mutation Status and Sidedness of Primary Tumour in Patients with Colorectal Cancer and Synchronous Liver Metastases: A Subset Analysis of the CoSMIC Study

Patients with colorectal cancer presenting with synchronous liver metastases have less favourable outcomes than those with primary-only disease. There is evidence of different genetic mutational signatures according to the sidedness of the primary tumour. KRAS mutations are key driver mutations in colorectal cancer progression. This post hoc analysis of the previously reported CoSMIC inception cohort explores the association between primary tumour sidedness and KRAS mutational status on the outcome of patients with colorectal cancer and synchronous liver metastases. Patients diagnosed with synchronous disease were recruited between April 2014 and March 2017 and, after exclusions, 83 patients undergoing colorectal primary KRAS mutation testing constituted the final study population. Data were collected prospectively on demographic profiles, treatment, and outcomes. Twenty-one patients (25%) had right-sided tumours and 62 (75%) had left-sided tumours, with 46 (55%) and 37 (45%) exhibiting wildtype and mutated KRAS, respectively. There was no difference in distribution of liver metastases by KRAS status (unilobar vs. bi-lobar; p = 0.58; Fisher’s Exact test) and no difference in 5-year survival according to KRAS mutation status (Log-rank test, p = 0.82) or tumour sidedness (p = 0.16). In summary, in this cohort of patients with colorectal cancer and synchronous liver metastases, neither KRAS mutation status nor tumour sidedness influenced survival.

The evolving role of radiation therapy as treatment for liver metastases

Liver metastases occur commonly in many solid malignancies. With advances in systemic therapies and increased life expectancy, the role of using local therapies in oligo-metastases is rapidly increasing. Stereotactic body radiotherapy (SBRT) is an emerging precision therapy that is being used more frequently in the treatment for unresectable liver metastases. This review focuses on the role of SBRT for liver metastases, principles of treatment, clinical outcomes, toxicity, and optimal patient selection.

Molecular characterization of colorectal cancer related peritoneal metastatic disease

A significant proportion of colorectal cancer (CRC) patients develop peritoneal metastases (PM) in the course of their disease. PMs are associated with a poor quality of life, significant morbidity and dismal disease outcome. To improve care for this patient group, a better understanding of the molecular characteristics of CRC-PM is required. Here we present a comprehensive molecular characterization of a cohort of 52 patients. This reveals that CRC-PM represent a distinct CRC molecular subtype, CMS4, but can be further divided in three separate categories, each presenting with unique features. We uncover that the CMS4-associated structural protein Moesin plays a key role in peritoneal dissemination. Finally, we define specific evolutionary features of CRC-PM which indicate that polyclonal metastatic seeding underlies these lesions. Together our results suggest that CRC-PM should be perceived as a distinct disease entity.