Extended Molecular Profiling Improves Stratification and Prediction of Survival After Resection of Colorectal Liver Metastases. Ann Surg. 2019;270:799-805. [PMID: 31634180 DOI: 10.1097/sla.0000000000003527]

Comparing baseline VAF in circulating tumor DNA and tumor tissues predicting prognosis of patients with colorectal cancer liver metastases after curative resection

INTRODUCTION

The prognostic value of baseline variant allele frequency (VAF) in circulating tumor DNA (ctDNA) of colorectal cancer liver metastases (CRLM) patients after curative resection was rarely investigated.

METHODS

A single-center prospective study was performed to investigate the prognostic impact of baseline VAF in ctDNA and matched tumor tissues of CRLM patients after curative resection between May 2019 and May 2021 by the Illumina NovoSeq 6000 platform. The relationship of the tumor burden score (TBS) and the VAF in ctDNA and matched tumor tissues was evaluated by the Pearson correlation method. The survival curves of recurrence-free survival (RFS) and overall survival (OS) were plotted. Factors associated with RFS were calculated using Cox regression analysis, and an integrated prognostic model using significant baseline variables was proposed.

RESULTS

There were 121 patients with baseline ctDNA and matched tumor tissues enrolled in the study. A total of 417 mutations spanning 20 genes were identified in baseline tumor tissues of 119/121 (98.3 %) cases. The overall mutations in tumor tissues were completely covered by ctDNA in 52 of 121(43.0 %) patients. Baseline VAF in ctDNA but not in tumor tissues was significantly correlated to TBS of CRLM (R = 0.36, p < 0.001). Significantly longer RFS but not OS was observed in patients with lower VAF in ctDNA compared to those with higher one (p < 0.001 and p = 0.33 respectively). Multivariate Cox regression analysis showed higher VAF in baseline ctDNA was an independent risk factor for RFS. An integrated prognostic model including baseline metastasis location and VAF in ctDNA outperformed the traditional CRS model in predicting RFS.

CONCLUSION

Baseline VAF in ctDNA but not in tumor tissues influenced RFS of CRLM patients after curative resection.

Evaluating Combinations of Biological and Clinicopathologic Factors Linked to Poor Outcomes in Resected Colorectal Liver Metastasis: An External Validation Study

BACKGROUND

Recent studies have suggested that certain combinations of KRAS or BRAF biomarkers with clinical factors are associated with poor outcomes and may indicate that surgery could be "biologically" futile in otherwise technically resectable colorectal liver metastasis (CRLM). However, these combinations have yet to be validated through external studies.

PATIENTS AND METHODS

We conducted a systematic search to identify these studies. The overall survival (OS) of patients with these combinations was evaluated in a cohort of patients treated at 11 tertiary centers. Additionally, the study investigated whether using high-risk KRAS point mutations in these combinations could be associated with particularly poor outcomes.

RESULTS

The recommendations of four studies were validated in 1661 patients. The first three studies utilized KRAS, and their validation showed the following median and 5-year OS: (1) 30 months and 16.9%, (2) 24.3 months and 21.6%, and (3) 46.8 months and 44.4%, respectively. When analyzing only patients with high-risk KRAS mutations, median and 5-year OS decreased to: (1) 26.2 months and 0%, (2) 22.3 months and 15.1%, and (3) not reached and 44.9%, respectively. The fourth study utilized BRAF, and its validation showed a median OS of 10.4 months, with no survivors beyond 21 months.

CONCLUSION

The combinations of biomarkers and clinical factors proposed to render surgery for CRLM futile, as presented in studies 1 (KRAS high-risk mutations) and 4, appear justified. In these studies, there were no long-term survivors, and survival was similar to that of historic cohorts with similar mutational profiles that received systemic therapies alone for unresectable disease.

Proteogenomic Characterization of Early Intrahepatic Recurrence after Curative-Intent Treatment of Colorectal Liver Metastases

Clinical and pathological factors are insufficient to accurately identify patients at risk of early recurrence after curative-intent treatment of colorectal liver metastases (CRLM). This study aimed to identify candidate prognostic proteogenomic biomarkers for early intrahepatic recurrence after curative-intent resection of CRLM. Patients diagnosed with intrahepatic recurrence within 6 months of liver resection were categorized as the "early recurrence" group, while those who achieved a recurrence-free status for 10 years were designated as "durable remission". Comprehensive genomic and proteomic profiling of fresh frozen samples from these prognostically distinct groups was performed using the TruSight Oncology 500 assay and label-free data-dependent acquisition liquid chromatography-mass spectrometry. Genetic alterations were identified in 117 of the 523 profiled genes in patients with early recurrence. The most common somatic mutations linked to early recurrence were TP53 (88%), APC (71%), KRAS (38%), and SMAD4 (21%). SMAD4 alterations were absent in samples from patients with a durable remission. Calponin-2, versican core protein, glutathione peroxidase 3, fibulin-5, and amyloid-β precursor protein were upregulated more than 2-fold in early recurrence. Exploratory analysis of these proteogenomic biomarkers suggests that SMAD4, calponin-2, and glutathione peroxidase 3 may have the potential to predict early recurrence, enabling improved prognostication and precision oncology in CRLM.

Patterns of recurrence after curative intent hepatic resection for colorectal liver metastasis

BACKGROUND

Improved surgical techniques and more intensive systemic therapy have increased the number of patients with oligometastatic colorectal cancer eligible for resection, but a significant percentage of these cases will ultimately recur. Furthermore, distinct recurrence patterns have been associated with different outcomes.

METHODS

Data for 195 patients who underwent curative-intent colorectal liver metastasis (CRLM) resection between 2016 and 2022 at Johns Hopkins Hospital were retrospectively collected. Cox regression univariate and multivariate analyses identified features associated with survival outcomes. Association between risk factors and site of recurrences was conducted via logistic regression with initial recurrences grouped into intrahepatic-only, extrahepatic-only, and concurrent intra- and extrahepatic recurrence.

RESULTS

The 1- and 2-year recurrence-free survival (RFS) rates were 46% and 22%, respectively. The 1- and 2-year overall survival (OS) rates were 95% and 88%, respectively. The median OS was 71.7 months. Multivariate analysis identified age <60 years, N2 nodal status, R1 liver margin, and higher preoperative carcinoembryonic antigen as top prognostic factors for worse RFS. Additionally, patients with left-sided primary tumors had a higher risk of intrahepatic-only recurrence, whereas mutant KRAS was associated with a higher risk of extrahepatic recurrence with or without liver recurrence.

CONCLUSION

These results from a recent cohort of patients treated with current standard-of-care therapies identify features associated with elevated risk and specific patterns of recurrence. These insights into CRLM recurrence patterns support a larger prospective study to identify subgroups of patients who may require additional therapies to prevent recurrence.

BRAF mutations and survival with surgery for colorectal liver metastases: A systematic review and meta-analysis

INTRODUCTION

Mutations in the BRAF gene (BRAFmut) are associated with an unfavorable prognosis in patients with metastatic colorectal cancer (CRC). The aim of this meta-analysis was to evaluate the prognosis of colorectal cancer (CRC) patients with liver metastases and the potential benefits of liver resection in patients with BRAFmut CRC.

MATERIAL AND METHODS

A systematic search of PubMed, Cochrane Central Controlled Trials, and Embase databases was conducted on May 31, 2023. The inclusion criteria were as follows:1) reporting of outcomes in patients with BRAFmut CRC who underwent surgery for liver metastases and/or comparison of outcomes between those who underwent and those who did not undergo resection; 2) reporting of survival information as hazard ratios (HR); and 3) publication in English.

RESULTS

34 studies were included. Median follow up was 48 months for prognostic BRAF status meta-analysis. BRAFmut status showed a significantly increased risk of mortality (hazard ratio [HR] = 2.56, 95% confidence interval [CI] 2.04-3.22; P < 0.01) and relapse (HR = 1.97, 95% CI 1.44-2.71; P < 0.01). Resection of liver metastases was associated with a survival benefit (median follow up 46 months). The HR for survival was 0.44 (95% confidence interval [CI] 0.33-0.59; P < 0.01) in favor of surgery.

CONCLUSIONS

and Relevance: Our analysis indeed confirms that BRAF mutation is associated with poor survival outcomes after liver resection of CRC metastases. However, upon quantitatively assessing the survival benefit of surgical intervention in patients with BRAF-mutated CRC liver metastases, we identified a significant 56% reduction in the risk of death.

Somatic Mutations in Surgically Treated Colorectal Liver Metastases: An Overview

Colorectal cancer is the second most common cause of cancer death in the United States, and up to half of patients develop colorectal liver metastases (CRLMs). Notably, somatic genetic mutations, such as mutations in RAS, BRAF, mismatch repair (MMR) genes, TP53, and SMAD4, have been shown to play a prognostic role in patients with CRLM. This review summarizes and appraises the current literature regarding the most relevant somatic mutations in surgically treated CRLM by not only reviewing representative studies, but also providing recommendations for areas of future research. In addition, advancements in genetic testing and an increasing emphasis on precision medicine have led to a more nuanced understanding of these mutations; thus, more granular data for each mutation are reviewed when available. Importantly, such knowledge can pave the way for precision medicine with the ultimate goal of improving patient outcomes.

A novel targeted NGS panel identifies numerous homologous recombination deficiency (HRD)-associated gene mutations in addition to known BRCA mutations

Deleterious mutations in the BRCA1 and BRCA2 genes have significant therapeutic relevance in clinical settings regarding personalized therapy approaches. BRCA1 and BRCA2 play a pivotal role in homologous recombination (HR) and thus are sensitive for PARP inhibitors (PARPi). Beyond the narrow scope of evaluating only the BRCA mutation status, PARPi can be beneficial for HR deficient (HRD) patients, who harbor mutations in other HR-associated genes. In the present retrospective study, a novel targeted HRD gene panel was validated and implemented for use with FFPE tissue. Samples of patients with ovarian, breast, pancreatic and prostate cancer were included. Variants were robustly detected with various DNA input amounts and the use of test samples showed complete concordance between previously known mutations and HRD panel results. From all the 90 samples included in this cohort, TP53 was the most frequently altered gene (73%). Deleterious BRCA1/2 mutations were found in 20 (22%) of all samples. New pathogenic or likely pathogenic mutations in additional HR-associated genes were identified in 22 (24%) patients. Taken together, the present study proves the feasibility of a new HRD gene panel with reliable panel performance and offers the possibility to easily screen for resistance mutations acquired over treatment time.Mutations in HR-associated genes, besides BRCA1/2, might represent promising potential targets for synthetic lethality approaches. Thus, a substantial number of patients may benefit from expanding the scope of therapeutic agents like PARPi.

Integration of Next-Generation Sequencing in the Surgical Management of Colorectal Liver Metastasis

Hepatic resection remains the treatment of choice for colorectal liver metastases. The advancement of surgical technique and use of perioperative systemic therapy has expanded the number and complexity of patients eligible for surgical resection. In recent years, investigation into gene mutations, such as RAS/RAF pathway, have led to targeted therapies that have significantly improved outcomes. Next-generation sequencing allows analysis of large number of genes that may have potential prognostic relevance in the clinical setting. This review summarizes the current applications of next-generation sequencing technology in metastatic colorectal cancer, focusing on its prognostic implications on patient management.

Five-year survival post hepatectomy for colorectal liver metastases in a real-world Chinese cohort: Recurrence patterns and prediction for potential cure

BACKGROUND

Patients with a 5-year recurrence-free survival post liver resection for colorectal cancer liver metastases (CRLM) are considered to be potentially cured. However, there is a deficit of data on long-term follow-up and the recurrence status among these patients in the Chinese population. We analyzed real-world follow-up data of patients with CRLM who underwent hepatectomy, explored the recurrence patterns, and established a prediction model for a potential cure scenario.

METHODS

Patients who underwent radical hepatic resection for CRLM during 2000-2016, with actual follow-up data for at least 5 years, were enrolled. The observed survival rate was calculated and compared among the groups with different recurrence patterns. The predictive factors for 5-year non-recurrence were determined using logistic regression analysis; a recurrence-free survival model was developed to predict long-term survival.

RESULTS

A total of 433 patients were included, of whom 113 patients were found non-recurrence after 5 years follow-up, with a potential cure rate of 26.1%. Patients with late recurrence (>5 months) and lung relapse showed significantly superior survival. Repeated localized treatment significantly improved the long-term survival of patients with intrahepatic or extrahepatic recurrences. Multivariate analysis showed that RAS wild-type CRC, preoperative CEA <10 ng/ml, and liver metastases ≤3 were independent factors for a 5-year disease-free recurrence. A cure model was developed based on the above factors, achieving good performance in predicting long-term survival.

CONCLUSIONS

About one quarter patients with CRLM could achieve potential cure with non-recurrence at 5-year after surgery. The recurrence-free cure model could well distinguish the long-term survival, which would aid clinicians in determining the treatment strategy.

Predicting early extrahepatic recurrence after local treatment of colorectal liver metastases

BACKGROUND

Patients who develop early extrahepatic recurrence (EHR) may not benefit from local treatment of colorectal liver metastases (CRLMs). This study aimed to develop a prediction model for early EHR after local treatment of CRLMs using a national data set.

METHODS

A Cox regression prediction model for EHR was developed and validated internally using data on patients who had local treatment for CRLMs with curative intent. Performance assessment included calibration, discrimination, net benefit, and generalizability by internal-external cross-validation. The prognostic relevance of early EHR (within 6 months) was evaluated by landmark analysis.

RESULTS

During a median follow-up of 35 months, 557 of the 1077 patients had EHR and 249 died. Median overall survival was 19.5 (95 per cent c.i. 15.6 to 23.0) months in patients with early EHR after CRLM treatment, compared with not reached (45.3 months to not reached) in patients without an early EHR. The EHR prediction model included side and stage of the primary tumour, RAS/BRAFV600E mutational status, and number and size of CRLMs. The range of 6-month EHR predictions was 5.9-56.0 (i.q.r. 12.9-22.0) per cent. The model demonstrated good calibration and discrimination. The C-index through 6 and 12 months was 0.663 (95 per cent c.i. 0.624 to 0.702) and 0.661 (0.632 to 0.689) respectively. The observed 6-month EHR risk was 6.5 per cent for patients in the lowest quartile of predicted risk compared with 32.0 per cent in the highest quartile.

CONCLUSION

Early EHR after local treatment of CRLMs can be predicted.

Mutational Status of SMAD4 and FBXW7 Affects Clinical Outcome in TP53-Mutated Metastatic Colorectal Cancer

Next-generation sequencing (NGS) provides a molecular rationale to inform prognostic stratification and to guide personalized treatment in cancer patients. Here, we determined the prognostic and predictive value of actionable mutated genes in metastatic colorectal cancer (mCRC). Among a total of 294 mCRC tumors examined by targeted NGS, 200 of them derived from patients treated with first-line chemotherapy plus/minus monoclonal antibodies were included in prognostic analyses. Discriminative performance was assessed by time-dependent estimates of the area under the curve (AUC). The most recurrently mutated genes were TP53 (64%), KRAS or NRAS (49%), PIK3CA (15%), SMAD4 (14%), BRAF (13%), and FBXW7 (9.5%). Mutations in FBXW7 correlated with worse OS rates (p = 0.036; HR, 2.24) independently of clinical factors. Concurrent mutations in TP53 and FBXW7 were associated with increased risk of death (p = 0.02; HR, 3.31) as well as double-mutated TP53 and SMAD4 (p = 0.03; HR, 2.91). Analysis of the MSK-IMPACT mCRC cohort (N = 1095 patients) confirmed the same prognostic trend for the previously identified mutated genes. Addition of the mutational status of these genes upon clinical factors resulted in a time-dependent AUC of 87%. Gene set enrichment analysis revealed specific molecular pathways associated with SMAD4 and FBXW7 mutations in TP53-defficient tumors. Conclusively, SMAD4 and FBXW7 mutations in TP53-altered tumors were predictive of a negative prognostic outcome in mCRC patients treated with first-line regimens.

Intracellular and extracellular factors of colorectal cancer liver metastasis: a pivotal perplex to be fully elucidated

Metastasis is the leading cause of death in colorectal cancer (CRC) patients, and the liver is the most common site of metastasis. Tumor cell metastasis can be thought of as an invasion-metastasis cascade and metastatic organotropism is thought to be a process that relies on the intrinsic properties of tumor cells and their interactions with molecules and cells in the microenvironment. Many studies have provided new insights into the molecular mechanism and contributing factors involved in CRC liver metastasis for a better understanding of the organ-specific metastasis process. The purpose of this review is to summarize the theories that explain CRC liver metastasis at multiple molecular dimensions (including genetic and non-genetic factors), as well as the main factors that cause CRC liver metastasis. Many findings suggest that metastasis may occur earlier than expected and with specific organ-anchoring property. The emergence of potential metastatic clones, the timing of dissemination, and the distinct routes of metastasis have been explained by genomic studies. The main force of CRC liver metastasis is also thought to be epigenetic alterations and dynamic phenotypic traits. Furthermore, we review key extrinsic factors that influence CRC cell metastasis and liver tropisms, such as pre-niches, tumor stromal cells, adhesion molecules, and immune/inflammatory responses in the tumor microenvironment. In addition, biomarkers associated with early diagnosis, prognosis, and recurrence of liver metastasis from CRC are summarized to enlighten potential clinical practice, including some markers that can be used as therapeutic targets to provide new perspectives for the treatment strategies of CRC liver metastasis.

Patient-Derived Organoids from Colorectal Cancer with Paired Liver Metastasis Reveal Tumor Heterogeneity and Predict Response to Chemotherapy

There is no effective method to predict chemotherapy response and postoperative prognosis of colorectal cancer liver metastasis (CRLM) patients. Patient-derived organoid (PDO) has become an important preclinical model. Herein, a living biobank with 50 CRLM organoids derived from primary tumors and paired liver metastatic lesions is successfully constructed. CRLM PDOs from the multiomics levels (histopathology, genome, transcriptome and single-cell sequencing) are comprehensively analyzed and confirmed that this organoid platform for CRLM could capture intra- and interpatient heterogeneity. The chemosensitivity data in vitro reveal the potential value of clinical application for PDOs to predict chemotherapy response (FOLFOX or FOLFIRI) and clinical prognosis of CRLM patients. Taken together, CRLM PDOs can be utilized to deliver a potential application for personalized medicine.

Distinct Genomic Profiles are Associated With Conversion to Resection and Survival in Patients With Initially Unresectable Colorectal Liver Metastases Treated With Systemic and Hepatic Artery Chemotherapy

OBJECTIVE

To examine genomic correlates of conversion to resection (CTR and overall survival (OS) in patients with initially unresectable colorectal liver metastasis (IU-CRLM) treated with combination systemic and hepatic artery infusion (HAI) chemotherapy.

BACKGROUND

In patients presenting with IU-CRLM, combination systemic and HAI chemotherapy enables CTR with associated long-term OS in a subset of patients. Genomic correlates of CTR and OS in IU-CRLM have not been previously explored.

METHODS

Specimens from IU-CRLM patients receiving systemic/HAI chemotherapy (2003-2017) were submitted for next-generation sequencing. Fisher Exact test assessed associations with CTR, and Kaplan-Meier/Cox methods assessed associations with OS from HAI initiation.

RESULTS

Of 128 IU-CRLM patients, 51 (40%) underwent CTR at median 6 months (range: 3-35) from HAI initiation. CTR and persistently unresectable cohorts differed significantly in preoperative systemic chemotherapy exposure, node-positive primary status, and size of largest liver metastasis. Median and 5-year OS was 66 months and 51%. CTR was associated with prolonged survival (time-dependent HR 0.23,95% CI: 0.12-0.46, P < 0.001). The most frequently altered genes were APC (81%), TP53 (77%), and KRAS (37%). Oncogenic mutations in SOX9 and BRAF were associated with CTR. BRAF mutations, any RAS pathway alterations, and co-altered RAS/RAF-TP53 mutations wereassociated with worse survival. Classification and regression tree analysis defined prognostically relevant clusters of genomic risk to reveal co-altered RAS/RAF-TP53 as the highest risk subgroup. Co-altered RAS/RAF-TP53 remained independently associated with worse survival (HR 2.52, 95% CI: 1.37-4.64, P = 0.003) after controlling for CTR, number of liver metastases, and preoperative extrahepatic disease.

CONCLUSIONS

Distinct genomic profiles are associated with CTR and survival in patients with IU-CRLM treated with HAI/systemic chemotherapy. Presence of SOX9, BRAF , and co-altered RAS/RAF- TP53 mutations are promising biomarkers that, when validated in larger datasets, may impact treatment of IU-CRLM patients.

Precision surgery for colorectal liver metastases: Current knowledge and future perspectives

Precision surgery for colorectal liver metastases (CRLM) includes optimal selection of both the patient and surgery. Initial attempts of using clinical risk scores to identify patients for whom technically feasible surgery is oncologically futile failed. Since then, patient selection for single-stage hepatectomy followed three distinct approaches, all of which incorporated biomarkers. The BRAF V600E mutation, the G12V KRAS variant, and the triple mutation of RAS, TP53, and SMAD4 appear to be the most promising, but none can be used in isolation to deny surgery in otherwise resectable cases. Combining biomarkers with clinicopathologic factors that predict poor prognosis may be used to select patients for surgery, but external validation and matched analyses with medically treated counterparts are needed. Patient selection for special surgical procedures (two-stage hepatectomy [TSH], Associating Liver Partition and Portal vein Ligation for staged hepatectomy [ALPPS], and liver transplant [LT]) has been recently refined. Specifically, BRAF mutations and right-sided laterality have been proposed as separate contraindications to LT. A similar association of right-sided laterality, particularly when combined with RAS mutations, with very poor outcomes has been observed for ALPPS and has been suggested as a biologic contraindication. Data are scarce for TSH but RAS mutations may portend very poor survival following TSH completion. The selection of the best single-stage hepatectomy (optimal margin and type of resection) based on biomarkers remains debated, although there is some evidence that RAS may play a significant role. Lastly, although there are currently no criteria to select among the three special techniques based on their efficacy or appropriateness in different settings, RAS mutational status may be used to select patients for TSH, while right-sided tumor in conjunction with a RAS mutation may be a contraindication to LT and ALPPS.

Prognostic factors in colorectal liver metastases patients with various tumor numbers treated by liver resection: a single-center, retrospective study

BACKGROUND

Multiple liver metastases is considered a risk factor for overall survival of colorectal liver metastases patients (CRLM) after curative resection. However, whether the prognostic factors were constant in patients with various liver metastases (LM) numbers has not been adequately investigated. This retrospective study aimed to evaluate the changing of prognostic factors on overall survival (OS) in CRLM patients with various LM after curative resection.

METHODS

Patients who underwent liver resection for CRLM between January 2000 and November 2020 were retrospectively studied. They were divided into three subgroups according to LM numbers by X-tile analysis. Multivariable analysis identified prognostic factors in each subgroup. Nomograms were built using different prognostic factors in three subgroups, respectively. Performance of the nomograms was assessed according to the concordance index (C-index) and calibration plots. The abilities of different scoring systems predicting OS were compared by calculating the area under the time-dependent receiver operating characteristic (ROC) curve (AUC).

RESULTS

A total of 1095 patients were included. Multivariable analysis showed tumor number increasing was an independent risk factor. Patients were subsequently divided into 3 subgroups according to the number of LM by X-tile analysis, namely solitary (n = 375), 2-4 (n = 424), and ≥ 5 (n = 296). The 3-year and 5-year OS rates were 64.1% and 54.0% in solitary LM group, 58.1% and 41.7% in 2-4 LM group, and 50.9% and 32.0% in ≥ 5 LM group, respectively (p < 0.001). In multivariable analysis, RAS mutation was the only constant independent risk factor in all subgroups. The nomograms were built to predict survival based on independent factors in three subgroups. The C-index for OS prediction was 0.707 (95% CI 0.686-0.728) in the solitary LM group, 0.695 (95% CI 0.675-0.715) in the 2-4 LM group, and 0.687 (95% CI 0.664-0.710) in the ≥ 5 LM group. The time-dependent AUC values of nomograms developed using different risk factors after stratifying patients by tumor number were higher than the traditional scoring systems without patient stratification.

CONCLUSIONS

The prognostic factors varied among CRLM patients with different LM numbers. RAS mutation was the only constant risk factor. Building prediction models based on different prognostic factors improve patient stratification.

Characterization of Genomic Alterations in Colorectal Liver Metastasis and Their Prognostic Value

Colorectal liver metastases (CRLMs) are clinically heterogeneous lesions with poor prognosis. Genetic alterations play a crucial role in their progression. The traditional Fong clinical risk score (Fong-CRS) is commonly used for risk stratification and prognosis prediction. By identifying the genomic alterations of CRLMs, we aimed to develop a mutation-based gene-signature-based clinical score (mut-CS) system to improve clinical prognostication. Tumour tissues from 144 patients with CRLMs were analysed with next-generation sequencing (NGS). A mut-CS scoring system considering the unique mutation-based gene signature, primary site, and Fong-CRS was developed and could identify CRLM patients with poor prognosis. The mean time-dependent receiver operating characteristic curve AUC value of the mut-CS system was greater than that of previously established scoring measures (the Fong-CRS, the e-clinical score, the presence of concomitant RAS and TP53 mutations, and other clinical traits). Taking together, we identified a mutant signature that exhibits a strong prognostic effect for CRLMs. Traditional clinical scoring system characteristics were incorporated into the new mut-CS scoring system to help determine the appropriate treatment for CRLMs.

Prognostic Models Incorporating RAS Mutation to Predict Survival in Patients with Colorectal Liver Metastases: A Narrative Review

Recurrence and survival vary widely among patients who undergo curative-intent resection of colorectal liver metastases (CRLM). Prognostic models provide estimated probabilities of these outcomes and allow the effects of multiple potentially interacting variables to be adjusted and assessed simultaneously. Although many prognostic models based on clinicopathologic factors have been developed since the 1990s to predict survival after resection of CRLM, these models vary in their predictive performance when applied to contemporary cohorts. Rat sarcoma viral oncogene homolog (RAS) mutation status is routinely tested in patients with metastatic colorectal cancer to predict response to anti-epidermal growth factor therapy. In addition, mutations in RAS predict survival and recurrence in patients undergoing hepatectomy for CRLM. Several recent prognostic models have incorporated RAS mutation status as a surrogate of tumor biology and combined revised clinicopathologic variables to improve the prediction of recurrence and survival. This narrative review aims to evaluate the differences between contemporary prognostic models incorporating RAS mutation status and their clinical applicability in patients considered for curative-intent resection of CRLM.

Preoperative leukocytosis is an independent risk factor for morbidity and survival after resection of colorectal liver metastases

BACKGROUND

Although surgical resection of colorectal liver metastases (CRLM) remains to be the only option for long term survival, traditional surgical concepts have been challenged by the introduction of the liver first approach or neoadjuvant chemotherapy in resectable CRLM and interventional therapies. The aim of this study was to identify prognostic factors for postoperative morbidity and survival and to externally evaluate the recently introduced resection severity index (RSI), in order to optimize patient selection and treatment strategies.

METHODS

This is a retrospective single centre analysis of 213 patients undergoing surgery for CRLM in curative intent between January 2010 and December 2018.

RESULTS

Median follow up after liver resection was 28.56 (0.01-111.46) months. Severe postoperative complications (Clavien-Dindo ≥ IIIa) were observed in 46 (21.6%) cases. Preoperative leukocytosis (OR: 3.114, CI-95%: 1.089-8.901; p = 0.034) and operation time in minutes (OR: 1.007, CI-95%: 1.002-1.011; p = 0.002) were determined as independent risk factors. Overall survival (OS) was 46.68 months with a 5-year survival rate of 40.5%. Independent prognostic factors were preoperative leukocytosis (HR: 2.358, CI-95%: 1.170-4.752; p = 0.016), major hepatectomy (HR: 1.741, CI-95%: 1.098-2.759; p = 0.018) and low grading of the primary intestinal tumour (HR: 0.392, CI-95%: 0.231-0.667; p < 0.001). The RSI (ASAT (U/l) divided by Quick (%) multiplied by the extent of liver resection in points) was identified as independent risk factor for OS only in patients without neoadjuvant chemotherapy.

CONCLUSIONS

Detection of leukocytosis in patients prior resection of CRLM was associated with increased postoperative morbidity and decreased OS and could therefore prove valuable for perioperative risk stratification.

External Validation of Two Established Clinical Risk Scores Predicting Outcome after Local Treatment of Colorectal Liver Metastases in a Nationwide Cohort

Optimized surgical techniques and systemic therapy have increased the number of patients with colorectal liver metastases (CRLM) eligible for local treatment. To increase postoperative survival, we need to stratify patients to customize therapy. Most clinical risk scores (CRSs) which predict prognosis after CRLM resection were based on the outcome of studies in specialized centers, and this may hamper the generalizability of these CRSs in unselected populations and underrepresented subgroups. We aimed to externally validate two CRSs in a population-based cohort of patients with CRLM. A total of 1105 patients with local treatment of CRLM, diagnosed in 2015/2016, were included from a nationwide population-based database. Survival outcomes were analyzed. The Fong and more recently developed GAME CRS were externally validated, including in pre-specified subgroups (≤70/>70 years and with/without perioperative systemic therapy). The three-year DFS was 22.8%, and the median OS in the GAME risk groups (high/moderate/low) was 32.4, 46.7, and 68.1 months, respectively (p < 0.005). The median OS for patients with versus without perioperative therapy was 47.6 (95%CI [39.8, 56.2]) and 54.9 months (95%CI [48.8, 63.7]), respectively (p = 0.152), and for below/above 70 years, it was 54.9 (95%CI [49.3−64.1]) and 44.2 months (95%CI [37.1−54.3]), respectively (p < 0.005). The discriminative ability for OS of Fong CRS was 0.577 (95%CI [0.554, 0.601]), and for GAME, it was 0.596 (95%CI [0.572, 0.621]), and was comparable in the subgroups. In conclusion, both CRSs showed predictive ability in a population-based cohort and in predefined subgroups. However, the limited discriminative ability of these CRSs results in insufficient preoperative risk stratification for clinical decision-making.

Progress of targeted and immunotherapy for hepatocellular carcinoma and the application of next-generation sequencing

Hepatocellular carcinoma (HCC), leading cancer worldwide, has a high degree of genetic heterogeneity; next-generation sequencing (NGS) technology has contributed significantly to the discovery of driving genes as well as high-frequency mutations in HCC. The detection of gene alterations may allow us to predict prognosis and adverse drug reactions for individuals, paving the way for personalized medicine in HCC patients. In this review, we summarized the common systemic therapy regimens for HCC and the predictive efficacy of genetic biomarkers on the prognosis of patients under these treatments. Finally, we put forward a future perspective on the potential of NGS technology for the guidance of targeted therapy and immunotherapy in HCC.

Neither Surgical Margin Status nor Somatic Mutation Predicts Local Recurrence After R0-intent Resection for Colorectal Liver Metastases

BACKGROUND

We evaluated the associations of surgical margin status and somatic mutations with the incidence of local recurrence (LR) and oncologic outcomes in patients undergoing R0-intent (microscopically negative margin) resection of colorectal liver metastases (CLM).

METHODS

Patients with CLM who underwent initial R0-intent resection and analysis of tumor tissue using next-generation sequencing during 2001-2018 were analyzed. Recurrences were classified as LR (at the resection margin), other intrahepatic recurrence, or extrahepatic recurrence. Predictors and survival effect of LR were evaluated using univariate and multivariate analysis.

RESULTS

Of 552 patients analyzed, 415 (75%) had R0 resection (margin width ≥ 1.0 mm), and 38 (7%) had LR. LR incidence was not affected by surgical margin width. RAS/TP53 co-mutation was associated with increased risk of intrahepatic recurrence (67% vs. 49%; p < 0.001) and overall recurrence (p < 0.001). However, incidence of LR did not differ significantly by RAS/TP53, BRAF, SMAD4, or FBXW7 mutation. Extrahepatic disease (hazard ratio [HR], 1.47; p = 0.034), > 8 cycles of preoperative chemotherapy (HR, 1.98; p = 0.033), tumor viability ≥ 50% (HR, 1.55; p = 0.007), RAS/TP53 co-mutation (HR, 1.69; p = 0.001), and SMAD4 mutation (HR, 2.44; p < 0.001) were independently associated with poor overall survival, but surgical margin status was not.

CONCLUSIONS

Although somatic mutations were associated with overall recurrence, neither surgical margin width nor somatic mutations affected LR risk after R0-intent hepatectomy for CLM. LR and prognosis were likely driven by individual tumor biology rather than surgical margins.

Effect of Co-mutation of RAS and TP53 on Postoperative ctDNA Detection and Early Recurrence after Hepatectomy for Colorectal Liver Metastases

BACKGROUND

Circulating tumor DNA (ctDNA) is a promising biomarker for patients undergoing hepatectomy for colorectal liver metastases (CLM). We hypothesized that post-hepatectomy ctDNA detection would identify patients at highest risk for early recurrence of CLM.

STUDY DESIGN

Patients with CLM who underwent curative-intent hepatectomy with ctDNA analysis within 180 days postoperatively (1/2013 and 6/2020) were included. Tissue somatic mutations and ctDNA analyses were performed by next-generation sequencing panels. Survival analyses determined factors associated with clinical recurrence 1 year or earlier after hepatectomy. Patients with primary tumors in situ and without 1-year follow-up were excluded. Median follow-up was 28.3 months.

RESULTS

Of 105 patients, 32 (30%) were ctDNA positive (ctDNA+) after curative-intent hepatectomy. Compared with ctDNA-negative patients, ctDNA+ patients had multiple CLM (84% vs 55%, p = 0.002) and co-mutated RAS/TP53 (47% vs 23%, p = 0.018). Multiple CLM (odds ration (OR), 5.43; p = 0.005) and co-mutated RAS/TP53 (OR, 3.30; p = 0.019) were independently associated with post-hepatectomy ctDNA. Although perioperative carcinoembryonic antigen levels were not prognostic, postoperative ctDNA+ (hazard ratio (HR), 2.04; p = 0.011) and extrahepatic disease (HR, 2.45, p = 0.004) were independently associated with worse recurrence-free survival. After adjusting for extrahepatic disease, preoperative chemotherapy, multiple CLM, tumor viability of 50% or greater, and co-mutated RAS/TP53, ctDNA+ within 180 days was the only independent risk factor for recurrence 1 year or earlier after hepatectomy (94% vs 49%; HR, 11.8; p = 0.003).

CONCLUSION

Postoperative ctDNA detection is associated with early recurrence 1 year or earlier after curative-intent hepatectomy for CLM, and RAS/TP53 co-mutations result in a more than 3-fold increased risk for postoperative ctDNA positivity. This highlights the complementary effect of tumor tissue and circulating mutational profiling for patients with CLM.

[Oncological surgery in the interdisciplinary context-On the way to personalized medicine]

Oncological surgery is a discipline which closely interacts with other clinical partners and remains in many cases the cornerstone of a curative treatment of solid tumors. Due to the progress in the field of systemic tumor treatment as well as innovations in surgical techniques, the indications in oncological surgery are also changing, such as extended indications for patients with oligometastatic disease. Surgery of metastases has long been established for colorectal cancer and is being further tested for other entities, such as pancreatic and gastric cancer, within randomized controlled clinical trials (e.g. RENAISSANCE and METAPANC). A new challenge is the handling of a clinical complete remission after total neoadjuvant therapy, for example in locally advanced rectal cancer or in esophageal cancer. Here, organ and function preservation are increasingly propagated but should only be performed within clinical trials until stratification enables the identification of patients in whom this concept is oncologically safe. The personalized use of oncological surgery is dependent on the patient, the tumor and on the total multimodal concept.

Is precision medicine for colorectal liver metastases still a utopia? New perspectives by modern biomarkers, radiomics, and artificial intelligence

The management of patients with liver metastases from colorectal cancer is still debated. Several therapeutic options and treatment strategies are available for an extremely heterogeneous clinical scenario. Adequate prediction of patients’ outcomes and of the effectiveness of chemotherapy and loco-regional treatments are crucial to reach a precision medicine approach. This has been an unmet need for a long time, but recent studies have opened new perspectives. New morphological biomarkers have been identified. The dynamic evaluation of the metastases across a time interval, with or without chemotherapy, provided a reliable assessment of the tumor biology. Genetics have been explored and, thanks to their strong association with prognosis, have the potential to drive treatment planning. The liver-tumor interface has been identified as one of the main determinants of tumor progression, and its components, in particular the immune infiltrate, are the focus of major research. Image mining and analyses provided new insights on tumor biology and are expected to have a relevant impact on clinical practice. Artificial intelligence is a further step forward. The present paper depicts the evolution of clinical decision-making for patients affected by colorectal liver metastases, facing modern biomarkers and innovative opportunities that will characterize the evolution of clinical research and practice in the next few years.

Patient-centered developments in colon- and rectal cancer with a multidisciplinary international team: From translational research to national guidelines

Rarely, scientific developments centered around the patient as a whole are published. Our multidisciplinary group, headed by gastrointestinal surgeons, applied this research philosophy considering the most important aspects of the diseases "colon- and rectal cancer" in the long-term developments. Good expert cooperation/knowledge at the Comprehensive Cancer Center Ulm (CCCU) were applied in several phase III trials for multimodal treatments of primary tumors (MMT) and metastatic diseases (involving nearly 2000 patients and 64 centers), for treatment individualization of MMT and of metastatic disease, for psycho-oncology/quality of life involving the patients' wishes, and for disease prevention. Most of the targets initially were heavily rejected/discussed in the scientific communities, but now have become standards in treatments and national guidelines or are topics in modern translational research protocols involving molecular biology for e.g., "patient centered individualized treatment". In this context we also describe the paths we had to tread in order to realize our new goals, which at the end were highly beneficial for the patients from many points of view. This description is also important for students and young researchers who, with an actual view on our recent developments, might want to know how medical progress was achieved.

Prognostic and Therapeutic Implications of Tumor Biology in Colorectal Liver Metastases

Prognostic models allow clinicians to predict survival outcomes, facilitate patient-physician discussions, and identify subgroups with potentially distinct prognoses [...].

Cancer gene related characterization of patterns and point of recurrence after resection of colorectal liver metastases

Background

Outcome after resection of CRLM is hampered by a high rate of recurrence. There are little data about the role of cancer related genes and their mutations in this scenario. The aim of our analysis was to assess the predictive power of cancer-related genes and their mutations on risk for and distribution of recurrence and the time of occurrence after resection of colorectal liver metastases (CRLM).

Methods

We included 130 patients with 167 liver resections. The work-up consisted of the analysis of a total of 720 cancer-related genes by next-generation sequencing (NGS). Results were correlated with the patterns and time of recurrence and survival.

Results

At the time of analysis, 89/130 patients (68%) had developed recurrence. This included liver only recurrence in 52%, lung only recurrence in 11% and disseminated disease in 37% of cases. In univariate analysis, alterations in the RAS/RAF pathway and in the SMAD family had significant predictive power for the time of recurrence (P<0.0001) whereas single mutations did not reach statistical significance in multivariate analysis. Mutations of PIK3CA were associated with a better prognosis and a later occurrence of relapse. A recurrence risk score (r-RS) based on mutations in these cancer related genes is predictive of the time of recurrence.

Conclusions

In conclusion, mutations in the RAS/RAF pathway and the SMAD family are risk factors for early recurrence. Mutations of PIK3CA are associated with a lower risk for recurrence after resection of CRLM. Cancer related genes and their mutations do not correlate with patterns of recurrence but are predictive for the timely onset of recurrence.

Management of Colorectal Cancer with Synchronous Liver Metastases: An Inception Cohort Study (CoSMIC)

BACKGROUND

Approximately one-fifth of patients with colorectal cancer present with hepatic metastases. There are limited prospective data on the outcomes of synchronous combined liver and bowel surgery and liver-first or bowel-first routes where contemporary chemo(radio)therapy is integrated into management.

METHODS

Between 1 April 2014 and 31 March 2017, 125 patients with colorectal cancer and synchronous liver metastases were recruited. Data are reported on pathway-specific outcomes, including perioperative complications, treatment completion, and overall and disease-free survival. The study was registered with ClinicalTrials.gov (NCT02456285).

RESULTS

There was no difference in age, body mass index, or Charlson score between surgical groups. Neoadjuvant chemotherapy was used in 50 (40%) patients for a mean duration of 4.6 months (standard deviation [SD] 5.4), and mean time from completion of chemotherapy to surgery was 2.6 months (SD 1.9). Complications were similar between patients completing the synchronous and staged pathways (p = 0.66). Mean total inpatient stay was 16.5 days (SD 8.1) for staged surgery compared with 16.8 days (SD 10.3) for the synchronous group (t-test; p = 0.91). There was no difference in time to treatment completion between pathways. Thirty six (35%) patients were disease-free at 12 months, with no significant difference between groups (Chi-square, p = 0.448). Quality of life was similar in all surgical groups.

CONCLUSIONS

Perioperative complications and oncological and healthcare occupancy outcomes are equivalent between patients completing staged and synchronous pathways for the management of patients with colorectal cancer and synchronous liver metastases. Future studies should focus on optimizing the criteria for pathway selection, incorporation of cancer genomics data, and patient (user) preferences.

Composite Score: prognostic tool to predict survival in patients undergoing surgery for colorectal liver metastases

BACKGROUND

Several existing scoring systems predict survival of patients with colorectal liver metastases. Many lack validation, rely on old clinical data, and have been found to be less accurate since the introduction of chemotherapy. This study aimed to construct and validate a clinically relevant preoperative prognostic model for patients with colorectal liver metastases.

METHODS

A predictive model with data available before surgery was developed. Survival was analysed by Cox regression analysis, and the quality of the model was assessed using discrimination and calibration. The model was validated using multifold cross-validation.

RESULTS

The model included 1212 consecutive patients who underwent liver resection for colorectal liver metastases between 2005 and 2015. Prognostic factors for survival included advanced age, raised C-reactive protein level, hypoalbuminaemia, extended liver resection, larger number of metastases, and midgut origin of the primary tumour. A Composite Score was developed based on the prognostic variables. Patients were classified into those at low, medium, and high risk. Survival differences between the groups were significant; median overall survival was 87.4 months in the low-risk group, 50.1 months in the medium-risk group, and 22.6 months in the high-risk group. The discriminative performance, assessed by the concordance index, was 0.71, 0.67, and 0.67 respectively at 1, 3, and 5 years. Calibration, assessed graphically, was close to perfect. A multifold cross-validation of the model confirmed its internal validity (C-index 0.63 versus 0.62).

CONCLUSION

The Composite Score categorizes patients into risk strata, and may help identify patients who have a poor prognosis, for whom surgery is questionable.

Genetic mutations associated with sensitivity to neoadjuvant chemotherapy in metastatic colon cancer: A case report and review of literature

BACKGROUND

Colorectal liver metastases (CLM) occur in 15%-30% of patients with colorectal cancer (CRC). Advancements in next generation sequencing (NGS) can provide more precise prognoses for cancer patients and help guide clinical treatment. However, the genetic variants that predict high sensitivity to neoadjuvant chemotherapy remain unclear, especially in patients with CLM. The aim of this study was to identify the relevant genetic variants in a single CLM patient and to summarize the current evidence on mutations and single nucleotide polymorphisms (SNPs) that objectively predict sensitivity to neoadjuvant chemotherapy.

CASE SUMMARY

A 76-year-old male patient, who was diagnosed as stage IV colon cancer with liver metastases, was found to have APC/TP53/KRAS mutations. He showed a good therapeutic response to 12 courses of oxaliplatin regimens combined with Bevacizumab. Genetic analysis of the patient identified 5 genes with 7 detected SNPs that may be related to a better response to chemotherapy drugs. In addition, a critical literature review was performed based on a standardized appraisal form after selecting the articles. Ultimately, 21 eligible studies were appraised to assess the association between gene mutations and good prognosis. Mutations in KRAS, TP53, SMAD4, and APC were identified as being associated with a poor response to chemotherapy drugs, whereas mutations of CREBBP and POLD1 were associated with longer overall survival.

CONCLUSION

NGS can identify precise predictors of response to neoadjuvant chemotherapy, leading to improved outcomes for CRC patients.

Comparative analysis of nuclear and mitochondrial DNA from tissue and liquid biopsies of colorectal cancer patients

The current standard for molecular profiling of colorectal cancer (CRC) is using resected or biopsied tissue specimens. However, they are limited regarding sampling frequency, representation of tumor heterogeneity, and sampling can expose patients to adverse side effects. The analysis of cell-free DNA (cfDNA) from blood plasma, which is part of a liquid biopsy, is minimally invasive and in principle enables detection of all tumor-specific mutations. Here, we analyzed cfDNA originating from nucleus and mitochondria and investigated their characteristics and mutation status in a cohort of 18 CRC patients and 10 healthy controls using targeted next-generation sequencing (NGS) and digital PCR. Longitudinal analyses of nuclear cfDNA level and size during chemotherapy revealed a decreasing cfDNA content and a shift from short to long fragments, indicating an appropriate therapy response, while shortened cfDNAs and increased cfDNA content corresponded with tumor recurrence. Comparative NGS analysis of nuclear tissue and plasma DNA demonstrated a good patient-level concordance and cfDNA revealed additional variants in three of the cases. Analysis of mitochondrial cfDNA surprisingly revealed a higher plasma copy number in healthy subjects than in CRC patients. These results highlight the potential clinical utility of liquid biopsies in routine diagnostics and surveillance of CRC patients as complementation to tissue biopsies or as an attractive alternative in cases where tissue biopsies are risky or the quantity/quality does not allow testing.

Colon Rectal Liver Metastases: The Role of the Liver Transplantation in the Era of the Transplant Oncology and Precision Medicine

The development of liver metastases in colon rectal cancer has a strong impact on the overall survival (OS) of the patient, with a 5-year survival rate of 5% with palliative treatment. Surgical resection combined with pharmacological treatment can achieve a 5-year OS rate of 31-58%. However, in only 20% of patients with colon rectal liver metastases (CRLMs), liver resection is feasible. In highly selected patients, recent trials and studies proved that liver transplantation (LT) for non-resectable CRLM is a surgical option with an excellent long-term OS. The paper aims to review the indications and outcome of LT for CRLMs, with a special focus on immunosuppressive therapy and the management of local and extrahepatic recurrence after LT.

Characterization of genomic alterations in Chinese colorectal cancer patients with liver metastases

Background

The exploration of genomic alterations in Chinese colorectal liver metastasis (CRLM) is limited, and corresponding genetic biomarkers for patient’s perioperative management are still lacking. This study aims to understand genome diversification and complexity that developed in CRLM.

Methods

A custom-designed IDT capture panel including 620 genes was performed in the Chinese CRLM cohort, which included 396 tumor samples from metastatic liver lesions together with 133 available paired primary tumors.

Results

In this Chinese CRLM cohort, the top-ranked recurrent mutated genes were TP53 (324/396, 82%), APC (302/396, 76%), KRAS (166/396, 42%), SMAD4 (54/396, 14%), FLG (52/396, 13%) and FBXW7 (43/396, 11%). A comparison of CRLM samples derived from left- and right-sided primary lesions confirmed that the difference in survival for patients with different primary tumor sites could be driven by variations in the transforming growth factor β (TGF-β), phosphatidylinositol 3-kinase (PI3K) and RAS signaling pathways. Certain genes had a higher variant rate in samples with metachronous CRLM than in samples with simultaneous metastasis. Overall, the metastasis and primary tumor samples displayed highly consistent genomic alterations, but there were some differences between individually paired metastases and primary tumors, which were mainly caused by copy number variations.

Conclusion

We provide a comprehensive depiction of the genomic alterations in Chinese patients with CRLM, providing a fundamental basis for further personalized therapy applications.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12967-021-02986-0.

Reevaluating the prognostic value of RAS mutation status in patients with resected liver metastases from colorectal cancer: A systematic review and meta-analysis

BACKGROUND

Although the value of Rat Sarcoma Oncogene (RAS) mutation status in predicting long-term outcomes in patients with colorectal liver metastases (CRLM) is widely accepted, the magnitude of its impact has recently been challenged by three large cohort studies. The aim of this meta-analysis is to reevaluate the impact of RAS mutations on overall survival (OS) and disease-free survival (DFS) in patients who underwent curative-intent resection of CRLM.

METHODS

A comprehensive literature search was performed for studies reporting outcomes of patients undergoing curative-intent surgery stratified by RAS mutation status. Exclusion criteria were defined a priori. Subgroup analysis was performed to evaluate the effect of publication date, sample size, and KRAS vs any RAS mutation on overall outcomes.

RESULTS

Ten studies incorporating 3115 patients with known RAS status were identified. Pooled results revealed significantly worse OS (Hazard Ratio 1.5, 95% CI 1.31-1.71) and DFS (Hazard Ratio 1.36, 95% CI 1.22-1.52) in RAS-mutated patients. Subgroup analyses revealed that studies including more than 300 patients or published after 2015 reported lower HR than their counterparts.

CONCLUSION

The results of this meta-analysis suggest that the prognostic value of RAS mutation status in patients with CRLM has been previously overestimated.

Prognostic and Therapeutic Implications of Tumor Biology, Including Gene Alterations, in Colorectal Liver Metastases

BACKGROUND

For patients with colorectal liver metastases (CLM), the combination of surgical resection with other therapeutic options is essential. This article shows how recent advances in knowledge of tumor biology, including genetic alterations, affect the choice of therapeutic approach for patients with CLM.

METHODS

We reviewed the literature on recent advances in knowledge about CLM tumor biology including genetic profiles, clinical risk score models for CLM, preoperative therapy for CLM, and liver-directed therapy for CLM.

RESULTS

Studies showed that RAS alteration is a negative prognostic factor in addition to traditional clinical risk factors (e.g., larger diameter and higher number of CLM, spread of the primary tumor to regional lymph nodes). Although the response to preoperative chemotherapy is an important predictor of survival, poor response is not a contraindication to surgical resection. The combination of surgical therapy and percutaneous ablation can be considered in marginally resectable cases; however, a wider ablation margin is required for RAS-mutant CLM. More recently, genetic analysis using next-generation sequencing showed the negative prognostic impact of alterations in TP53, SMAD4, FBXW7, and RAS/BRAF in patients with CLM. In RAS-mutant CLM, intensive follow-up is required in patients who remain recurrence free 2 years after surgery.

DISCUSSION

In patients with CLM, RAS mutation status is important in predicting postoperative survival, selecting the treatment approach, and tailoring postoperative follow-up. In addition, more recent genetic analyses of CLM have identified additional predictors of survival.

Dynamic monitoring of circulating tumor DNA to predict prognosis and efficacy of adjuvant chemotherapy after resection of colorectal liver metastases

Rationale: Hepatectomy and adjuvant chemotherapy after resection of colorectal liver metastases (CRLM) may improve survival, however, patients which may benefit cannot currently be identified. Postoperative circulating tumor DNA (ctDNA) analysis can detect minimal residual disease (MRD) and predict the prognosis and efficacy of adjuvant chemotherapy. Our study aims to determine the impact of serial ctDNA analysis to predict the outcome among patients undergoing resection of CRLM. Methods: Between May 2018 and October 2019, 91 CRLM patients were prospectively enrolled. Whole exome sequencing was performed in 50 primary and 48 metastatic liver tissues. Targeted sequencing of 451 cancer relevant genes was performed in 50 baseline plasma to determine plasma-tissue concordance. We prospectively investigated changes in the amount and constitution of ctDNA in 271 serial plasma samples taken at different time points (baseline, pre-operation, post-operation, post-operative adjuvant chemotherapy (post-ACT) and recurrence) during the treatment of CRLM. Results: Detected molecular alterations were highly consistent among baseline ctDNA, primary and liver metastases tissue. Patients with a higher variant allele frequency (VAF) level at baseline ctDNA represent a higher tumor burden, and decreased ctDNA during pre-operative chemotherapy predicted better tumor response. Patients with detectable post-operative and post-ACT ctDNA were associated with significantly shorter recurrence-free survival (RFS). ROC analysis showed that post-ACT ctDNA status was superior to post-operative ctDNA status in predicting RFS with an AUROC of 0.79. A significant difference in overall recurrence rate was observed in patients with detectable vs undetectable levels of ctDNA after resection of CRLM (79.4% vs 41.7%) and after completion of adjuvant chemotherapy (77.3% vs 40.7%). During adjuvant chemotherapy, patients with decreased ctDNA VAF after adjuvant chemotherapy had a recurrence rate of 63.6%, compared to 92.3% in patients with increased ctDNA VAF. Conclusions: We envision that dynamic ctDNA analysis, especially in a post-ACT setting, might be used to not only reflect MRD but also to determine rational personalized adjuvant therapy after the resection of CRLM.

The Role of p53 Dysfunction in Colorectal Cancer and Its Implication for Therapy

Colorectal cancer (CRC) is one of the most common and fatal cancers worldwide. The carcinogenesis of CRC is based on a stepwise accumulation of mutations, leading either to an activation of oncogenes or a deactivation of suppressor genes. The loss of genetic stability triggers activation of proto-oncogenes (e.g., KRAS) and inactivation of tumor suppression genes, namely TP53 and APC, which together drive the transition from adenoma to adenocarcinoma. On the one hand, p53 mutations confer resistance to classical chemotherapy but, on the other hand, they open the door for immunotherapy, as p53-mutated tumors are rich in neoantigens. Aberrant function of the TP53 gene product, p53, also affects stromal and non-stromal cells in the tumor microenvironment. Cancer-associated fibroblasts together with other immunosuppressive cells become valuable assets for the tumor by p53-mediated tumor signaling. In this review, we address the manifold implications of p53 mutations in CRC regarding therapy, treatment response and personalized medicine.

Mutated DNA Damage Repair Pathways Are Prognostic and Chemosensitivity Markers for Resected Colorectal Cancer Liver Metastases

Deficiency of the DNA damage repair (DDR) signaling pathways is potentially responsible for genetic instability and oncogenesis in tumors, including colorectal cancer. However, the correlations of mutated DDR signaling pathways to the prognosis of colorectal cancer liver metastasis (CRLM) after resection and other clinical applications have not been fully investigated. Here, to test the potential correlation of mutated DDR pathways with survival and pre-operative chemotherapy responses, tumor tissues from 146 patients with CRLM were collected for next-generation sequencing with a 620-gene panel, including 68 genes in 7 DDR pathways, and clinical data were collected accordingly. The analyses revealed that 137 of 146 (93.8%) patients had at least one mutation in the DDR pathways. Mutations in BER, FA, HRR and MMR pathways were significantly correlated with worse overall survival than the wild-types (P < 0.05), and co-mutated DDR pathways showed even more significant correlations (P < 0.01). The number of mutated DDR pathways was also proved an independent stratifying factor of overall survival by Cox multivariable analysis with other clinical factors and biomarkers (hazard ratio = 9.14; 95% confidence interval, 1.21–68.9; P = 0.032). Additionally, mutated FA and MMR pathways were positively and negatively correlated with the response of oxaliplatin-based pre-operative chemotherapy (P = 0.0095 and 0.048, respectively). Mutated DDR signaling pathways can predict pre-operative chemotherapy response and post-operative survival in CRLM patients.

A novel prognostic nomogram for colorectal cancer liver metastasis patients with recurrence after hepatectomy

PURPOSE

We aimed to construct a nomogram to predict personalized post-recurrence survival (PRS) among colorectal cancer liver metastasis (CRLM) patients with post-hepatectomy recurrence.

METHODS

Colorectal cancer liver metastasis patients who received initial hepatectomy and had subsequent recurrence between 2001 and 2019 in Sun Yat-sen University Cancer Center from China were included in the study. Patients were randomly assigned to a training cohort and a validation cohort on a ratio of 2:1. Univariable analysis was first employed to select potential predictive factors for PRS. Then, the multivariable Cox regression model was applied to recognize independent prognostic factors. According to the model, a nomogram to predict PRS was established. The nomogram's predictive capacity was further assessed utilizing concordance index (C-index) values, calibration plots, and Kaplan-Meier curves.

RESULTS

About 376 patients were finally enrolled, with a 3-year PRS rate of 37.3% and a 5-year PRS rate of 24.6%. The following five independent predictors for PRS were determined to construct the nomogram: the largest size of liver metastases at initial hepatectomy, relapse-free survival, CEA level at recurrence, recurrent sites, and treatment for recurrence. The nomogram displayed fairly good discrimination and calibration. The C-index value was 0.742 for the training cohort and 0.773 for the validation cohort. Patients were grouped into three risk groups very well by the nomogram, with 5-year PRS rates of 45.2%, 23.3%, and 9.0%, respectively (p < 0.001) in the training cohort and 36.0%, 9.2%, and 4.6%, respectively (p < 0.001) in the validation cohort.

CONCLUSION

A novel nomogram was built and validated to enable the prediction of personal PRS in CRLM patients with post-hepatectomy recurrence. The nomogram may help physicians in decision making.

Impact of Preoperative Circulating Tumor DNA Status on Survival Outcomes After Hepatectomy for Resectable Colorectal Liver Metastases

BACKGROUND

The optimal perioperative management of patients who undergo hepatectomy for resectable colorectal liver metastases (CRLM) remains unclear due to the lack of reliable methods to stratify the risk of recurrence.

METHODS

A single-center retrospective study was performed to investigate the impact of preoperative circulating tumor DNA (ctDNA) on survival outcomes of patients who underwent initial hepatectomy for solitary resectable CRLM between January 2005 and December 2017 using the comprehensive genotyping platform Guardant360^®.

RESULTS

Of 212 patients who underwent initial hepatectomy for solitary resectable CRLM, 40 patients for whom pre-hepatectomy plasma was available underwent ctDNA analysis. Among them, 32 (80%) had at least 1 somatic alteration in their ctDNA, while the other 8 (20%) had no detectable ctDNA. Among the patients with undetectable ctDNA, only one had recurrence and none died during a median follow-up period of 39.0 months. The recurrence-free survival was significantly shorter in patients who were positive for ctDNA than in those who were negative for ctDNA [median, 12.5 months vs not reached (NR); HR, 7.6; P = 0.02]. The overall survival also tended to be shorter in patients who were positive for ctDNA than those who were negative for ctDNA (median, 78.1 months vs NR; P = 0.14; HR not available).

CONCLUSIONS

In patients undergoing hepatectomy for solitary resectable CRLM, the absence of detectable preoperative ctDNA identified patients with a high chance for a cure. Risk stratification according to preoperative ctDNA analysis may be an effective tool that can improve the perioperative management of these patients.

Alteration of FBXW7 is Associated with Worse Survival in Patients Undergoing Resection of Colorectal Liver Metastases

BACKGROUND

For patients undergoing resection of colorectal liver metastases (CLMs), the prognostic role of somatic gene alterations is increasingly recognized. F-box/WD repeat-containing protein 7 (FBXW7) is a tumor suppressor gene found in approximately 10% of patients with colorectal cancer. The aim of this study is to assess the association of FBXW7 with overall survival after CLM resection.

METHODS

Patients who underwent initial CLM resection during 2001-2016 and had genetic sequencing data were studied. Risk factors for overall survival (OS) were evaluated with Cox proportional hazards models using backward elimination.

RESULTS

Of 2045 patients who underwent CLM resection during the study period, 476 were included. The majority (90.5%) underwent prehepatectomy chemotherapy. A total of 27 patients (5.7%) had FBXW7 alteration, along with 240 (50.4%) RAS, 337 (70.8%) TP53, 51 (10.7%) SMAD4, and 27 (5.7%) BRAF. Cox proportional hazards model analyses including 5 somatic gene alteration status and 12 clinicopathologic factors revealed FBXW7(hazard ratio [HR] 1.99, P = 0.015), BRAF (HR 2.47, P = 0.023), RAS (HR 2.42, P < 0.001), TP53 (HR 2.00, P < 0.001), and SMAD4 alterations (HR 1.90, P = 0.004) as significantly associated with OS, together with three clinicopathologic factors, prehepatectomy chemotherapy > 6 cycles (HR 1.51, P = 0.021), number of CLM (HR 1.05, P = 0.007), and largest liver metastasis diameter (HR 1.07, P = 0.023). The covariate-adjusted 5-year OS was significantly lower in patients with FBXW7 alteration than in patients with FBXW7 wild-type (40.4% vs.59.4%, P = 0.015).

CONCLUSIONS

FBXW7 alterations are associated with worse survival after CLM resection. The information on multiple somatic gene alterations is imperative for risk stratification and patient selection for CLM resection.

Spectrum of Somatic Cancer Gene Variations Among Adults With Appendiceal Cancer by Age at Disease Onset

Importance

The incidence of appendiceal cancer (AC) is rising, particularly among individuals younger than 50 years (early-onset AC), with unexplained etiologies. The unique spectrum of somatic cancer gene variations among patients with early-onset AC is largely undetermined.

Objective

To characterize the frequency of somatic variations and genomic patterns among patients with early-onset (age <50 years) vs late-onset (age ≥50 years) AC.

Design, Setting, and Participants

This cohort study included individuals aged 18 years and older diagnosed with pathologically verified AC. Cases with clinical-grade targeted sequencing data from January 1, 2011, to December 31, 2019, were identified from the international clinicogenomic data-sharing consortium American Association for Cancer Research Project Genomics Evidence Neoplasia Information Exchange (GENIE). Data analysis was conducted from May to September 2020.

Exposures

Age at disease onset.

Main Outcomes and Measures

Somatic variation prevalence and spectrum in AC patients was determined. Variation comparisons between early-onset and late-onset AC were evaluated using multivariable logistic regression with adjustment for sex, race/ethnicity, histological subtype, sequencing center, and sample type.

Results

In total 385 individuals (mean [SD] age at diagnosis, 56.0 [12.4] years; 187 [48.6%] men; 306 [79.5%] non-Hispanic White individuals) with AC were included in this study, and 109 patients (28.3%) were diagnosed with early-onset AC. Race/ethnicity differed by age at disease onset; non-Hispanic Black individuals accounted for a larger proportion of early-onset vs late-onset cases (9 of 109 [8.3%] vs 11 of 276 [4.0%]; P = 0.04). Compared with patients aged 50 years or older at diagnosis, patients with early-onset AC had significantly higher odds of presenting with nonsilent variations in PIK3CA, SMAD3, and TSC2 (PIK3CA: odds ratio [OR], 4.58; 95% CI, 1.72-12.21; P = .002; SMAD3: OR, 7.37; 95% CI, 1.24-43.87; P = .03; TSC2: OR, 12.43; 95% CI, 1.03-149.59; P = .047). In contrast, patients with early-onset AC had a 60% decreased odds of presenting with GNAS nonsilent variations compared with patients with late-onset AC (OR, 0.40; 95% CI, 0.21-0.76, P = .006). By histological subtype, young patients with mucinous adenocarcinomas of the appendix had 65% decreased odds of variations in GNAS compared with late-onset cases in adjusted models (OR, 0.35; 95% CI, 0.15-0.79; P = .01). Similarly, patients with early-onset nonmucinous appendiceal adenocarcinomas had 72% decreased odds of presenting with GNAS variations vs late-onset cases, although these findings did not reach significance (OR, 0.28; 95% CI, 0.07-1.14; P = .08). GNAS and TP53 variations were mutually exclusive in ACs among early-onset and late-onset cases (P < .05).

Conclusions and Relevance

In the study, AC diagnosed among younger individuals harbored a distinct genomic landscape compared with AC diagnosed among older individuals. Development of therapeutic modalities that target these unique molecular features may yield clinical implications specifically for younger patients.

The Role of BRAF in Metastatic Colorectal Carcinoma-Past, Present, and Future

With a global incidence of 1.8 million cases, colorectal cancer represents one of the most common cancers worldwide. Despite impressive improvements in treatment efficacy through cytotoxic and biological agents, the cancer-related death burden of metastatic colorectal cancer (mCRC) is still high. mCRC is not a genetically homogenous disease and various mutations influence disease development. Up to 12% of mCRC patients harbor mutations of the signal transduction molecule BRAF, the most prominent being BRAFV600E. In mCRC, BRAFV600E mutation is a well-known negative prognostic factor, and is associated with a dismal prognosis. The currently approved treatments for BRAF-mutated mCRC patients are of little impact, and there is no treatment option superior to others. However, the gradual molecular understanding over the last decades of the extracellular signal-regulated kinase/mitogen-activated protein kinase pathway, resulted in the development of new therapeutic strategies targeting the involved molecules. Recently published and ongoing studies administering a combination of different inhibitors (e.g., BRAF, MEK, and EGFR) showed promising results and represent the new standard of care. In this review, we present, both, the molecular and clinical aspects of BRAF-mutated mCRC patients, and provide an update on the current and future treatment approaches that might direct the therapy of mCRC in a new era.

Integrative Concepts for Liver Surgery

BACKGROUND

Surgery is the standard treatment for primary tumors and metastases. Due to improvements in surgical outcomes as well as the efficacy of systemic treatments, the role of surgery has changed in recent years.

SUMMARY

Liver surgery has become safe and efficient, with resectability being increased by multimodality concepts as well as staged liver resections and orthotopic liver transplantation. These concepts may be applied to primary liver tumors but also to selected patients with liver metastases from various diseases. In addition, even debulking surgery may be indicated for selected patients with endocrine metastases. While patient selection for liver resections was limited to clinical parameters in the past, histological and molecular characteristics have become increasingly important. Moreover, the response to regional or systemic chemotherapy has been demonstrated to be strong for a beneficial course of the disease even in advanced diseases.

KEY-MESSAGES

Due to the variety of available treatment options, optimal patient selection is crucial. Besides liver surgery, staged concepts as well as liver transplantation are curative tools for many patients.