Meta-analysis of KRAS mutations and survival after resection of colorectal liver metastases

Adjuvant chemotherapy is associated with better oncological outcomes after ALPPS for colorectal liver metastases

ALPPS enables complete tumor resection in a shorter interval and a larger number of patients than classic two-stage hepatectomies. However, there is little evidence regarding long-term outcomes in patients with colorectal liver metastases (CLM). This study aims to evaluate the short and long-term outcomes of ALPPS in patients with CRM. Single-cohort, prospective, observational study. Patients with unresectable CLM due to insufficient liver remnant who underwent ALPPS between June 2011 and June 2021 were included. Of 32 patients treated, 21 were male (66%) and the median age was 56 years (range = 29-81). Both stages were completed in 30 patients (93.7%), with an R0 rate of 75% (24/32). Major morbidity was 37.5% and the mortality nil. Median overall survival (OS) and recurrence-free survival (RFS) were 28.1 and 8.8 months, respectively. The 1-3, and 5-year OS was 86%, 45%, and 21%, and RFS was 42%, 14%, and 14%, respectively. The only independent risk factor associated with poor RFS (5.7 vs 11.6 months; p = 0.038) and OS (15 vs 37 months; p = 0.009) was not receiving adjuvant chemotherapy. KRAS mutation was associated with worse OS from disease diagnosis (24.3 vs. 38.9 months; p = 0.025). ALPPS is associated with favorable oncological outcomes, comparable to traditional strategies to increase resectability in patients with CLM and high tumor burden. Our results suggest for the first time that adjuvant chemotherapy is independently associated with better short- and long-term outcomes after ALPPS. Selection of patients with KRAS mutations should be performed with caution, as this could affect oncological outcomes.

Personalized prediction of postoperative complication and survival among Colorectal Liver Metastases Patients Receiving Simultaneous Resection using machine learning approaches: A multi-center study

BACKGROUND

To predict clinical important outcomes for colorectal liver metastases (CRLM) patients receiving colorectal resection with simultaneous liver resection by integrating demographic, clinical, laboratory, and genetic data.

METHODS

Random forest (RF) models were developed to predict postoperative complications and major complications (binary outcomes), as well as progression-free survival (PFS) and overall survival (OS) (time-to-event outcomes) of the CRLM patients based on data from two hospitals. The models were validated on an external dataset from an independent hospital. The clinical utility of the models was assessed via decision curve analyses (DCA).

RESULTS

There were 1067 patients included in survival prediction analyses and 1070 patients included in postoperative complication prediction analyses. The RF models provided an assessment of the model contributions of features for outcomes and suggested KRAS, BRAF, and MMR status were salient for the PFS or OS predictions. RF model of PFS showed that the Brier scores at 1-, 3-, and 5-year PFS were 0.213, 0.202 and 0.188; and the AUCs of 1-, 3- and 5-year PFS were 0.702, 0.720 and 0.743. RF model of OS revealed that Brier scores of 1-,3-, and 5-year OS were 0.040, 0.183 and 0.211; and the AUCs of 1-, 3- and 5-year OS were 0.737, 0.706 and 0.719. RF model for postoperative complication resulted in an AUC of 0.716 and a Brier score of 0.196. DCA curves clearly demonstrated that the RF models for these outcomes exhibited a superior net benefit across a wide range of threshold probabilities, signifying their favorable clinical utility. The RF models consistently exhibited robust performance in both internal cross-validation and external validation. The individualized risk profile predicted by the models closely aligned with the actual survival outcomes observed for the patients. A web-based tool (https://kanli.shinyapps.io/CRLMRF/) was provided to demonstrate the practical use of the prediction models for new patients in the clinical setting.

CONCLUSION

The predictive models and a web-based tool for personalized prediction demonstrated a moderate predictive performance and favorable clinical utilities on several key clinical outcomes of CRLM patients receiving simultaneous resection, which could facilitate the clinical decision-making and inform future interventions for CRLM patients.

Clinical Prediction Models for Prognosis of Colorectal Liver Metastases: A Comprehensive Review of Regression-Based and Machine Learning Models

Colorectal liver metastasis (CRLM) is a disease entity that warrants special attention due to its high frequency and potential curability. Identification of "high-risk" patients is increasingly popular for risk stratification and personalization of the management pathway. Traditional regression-based methods have been used to derive prediction models for these patients, and lately, focus has shifted to artificial intelligence-based models, with employment of variable supervised and unsupervised techniques. Multiple endpoints, like overall survival (OS), disease-free survival (DFS) and development or recurrence of postoperative complications have all been used as outcomes in these studies. This review provides an extensive overview of available clinical prediction models focusing on the prognosis of CRLM and highlights the different predictor types incorporated in each model. An overview of the modelling strategies and the outcomes chosen is provided. Specific patient and treatment characteristics included in the models are discussed in detail. Model development and validation methods are presented and critically appraised, and model performance is assessed within a proposed framework.

The association between KRAS and histopathological growth patterns and the impact on resection margins around vasculature and bile ducts in colorectal liver metastases

The liver is the most frequent and often the only site of distant disease in colorectal cancer and, of all treatment protocols currently in use, resection is the most likely to result in long-term cure. Within the liver, tumour proximity to major vasculature and biliary structures poses a resection challenge, requiring a balance of achieving negative margins while preserving adequate vascular circulation and biliary drainage. The focus on parenchymal sparing resections are important but just as important may be the 'biological' behaviour of the tumour. In colorectal liver metastases (CRLM), biomarkers such as the Kirsten rat sarcoma oncogene homologue (KRAS) gene and histological growth patterns (HGPs) further improve the prognostication after resection. However, to date, the association between the KRAS status and HGPs in CRLM and their impact on resection margins around major vasculature or biliary structures in terms of overall survival and recurrence rates are unclear. The aim of this review was to explore the available evidence for the association between KRAS and HGPs in CRLM and attempt to define their impact on resection margins near major structures.

Combined Resection Approaches: Decision Making for Synchronous Resection, Timing of Staged Intervention to Optimize Outcome

Advancement in systemic and regional radiation therapy, surgical technique, and anesthesia has provided a path for increased long-term survival and potential cure for more patients with stage IV rectal cancer in recent years. When patients have resectable disease, the sequence for surgical resection is classified in three strategies: classic, simultaneous, or combined, and reversed. The classic approach consists of rectal cancer resection followed by metastatic disease at a subsequent operation. Simultaneous resection addresses both rectal and metastatic disease in a single surgery. The reversed approach treats metastatic disease first, followed by the primary tumor in several months. Simultaneous resection is appropriate for selected patients to avoid delay of definitive surgery, and reduce number of surgeries, hospital stay, and cost to the health care system. It may also improve patients' psychological effect. Multidisciplinary discussions including colorectal and liver surgeons to review patients' baseline medical conditions, tumor biology and behavior, and disease burden and distribution is imperative to guide proper patient selection for simultaneous resection and perioperative treatments.

Preoperative chemotherapy in upfront resectable colorectal liver metastases: New elements for an old dilemma?

The use of preoperative or "neoadjuvant" chemotherapy (NAC) has long been controversial for resectable colorectal liver metastases (CRLM). The European Society of Medical Oncology (ESMO) 2023 guidelines on metastatic colorectal cancer (CRC) indicate a combination of surgical/technical and oncologic/prognostic criteria as the two determinants for allocating patients to NAC or upfront hepatectomy. However, surgical and technical criteria have evolved, and oncologic prognostic criteria date from the pre-modern chemotherapy era and lack prospective validation. The traditional literature is interpreted as not supporting the use of NAC because several studies fail to demonstrate a benefit in overall survival (OS) compared to upfront surgery; however, OS may not be the most appropriate endpoint to consider. Moreover, the commonly quoted studies against NAC contain many limitations that may explain why NAC failed to demonstrate its value. The query of the recent literature focused primarily on other aspects than OS, such as surgical technique, the impact of side effects of chemotherapy, the histological growth pattern of metastases, or the detection of circulating tumor DNA, shows data that support a more widespread use of NAC. These should prompt a critical reappraisal of the use of NAC, leading to a more precise selection of patients who could benefit from it.

Consideration of Metastasis-Directed Therapy for Patients With Metastatic Colorectal Cancer: Expert Survey and Systematic Review

BACKGROUND

A survey of medical oncologists (MOs), radiation oncologists (ROs), and surgical oncologists (SOs) who are experts in the management of patients with metastatic colorectal cancer (mCRC) was conducted to identify factors used to consider metastasis-directed therapy (MDT).

MATERIALS AND METHODS

An online survey to assess clinical factors when weighing MDT in patients with mCRC was developed based on systematic review of the literature and integrated with clinical vignettes. Supporting evidence from the systematic review was included to aid in answering questions.

RESULTS

Among 75 experts on mCRC invited, 47 (response rate 62.7%) chose to participate including 16 MOs, 16 ROs, and 15 SOs. Most experts would not consider MDT in patients with 3 lesions in both the liver and lung regardless of distribution or timing of metastatic disease diagnosis (6 vs. 36 months after definitive treatment). Similarly, for patients with retroperitoneal lymph node and lung and liver involvement, most experts would not offer MDT regardless of timing of metastatic disease diagnosis. In general, SOs were willing to consider MDT in patients with more advanced disease, ROs were more willing to offer treatment regardless of metastatic site location, and MOs were the least likely to consider MDT.

CONCLUSIONS

Among experts caring for patients with mCRC, significant variation was noted among MOs, ROs, and SOs in the distribution and volume of metastatic disease for which MDT would be considered. This variability highlights differing opinions on management of these patients and underscores the need for well-designed prospective randomized trials to characterize the risks and potential benefits of MDT.

RAS Mutations Predict Recurrence-Free Survival and Recurrence Patterns in Colon Cancer: A Unicenter Study in Morocco

PURPOSE

To date, only a few studies have investigated the role of molecular alterations in cancer recurrence. This exploratory study aimed to evaluate the impact of molecular alterations on the time and site of recurrence in patients with stage I-IV CRC and to identify the risk factors predicting recurrence-free survival in colon cancer.

METHODS

A total of 270 patients were retrospectively included. We assessed the full RAS status using Sanger and pyrosequencing. MSI status was determined by immunohistochemical analysis. Molecular alterations were correlated with recurrence timing (early or late), recurrence patterns, and recurrence-free survival. Statistical analysis was performed using the Kaplan-Meier method and the log-rank test.

RESULTS

Of the 270 patients, 85 (31%) experienced recurrence, among whom 53% had mutant full RAS status, 48% had KRAS mutations, and 31.4% had KRAS p. G12V mutation subtype. Compared with those with late recurrence, patients with early recurrence were significantly older (P = 0.02) and more likely to have poorly differentiated tumors, a higher rate of positive lymph nodes, KRAS mutations, and especially KRAS p. G12V mutation variant. RAS mutation status, KRAS mutations, and rare mutations are more common in patients with lung cancer recurrence. Multivariate logistic regression analysis revealed that differentiation, perineural invasion, full RAS mutation status, and KRAS codon 13 mutations were independent factors for recurrence-free survival in colon cancer.

CONCLUSION

In this cohort, the timing and patterns of recurrence appeared to be associated with the patient's molecular profile. KRAS codon 12 mutations were the worst predictors of recurrence-free survival at all stages in our population.

Does RAS Status Increase the Prevalence of Positive Resection Margin in Colorectal Liver Metastasis? A Systematic Review and Meta-Analysis

BACKGROUND

Colorectal liver metastasis has a high incidence, and RAS oncogene mutation status carries significant prognostic information. We aimed to assess whether RAS-mutated patients present more or less frequently with positive margins in their hepatic metastasectomy.

METHODS

We performed a systematic review and meta-analysis of studies from PubMed, Embase, and Lilacs databases. We analyzed liver metastatic colorectal cancer studies, which included information on RAS status and had surgical margin analysis of the liver metastasis. Odds ratios were computed using a random-effect model due to anticipated heterogeneity. We further performed a subanalysis limited to studies that included only patients with KRAS instead of all-RAS mutations.

RESULTS

From the 2,705 studies screened, 19 articles were included in the meta-analysis. There were 7,391 patients. The prevalence of positive resection margin was not significantly different between patients carrier vs non-carrier for the all-RAS mutations (OR .99; 95% CI 0.83-1.18; P = .87), and for only KRAS mutation (OR .93; 95% CI 0.73-1.19; P = .57).

CONCLUSIONS

Despite the strong correlation between colorectal liver metastasis prognosis and RAS mutation status, our meta-analysis's results suggest no correlation between the RAS status and the prevalence of positive resection margins. The findings contribute to a better understanding of the RAS mutation's role in the surgical resections of colorectal liver metastasis.

Prognostic Impact of Tumor Markers (CEA and CA19-9) on Patients with Resectable Colorectal Liver Metastases Stratified by Tumor Number and Size: Potentially Valuable Biologic Markers for Preoperative Treatment

BACKGROUND

Although patients with resectable colorectal liver metastasis (CLM), a population with good prognosis, have been treated with upfront surgery, some patients have had a poor prognosis. This study aimed to investigate biologic prognostic factors in patients with resectable CLMs.

METHODS

This single-center retrospective study enrolled consecutive patients who underwent liver resection for initial CLMs at the Cancer Institute Hospital between 2010 and 2020. The study defined CLMs as resectable (tumor size < 5 cm; < 4 tumors; no extrahepatic metastasis) or borderline resectable (BR). Preoperative chemotherapy was administered to patients with BR CLMs.

RESULTS

During the study period, 309 CLMs were classified as resectable without preoperative chemotherapy and 345 as BR with preoperative chemotherapy. For the 309 patients with resectable CLMs, the independent poor prognostic factors associated with overall survival in the multivariable analysis were high tumor marker levels (CEA ≥ 25 ng/mL and/or CA19-9 ≥ 50 U/mL; (hazard ratio [HR], 2.45; p = 0.0007), no adjuvant chemotherapy (HR, 1.69; p = 0.043), and age of 75 years or older (HR, 2.09; p = 0.012). The 5-year survival rates for the patients with high tumor marker (TM) levels (CEA ≥25 ng/mL and/or CA19-9 ≥50 U/mL) were significantly worse than for those with low TM levels (CEA < 25 ng/mL and CA19-9 < 50 U/mL) (55.3% vs. 81.1%; p <0.0001) and similar to the rate for those with BR CLMs (52.1%; p = 0.864). Postoperative adjuvant chemotherapy had an impact on prognosis only in the high-TM group (HR, 2.65; p = 0.007).

CONCLUSIONS

High TM levels have a prognostic impact on patients with resectable CLMs stratified by tumor number and size. Perioperative chemotherapy improves long-term outcomes for patients with CLM and high TM levels.

Impact of Molecular Status on Metastasectomy of Colorectal Cancer Liver Metastases

Although surgical resection could provide better survival for patients with colorectal cancer liver metastases (CRLM), the recurrence rate after resection of CRLM remains high. The progress of genome sequencing technologies has greatly improved the molecular understanding of colorectal cancer. In the era of genomics and targeted therapy, genetic mutation analysis is of great significance to guide systemic treatment and identify patients who can benefit from resection of CRLM. RAS and BRAF mutations and microsatellite instability/deficient deoxyribonucleic acid (DNA) mismatch repair status have been incorporated into current clinical practice. Other promising molecular biomarkers such as coexisting gene mutations and circulating tumor DNA are under active investigation. This study aimed to review the prognostic significance of molecular biomarkers in patients with CRLM undergoing metastasectomy based on the current evidence.

Association between primary tumor characteristics and histopathological growth pattern of liver metastases in colorectal cancer

INTRODUCTION

The microarchitecture of liver metastases (LMs), or histopathological growth pattern (HGP), has been demonstrated to be a significant prognostic factor in patients undergoing resection of colorectal liver metastases (CRLMs). Currently, however, HGP can be only determined on the operative specimen. Therefore, the development of new tools to predict the HGP of CRLMs before surgery and to understand the mechanisms that drive these patterns is important for improving individualization of therapeutic management. In this study, we analyzed data from a retrospective series of patients who underwent surgery for CRLMs to compare primary tumor characteristics, including markers of local aggressiveness and migratory capacity, and HGP of liver metastases.

METHODS

Data from a retrospective series of 167 patients who underwent curative-intent resection of CRLMs and in whom pathological samples from both primary tumor and liver metastases were available were reviewed. At the primary tumor level, KRAS mutational status, grade of differentiation, and tumor budding were assessed. HGP was scored in each resected CRLM, according to consensus guidelines, and classified as desmoplastic (dHGP) or non-desmoplastic (non-dHGP). Associations between primary tumor characteristics and HGP of CRLMs were evaluated using a binary logistic regression model. Overall survival and disease-free survival were evaluated using Kaplan-Meier and multivariable Cox regression analyses.

RESULTS

CRLMs were classified as dHGP in 36% of the patients and as non-dHGP in 64%. Higher rates of moderately or poorly differentiated primary tumors were observed in the non-dHGP CRLM group (80%), as compared with the dHGP group (60%) (OR = 3.6; 95%CI: 1.6-7.05; p = 0.001). Higher rates of tumor budding were observed in the non-dHGP CRLM group, with a median tumor budding value of 4 as compared with 2.5 in the dHGP group (p = 0.042). In the entire series, 5-year overall and disease-free survival were 43% and 32.5%, respectively. The non-dHGP CRLM group had worse post-hepatectomy survival, with 5-year overall and disease-free survival of 32.2% and 24.6%, respectively, as compared with 60.8% and 45.9%, respectively, for the dHGP group (p = 0.02).

CONCLUSION

Colorectal tumors with moderate or poor differentiation and those with high tumor budding are more frequently associated with CRLMs with a non-dHGP. This suggests that primary tumor characteristics of local aggressiveness and migratory capacity could preferentially promote the development of CRLMs with an infiltrating pattern and that these parameters should be considered as part of new scores for predicting HGP before surgery. This finding may stimulate new lines of research for more individualized therapeutic decision in patients with CRLM candidate to surgery.

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.

PINK1 Immunoexpression Predicts Survival in Patients Undergoing Hepatic Resection for Colorectal Liver Metastases

PTEN-induced kinase-1 (PINK1) is the initiator of the canonical mitophagy pathway. Our aim was to study the immunoexpression of PINK1 in surgical specimens from ninety patients with metastatic colorectal adenocarcinoma (CRC) to the liver (CRLM). Tissue arrays were produced, and immunohistochemical studies were analyzed by the H-Score method. The mean immunoexpression of PINK1 in normal tissues was between 40 to 100 points. In tumoral tissues, positive PINK1 immunoexpression was observed in all samples, and no differences were noted between CRCs. In CRLMs, a significant under-expression was noted for PINK1 from the rectum (71.3 ± 30.8; p < 0.042) compared to other sites. Altered PINK1 immunoexpression in CRCs, either higher than 100 points or lower than 40 points, was associated with worse overall survival (OS) (p < 0.012) due to a shorter post-metastatic survival (PMS) (p < 0.023), and it was found to be a significant independent predictor of prognosis in a multivariate model for OS and PMS (HR = 1.972, 95% CI 0.971–4.005; p = 0.022. HR = 2.023, 95% CI 1.003–4.091; p = 0.037, respectively). In conclusion, altered PINK1 immunoexpression determined in CRCs with resected CRLM predicts a worse prognosis, possibly due to the abnormal function of mitophagy.

Tumor biology reflected by histological growth pattern is more important than surgical margin for the prognosis of patients undergoing resection of colorectal liver metastases

INTRODUCTION

The histological growth pattern (HGP) of colorectal liver metastases (CRLMs) reflects tumor biology and local infiltrating behavior. In patients undergoing surgery for CRLMs, we investigated whether HGP and surgical margin status interact when influencing prognosis.

METHODS

Clinicopathological data, margin status, and HGP were reviewed in patients who underwent resection of CRLMs. R1 margin was defined when cancer cells were present at any point along the margin. HGPs were scored according to international guidelines, identifying patients with desmoplastic (DHGP) or non-desmoplastic (non-DHGP) CRLMs.

RESULTS

Among 299 patients, 16% had R1 resection and 81% had non-DHGP CRLMs. Non-DHGP was the only predictive factor for R1 resection (18.7% versus 7.4% in DHGP, p = 0.04). Poorer 5-year overall survival was observed in both R1 and non-DHGP groups in univariate analysis (27.6% in R1 versus 45.6% in R0, p = 0.026, and 37.2% in non-DHGP versus 59.2% in DHGP, p = 0.013), whereas non-DHGP but not R1 remained associated with worse prognosis in multivariate analysis. In patients with non-DHGP, R1 margin has no prognostic impact.

CONCLUSIONS

In patients undergoing resection of CRLMs, the prognostic value of poor tumor biology, such as in patients with non-DHGP, exceeds that of surgical radicality.

Potential for cure and predictors of long-term survival after radiofrequency ablation for colorectal liver metastases: A 20-years single-center experience

BACKGROUND

Additional radiofrequency ablation (RFA) of liver-limited colorectal liver metastases (CRLM) improves overall (OS) and recurrence-free survival (RFS) over systemic therapy alone. We aimed to assess the potential and predictive factors of long-term survival and cure to optimize patient selection for RFA application.

METHODS

Retrospective review of a prospectively maintained single-center database of consecutive patients undergoing RFA for liver-limited CRLM after systemic therapy between 2002 and 2020. Clinicopathologic characteristics and KRAS/BRAF-genotype data (tested routinely since 2010) were correlated to RFS and OS. Cure was defined as ≥10-years RFS (long-term survival as ≥5-years OS) following RFA.

RESULTS

For the entire cohort of 158 patients (median follow-up 13.6 years), co-occurrence of three factors, RECIST-defined response, number of ≤3 CRLM, and ≤3 cm maximum size determined a survival plateau that distinguished cured from non-cured patients (10-years RFS: 15.5% vs 0%, p < 0.0001). Among 59 patients (37.3%) being tested, 4(6.8%) were BRAF-mt, 15(25.4%) KRAS-mt, and 40(67.8%) KRAS/BRAF-wt. OS (median follow-up 8.3 years) was estimated to be higher with KRAS/BRAF-wt compared to a mutant KRAS or BRAF status (5-years OS: 22.8% vs 3.4%, p = 0.0018).

CONCLUSION

This study indicates about 15% chance of cure following RFA of low-volume liver-limited CRLM after downsizing by systemic therapy and a negative effect of KRAS or BRAF mutation on long-term survival after CRLM ablation. These findings may improve clinical decision-making in patients potentially candidate to RFA of CRLM and encourage further investigations on molecular factors determining an oligometastatic state of CRLM curable with focal ablative therapy.

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.

Impact of Preoperative Chemotherapy Features on Patient Outcomes after Hepatectomy for Initially Unresectable Colorectal Cancer Liver Metastases: A LiverMetSurvey Analysis

Background: Prognostic factors have been extensively reported after resection of colorectal liver metastases (CLM); however, specific analyses of the impact of preoperative systemic anticancer therapy (PO-SACT) features on outcomes is lacking. Methods: For this real-world evidence study, we used prospectively collected data within the international surgical LiverMetSurvey database from all patients with initially-irresectable CLM. The main outcome was Overall Survival (OS) after surgery. Disease-free (DFS) and hepatic-specific relapse-free survival (HS-RFS) were secondary outcomes. PO-SACT features included duration (cumulative number of cycles), choice of the cytotoxic backbone (oxaliplatin- or irinotecan-based), fluoropyrimidine (infusional or oral) and addition or not of targeted monoclonal antibodies (anti-EGFR or anti-VEGF). Results: A total of 2793 patients in the database had received PO-SACT for initially irresectable diseases. Short (<7 or <13 cycles in 1st or 2nd line) PO-SACT duration was independently associated with longer OS (HR: 0.85 p = 0.046), DFS (HR: 0.81; p = 0.016) and HS-RFS (HR: 0.80; p = 0.05). All other PO-SACT features yielded basically comparable results. Conclusions: In this international cohort, provided that PO-SACT allowed conversion to resectability in initially irresectable CLM, surgery performed as soon as technically feasible resulted in the best outcomes. When resection was achieved, our findings indicate that the choice of PO-SACT regimen had a marginal if any, impact on outcomes.

Embryologic Origin of the Primary Tumor and RAS Status Predict Survival after Resection of Colorectal Liver Metastases

Background and objectives. In colorectal cancers, the embryologic origin of the primary tumor determines important molecular dissimilarities between right-sided (RS) and left-sided (LS) carcinomas. Although important prognostic differences have been revealed between RS- and LS-patients with resected colorectal liver metastases (CLMs), it is still unclear if this observation depends on the RAS mutational status. To refine the impact of primary tumor location (PTL) on the long-term outcomes of patients with resected CLMs, the rates of overall survival (OS), relapse-free survival (RFS) and survival after recurrence (SAR) were compared between RS- vs. LS-patients, according to their RAS status. Material and Methods. All patients with known RAS status, operated until December 2019, were selected from a prospectively maintained database, including all patients who underwent hepatectomy for histologically-proven CLMs. A log-rank test was used to compare survival rates between the RS- vs. LS-group, in RAS-mut and RAS-wt patients, respectively. A multivariate analysis was performed to assess if PTL was independently associated with OS, RFS or SAR. Results. In 53 patients with RAS-mut CLMs, the OS, RFS and SAR rates were not significantly different (p = 0.753, 0.945 and 0.973, respectively) between the RS and LS group. In 89 patients with RAS-wt CLMs, the OS and SAR rates were significantly higher (p = 0.007 and 0.001, respectively) in the LS group vs. RS group, while RFS rates were similar (p = 0.438). The multivariate analysis performed in RAS-wt patients revealed that RS primary (p = 0.009), extrahepatic metastases (p = 0.001), N-positive (p = 0.014), age higher than 65 (p = 0.002) and preoperative chemotherapy (p = 0.004) were independently associated with worse OS, while RS location (p < 0.001) and N-positive (p = 0.007) were independent prognostic factors for poor SAR. Conclusions. After resection of CLMs, PTL had no impact on long-term outcomes in RAS-mut patients, while in RAS-wt patients, the RS primary was independently associated with worse OS and SAR.

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.

Surgical Therapy in Patients with Colorectal Liver Metastases

BACKGROUND

Liver metastases (LM) occur in about 50% of patients with colorectal cancer. Besides the multimodal treatment of the primary tumor, the only way to cure patients with colorectal LM (CRLM) is complete resection. Different surgical procedures for this purpose are available depending on location, size, and number of LM. Additional concepts for patients with primary unresectable LM exist, ranging from Chemotherapy to induction of liver hypertrophy and even liver transplantation. This review intends to provide an overview of the surgical approach.

SUMMARY

Surgical options in the treatment of CRLM are defined and limited by their intraparenchymal location and their proximity to major vessels and intrahepatic bile ducts. Lesions located in the periphery can be excised in a parenchymal sparing fashion with a small tumor-surrounding resection margin of healthy liver parenchyma. If this is not possible, anatomical resections based on segmental boundaries are performed. In these cases, a sufficient functional volume of liver parenchyma after resection (future liver remnant volume [FLRV]) has to be preserved. This FLRV depends on various factors such as bodyweight and possible preexisting liver damage, such as cirrhosis, fibrosis, or chemotherapy-induced liver impairment. Liver hypertrophy via partial occlusion of the portal venous system is a standard procedure for patients with primary unresectable LM to increase FLRV. Furthermore, discussion of liver transplantation in cases of unresectable LM is gaining importance again. A combination of surgery and adjuvant and/or neoadjuvant chemotherapy may be indicated in individual cases, but general evidence-based recommendations cannot be given without further studies.

KEY MESSAGES

Surgical removal of all metastases represents the only option of a potentially curative treatment of UICC stage IV colorectal carcinoma with liver involvement. An interdisciplinary approach consisting of chemotherapeutical downsizing and hypertrophy of the FLRV offers potential curative treatment for patients with initially unresectable metastases. For all others, liver transplantation is seeing a revival showing promising results in overall survival compared to chemotherapy alone.

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.

Predicting 10-year survival after resection of colorectal liver metastases; an international study including biomarkers and perioperative treatment

BACKGROUND

The aim of this study was to develop a prediction model for 10-year overall survival (OS) after resection of colorectal liver metastasis (CRLM) based on patient, tumour and treatment characteristics.

METHODS

Consecutive patients after complete resection of CRLM were included from two centres (1992-2019). A prediction model providing 10-year OS probabilities was developed using Cox regression analysis, including KRAS, BRAF and histopathological growth patterns. Discrimination and calibration were assessed using cross-validation. A web-based calculator was built to predict individual 10-year OS probabilities.

RESULTS

A total of 4112 patients were included. The estimated 10-year OS was 30% (95% CI 29-32). Fifteen patient, tumour and treatment characteristics were independent prognostic factors for 10-year OS; age, gender, location and nodal status of the primary tumour, disease-free interval, number and diameter of CRLM, preoperative CEA, resection margin, extrahepatic disease, KRAS and BRAF mutation status, histopathological growth patterns, perioperative systemic chemotherapy and hepatic arterial infusion pump chemotherapy. The discrimination at 10-years was 0.73 for both centres. A simplified risk score identified four risk groups with a 10-year OS of 57%, 38%, 24%, and 12%.

CONCLUSIONS

Ten-year OS after resection of CRLM is best predicted with a model including 15 patient, tumour, and treatment characteristics. The web-based calculator can be used to inform patients. This model serves as a benchmark to determine the prognostic value of novel biomarkers.

The management of colorectal liver metastases amenable of surgical resection: How to shape treatment strategies according to clinical, radiological, pathological and molecular features

Metastatic colorectal cancer (mCRC) patients have poor chances of long term survival, being < 15% of them still alive after 5 years from diagnosis. Nonetheless, patients with colorectal liver metastases (CRLM) may be eligible for metastases resection thus being able to achieve long-term disease remission and survival. The likelihood for patients with CRLM of being or becoming eligible for liver metastasectomy is increasing, thanks to the evolution of surgical techniques, the availability of active systemic treatments and the widespread diffusion of experienced multidisciplinary boards to manage these patients. However, disease relapse after liver surgery is common and occurs in two-thirds of resected patients. Therefore, adequate radiological staging and risk stratification is crucial for the optimal selection of patients candidate to surgery in order to maximize the benefit-risk ratio of liver metastasectomy and to individualize the treatment strategy. Based on the multidimensional assessment, three possible approaches are available: upfront liver surgery followed by adjuvant chemotherapy, perioperative chemotherapy preceding and following liver surgery, and an upfront systemic treatment including chemotherapy plus a targeted agent, both chosen according to patients' and tumours' characteristics, then followed by liver surgery if indicated. In this review, we describe the most important factors impacting the therapeutic choices in patients with resectable and potentially resectable CRLM, and we discuss the most promising factors that may reshape the future decision-making process of these patients.

Adjuvant intra-arterial chemotherapy for patients with resected colorectal liver metastases: a systematic review and meta-analysis

BACKGROUND

The practice of adjuvant hepatic arterial infusion chemotherapy (HAIC) for colorectal liver metastasis (CRLM) varies widely. This meta-analysis investigates the effectiveness of adjuvant HAIC and the influence of variations in HAIC treatment in patients with resected CRLM.

METHODS

PRISMA guidelines were followed for this study. The search was limited to comparative studies (HAIC vs non-HAIC) for overall survival. Subgroup meta-analyses using random-effects were performed for type of intra-arterial drug, method of catheter insertion, use of concomitant adjuvant systemic chemotherapy, and study design.

RESULTS

Eighteen eligible studies were identified. After excluding overlapping cohorts, fifteen studies were included in the quantitative analysis, corresponding to 3584 patients. HAIC was associated with an improved overall survival (pooled hazard ratio (HR) 0.77; 95%CI 0.64-0.93). Survival benefit of HAIC was most pronounced in studies using floxuridine (HR 0.76; 95%CI: 0.62-0.94), surgical catheter insertion with subcutaneous pump (HR 0.71; 95%CI: 0.61-0.84), and concomitant adjuvant systemic chemotherapy (HR 0.75; 95%CI: 0.59-0.96). The pooled HR of RCTs was 0.91 (95%CI 0.72-1.14), of which only 3 used floxuridine.

CONCLUSION

Adjuvant HAIC is a promising treatment for patients with resectable CRLM, in particular HAIC with floxuridine using a surgically placed catheter and a subcutaneous pump, and concomitant systemic chemotherapy.

Is Laterality Prognostic in Resected KRAS-Mutated Colorectal Liver Metastases? A Systematic Review and Meta-Analysis

Simple Summary

Primary tumor laterality (PTL) is the most recently identified prognostic factor associated with mortality in patients with resected colorectal cancer liver metastases, but whether it is prognostic in all patients or only those with wild-type KRAS tumors is debated. The aim of this meta-analysis was to identify all relevant articles and synthesize their evidence to estimate the effect of PTL per KRAS mutational status. We found that PTL and KRAS mutational status have a statistically significant interaction. Specifically, PTL has a variable effect in patients with wild-type versus KRAS-mutated tumors, with right-sided tumors associated with worse survival only in the former. This meta-analysis appears to resolve a long-lasting debate.

Abstract

Background: It is debated whether primary tumor laterality (PTL) is prognostic in all patients with colorectal liver metastases (CRLM) or only those with KRAS wild-type or KRAS-mutated tumors; Methods: We systematically reviewed PubMed for studies reporting on resected CRLM originating from left-sided (LS) versus right-sided (RS) colon cancer stratified by KRAS status. Individual participant data (IPD) were used if available. Given that there are two definitions of PTL, we performed two meta-analyses for KRAS-mutated and two for wild-type patients. To assess if an interaction underlies the possible difference between the effects of PTL in KRAS-mutated vs. wild-type CRLM, we similarly performed two meta-analyses of interaction terms; Results: The meta-analyses included eight studies and 7475 patients. PTL had a prognostic association with OS in patients with wild-type tumors (HR for LS: 0.71 [0.60–0.84]), but not in those with KRAS-mutated tumors (HR: 0.99 [0.82–1.19]). This difference stemmed from a truly variable effect of PTL for each KRAS status (mutated vs. wild-type) as the meta-analysis of interaction terms showed a significant interaction between them (HR:1.38 [1.24–1.53]). Similar results were obtained when the second definition of PTL (LS to not include the rectum) was used; Conclusions: KRAS status modifies the association of tumor site with survival. Right-sided tumors are associated with worse OS only in patients with wild-type CRLM.

Shifting concepts in the management of colorectal liver metastases

Management of patients with colorectal liver metastases has evolved considerably due to a better understanding of the biology of the disease with concurrent improvements in surgical techniques, oncological strategies and radiological interventions. This review article examines the factors that have contributed to this radical change. Management will be discussed in relation to chemotherapy, surgery and interventional radiology. The addition of chemotherapy and biological agents has greatly extended the reach and scope of surgery. Parenchymal sparing resections, repeat resections, two stage hepatectomy and Associating Liver Partition and Portal Vein ligation are all available to the hepatobiliary surgeon who deals with colorectal liver metastases. Interventional radiology techniques like liver venous deprivation may also replace established surgical practice. Whilst traditionally it was thought that only a few liver metastases could be treated effectively, nowadays tumour number is no longer a limiting factor provided enough functioning liver can be spared and the patient can tolerate the operation.

The Colorectal Cancer Tumor Microenvironment and Its Impact on Liver and Lung Metastasis

Simple Summary

Colorectal cancer (CRC) is the third most common cancer worldwide. Metastasis to secondary organs, such as the liver and lungs, is a key driver of CRC-related mortality. The tumor microenvironment, which consists of the primary cancer cells, as well as associated support and immune cells, significantly affects the behavior of CRC cells at the primary tumor site, as well as in metastatic lesions. In this paper, we review the role of the individual components of the tumor microenvironment on tumor progression, immune evasion, and metastasis, and we discuss the implications of these components on antitumor therapies.

Abstract

Colorectal cancer (CRC) is the third most common malignancy and the second most common cause of cancer-related mortality worldwide. A total of 20% of CRC patients present with distant metastases, most frequently to the liver and lung. In the primary tumor, as well as at each metastatic site, the cellular components of the tumor microenvironment (TME) contribute to tumor engraftment and metastasis. These include immune cells (macrophages, neutrophils, T lymphocytes, and dendritic cells) and stromal cells (cancer-associated fibroblasts and endothelial cells). In this review, we highlight how the TME influences tumor progression and invasion at the primary site and its function in fostering metastatic niches in the liver and lungs. We also discuss emerging clinical strategies to target the CRC TME.

Age-dependent prognostic value of KRAS mutation in metastatic colorectal cancer

Background: The age-dependent prognostic impact of KRAS status in metastatic colorectal cancer (mCRC) is unknown. Materials & Methods: We used the National Cancer Database to evaluate the survival by KRAS status for age-groups <50, 50-69 and ≥70, adjusting for relevant patient and tumor characteristics. Results: mCRC patients (n = 26,095; 33.5%) had KRAS status reported, and 11,338 of these patients (43.4%) had mutations in the KRAS gene. Patients with KRAS mutations had worse overall survival than wild-type KRAS patients. In age-groups <50 years (23 vs 29 months; p < 0.001) and 50-69 (21 vs 23.4 months; p < 0.001), KRAS mutations were significantly associated with worse survival, whereas in the ≥70-year age-group, there was no significant association (14 vs 14 months; p = 0.34). Conclusion: We conclude that the age of patients influences the prognostic value of KRAS mutation in metastatic colorectal cancer.

Liver transplantation for non-resectable colorectal liver metastases: the International Hepato-Pancreato-Biliary Association consensus guidelines

Colorectal cancer is a prevalent disease worldwide, with more than 50% of patients developing metastases to the liver. Despite advances in improving resectability, most patients present with non-resectable colorectal liver metastases requiring palliative systemic therapy and locoregional disease control strategies. There is a growing interest in the use of liver transplantation to treat non-resectable colorectal liver metastases in well selected patients, leading to a surge in the number of studies and prospective trials worldwide, thereby fuelling the emerging field of transplant oncology. The interdisciplinary nature of this field requires domain-specific evidence and expertise to be drawn from multiple clinical specialities and the basic sciences. Importantly, the wider societal implication of liver transplantation for non-resectable colorectal liver metastases, such as the effect on the allocation of resources and national transplant waitlists, should be considered. To address the urgent need for a consensus approach, the International Hepato-Pancreato-Biliary Association commissioned the Liver Transplantation for Colorectal liver Metastases 2021 working group, consisting of international leaders in the areas of hepatobiliary surgery, colorectal oncology, liver transplantation, hepatology, and bioethics. The aim of this study was to standardise nomenclature and define management principles in five key domains: patient selection, evaluation of biological behaviour, graft selection, recipient considerations, and outcomes. An extensive literature review was done within the five domains identified. Between November, 2020, and January, 2021, a three-step modified Delphi consensus process was undertaken by the workgroup, who were further subgrouped into the Scientific Committee, Expert Panel, and Transplant Centre Representatives. A final consensus of 44 statements, standardised nomenclature, and a practical management algorithm is presented. Specific criteria for clinico-patho-radiological assessments with molecular profiling is crucial in this setting. After this, the careful evaluation of biological behaviour with bridging therapy to transplantation with an appropriate assessment of the response is required. The sequencing of treatment in synchronous metastatic disease requires special consideration and is highlighted here. Some ethical dilemmas within organ allocation for malignant indications are discussed and the role for extended criteria grafts, living donor transplantation, and machine perfusion technologies for non-resectable colorectal liver metastases are reviewed. Appropriate immunosuppressive regimens and strategies for the follow-up and treatment of recurrent disease are proposed. This consensus guideline provides a framework by which liver transplantation for non-resectable colorectal liver metastases might be safely instituted and is a meaningful step towards future evidenced-based practice for better patient selection and organ allocation to improve the survival for patients with this disease.

Tailored Systemic Therapy for Colorectal Cancer Liver Metastases

Liver metastases are the most common site of metastatic spread in colorectal cancer. Current treatment approaches involve effective systemic therapies in combination with surgical and/or interventional strategies. Multimodal strategies greatly improved clinical outcomes of patients with metastatic colorectal cancer over the last decades. Identification of predictive and prognostic biomarkers helped to comprehensively refine individual targeted treatment approaches and resulted in median overall survival rates of 30 months or longer. Current guidelines, thus, recommend treatment selection according to patients' performance status, tumor localization and stage as well as the tumor's molecular and genetic status. Here, we outline the latest developments in molecular decision-making for patients with upfront resectable, potentially or initially unresectable and non/never-resectable colorectal cancer liver metastases.

Neoadjuvant immunotherapy in primary and metastatic colorectal cancer

BACKGROUND

Colorectal cancer (CRC) is the second most common solid organ cancer. Traditional treatment is with surgery and chemotherapy. Immunotherapy has recently emerged as a neoadjuvant therapy that could change treatment strategy in both primary resectable and metastatic CRC.

METHODS

A literature review of PubMed with a focus on studies exploring upfront immunotherapy in operable CRC, either for primary resectable stage I-III cancers or for (potentially) operable liver metastasis.

RESULTS

Immune checkpoint blockade by the programmed cell death 1 (PD-1) receptor inhibitors nivolumab and pembrolizumab and the cytotoxic T cell-associated protein 4 (CTLA-4) inhibitor ipilimumab has shown good results in both early-stage and advanced CRC. The effects of immune checkpoint inhibitors have so far been demonstrated in small phase I/II studies and predominantly in treatment-refractory stage IV disease with defect Mismatch repair (dMMR). However, recent data from phase I/II (NICHE-1) studies suggest an upfront role for immunotherapy in operable stage I-III disease. By blocking crucial immune checkpoints, cytotoxic T cells are activated and release cytotoxic signals that initiate cancer cell destruction. The very high complete response rate in dMMR operable CRC with neoadjuvant immunotherapy with nivolumab and ipilimumab, and even partial pathological response in some patients with proficient MMR (pMMR) CRC, calls for further attention to patient selection for neoadjuvant treatment, beyond MMR status alone.

CONCLUSION

Early data on the effect of immunotherapy in CRC provide new strategic thinking of treatment options in CRC for both early-stage and advanced disease, with prospects for new trials.

Repeat Local Treatment of Recurrent Colorectal Liver Metastases, the Role of Neoadjuvant Chemotherapy: An Amsterdam Colorectal Liver Met Registry (AmCORE) Based Study

This cohort study aimed to evaluate efficacy, safety, and survival outcomes of neoadjuvant chemotherapy (NAC) followed by repeat local treatment compared to upfront repeat local treatment of recurrent colorectal liver metastases (CRLM). A total of 152 patients with 267 tumors from the prospective Amsterdam Colorectal Liver Met Registry (AmCORE) met the inclusion criteria. Two cohorts of patients with recurrent CRLM were compared: patients who received chemotherapy prior to repeat local treatment (32 patients) versus upfront repeat local treatment (120 patients). Data from May 2002 to December 2020 were collected. Results on the primary endpoint overall survival (OS) and secondary endpoints local tumor progression-free survival (LTPFS) and distant progression-free survival (DPFS) were reviewed using the Kaplan-Meier method. Subsequently, uni- and multivariable Cox proportional hazard regression models, accounting for potential confounders, were estimated. Additionally, subgroup analyses, according to patient, initial and repeat local treatment characteristics, were conducted. Procedure-related complications and length of hospital stay were compared using chi-square test and Fisher's exact test. The 1-, 3-, and 5-year OS from date of diagnosis of recurrent disease was 98.6%, 72.5%, and 47.7% for both cohorts combined. The crude survival analysis did not reveal a significant difference in OS between the two cohorts (p = 0.834), with 1-, 3-, and 5-year OS of 100.0%, 73.2%, and 57.5% for the NAC group and 98.2%, 72.3%, and 45.3% for the upfront repeat local treatment group, respectively. After adjusting for two confounders, comorbidities (p = 0.010) and primary tumor location (p = 0.023), the corrected HR in multivariable analysis was 0.839 (95% CI, 0.416-1.691; p = 0.624). No differences between the two cohorts were found with regards to LTPFS (HR = 0.662; 95% CI, 0.249-1.756; p = 0.407) and DPFS (HR = 0.798; 95% CI, 0.483-1.318; p = 0.378). No heterogeneous treatment effects were detected in subgroup analyses according to patient, disease, and treatment characteristics. No significant difference was found in periprocedural complications (p = 0.843) and median length of hospital stay (p = 0.600) between the two cohorts. Chemotherapy-related toxicity was reported in 46.7% of patients. Adding NAC prior to repeat local treatment did not improve OS, LTPFS, or DPFS, nor did it affect periprocedural morbidity or length of hospital stay. The results of this comparative assessment do not substantiate the routine use of NAC prior to repeat local treatment of CRLM. Because the exact role of NAC (in different subgroups) remains inconclusive, we are currently designing a phase III randomized controlled trial (RCT), COLLISION RELAPSE trial, directly comparing upfront repeat local treatment (control) to neoadjuvant systemic therapy followed by repeat local treatment (intervention).

Neoadjuvant chemotherapy for colorectal liver metastases: A contemporary review of the literature

Colorectal carcinoma (CRC) is one of the leading causes of cancer-related deaths worldwide, and up to 50% of patients with CRC develop colorectal liver metastases (CRLM). For these patients, surgical resection remains the only opportunity for cure and long-term survival. Over the past few decades, outcomes of patients with metastatic CRC have improved significantly due to advances in systemic therapy, as well as improvements in operative technique and perioperative care. Chemotherapy in the modern era of oxaliplatin- and irinotecan-containing regimens has been augmented by the introduction of targeted biologics and immunotherapeutic agents. The increasing efficacy of contemporary systemic therapies has led to an expansion in the proportion of patients eligible for curative-intent surgery. Consequently, the use of neoadjuvant strategies is becoming progressively more established. For patients with CRLM, the primary advantage of neoadjuvant chemotherapy (NCT) is the potential to down-stage metastatic disease in order to facilitate hepatic resection. On the other hand, the routine use of NCT for patients with resectable metastases remains controversial, especially given the potential risk of inducing chemotherapy-associated liver injury prior to hepatectomy. Current guidelines recommend upfront surgery in patients with initially resectable disease and low operative risk, reserving NCT for patients with borderline resectable or unresectable disease and high operative risk. Patients undergoing NCT require close monitoring for tumor response and conversion of CRLM to resectability. In light of the growing number of treatment options available to patients with metastatic CRC, it is generally agreed that these patients are best served at tertiary centers with an expert multidisciplinary team.

Reevaluating the prognostic role of BRAF mutation in colorectal cancer liver metastases

INTRODUCTION

Mutations in the BRAF proto-oncogene have been shown to predict poor patient survival following curative-intent liver surgery for metastatic colorectal cancer. The aim of the present systematic review and meta-analysis is to evaluate the effect of mutated BRAF status (mutBRAF) on the overall (OS) and disease-free survival (DFS) in these patients.

METHODS

A comprehensive literature search was performed for studies reporting outcomes of patients undergoing curative-intent surgery stratified by BRAF mutation status. Subgroup analysis was performed to evaluate whether inclusion of KRAS mutation status significantly influenced the results.

RESULTS

Six studies incorporating 1857 patients with known BRAF status were identified. Pooled results revealed significantly worse OS (Hazard Ratio 2.8, 95% C.I. 2.09 to 3.77) and DFS (Hazard Ratio 2.29, 95% C.I. 2.09 to 3.77) in mutBRAF patients. Subgroup analysis revealed no statistically significant impact of including KRAS status testing on the obtained results.

CONCLUSIONS

Patients with metastatic colorectal cancer carrying BRAF mutations have significantly worse oncologic outcomes following surgery and more aggressive disease phenotype overall.

Primary Tumor Sidedness, RAS and BRAF Mutations and MSI Status as Prognostic Factors in Patients with Colorectal Liver Metastases Treated with Surgery and Thermal Ablation: Results from the Amsterdam Colorectal Liver Met Registry (AmCORE)

The aim of this study was to assess primary tumor sidedness of colorectal cancer (CRC), rat sarcoma viral oncogene homolog (RAS) and v-raf murine sarcoma viral oncogene homolog B (BRAF) mutations and microsatellite instability (MSI) status as prognostic factors predicting complications, survival outcomes, and local tumor progression (LTP) following surgery and thermal ablation in patients with colorectal liver metastases (CRLM). This Amsterdam Colorectal Liver Met Registry (AmCORE) based study included 520 patients, 774 procedures, and 2101 tumors undergoing local treatment (resection and/or thermal ablation) from 2000 to 2021. Outcomes following local treatment were analyzed for primary tumor sidedness of CRC, RAS, and BRAF mutations and MSI status. The Kaplan–Meier method was used to estimate local tumor progression-free survival (LTPFS), local control (LC), distant progression-free survival (DPFS), and overall survival (OS). Uni- and multivariable analyses were performed based on Cox proportional hazards model. The chi-square test was used to analyze complications. Complications (p = 0.485), OS (p = 0.252), LTPFS (p = 0.939), and LC (p = 0.423) was not associated with tumor-sidedness. Compared to right-sided colon cancer (CC) (reference HR 1.000), DPFS was superior for left-sided CC and rectal cancer (p = 0.018) with an HR for left-sided CC of 0.742 (95% CI, 0.596–0.923) and for RC of 0.760 (95% CI, 0.597–0.966). Regarding RAS mutations, no significant difference was found in OS (p = 0.116). DPFS (p = 0.001), LTPFS (p = 0.039), and LC (p = 0.025) were significantly lower in the RAS mutation group. Though no difference in LTPFS was found between RAS wildtype and RAS mutated CRLM following resection (p = 0.532), LTPFS was worse for RAS mutated tumors compared to RAS wildtype following thermal ablation (p = 0.037). OS was significantly lower in the BRAF mutation group (p < 0.001) and in the MSI group (p < 0.001) following local treatment, while both did not affect DPFS, LTPFS, and LC. This AmCORE based study suggests the necessity of wider margins to reduce LTP rates in patients with RAS mutated CRLM, especially for thermal ablation. Upfront knowledge regarding molecular biomarkers may contribute to improved oncological outcomes.

Association of emergence of new mutations in circulating tumuor DNA during chemotherapy with clinical outcome in metastatic colorectal cancer

BACKGROUND

The understanding of molecular changes in mCRC during treatment could be used to personalise therapeutic strategies. The aim of our study was to explore the association of circulating tumour DNA (ctDNA) with clinical outcome in metastatic colorectal cancer (mCRC).

METHODS

Sequential patients with mCRC receiving standard first-line chemotherapy were included prospectively. Both plasma ctDNA and serum CEA were assessed in samples obtained before treatment and after 4 cycles of chemotherapy (C4). Computed tomography (CT) scans were carried out at baseline and post-C4 (8-10 weeks) and were assessed using Response Evaluation Criteria In Solid Tumours version 1.1 (RECIST v1.1). Target-capture deep sequencing with a panel covering 1021 genes was performed to detected somatic mutations in ctDNA.

RESULTS

A total of 20 patients were prospectively included and treated with either leucovorin, fluorouracil, and oxaliplatin (FOLFOX) (15/20) or leucovorin, fluorouracil, and irinotecan (FOLFIRI) (5/20). Median follow-up was 6.9 months (range 1.6-26.6). Somatic mutations for baseline ctDNA analysis were identified in 85% (17/20) of the patients. Mutation variations of ctDNA after chemotherapy were tested in 16/20 (80.0%) of the patients. In multivariate analyses, a high baseline molecular tumour burden index (mTBI) in ctDNA was associated with a higher risk of disease progression, as well as emergence of new mutations in ctDNA during chemotherapy. Patients with newly detected mutations had shorter progression-free survival (PFS) compared to those without (median 3.0 versus 7.3 months; hazard ratio (HR), 5.97; 95% confidence interval (CI), 0.70-50.69; P = 0.0003). Fold changes in mTBI from baseline to post-C4 were obtained in 80.0% (16/20) of the patients, which were also related to PFS. Patients with fold reduction in mTBI above 0.8-fold had longer PFS compared to those below (median 9.3 versus 4.1 months; HR, 4.51; 95% CI, 1.29-15.70; P = 0.0008).

CONCLUSIONS

Newly detected mutations in ctDNA during treatment might potentially be associated with clinical outcome in mCRC and may provide important clinical information.

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.

Molecular Determinants and Other Factors to Guide Selection of Patients for Hepatic Resection of Metastatic Colorectal Cancer

OPINION STATEMENT

Treatment for metastatic colorectal cancer (CRC) has changed significantly over the last few decades as cytotoxic and targeted chemotherapies have evolved and resection of (technically feasible) colorectal liver metastases (CRLM) has become standard of care for eligible patients. Overall, survival for metastatic CRC has considerably improved, but recurrences are common. Numerous clinical risk scores have been suggested to guide patient selection for CRLM resection, but none perfectly predict outcomes; therefore, a personalized approach to metastatic CRC treatment using genetic profiles for risk stratification and prognostication is a critically important advancement. All patients with suspected metastatic CRC should undergo genetic testing for common oncogene mutations (e.g., KRAS, BRAF, and NRAS) in addition to a triphasic CT scan of the chest, abdomen, and pelvis; if hepatectomy may be entertained and there is concern about the future liver remnant (FLR), liver volumetrics should also be performed. MRI and PET are useful adjuncts for cases in which diagnosis or extent of disease is unclear. The decision to operate should be individualized and based on each patient's condition, tumor biology, and technical resectability. Genetic profiles should be used to inform multidisciplinary meetings surrounding topics of chemotherapy and surgical resection, as well as patient discussions concerning the risks and benefits of surgery. In the end, most patients with technically resectable colorectal cancers and adequate cardiopulmonary fitness benefit from surgical resection, as it remains the only chance of long-term survival.

Effective Strategies to Predict Survival of Colorectal Peritoneal Metastases Patients Eligible for Cytoreductive Surgery and HIPEC

Cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC), often combined with systemic therapy, can be offered to selected colorectal peritoneal metastases (PM) patients. However, clinical heterogeneity and the lack of high-level evidence challenges determination of the correct treatment strategy. This review aims to provide an overview of current strategies to predict survival of colorectal PM patients treated with CRS and HIPEC, guiding clinicians to select a suitable treatment-strategy and to inform patients about their prognosis. First, the prognostic relevance of several clinicopathological prognostic factors, such as extent of PM, location of primary tumor, histology type, and the presence of lymph node or liver metastases will be discussed. Subsequently, special attention will be given to recent developments in several aspects of tumor biology such as RAF/RAS mutations, circulating tumor DNA, immunoprofiling, and consensus molecular subtypes. Finally, currently available prognostic models to predict survival will be evaluated, concluding these models perform moderate to good, but most of them partly rely on intra-operative data. New insights in tumor biology, as well as the reliable assessment of extent of peritoneal disease by diffusion weighted MRI pose promising opportunities to establish an adequate and clinically meaningful preoperative prognostic model in the near future.

Phosphorylated mTOR expression as a predictor of survival after liver resection for colorectal liver metastases

BACKGROUND

Phosphorylated mammalian target of rapamycin (p-mTOR) plays a crucial role in the process of cancer progression. Common gene mutations of colorectal cancer lead to the activation of the PI3k/Akt/mTOR pathway. In this study, we determined whether p-mTOR expression in colorectal liver metastases is a predictive marker of prognosis following liver resection.

METHODS

Eighty-one patients with colorectal liver metastases who had undergone curative resection were evaluated using immunohistochemistry of p-mTOR. Data regarding clinicopathological features and patient survival were analyzed.

RESULTS

The p-mTOR expression in colorectal liver metastases was detected in 55 (67.9%) patients. Patients whose metastases had high p-mTOR expression showed a significantly lower overall survival rate after resection as compared to patients with low p-mTOR expression (p = 0.016), while there was no significant difference in the disease-free survival between the two groups. Repeat resection for recurrence was performed more frequently in patients with p-mTOR positive than others (p = 0.024). Multivariate analysis showed that p-mTOR expression was an independent prognostic factor of overall survival after liver resection (p = 0.019).

CONCLUSIONS

mTOR was frequently activated in colorectal liver metastases, and the p-mTOR expression was a biological marker for predicting the overall survival of patients with colorectal liver metastases following liver resection.

Optimizing Loco Regional Management of Oligometastatic Colorectal Cancer: Technical Aspects and Biomarkers, Two Sides of the Same Coin

Simple Summary

The treatments for patients with oligometastatic colorectal carcinoma are rapidly evolving. The present review focuses on the role of minimally invasive techniques since they can now be used as an alternative to surgical management in selected cases in association with systemic therapies according to ESMO and NCCN guidelines. In recent years, biomarkers (both at molecular and imaging level) have emerged as a relevant and potential criteria for treatment strategy decision and will be crucial in the future for patients selection. Tumor molecular profile impacts on local outcome of image guide ablation as well as metabolic imaging which predicts the outcome of both percutaneous and trans-arterial treatments. Oncologists should be aware of advantages and disadvantages of those treatments options as well as the potential role of molecular profile for a better patient selection.

Abstract

Colorectal cancer (CRC) is the third most common cancer worldwide and has a high rate of metastatic disease which is the main cause of CRC-related death. Oligometastatic disease is a clinical condition recently included in ESMO guidelines that can benefit from a more aggressive locoregional approach. This review focuses the attention on colorectal liver metastases (CRLM) and highlights recommendations and therapeutic locoregional strategies drawn from the current literature and consensus conferences. The different percutaneous therapies (radiofrequency ablation, microwave ablation, irreversible electroporation) as well as trans-arterial approaches (chemoembolization and radioembolization) are discussed. Ablation margins, the choice of the imaging guidance as well as characteristics of the different ablation techniques and other technical aspects are analyzed. A specific attention is then paid to the increasing role of biomarkers (in particular molecular profiling) and their role in the selection of the proper treatment for the right patient. In conclusion, in this review an up-to-date state of the art of the application of locoregional treatments on CRLM is provided, highlighting both technical aspects and the role of biomarkers, two sides of the same coin.

Accuracy of Modern Clinical Risk Score Including RAS Status Changes Based on Whether Patients Received Perioperative Chemotherapy for Colorectal Liver Metastases

BACKGROUND

A modified Fong clinical score (m-Fong CS) that includes the RAS mutation status has recently been proposed and offered an improved survival stratification of patients who undergo surgery and systemic chemotherapy for colorectal liver metastases (CLM). The aim of this study is to assess whether a CS that includes RAS status is influenced by whether patients receive perioperative chemotherapy.

METHODS

We created a new CS using multivariate analysis of data of patients who underwent hepatectomy for CLM for the first time between 2010 and 2016 at a single hospital (n = 341, 79% received perioperative chemotherapy). The resulting CS and m-Fong CS were then validated in the patient cohort at three other hospitals (n = 309). Furthermore, the applicability of the two CS in the total cohort (n = 650) was tested according to whether the patients received perioperative chemotherapy.

RESULTS

The new CS comprised mutant RAS status, ≥4 CLMs, and a CA19-9 level ≥100 U/mL (1 point per factor). Both the new CS and m-Fong CS failed to stratify the survival of the 309 patients in the validation cohort, including those who did not receive perioperative chemotherapy (29%). Both of the CS accurately stratified the survival of patients who underwent perioperative chemotherapy but not of those who underwent surgery alone.

CONCLUSION

A CS that includes the RAS mutation status can stratify the survival of patients who undergo hepatectomy combined with perioperative chemotherapy, but it has limited value for patients who undergo surgery alone.

Clinico-metabolic characterization improves the prognostic value of histological growth patterns in patients undergoing surgery for colorectal liver metastases

BACKGROUND AND OBJECTIVES

The histological growth pattern (HGP) represents a strong prognostic factor in patients undergoing surgery for colorectal liver metastases (CRLM). We evaluated whether the combination of HGP with clinico-metabolic parameters could improve its prognostic value.

METHODS

In a series of 108 patients undergoing resection of CRLM, the HGP of CRLM was scored according to international guidelines. Baseline clinico-metabolic clinical status was evaluated using a metabolic-Clinical Risk Score (mCRS), combining traditional Memorial Sloan Kettering-CRS parameters with the tumor-to-liver glucose uptake ratio as measured with ¹⁸ Fluorodeoxyglucose/positron emission tomography.

RESULTS

In patients with desmoplastic HGP (DHGP) CRLM (20% of all patients), 5- and 10-years overall survival (OS) and disease free survival (DFS) were 66% and 43% and 37% and 24.5%, as compared with 35% and 21% and 11% and 11% in the non-DHGP group (p = 0.07 and 0.054). Among DHGP patients, those with a low-risk mCRS had improved postoperative outcomes, 5- and 10-years OS and DFS reaching 83.3% and 62.5% and 50% and 33%, as compared with 18% and 0% and 0% and 0% in high-risk mCRS patients (p = 0.007 and 0.003). In contrast, mCRS did not influence postoperative survivals in non-DHGP patients.

CONCLUSIONS

Combining the clinico-metabolic characteristics with the HGP may improve prognostication in patients undergoing surgery for CRLM.

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.

APC and PIK3CA Mutational Cooperativity Predicts Pathologic Response and Survival in Patients Undergoing Resection for Colorectal Liver Metastases

OBJECTIVE

The aim of the study was to determine the prognostic impact of co-existence of APC and PIK3CA mutations in patients undergoing preoperative chemotherapy and resection for colorectal liver metastases (CLM).

BACKGROUND

Co-occurring genetic events have been shown to drive carcinogenesis in multiple malignancies.

METHODS

We identified 396 patients with primary colorectal cancer and known somatic mutation status by next-generation sequencing who underwent hepatectomy for CLM (2005-2015). Survival after hepatectomy in patients with double mutation of APC and PIK3CA and others was analyzed. Predictors of pathologic response and survival were determined. The prognostic value of double mutation was evaluated with a separate cohort of 157 patients with CLM undergoing chemotherapy alone.

RESULTS

Forty-five patients had double mutation of APC and PIK3CA; 351 did not. Recurrence-free survival (RFS) and overall survival (OS) after hepatectomy were worse in patients with double mutation (3-year RFS, 3.1% vs 20% [P < 0.001]; 3-year OS, 44% vs 84% [P < 0.001]). Independent predictors of major pathologic response were bevacizumab use (odds ratio [OR] 2.22; P = 0.001), tumor size <3 cm (OR 1.97; P = 0.004), wild-type RAS (OR 2.00; P = 0.003), and absence of double mutation (OR 2.91; P = 0.002). Independent predictors of worse OS were primary advanced T category (hazard ratio [HR] 2.12; P = 0.021), RAS mutation (HR 1.74; P = 0.015), and double mutation (HR 3.09; P < 0.001). In the different medical cohort, patients with double mutation had worse 3-year OS of 18%, compared with 35% without double mutation (P = 0.023).

CONCLUSIONS

Double mutation of APC and PIK3CA predicts inferior response to preoperative chemotherapy and poor survival in patients with CLM.

Impact and clinical usefulness of genetic data in the surgical management of colorectal cancer liver metastasis: a narrative review

Importance

In patients who undergo surgery for colorectal cancer liver metastases (CRLM), a number of somatic mutations have been associated with worse overall (OS) and recurrence-free survival (RFS). Although useful, an association with prognosis does not necessarily equate to an impact on surgical management.

Objective

The aim of this review was to investigate whether the best-studied somatic mutations impact surgical management of CRLM by informing: (I) post-hepatectomy surveillance; (II) selection of surgical technique; (III) selection of optimal margin width; and (IV) selection of patients for surgery. Lastly, we discuss the refinement of genetic data from overall mutation status to specific variants, as well as lesser studied somatic mutations.

Evidence Review

We conducted a computerized search using PubMed and Google Scholar for reports published so far, using mesh headings and keywords related to genetic data and CRLM.

Findings

Genetic data may impact surgical management of CRLM in three ways. Firstly, KRAS mutations can predict lung recurrences. Secondly, KRAS mutations may help tailor margin width. Thirdly, KRAS mutations may help tailor surgical technique.

Conclusions

Although genetic data may impact post-hepatectomy surveillance, selection of surgical technique and optimal margin width, their use to guide surgical selection remains elusive, as the data cannot support denying surgery to patients according to their somatic mutation profile.