Contour prognostic model for predicting survival after resection of colorectal liver metastases: development and multicentre validation study using largest diameter and number of metastases with RAS mutation status

Associations of KRAS Point Mutations with Survival of Patients Who Underwent Curative-Intent Resection of Colorectal Liver Metastases

BACKGROUND

The oncologic significance of specific KRAS point mutations for patients with colorectal liver metastases (CLM) is uncertain. This study aimed to assess the prognostic impact of KRAS point mutations on patients who underwent surgery for CLM.

METHODS

Patients who underwent curative-intent surgery for CLM from 2001 to 2020 were selected for the study. In the study, KRAS point mutations and other clinicopathologic variables were examined for association with survival.

RESULTS

The study classified 798 patients into five groups by KRAS mutation status as follows: wild-type (n = 412, 51.6%), G12D (n = 123, 15.4%), G12V (n = 88, 11.0%), G13D (n = 61, 7.6%), and "Other" mutations (n = 114, 14.3%). For the patients with G12V substitutions, TP53 mutation was associated with worse overall survival (OS) (hazard ratio [HR], 2.64; 95% confidence interval [CI], 1.04-6.66; P = 0.041), but was not associated with a survival difference for the other four groups. The patients with co-occurring KRAS G12V and TP53 had a median OS of 4.4 years and a 5-year OS rate of 39.8%. In contrast, the patients with KRAS G12V mutation and wild-type TP53 had a median OS of 7.3 years and a 5-year OS rate of 75.9%, similar to the corresponding values for the patients with wild-type KRAS. Co-occurring KRAS G12V and TP53 mutations were independently associated with worse OS in the entire cohort (HR, 2.08; 95% CI, 1.15-3.76; P = 0.015).

CONCLUSIONS

This study showed that KRAS G12V mutation is associated with worse OS for patients undergoing curative-intent CLM resection, but only those with co-occurring TP53 mutation. Prognosis after surgery for CLM should not be stratified by KRAS mutation site alone.

Simultaneous curative resection may improve the long-term survival of patients diagnosed with colorectal liver metastases: A propensity score-matching study

BACKGROUND

The benefit of simultaneous curative resection in patients with colorectal liver metastases has been unclear. Adjuvant chemotherapy is still considered an effective and priority treatment for advanced-stage colorectal patients.

METHODS

We retrospectively collected patients with colorectal liver metastases from January 2012 to October 2023 at the Guangxi Medical University Cancer Hospital. The baseline information was compared between a simultaneous curative resection group and a palliative treatment group. Propensity score matching with a 1:1 ratio was applied to develop comparable cohorts of curative resection and palliative treatment resection. Kaplan-Meier survival and Cox regression analyses were performed to determine the impact of curative resection on survival of colorectal liver metastasis patients. Prognostic nomogram and a web-version calculator were developed based on the multivariate Cox regression method. Then, the concordance index (C-index), receiver operating characteristic, calibration plots, and decision curves analysis were applied to evaluate the prognostic performance of the nomogram.

RESULTS

A total of 716 patients with colorectal liver metastases were enrolled in the study, of whom 131 patients received curative resection. There was no significant difference in terms of baseline information between the curative resection group and the palliative treatment group after propensity score matching. Multivariable Cox regression analysis showed that curative resection was an independent prognostic factor affecting overall survival (P = .001, hazard ratio = 1.95, 95% confidence interval 1.30-2.91). Compared with patients who did not receive curative resection, patients who received simultaneous curative resection had a significant improvement in overall survival before and after propensity score matching (P < .0001 and P = .0047, respectively). Overall survival nomogram showed excellent predictive performance with the C-indexes of 0.686 (95% confidence interval 0.556-0.792). The areas under the receiver operating characteristic curves were 0.75 (95% confidence interval 64.43-96.05), 0.75 (67.22-82.58), and 0.76 (66.10-85.98) for predicting 1-, 3-, and 5-year survival, respectively. The calibration plots and decision curves analysis also indicated the good predictability of the predictive nomogram. Finally, subgroup analysis further demonstrated a favorable impact of curative resection on overall survival in colorectal liver metastasis patients after propensity score matching.

CONCLUSIONS

Simultaneous curative resection may improve the overall survival of patients with colorectal liver metastases and is an independent and effective indicator for predicting overall survival. The nomogram may provide a personalized treatment strategy.

The impact of neoadjuvant therapy on the prognostic value of preoperative neutrophil-to-lymphocyte ratio for colorectal liver metastases: a multi-center cohort study

BACKGROUND

Neutrophil-to-lymphocyte ratio (NLR) is a promising prognostic marker for patients undergoing hepatectomy for colorectal liver metastases (CRLM). However, its prognostic value in patients receiving neoadjuvant therapy (NAT) has not been sufficiently addressed.

METHODS

From 2013 to 2023, a cohort of 692 patients with CRLM receiving hepatectomy were enrolled in five centers. Clinicopathological characteristics were obtained from a prospectively maintained multi-center database. The effect of NLR (> 2 versus ≤ 2) on overall survival (OS) and recurrence-free survival was estimated by Kaplan-Meier analysis. Univariable and multivariable Cox regression analysis was applied to investigate the influence of individual clinicopathological parameters on OS.

RESULTS

In the entire cohort, the median NLR level was 2.11 (0.30-16.33). There were 307 (44.4%) patients receiving NAT followed by hepatectomy, while 385 (55.6%) patients undergoing upfront surgery. Notably, patients in the NAT group showed significantly lower NLR level than those in the upfront surgery group (1.83 versus 2.32, P < 0.001). In the upfront surgery group, high NLR was significantly associated with worse OS, independent of other factors (HR = 1.49, 95% CI 1.08-2.05, P = 0.02). In the NAT group, there was no significant difference in OS between the high NLR and low NLR group.

CONCLUSION

The prognostic value of NLR in surgically resected CRLM is potentially influenced by NAT in the modern era.

Patterns and Predictors of Recurrence After Curative Resection of Colorectal Liver Metastasis (CRLM)

BACKGROUND

Our study aims to determine the predictors and patterns of relapses after curative colorectal liver metastasis (CRLM) resection.

METHODS

A single-centre, retrospective study of CRLM patients operated between 2010 and 2022 was performed. The site of first recurrence was either hepatic (marginal (≤ 1 cm) or extramarginal), extrahepatic, or both. Factors that predicted relapse patterns and overall survival were determined by multivariable Cox regression analysis with backward elimination of variables.

RESULTS

The study consisted of 258 patients, with a similar proportion of synchronous (144; 56%) and metachronous(114; 43%) metastasis. At a 43-month median follow-up, 156 patients (60.4%) developed recurrences with 33 (21.1%) in the liver, 62(24.03%) extra-hepatic recurrences, and 58 (22.48%) having both. Isolated marginal liver relapses were seen in seven (9.89%) liver recurrence patients. The median overall and relapse-free survivals were 38 months (30-54) and 13 months (11-16), respectively. The 3-year liver-relapse-free survival was 54.4% (44.9-60.6). Size of liver metastases > 5 cm (HR 2.06 (1.34-3.17), involved surgical margins (HR 2.16 (1.27-3.68)), and adjuvant chemotherapy (HR 1.89 (1.07-3.35)) were predictors of hepatic recurrences. Node positivity of primary (HR 1.61 (1.02-2.56)), presence of baseline extra-hepatic metastases (HR 0.30 (0.18-0.51)), size of liver metastases > 5 cm (HR 2.02 (1.37-2.99)), poorly differentiated histology (HR 2.25 (1.28-3.49)), presence of LVI (HR 2.25 (1.28-3.94)), and adjuvant chemotherapy (HR 2.15 (1.28-3.61)) were predictors of extra-hepatic recurrences.

CONCLUSION

The study found majority relapses occurred at extrahepatic sites whilst isolated marginal recurrences were few. The consistent predictors of recurrence were size and inability to deliver adjuvant therapy. A tailored adjuvant therapy might improve outcomes after liver metastasectomy in colorectal cancers.

The challenge of molecular selection in liver-limited metastatic colorectal cancer for surgical resection: a systematic review and meta-analysis in the context of current and future approaches

Objectives

Treatment of metastatic colorectal cancer (mCRC) includes resection of liver metastases (LM), however, no validated biomarker identifies patients most likely to benefit from this procedure. This meta-analysis aimed to assess the impact of the most relevant molecular alterations in cancer-related genes of CRC (i.e., RAS, BRAF, SMAD4, PIK3CA) as prognostic markers of survival and disease recurrence in patients with mCRC surgically treated by LM resection.

Methods

A systematic literature review was performed to identify studies reporting data regarding survival and/or recurrence in patients that underwent complete liver resection for CRC LM, stratified according to RAS, BRAF, PIK3CA, and SMAD4 mutational status. Hazard ratios (HRs) from multivariate analyses were pooled in the meta-analysis and various adjustment strategies for confounding factors were combined. The search was conducted in numerous databases, including MEDLINE (PubMed), Embase, Cumulative Index to Nursing and Allied Health Literature (CINAHL) (EBSCO host), and WHO Global Index Medicus, through March 18th, 2022. Meta-analyses, editorials, letters to the editor, case reports, studies on other primary cancers, studies with primary metastatic sites other than the liver, studies lacking specific oncological outcome variables or genetic data, non-English language studies, and studies omitting residual disease data from liver metastasectomy were excluded. The remaining 47 studies were summarized in a descriptive table which outlines the key characteristics of each study and final results were graphically presented.

Results

RAS mutation status was negatively associated with overall survival (OS) (HR, 1.68; 95% CI, 1.54-1.84) and recurrence free survival (RFS) (HR, 1.46; 95% CI, 1.33-1.61). A negative association was also found for BRAF regarding OS (HR, 2.64; 95% CI, 2.15-3.24) and RFS (HR, 1.89; 95% CI, 1.32-2.73) and SMAD4 regarding OS (HR, 1.93; 95% CI, 1.56-2.38) and RFS (HR, 1.95; 95% CI, 1.31-2.91). For PIK3CA only three studies were eligible and no significant association with either OS or RFS could be highlighted.

Conclusion

RAS, BRAF, and SMAD4 are negatively associated with OS and RFS in patients undergoing curative liver metastasectomy from colorectal cancer. No conclusion can be drawn for PIK3CA due to the limited literature availability. These data support the integration of RAS, BRAF, and SMAD4 mutational status in the surgical decision-making for colorectal liver metastasis. Nevertheless, we have to consider several limitations, the major ones being the pooling of results from studies that evaluated patient outcomes as either disease-free survival (DFS) or RFS; the inclusion of patients with minimal residual disease and unconsidered potential confounding factors, such as variability in resectability definitions, chemotherapy use, and a potential interaction between biological markers and pre- and post-resection pharmacological treatments.

Importance of resection margin after resection of colorectal liver metastases in the era of modern chemotherapy: population-based cohort study

BACKGROUND

Resection margin has been associated with overall survival following liver resection for colorectal liver metastasis. The aim of this study was to examine how resection margins of 0.0 mm, 0.1-0.9 mm and ≥1 mm influence overall survival in patients resected for colorectal liver metastasis in a time of modern perioperative chemotherapy and surgery.

METHODS

Using data from the national registries Swedish Colorectal Cancer Registry and Swedish National Quality Registry for Liver, Bile Duct and Gallbladder Cancer, patients that had liver resections for colorectal liver metastasis between 2009 and 2013 were included. In patients with a narrow or unknown surgical margin the original pathological reports were re-reviewed. Factors influencing overall survival were analysed using a Cox proportional hazard model.

RESULTS

A total of 754 patients had a known margin status, of which 133 (17.6%) patients had a resection margin <1 mm. The overall survival in patients with a margin of 0 mm or 0.1-0.9 mm was 42 (95% c.i. 31 to 53) and 48 (95% c.i. 35 to 62) months respectively, compared with 75 (95% c.i. 65 to 85) for patients with ≥1 mm margin, P < 0.001. Margins of 0 mm or 0.1-0.9 mm were associated with poor overall survival in the multivariable analysis, HR 1.413 (95% c.i. 1.030 to 1.939), P = 0.032, and 1.399 (95% c.i. 1.025 to 1.910), P = 0.034, respectively.

CONCLUSIONS

Despite modern chemotherapy the resection margin is still an important factor for the survival of patients resected for colorectal liver metastasis, and a margin of ≥1 mm is needed to achieve the best possible outcome.

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.

Drug-eluting beads transcatheter arterial chemoembolization combined with systemic therapy versus systemic therapy alone as first-line treatment for unresectable colorectal liver metastases

Purpose

The purpose of this retrospective study was to compare the therapeutic efficacy and safety of drug-eluting bead transarterial chemoembolization (DEB-TACE) combined with systemic therapy to systemic therapy alone as first-line treatment for unresectable patients with colorectal liver metastases (CRLM).

Methods

From December 2017 to December 2022, patients with unresectable CRLM who received systemic therapy with or without DEB-TACE as first-line treatment were included in the study. The primary endpoint was progression-free survival (PFS). Secondary endpoints were tumor response, conversion rate and adverse events.

Results

Ninety-eight patients were enrolled in this study, including 46 patients who received systemic therapy combined with DEB-TACE (DEB-TACE group) and 52 patients who received systemic therapy alone (control group). The median PFS was elevated in the DEB-TACE group compared with the control group (12.1 months vs 8.4 months, p = 0.008). The disease control rate was increased in the DEB-TACE group compared with the control group (87.0% vs 67.3%, p = 0.022). Overall response rates (39.1% vs 25.0%; p = 0.133) and conversion rate to liver resection (33.8% vs 25.0%; p = 0.290) were no different between the two groups. The multivariate analysis showed that treatment options, size of liver metastasis, number of liver metastasis, synchronous metastases, and extrahepatic metastases were independent prognostic factor of PFS. Further subgroup analyses illustrated that PFS was beneficial with the DEB-TACE group in patients with age ≥ 60, male, left colon, synchronous metastases, bilobar, number of liver metastasis > 5, extrahepatic metastases, non-extrahepatic metastases, CEA level < 5 (ng/ml), and KRAS wild-type. No grade 4 or 5 toxicities related to DEB-TACE procedures were observed.

Conclusion

In patients with unresectable CRLM, systemic chemotherapy with DEB-TACE as first-line treatment may improve progression-free survival and disease control rate outcomes over systemic chemotherapy alone with manageable safety profile.

Predicting early recurrence after resection of initially unresectable colorectal liver metastases: the role of baseline and pre-surgery clinical, radiological and molecular factors in a real-life multicentre experience

BACKGROUND

Advances in surgical techniques and systemic treatments have increased the likelihood of achieving radical surgery and long-term survival in metastatic colorectal cancer (mCRC) patients with initially unresectable colorectal liver metastases (CRLMs). Nonetheless, roughly half of the patients resected after an upfront systemic therapy experience disease relapse within 6 months from surgery, thus leading to the question whether surgery is actually beneficial for these patients.

MATERIALS AND METHODS

A real-world dataset of mCRC patients with initially unresectable liver-limited disease treated with conversion chemotherapy followed by radical resection of CRLMs at three high-volume Italian institutions was retrospectively assessed with the aim of investigating the association of baseline and pre-surgical clinical, radiological and molecular factors with the risk of relapse within 6 or 12 months from surgery.

RESULTS

Overall, 268 patients were included in the analysis and 207 (77%) experienced recurrence. Ninety-six (46%) of them had disease relapse within 6 months after CRLM resection and in spite of several variables associated with early recurrence at univariate analyses, only primary tumour resection at diagnosis [odds ratio (OR) 0.53, 95% confidence interval (CI) 0.32-0.89, P = 0.02] remained significant in the multivariable model. Among patients with resected primary tumours, pN+ stage was associated with higher risk of disease relapse within 6 months (OR 3.02, 95% CI 1.23-7.41, P = 0.02). One hundred and forty-nine patients (72%) had disease relapse within 12 months after CRLMs resection but none of the analysed variables was independently associated with outcome.

CONCLUSIONS

Clinical, radiological and molecular factors assessed before and after conversion chemotherapy do not reliably predict early recurrence after secondary resection of initially unresectable CRLMs. While novel markers are needed to optimize the cost/efficacy balance of surgical procedures, CRLM resection should be offered as soon as metastases become resectable during first-line chemotherapy to all patients eligible for surgery.

Evolving survival gains in patients with young-onset colorectal cancer and synchronous resectable liver metastases

We aimed to evaluate the practice and the associated outcomes of surgical treatment for young-onset colorectal cancer (YOCRC) patients presenting with synchronous liver metastases. The study cohort was divided into two groups according to surgery date: 131 patients in the early era (EE, 1998-2011) and 179 in the contemporary era (CE, 2012-2020). The CE had a higher rate of node-positive primary tumors, higher carcinoembryonic antigen level, and lower rate of RAS/BRAF mutations. The CE had higher rates of reverse or combined resection, multi-drug prehepatectomy chemotherapy, and two-stage hepatectomy. The median survival was 8.4 years in the CE and 4.3 years in the EE (p = 0.011). On multivariate analysis, hepatectomy in the CE was independently associated with improved overall survival (HR 0.48, p = 0.001). With a combination of perioperative systemic therapy, careful selection of treatment approach, and coordinated resections, durable cure can be achieved in YOCRC patients.

Circulating Tumor DNA: Towards More Individualized Treatment for Patients with Resectable Colorectal Cancer

PURPOSE

Despite curative-intent treatment, recurrence is common for patients with colorectal cancer (CRC).  Currently, prediction of disease recurrence and prognostication following surgery is based upon vague clinical factors and more precise and dynamic biomarkers for risk stratification and treatment decisions are urgently needed.  Circulating tumor DNA (ctDNA) is a promising biomarker for patients undergoing treatment for resectable CRC.

METHODS

In this review, we provide an overview of the data supporting current uses of ctDNA for CRC, including localized CRC and resectable colorectal liver metastases (CLM), as well as descriptions of important ongoing clinical trials using ctDNA in the care of patients with CRC.

RESULTS

The detection of ctDNA following curative-intent therapy is associated with disease recurrence, and multiple trials are investigating its role in determining need and duration for adjuvant therapy for localized CRC. In addition, ctDNA reliably predicts prognosis for patients with CLM, with trials underway studying ctDNA-guided treatment sequencing and intensity.

CONCLUSION

The detection of ctDNA is a sensitive and dynamic biomarker for disease recurrence in CRC. Many investigations are underway into ctDNA's potential role in surveillance and treatment algorithms, and it has the potential to become a critical biomarker to determine individualized strategies for treatment sequencing, choice, and duration of therapies.

The Usefulness of Total Tumor Volume as a Prognostic Factor and in Selecting the Optimal Treatment Strategy of Chemotherapeutic Intervention in Patients with Colorectal Liver Metastases

BACKGROUND

Few reports have discussed the association between total tumor volume (TTV) and prognosis in patients with colorectal liver metastases (CRLM). The present study aimed to evaluate the usefulness of TTV for predicting recurrence-free survival and overall survival (OS) in patients receiving initial hepatic resection or chemotherapy, and to investigate the value of TTV as an indicator for optimal treatment selection for patients with CRLM.

PATIENTS AND METHODS

This retrospective cohort study included patients with CRLM who underwent hepatic resection (n = 93) or chemotherapy (n = 78) at the Kobe University Hospital. TTV was measured using 3D construction software and computed tomography images.

RESULTS

A TTV of 100 cm3 has been previously reported as a significant cut-off value for predicting OS of CRLM patients receiving initial hepatic resection. For patients receiving hepatic resection, the OS for those with a TTV ≥ 100 cm3 was significantly reduced compared with those with a TTV < 100 cm3. For patients receiving initial chemotherapy, there were no significant differences between the groups divided according to TTV cut-offs. Regarding OS of patients with TTV ≥ 100 cm3, there was no significant difference between hepatic resection and chemotherapy (p = 0.160).

CONCLUSIONS

TTV can be a predictive factor of OS for hepatic resection, unlike for initial chemotherapy treatment. The lack of significant difference in OS for CRLM patients with TTV ≥ 100 cm3, regardless of initial treatment, suggests that chemotherapeutic intervention preceding hepatic resection may be indicated for such patients.

Survival after combined resection and ablation is not inferior to that after resection alone, in patients with four or more colorectal liver metastases

PURPOSE

Colorectal liver metastases (CRLM) are the predominant factor limiting survival in patients with colorectal cancer. Multimodal treatment strategies are frequently necessary to achieve total tumor elimination. This study examines the efficacy of liver resection combined with local ablative therapy in comparison to liver resection only, in the treatment of patients with ≥ 4 CRLM.

METHODS

This retrospective cohort study was conducted at the University Hospital RWTH Aachen, Germany. Patients with ≥ 4 CRLM in preoperative imaging, who underwent curative resection between 2010-2021, were included. Recurrent resections and deaths in the early postoperative phase were excluded. Ablation modalities included radiofrequency or microwave ablation, and irreversible electroporation. Differences in overall- (OS) and recurrence-free-survival (RFS) between patients undergoing combined resection-ablation vs. resection only, were examined.

RESULTS

Of 178 included patients, 46 (27%) underwent combined resection-ablation and 132 (73%) resection only. Apart from increased rates of adjuvant chemotherapy in the first group (44% vs. 25%, p = 0.014), there were no differences in perioperative systemic therapy. Kaplan-Meier and log-rank test analyses showed no statistically significant differences in median OS (36 months for both, p = 0.638) or RFS (9 months for combined resection-ablation vs. 8 months, p = 0.921). Cox regression analysis showed a hazard ratio of 0.891 (p = 0.642) for OS and 0.981 (p = 0.924) for RFS, for patients undergoing resection only.

CONCLUSION

For patients with ≥ 4 CRLM, combined resection-ablation is a viable option in terms of OS and RFS. Therefore, combined resection-ablation should be considered for complete tumor clearance, in patients with multifocal disease.

Outcomes Following Different Thermal Ablation Strategies in Patients with Unresectable Colorectal Liver Metastases

Background For patients with unresectable colorectal liver metastases (CRLM), clinical guidelines recommend imaging-guided thermal ablation combined with systemic therapy. However, the optimal thermal ablation strategy remains unclear. Purpose To compare long-term outcomes between patients who underwent upfront ablation or delayed ablation for unresectable CRLM. Materials and Methods This retrospective study included patients with unresectable CRLM (three or fewer lesions; diameter, <3 cm) admitted to one of seven hospitals between October 2009 and December 2020. Upfront ablation was performed 2-4 weeks before the start of systemic therapy, and delayed ablation was performed 2-3 months after the start of systemic therapy. Propensity score matching was applied to adjust for differences in baseline variables between groups. Disease-free survival (DFS) was the primary outcome. Overall survival (OS), complications, and adverse events were secondary outcomes. Outcomes were compared between groups by using the log-rank test. Results In total, 255 patients who underwent delayed ablation (mean age, 57 years ± 11 [SD]; 184 men [72%]) and 103 patients who underwent upfront ablation (mean age, 56 years ± 12; 72 men [70%]) were included. After propensity score matching (n = 100 in both groups), the 5-year DFS for patients who underwent upfront ablation was better compared with patients who underwent delayed ablation (36% vs 21%; P = .02). For 5-year OS, no evidence of a difference was observed between ablation strategies (delayed ablation, 59% vs upfront ablation, 64%; P = .49). Additionally, no differences were observed between ablation strategies with respect to the rates of ablative complications (delayed ablation, 6% vs upfront ablation, 5%; P = .76) or drug-related adverse events (delayed and upfront ablation both 9%; P = .99). Conclusion In patients with relatively few (three or fewer) and small (<3 cm) unresectable CRLM, upfront thermal ablation combined with adjuvant systemic therapy led to better DFS compared with delayed ablation. © RSNA, 2023 Supplemental material is available for this article. See also the editorial by Georgiades in this issue.

Posthepatectomy but not prehepatectomy chemotherapy was associated with a longer time to recurrence in patients with resectable colorectal liver metastases: Inverse probability of treatment weighting analysis

BACKGROUND

Patients with resectable colorectal liver metastases (CLM) are treated with surgery alone, surgery and posthepatectomy chemotherapy, or prehepatectomy chemotherapy and surgery. The optimal approach in terms of survival is unclear. We compared survival in the three treatment groups using inverse probability of treatment weighting (IPTW) analysis.

METHODS

Data from patients undergoing initial CLM resection in 2005-2018 were obtained from a prospectively maintained database. Our group treated resectable CLM with surgery alone but gradually adopted post- and prehepatectomy chemotherapy for patients with CLM number ≥5 after 2015. IPTW analysis was employed to adjust the characteristics of the three groups.

RESULTS

Of the 439 patients meeting the inclusion criteria, 175 underwent surgery alone, 135 underwent surgery and posthepatectomy chemotherapy, and 129 underwent prehepatectomy chemotherapy and surgery. After the IPTW adjustment, the demographic and clinicopathological characteristics were well balanced. The IPTW analysis revealed that the recurrence-free survival was better in patients undergoing surgery and posthepatectomy chemotherapy than in patients undergoing surgery alone (median recurrence-free survival, 1.3 years vs 0.7 years; P = .018). Overall survival was not significantly different between the three treatment approaches.

CONCLUSION

Posthepatectomy but not prehepatectomy chemotherapy prolongs the time to recurrence after curative-intent resection of CLM.

Locoregional treatment for colorectal liver metastases aiming for precision medicine

In patients with colorectal liver metastases (CLM), surgery is potentially curative. The use of novel surgical techniques and complementary percutaneous ablation allows for curative-intent treatment even in marginally resectable cases. Resection is used as part of a multidisciplinary approach, which for nearly all patients will include perioperative chemotherapy. Small CLM can be treated with parenchymal-sparing hepatectomy (PSH) and/or ablation. For small CLM, PSH results in better survival and higher rates of resectability of recurrent CLM than non-PSH. For patients with extensive bilateral distribution of CLM, two-stage hepatectomy or fast-track two-stage hepatectomy is effective. Our increasing knowledge of genetic alterations allows us to use them as prognostic factors alongside traditional risk factors (e.g. tumor diameter and tumor number) to select patients with CLM for resection and guide surveillance after resection. Alteration in RAS family genes (hereafter referred to as "RAS alteration") is an important negative prognostic factor, as are alterations in the TP53, SMAD4, FBXW7, and BRAF genes. However, APC alteration appears to improve prognosis. RAS alteration, increased number and diameter of CLM, and primary lymph node metastasis are well-known risk factors for recurrence after CLM resection. In patients free of recurrence 2 y after CLM resection, only RAS alteration is associated with recurrence. Thus, surveillance intensity can be stratified by RAS alteration status after 2 y. Novel diagnostic instruments and tools, such as circulating tumor DNA, may lead to further evolution of patient selection, prognostication, and treatment algorithms for CLM.

Survival improvement for patients with metastatic colorectal cancer over twenty years

Over the past two decades of successive clinical trials in metastatic colorectal cancer (CRC), the median overall survival of both control and experimental arms has steadily improved. However, the incremental change in survival for metastatic CRC patients not treated on trial has not yet been quantified. We performed a retrospective review of 1420 patients with de novo metastatic CRC who received their primary treatment at the University of Texas M.D. Anderson Cancer Center (UTMDACC) from 2004 through 2019. Median OS was roughly stable for patients diagnosed between 2004 and 2012 (22.6 months) but since has steadily improved for those diagnosed in 2013 to 2015 (28.8 months), and 2016 to 2019 (32.4 months). Likewise, 5-year survival rate has increased from 15.7% for patients diagnosed from 2004 to 2006 to 26% for those diagnosed from 2013 to 2015. Notably, survival improved for patients with BRAFV600E mutant as well as microsatellite unstable (MSI-H) tumors. Multivariate regression analysis identified surgical resection of liver metastasis (HR = 0.26, 95% CI, 0.19-0.37), use of immunotherapy (HR = 0.44, 95% CI, 0.29-0.67) and use of third line chemotherapy (regorafenib or trifluridine/tipiracil, HR = 0.74, 95% CI, 0.58-0.95), but not year of diagnosis (HR = 0.99, 95% CI, 0.98-1), as associated with better survival, suggesting that increased use of these therapies are the drivers of the observed improvement in survival.

Histopathological Growth Pattern in Colorectal Liver Metastasis and The Tumor Immune Microenvironment

Almost half of all patients with colorectal cancer present with or eventually develop metastasis, most frequently in the liver. Understanding the histopathological growth patterns and tumor immune microenvironment of colorectal liver metastases may help determine treatment strategies and assess prognosis. A literature search was conducted to gather information on cancer biology, histopathological growth patterns, and the tumor immune microenvironment in colorectal liver metastases, including their mechanisms and their impact on clinical outcomes. A first consensus on histopathological growth patterns emerged in 2017, identifying five growth patterns. Later studies found benefits from a two-tier system, desmoplastic and non-desmoplastic, incorporated into the updated 2022 consensus. Furthermore, the tumor immune microenvironment shows additional characteristic features with relevance to cancer biology. This includes density of T-cells (CD8+), expression of claudin-2, presence of vessel co-option versus angiogenesis, as well as several other factors. The relation between histopathological growth patterns and the tumor immune microenvironment delineates distinct subtypes of cancer biology. The distinct subtypes are found to correlate with risk of metastasis or relapse, and hence to clinical outcome and long-term survival in each patient. In order to optimize personalized and precision therapy for patients with colorectal liver metastases, further investigation into the mechanisms of cancer biology and their translational aspects to novel treatment targets is warranted.

Oncological outcomes of neoadjuvant chemotherapy in patients with resectable synchronous colorectal liver metastasis: A result from a propensity score matching study

Background

The efficacy and safety of neoadjuvant chemotherapy (NAC) in treating resectable synchronous colorectal liver metastases (CRLM) remain controversial.

Methods

Data from CRLM patients who underwent simultaneous liver resection between January 2015 and December 2019 were collected from the Surveillance, Epidemiology, and End Results (SEER) database (SEER cohort, n=305) and a single Chinese Cancer Center (NCC cohort, n=268). Using a 1:2 ratio of propensity score matching (PSM), the prognostic impact of NAC for patients who underwent NAC before surgical treatment and patients who underwent surgical treatment alone was evaluated.

Results

After PSM, there was no significant difference in overall survival (OS) between patients receiving NAC prior to CRLM resection and those undergoing surgery only, in both the NCC and SEER cohorts (each P > 0.05). Age was an independent predictor of OS only in the SEER cohort (P = 0.040), while the pN stage was an independent predictor for OS only in the NCC cohort (P = 0.002). Furthermore, Disease-free survival (DFS) was comparable between the two groups in the NCC cohort. In a subgroup analysis, the DFS and OS in the NAC- group were significantly worse than those in the NAC+ group for patients with more than two liver metastases in the NCC cohort (P < 0.05 for both).

Conclusion

NAC did not have a significant prognostic impact in patients with resectable synchronous CRLM. However, patients with more than two liver metastases could be good candidates for receiving NAC.

Surgery combined with intra-operative microwaves ablation for the management of colorectal cancer liver metastasis: A case-matched analysis and evaluation of recurrences

Background

Hepatic resection is the only chance of cure for a subgroup of patients with colorectal cancer liver metastasis. As the oncologic outcomes of intra-operative microwaves ablation combined with hepatic resection still remain uncertain in this setting, we aimed to compare this approach with surgery alone in patient's candidate to metastases resection with radical intent.

Methods

Using a case-matched methodology based on age, gender, American Society of Anesthesiology score, Body Mass Index, and burden that take in consideration the number and maximum size of lesions, 20 patients undergoing hepatic resection plus intra-operative microwaves (SURG + IMW group) and 20 patients undergoing hepatic resection alone (SURG group), were included. Relapse-free Survival and post-resection Overall Survival were compared between patients of two groups.

Results

At the median follow up of 22.4 ± 17.8, 12/20 patients (60%) in SURG +IMW group and 13/20 patients (65%) in the SURG group experienced liver metastasis recurrence (p=0.774). None of them had recurrence at the same surgical or ablation site of the first hepatic treatment. 7/12 patients in the SURG+IMW group and 7/13 patients in the SURG group underwent at least one further surgical treatment after relapse (p = 1.000). No difference was reported between the two groups in terms of Relapse-free Survival (p = 0.685) and post-resection Overall Survival (p = 0.151). The use of intra-operative microwaves was not an independent factor affecting Relapse-free Survival and post-resection Overall Survival at univariate and multivariate analysis.

Conclusions

Patients with colorectal cancer liver metastasis undergoing surgery plus intra-operative microwaves have similar post-operative results compared with surgery alone group. The choice between the two approaches could be only technical, depending on the site, number, and volume of the metastases. This approach could also be used in patients with liver metastasis relapse who have already undergone hepatic surgery.

Survival Study: International Multicentric Minimally Invasive Liver Resection for Colorectal Liver Metastases (SIMMILR-2)

Introduction: Study: International Multicentric Minimally Invasive Liver Resection for Colorectal Liver Metastases (SIMMILR-CRLM) was a propensity score matched (PSM) study that reported short-term outcomes of patients with CRLM who met the Milan criteria and underwent either open (OLR), laparoscopic (LLR) or robotic liver resection (RLR). This study, designated as SIMMILR-2, reports the long-term outcomes from that initial study, now referred to as SIMMILR-1. Methods: Data regarding neoadjuvant chemotherapeutic (NC) and neoadjuvant biological (NB) treatments received were collected, and Kaplan−Meier curves reporting the 5-year overall (OS) and recurrence-free survival (RFS) for OLR, LLR and RLR were created for patients who presented with synchronous lesions only, as there was insufficient follow-up for patients with metachronous lesions. Results: A total of 73% of patients received NC and 38% received NB in the OLR group compared to 70% and 28% in the LLR group, respectively (p = 0.5 and p = 0.08). A total of 82% of patients received NC and 40% received NB in the OLR group compared to 86% and 32% in the RLR group, respectively (p > 0.05). A total of 71% of patients received NC and 53% received NB in the LLR group compared to 71% and 47% in the RLR group, respectively (p > 0.05). OS at 5 years was 34.8% after OLR compared to 37.1% after LLR (p = 0.4), 34.3% after OLR compared to 46.9% after RLR (p = 0.4) and 30.3% after LLR compared to 46.9% after RLR (p = 0.9). RFS at 5 years was 12.1% after OLR compared to 20.7% after LLR (p = 0.6), 33.3% after OLR compared to 26.3% after RLR (p = 0.6) and 22.7% after LLR compared to 34.6% after RLR (p = 0.6). Conclusions: When comparing OLR, LLR and RLR, the OS and RFS were all similar after utilization of the Milan criteria and PSM. Biological agents tended to be utilized more in the OLR group when compared to the LLR group, suggesting that highly aggressive tumors are still managed through an open approach.

Prognostic significance of intrahepatic lymphatic invasion in colorectal liver metastases

BACKGROUND

Intrahepatic lymphatic invasion is an adverse prognostic factor after hepatectomy for colorectal liver metastases (CLMs). However, most patients in previous reports had liver resection before the era of FOLFOX/FIRI-based chemotherapy.

METHODS

Forty-six patients who underwent hepatectomy for CLMs from 2004 to 2020 were evaluated. We histologically evaluated portal invasion, intrahepatic lymphatic invasion, and biliary invasion on hematoxylin-eosin slides. We also collected the following clinicopathologic factors: gender, age, timing, the number and maximum size of CLMs, preoperative tumor markers, neutrophil/lymphocyte ratio, location, and lymph node metastases of primary cancer, and chemotherapy after hepatectomy. A multivariate Cox proportional hazard model was used to define the relationship between overall (OS) or disease-free survival (DFS) and clinicopathologic factors.

RESULTS

Histological invasions were portal invasion in 8 (17.4 %), intrahepatic lymphatic invasion in 6 (13.0 %), and biliary invasion in 5 (10.9 %). Chemotherapy for recurrence after hepatectomy (n = 29) was performed in 22 and 14 of those who received FOLFOX/FIRI-based chemotherapy. By multivariate analysis, the number of CLMs (p < 0. 01) and presence of intrahepatic lymphatic invasion (p = 0.02) were independent predictors of recurrence. The number of CLMs (p = 0.02) and prehepatectomy carcinoembryonic antigen level (p = 0.02), but not intrahepatic lymphatic invasion (p = 0.18), were independent predictors of survival using multivariate analysis.

CONCLUSIONS

The presence of intrahepatic lymphatic invasion adversely affected patient's DFS, but not OS in patients with CLMs in the era of FOLFOX/FIRI chemotherapy. FOLFOX/FIRI-based chemotherapy might improve OS, even in patients with positive intrahepatic lymphatic invasion.

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.

Machine Learning Approach to Stratifying Prognosis Relative to Tumor Burden after Resection of Colorectal Liver Metastases: An International Cohort Analysis

BACKGROUND

Assessing overall tumor burden on the basis of tumor number and size may assist in prognostic stratification of patients after resection of colorectal liver metastases (CRLM). We sought to define the prognostic accuracy of tumor burden by using machine learning (ML) algorithms compared with other commonly used prognostic scoring systems.

STUDY DESIGN

Patients who underwent hepatectomy for CRLM between 2001 and 2018 were identified from a multi-institutional database and split into training and validation cohorts. ML was used to define tumor burden (ML-TB) based on CRLM tumor number and size thresholds associated with 5-year overall survival. Prognostic ability of ML-TB was compared with the Fong and Genetic and Morphological Evaluation scores using Cohen's d.

RESULTS

Among 1,344 patients who underwent resection of CRLM, median tumor number (2, interquartile range 1 to 3) and size (3 cm, interquartile range 2.0 to 5.0) were comparable in the training (n = 672) vs validation (n = 672) cohorts; patient age (training 60.8 vs validation 61.0) and preoperative CEA (training 10.2 ng/mL vs validation 8.3 ng/mL) was also similar (p > 0.05). ML empirically derived optimal cutoff thresholds for number of lesions (3) and size of the largest lesion (1.3 cm) in the training cohort, which were then used to categorize patients in the validation cohort into 3 prognostic groups. Patients with low, average, or high ML-TB had markedly different 5-year overall survival (51.6%, 40.9%, and 23.1%, respectively; p < 0.001). ML-TB was more effective at stratifying patients relative to 5-year overall survival (low vs high ML-TB, d = 2.73) vs the Fong clinical (d = 1.61) or Genetic and Morphological Evaluation (d = 0.84) scores.

CONCLUSIONS

Using a large international cohort, ML was able to stratify patients into 3 distinct prognostic categories based on overall tumor burden. ML-TB was noted to be superior to other CRLM prognostic scoring systems.

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.

Improved Survival over Time After Resection of Colorectal Liver Metastases and Clinical Impact of Multigene Alteration Testing in Patients with Metastatic Colorectal Cancer

BACKGROUND

The past 20 years have seen advances in colorectal cancer management. We sought to determine whether survival in patients undergoing resection of colorectal liver metastases (CLM) has improved in association with three landmark advances: introduction of irinotecan- and/or oxaliplatin-containing regimens, molecular targeted therapy, and multigene alteration testing.

METHODS

Patients undergoing CLM resection during 1998-2014 were identified and grouped by resection year. The influence of alterations in RAS, TP53, and SMAD4 was evaluated and validated in an external cohort including patients with unresectable metastatic colorectal cancer.

RESULTS

Of 1961 patients, 1599 met the inclusion criteria. Irinotecan- and/or oxaliplatin-containing regimens and molecular targeted therapy were used for more than 50% of patients starting in 2001 and starting in 2006, respectively, so patients were grouped as undergoing resection during 1998-2000, 2001-2005, or 2006-2014. Liver resectability indications expanded over time. The 5-year overall survival (OS) rate was significantly better in 2006-2014, vs. 2001-2005 (56.5% vs. 44.1%, P < 0.001). RAS alteration was associated with worse 5-year OS than RAS wild-type (44.8% vs. 63.3%, P < 0.001). However, OS did not differ significantly between patients with RAS alteration and wild-type TP53 and SMAD4 and patients with RAS wild-type in our cohort (P = 0.899) or the external cohort (P = 0.932). Of 312 patients with genetic sequencing data, 178 (57.1%) had clinically actionable alterations.

CONCLUSION

OS after CLM resection has improved with advances in medical therapy and surgical technique. Multigene alteration testing is useful for prognostication and identification of potential therapeutic targets.

Implications of RAS Mutations on Oncological Outcomes of Surgical Resection and Thermal Ablation Techniques in the Treatment of Colorectal Liver Metastases

Colorectal cancer (CRC) is the third most common cancer worldwide and the second leading cause of cancer-related death. More than 50% of patients with CRC will develop liver metastases (CRLM) during their disease. In the era of precision surgery for CRLM, several advances have been made in the multimodal management of this disease. Surgical treatment, combined with a modern chemotherapy regimen and targeted therapies, is the only potential curative treatment. Unfortunately, 70% of patients treated for CRLM experience recurrence. RAS mutations are associated with worse overall and recurrence-free survival. Other mutations such as BRAF, associated RAS /TP53 and APC/PIK3CA mutations are important genetic markers to evaluate tumor biology. Somatic mutations are of paramount interest for tailoring preoperative treatment, defining a surgical resection strategy and the indication for ablation techniques. Herein, the most relevant studies dealing with RAS mutations and the management of CRLM were reviewed. Controversies about the implication of this mutation in surgical and ablative treatments were also discussed.

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 [...].

Effect of Diameter and Number of Hepatocellular Carcinomas on Survival After Resection, Transarterial Chemoembolization, and Ablation

INTRODUCTION

Most studies predicting survival after resection, transarterial chemoembolization (TACE), and ablation analyzed diameter and number of hepatocellular carcinomas (HCCs) as dichotomous variables, resulting in an underestimation of risk variation. We aimed to develop and validate a new prognostic model for patients with HCC using largest diameter and number of HCCs as continuous variables.

METHODS

The prognostic model was developed using data from patients undergoing resection, TACE, and ablation in 645 Japanese institutions. The model results were shown after balanced using the inverse probability of treatment-weighted analysis and were externally validated in an international multi-institution cohort.

RESULTS

Of 77,268 patients, 43,904 patients, including 15,313 (34.9%) undergoing liver resection, 13,375 (30.5%) undergoing TACE, and 15,216 (34.7%) undergoing ablation, met the inclusion criteria. Our model (http://www.u-tokyo-hbp-transplant-surgery.jp/about/calculation.html) showed that the 5-year overall survival (OS) in patients with HCC undergoing these procedures decreased with progressive incremental increases in diameter and number of HCCs. For patients undergoing resection, the inverse probability of treatment-weighted-adjusted 5-year OS probabilities were 10%-20% higher compared with patients undergoing TACE for 1-6 HCC lesions <10 cm and were also 10%-20% higher compared with patients undergoing ablation when the HCC diameter was 2-3 cm. For patients undergoing resection and TACE, the model performed well in the external cohort.

DISCUSSION

Our novel prognostic model performed well in predicting OS after resection and TACE for HCC and demonstrated that resection may have a survival benefit over TACE and ablation based on the diameter and number of HCCs.

Liver transplantation for advanced liver-only colorectal metastases

Liver transplantation provided a 5-year overall survival rate of 100 per cent in patients with colorectal cancer who had undergone liver resection previously. Patients with extensive liver metastases (over 20 lesions) and a left-sided primary tumour had long survival, whereas those with an ascending colonic primary tumour had inferior survival after liver transplantation.

Genomic Sequencing and Insight into Clinical Heterogeneity and Prognostic Pathway Genes in Patients with Metastatic Colorectal Cancer

BACKGROUND

An understanding of signaling pathways has not been fully incorporated into prognostication and therapeutic options. We evaluated the hypothesis that information about cancer-related signaling pathways can improve prognostic stratification and explain some of the clinical heterogeneity in patients with metastatic colorectal cancer.

STUDY DESIGN

We analyzed prognostic relevance of signaling pathways in patients undergoing resection of colorectal liver metastases (CLM) from 2004-2017, and clinical actionability of gene alterations in 7 signaling pathways: p53, Wnt, RTK-RAS, PI3K, TGFβ, Notch, and cell cycle. To assess the wide applicability, the results were validated in an external retrospective cohort including patients with unresectable metastatic colorectal cancer.

RESULTS

Of 579 patients, the numbers of patients with pathway alterations were as follows: p53, n = 420 (72.5%); Wnt, 340 (58.7%); RTK-RAS, 333 (57.5%); PI3K, 110 (19.0%); TGFβ, 65 (11.2%); Notch, 41 (7.1%); and cell cycle, 15 (2.6%). More than 80% of alterations in each pathway occurred in a single predominant gene TP53, APC, KRAS, PIK3CA, FBXW7, and RB1 in p53, Wnt, RTK-RAS, PI3K, Notch, and cell cycle pathways, respectively. Alterations of 4 pathways (p53, RTK-RAS, TGFβ, and Notch) and corresponding predominant genes (TP53, RAS/BRAF, SMAD4, and FBXW7) were significantly associated with worse overall survival (OS), and alterations of Wnt pathway (APC) were associated with better OS in the median follow-up duration of 3.8 years. Similarly, in the external cohort, alterations of p53 (TP53) and RTK-RAS (RAS/BRAF) were significantly associated with worse OS, whereas alteration of Wnt (APC) was associated with better OS in the median follow-up duration of 2.6 years.

CONCLUSIONS

Genomic sequencing provides insights into clinical heterogeneity and permits finer prognostic stratification in patients with metastatic colorectal cancer.