Tumor Biology Rather Than Surgical Technique Dictates Prognosis in Colorectal Cancer Liver Metastases

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.

Is Precision Surgery Applicable to Colorectal Liver Metastases? A Systematic Review and Meta-analysis of Studies that Investigate the Association of Surgical Technique with Outcomes in the Context of Distinct Tumor Biology

BACKGROUND

Although some data suggest that patients with mutRAS colorectal liver metastases (CRLM) may benefit from anatomic hepatectomy, this topic remains controversial. We performed a systematic review and meta-analysis to determine whether RAS mutation status was associated with prognosis relative to surgical technique [anatomic resection (AR) vs. nonanatomic resection (NAR)] among patients with CRLM.

PATIENTS AND METHODS

A systematic review and meta-analysis of studies were performed to investigate the association of AR versus NAR with overall and liver-specific disease-free survival (DFS and liver-specific DFS, respectively) in the context of RAS mutation status.

RESULTS

Overall, 2018 patients (831 mutRAS vs. 1187 wtRAS) were included from five eligible studies. AR was associated with a 40% improvement in liver-specific DFS [hazard ratio (HR) = 0.6, 95% confidence interval (CI) 0.44-0.81, p = 0.01] and a 28% improvement in overall DFS (HR = 0.72, 95% CI 0.54-0.95, p = 0.02) among patients with mutRAS tumors; in contrast, AR was not associated with any improvement in liver-specific DFS or overall DFS among wtRAS patients. These differences may have been mediated by the 40% decreased incidence in R1 resection among patients with mutRAS tumors who underwent AR versus NAR [relative risk (RR): 0.6, 95% CI 0.40-0.91, p = 0.02]. In contrast, the probability of an R1 resection was not decreased among wtRAS patients who underwent AR versus NAR (RR: 0.93, 95% CI 0.69-1.25, p = 0.62).

CONCLUSIONS

The data suggest that precision surgery may be relevant to CRLM. Specifically, rather than a parenchymal sparing dogma for all patients, AR may have a role in individuals with mutRAS tumors.

Multimodal Management of Colorectal Liver Metastases: State of the Art

Liver is the most common site of colorectal cancer (CRC) metastases. Treatment of CRC liver metastases (CRLM) includes different strategies, prevalently based on the clinical and oncological intent. Valid approaches in liver-limited or liver-prevalent disease include surgery, percutaneous ablative procedures (radiofrequency ablation, microwave ablation), intra-arterial perfusional techniques (chemo-embolization, radio-embolization) as well as stereotactic radiotherapy. Systemic treatments, including chemotherapy, immunotherapy and other biological agents, are the only options for patients with no chance of locoregional approaches. The use of chemotherapy in other settings, such as neoadjuvant, adjuvant or conversion therapy of CRLM, is commonly accepted in the clinical practice, although data from several clinical trials have been mostly inconclusive. The optimal integration of all these strategies, when applicable and clinically indicated, should be ever considered in patients affected by CRLM based on clinical evidence and multidisciplinary experience. Here we revised in detail all the possible therapeutic approaches of CRLM focusing on the current evidences, the studies still in progress and the often contradictory data.

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.

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.

Colorectal cancer hepatic metastases resection margins outcomes: a single-centre retrospective cohort study

Background

Surgical resection is the most efficient treatment for isolated colorectal cancer hepatic metastases. Among the known prognostic factors of this procedure, the impact of the resection margin width is still a controversial matter in the literature.

Methods

A retrospective cohort study was performed including 170 patients who underwent surgical resection of colorectal cancer liver metastases (CRLMs) between 2006 and 2016 in our hepatobiliary unit. Resection margin width was determined histologically by measuring the distance from the tumour in millimetres or centimetres. Patients' clinical characteristics were also collected. Patients were then stratified in two tumour margin groups: below 5 mm (group A) and equal to or above 5 mm (group B). Overall survival (OS) and disease-free survival (DFS) were the primary outcomes.

Results

Kaplan-Meier curves showed significantly better outcomes for cases having resection margins above 5 mm for both DFS with 1508.7 days (range 1151.2-1866.2) in group A, compared to 2463.9 days (range 2021.3-2906.5) in group B (P=0.049), and OS with 1557.8 days (range 1276.3-1839.3) for group A and 2303.8 days (range 1921.2--2686.4) for group B (P=0.020). This survival benefit was not significant for patients presenting with stage IV CRC at diagnosis or cases where extended (7+ segments) resections were performed.

Conclusion

Five-millimetre margins provide a significant survival advantage and should be aimed for in the treatment of CRLMs. Further research on the cause for this finding, including tumour biology's impact on survival, is required.

Combining Radiofrequency Ablation with Hepatic Resection for Liver-Only Colorectal Metastases: A Propensity-Score Based Analysis of Long-Term Outcomes

BACKGROUND

Combining liver resection (LR) with radiofrequency ablation (RFA) is nowadays an accepted option for treating colorectal liver metastases (CRLMs), but the number of lesions ablated is regularly described as a recurrence risk factor. In this study, we report our experience and determine the impact of RFA on long-term outcomes.

METHOD

This is a retrospective study including patients undergoing LR with or without RFA for CRLM. All variables influencing disease-free survival (DFS) and disease-specific survival (DSS) were examined through a Cox regression analysis before and after propensity-score matching (PSM).

RESULTS

Among the 128 patients included, 71 (55.5%) underwent LR alone and 57 (44.5%) underwent LR+RFA. With univariate analysis, LR+RFA showed a significantly worse DFS than LR alone (p = 0.028), which was not confirmed after PSM (p = 0.064). Thermal ablation did not influence DSS before or after matching (p = 0.282 and p = 0.189). When analyzing the subgroups of patients according to number of RFAs performed, no difference in long-term outcomes was observed (after PSM: p = 0.192 for DFS and p = 0.624 for DSS). Analysis of site of recurrence revealed that neither performing an RFA (p = 0.893) nor the number of lesions ablated (p = 0.093, p = 0.550, and p = 0.087 for 1, 2, and ≥ 2 RFAs) were associated with an increased risk of liver-only relapse.

DISCUSSION

In the setting of a parenchymal sparing strategy, combining RFA with LR is safe in terms of oncological outcomes. Tumor burden, rather than RFA performed, independently influences risk of recurrence and patient survival.

Prognostic impact of R1 resection margin in synchronous and simultaneous colorectal liver metastasis resection: a retrospective cohort study

BACKGROUND

A margin ≥ 1 mm is considered a standard resection margin for colorectal liver metastasis (CRLM). However, microscopic incomplete resection (R1) is not rare since aggressive surgical resection has been attempted in multiple and bilobar CRLM. This study aimed to investigate the prognostic impact of resection margins and perioperative chemotherapy in patients with CRLM.

METHODS

A total of 368 of 371 patients who underwent simultaneous colorectal and liver resection for synchronous CRLM between 2006 and June 2017, excluding three R2 resections, were included in this study. R1 resection was defined as either abutting tumor on the resection line or involved margin in the pathological report. The patients were divided into R0 (n = 304) and R1 (n = 64) groups. The clinicopathological characteristics, overall survival, and intrahepatic recurrence-free survival were compared between the two groups using propensity score matching.

RESULTS

The R1 group had more patients with ≥ 4 liver lesions (27.3 vs. 50.0%, P < 0.001), higher mean tumor burden score (4.4 vs. 5.8%, P = 0.003), and more bilobar disease (38.8 vs. 67.2%, P < 0.001) than the R0 group. Both R0 and R1 groups showed similar long-term outcomes in the total cohort (OS, P = 0.149; RFS, P = 0.414) and after matching (OS, P = 0.097, RFS: P = 0.924). However, the marginal recurrence rate was higher in the R1 group than in the R0 group (26.6 vs. 16.1%, P = 0.048). Furthermore, the resection margin did not have a significant impact on OS and RFS, regardless of preoperative chemotherapy. Poorly differentiated, N-positive stage colorectal cancer, liver lesion number ≥ 4, and size ≥ 5 cm were poor prognostic factors, and adjuvant chemotherapy had a positive impact on survival.

CONCLUSIONS

The R1 group was associated with aggressive tumor characteristics; however, no effect on the OS and intrahepatic RFS with or without preoperative chemotherapy was observed in this study. Tumor biological characteristics, rather than resection margin status, determine long-term prognosis. Therefore, aggressive surgical resection should be considered in patients with CRLM expected to undergo R1 resection in this multidisciplinary approach era.

Precision Surgery of Colorectal Liver Metastases in the Current Era: A Systematic Review

Liver resection for colorectal liver metastases (CRLM) is widely considered the treatment with the highest curative potential. However, not all patients derive the same oncological benefit, underlining the need for better patient stratification and treatment allocation. In this context, we performed a systematic review of the literature to determine the role of RAS status in selecting the optimal surgical strategy. Evidence comparing anatomical with non-anatomical resections depending on RAS mutational status was scarce and conflicting, with two studies reporting superiority in mutated RAS (mutRAS) patients and two studies reporting equivalent outcomes. The rate of incomplete microscopic resection (R1) was found to be increased among mutRAS patients, possibly due to higher micrometastatic spread lateral to the primary lesion. The impact of R1 resection margins was evaluated separately for mutRAS and wild-type patients in three studies, of which, two indicated an additive detriment to long-term survival in the former group. In the current era of precision surgery, RAS status can be utilized to predict the efficacy of liver resection in the treatment of CRLM, avoiding a potentially morbid operation in patients with adverse tumor profiles.

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

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

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.

Colorectal Cancer Liver Metastases: Is an R1 Hepatic Resection Accepted?

Metastatic colorectal cancer is associated with a rather dismal 5-year overall survival. The liver is the most commonly affected organ. Improved 5-year survival rates after successful hepatic resections for metastases confined to the liver have been reported. Certainly, a hepatectomy that results in an incomplete tumor resection, in terms of leaving macroscopic residual tumor in the future liver remnant, is not associated with survival benefits. However, the prognostic implications of a microscopically positive surgical margin or a clear margin of less than 1 mm (R1) on pathology are debatable. Although it has been a field of extensive research, the relevant literature often reports contradictory results. The purpose of the present study was to define, assess the risk factors for, and, ultimately, analyze the effect that an R1 hepatic resection for colorectal cancer liver metastases might have on local recurrence rates and long-term prognosis by reviewing the relevant literature. Achieving an R0 hepatic resection, optimally with more than 1 mm of clear margin, should always be the goal. However, in the era of the aggressive multimodality treatment of liver metastatic colorectal cancer, an R1 resection might be the cost of increasing the pool of patients finally eligible for resection. The majority of literature reports have highlighted the detrimental effect of R1 resections on local recurrence and overall survival. However, there are indeed studies that degraded the prognostic handicap as a consequence of an R1 resection in selected patients and highlighted the presence of RAS mutations, the response to chemotherapy, and, in general, factors that reflect the biology of the disease as important, if not the determinant, prognostic factors. In these patients, the aggressive disease biology seems to outperform the resection margin status as a prognostic factor, and the recorded differences between R1 and R0 resections are equalized. Properly and accurately defining this patient group is a future challenge in the field of the surgical treatment of colorectal cancer liver metastases.

Using Artificial Intelligence to Find the Optimal Margin Width in Hepatectomy for Colorectal Cancer Liver Metastases

Importance

In patients with resectable colorectal cancer liver metastases (CRLM), the choice of surgical technique and resection margin are the only variables that are under the surgeon's direct control and may influence oncologic outcomes. There is currently no consensus on the optimal margin width.

Objective

To determine the optimal margin width in CRLM by using artificial intelligence-based techniques developed by the Massachusetts Institute of Technology and to assess whether optimal margin width should be individualized based on patient characteristics.

Design, Setting, and Participants

The internal cohort of the study included patients who underwent curative-intent surgery for KRAS-variant CRLM between January 1, 2000, and December 31, 2017, at Johns Hopkins Hospital, Baltimore, Maryland, Memorial Sloan Kettering Cancer Center, New York, New York, and Charité-University of Berlin, Berlin, Germany. Patients from institutions in France, Norway, the US, Austria, Argentina, and Japan were retrospectively identified from institutional databases and formed the external cohort of the study. Data were analyzed from April 15, 2019, to November 11, 2021.

Exposures

Hepatectomy.

Main Outcomes and Measures

Patients with KRAS-variant CRLM who underwent surgery between 2000 and 2017 at 3 tertiary centers formed the internal cohort (training and testing). In the training cohort, an artificial intelligence-based technique called optimal policy trees (OPTs) was used by building on random forest (RF) predictive models to infer the margin width associated with the maximal decrease in death probability for a given patient (ie, optimal margin width). The RF component was validated by calculating its area under the curve (AUC) in the testing cohort, whereas the OPT component was validated by a game theory-based approach called Shapley additive explanations (SHAP). Patients from international institutions formed an external validation cohort, and a new RF model was trained to externally validate the OPT-based optimal margin values.

Results

This cohort study included a total of 1843 patients (internal cohort, 965; external cohort, 878). The internal cohort included 386 patients (median [IQR] age, 58.3 [49.0-68.7] years; 200 men [51.8%]) with KRAS-variant tumors. The AUC of the RF counterfactual model was 0.76 in both the internal training and testing cohorts, which is the highest ever reported. The recommended optimal margin widths for patient subgroups A, B, C, and D were 6, 7, 12, and 7 mm, respectively. The SHAP analysis largely confirmed this by suggesting 6 to 7 mm for subgroup A, 7 mm for subgroup B, 7 to 8 mm for subgroup C, and 7 mm for subgroup D. The external cohort included 375 patients (median [IQR] age, 61.0 [53.0-70.0] years; 218 men [58.1%]) with KRAS-variant tumors. The new RF model had an AUC of 0.78, which allowed for a reliable external validation of the OPT-based optimal margin. The external validation was successful as it confirmed the association of the optimal margin width of 7 mm with a considerable prolongation of survival in the external cohort.

Conclusions and Relevance

This cohort study used artificial intelligence-based methodologies to provide a possible resolution to the long-standing debate on optimal margin width in CRLM.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Prognostic factors of survival and a new scoring system for liver resection of colorectal liver metastasis

BACKGROUND

Hepatic resection has become the preferred treatment of choice for colorectal liver metastasis (CLM) patients.

AIM

To identify the prognostic factors and to formulate a new scoring system for management of CLM.

METHODS

Clinicopathologic and long-term survival data were analyzed to identify the significant predictors of survival by univariate and multivariate analyses with the Cox model. A clinical score was constructed based on the analysis results.

RESULTS

Three factors of worse overall survival were identified in the multivariate analysis. They were number of liver metastases ≥ 5, size of the largest liver lesion ≥ 4 cm, and the presence of nodal metastasis from the primary tumor. These three factors were chosen as criteria for a clinical risk score for overall survival. The clinical score highly correlated with median overall survival and 5-year survival (P = 0.002).

CONCLUSION

Priority over surgical resection should be given to the lowest score groups, and alternative oncological treatment should be considered in patients with the highest score.

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 [...].

Not All Kirsten Rat Sarcoma Viral Oncogene Homolog Mutations Predict Poor Survival in Patients With Unresectable Colorectal Liver Metastasis

Objective: To assess the characteristics of Kirsten rat sarcoma viral oncogene homolog (KRAS) mutations and investigated whether all KRAS mutations predict poor prognosis in patients with unresectable colorectal liver metastasis (CRLM). Methods: Correlations between KRAS-mutation status and clinicopathological characteristics of 93 patients with unresectable CRLM at our institution between 2010 and 2018 were retrospectively analyzed. Kaplan–Meier and Cox proportional hazard models were used to evaluate the prognostic significance of KRAS mutations. Results:KRAS were primarily single-point mutations, identified in 41.9% of patients. There were no significant differences in clinicopathological characteristics between wild-type KRAS and mutant KRAS. Patients with mutant KRAS had significantly worse overall survival (OS) and progression-free survival (PFS) than those with wild-type KRAS. Moreover, patients with codon 12 mutations had worse OS and PFS than those with wild-type KRAS, whereas mutations in codon 13 were not associated with a worse prognosis. Among the 5 most common mutations in codons 12, G12V, and G12D were associated with worse OS, furthermore, G12C mutation seemed to associated with worse PFS than patients with wild-type KRAS. Conclusion:KRAS codon 12 mutations were predictive for a poor prognosis in patients with unresectable CRLM. G12D and G12V mutations were associated with worse OS, whereas G12C mutation seemed to be associated with decreased PFS.

Mutant KRAS as a prognostic biomarker after hepatectomy for rectal cancer metastases: Does the primary disease site matter?

BACKGROUND

The prognostic implication of mutant KRAS (mKRAS) among patients with primary disease in the rectum remains unknown.

METHODS

From 2000 to 2018, patients undergoing hepatectomy for colorectal liver metastases at 10 collaborating international institutions with documented KRAS status were surveyed.

RESULTS

A total of 834 (65.8%) patients with primary colon cancer and 434 (34.2%) patients with primary rectal cancer were included. In patients with primary colon cancer, mKRAS served as a reliable prognostic biomarker of poor overall survival (OS) (hazard ratio [HR]: 1.58, 95% CI 1.28-1.95) in the multivariable analysis. Although a trend towards significance was noted, mKRAS was not found to be an independent predictor of OS in patients with primary rectal tumors (HR 1.34, 95% CI 0.98-1.80). For colon cancer, the specific codon impacted in mKRAS appears to reflect underlying disease biology and oncologic outcomes, with codon 13 being associated with particularly poor OS in patients with left-sided tumors (codon 12, HR 1.56, 95% CI 1.22-1.99; codon 13, HR 2.10 95% CI 1.43-3.08;). Stratifying the rectal patient population by codon mutation did not confer prognostic significance following hepatectomy.

CONCLUSIONS

While the left-sided colonic disease is frequently grouped with rectal disease, our analysis suggests that there exist fundamental biologic differences that drive disparate outcomes. Although there was a trend toward significance of KRAS mutations for patients with primary rectal cancers, it failed to achieve statistical significance.

The prognostic impact of resection margin status varies according to the genetic and morphological evaluation (GAME) score for colorectal liver metastasis

BACKGROUND

Surgical margin status remains a controversial factor in predicting the outcome of colorectal liver metastases (CRLM) resection. Our study aims to evaluate the effects of surgical margins on oncologic outcomes with regard to the genetic and morphological evaluation (GAME) score.

METHODS

R1 resection was defined as having a less than 1 mm margin width. Patients who underwent surgery for CRLM from January 2005 to December 2018 were recruited. The patients were divided into two risk subgroups, namely, the low or medium risk (GAME 0-3) and high-risk (GAME score 4 or more) groups. The effects of margin status on overall survival (OS) and recurrence-free survival rate (RFS) were examined.

RESULTS

In total, 661 patients were recruited, among which 159 (24.1%) had R1 resection. Before hepatectomy, 514 patients showed a low or medium risk (R1 resection: n = 124), while 147 patients demonstrated a high risk (R1 resection: n = 35). In the whole cohort, multivariable analysis did show that R1 resection was associated with worse RFS and OS. While further research only found that in the low or medium risk group, R1 resection was related to poor OS and RFS. Meanwhile, in the high risk group, no significant difference was found in the median OS and RFS among patients with R0 or R1 resection.

CONCLUSION

The prognostic role of margin status varied according to the GAME score. Margin clearance only improved survival rates in patients with low or medium GAME score. In contrast, R1 resection demonstrated similar oncologic outcomes with R0 resection in patients with high GAME score.

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.

Prognostic Impact of Pedicle Clamping during Liver Resection for Colorectal Metastases

Pedicle clamping (PC) during liver resection for colorectal metastases (CRLM) is used to reduce blood loss and allogeneic blood transfusion (ABT). The effect on long-term oncologic outcomes is still under debate. A retrospective analysis of the impact of PC on ABT-demand regarding overall (OS) and recurrence-free survival (RFS) in 336 patients undergoing curative resection for CRLM was carried out. Survival analysis was performed by both univariate and multivariate methods and propensity-score (PS) matching. PC was employed in 75 patients (22%). No increased postoperative morbidity was monitored. While the overall ABT-rate was comparable (35% vs. 37%, p = 0.786), a reduced demand for more than two ABT-units was observed (p = 0.046). PC-patients had better median OS (78 vs. 47 months, p = 0.005) and RFS (36 vs. 23 months, p = 0.006). Multivariate analysis revealed PC as an independent prognostic factor for OS (HR = 0.60; p = 0.009) and RFS (HR = 0.67; p = 0.017). For PC-patients, 1:2 PS-matching (N = 174) showed no differences in the overall ABT-rate compared to no-PC-patients (35% vs. 40%, p = 0.619), but a trend towards reduced transfusion requirement (>2 ABT-units: 9% vs. 21%, p = 0.052; >4 ABT-units: 2% vs. 11%, p = 0.037) and better survival (OS: 78 vs. 44 months, p = 0.088; RFS: 36 vs. 24 months; p = 0.029). Favorable long-term outcomes and lower rates of increased transfusion demand were observed in patients with PC undergoing resection for CRLM. Further prospective evaluation of potential oncologic benefits of PC in these patients may be meaningful.

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.

Colorectal liver metastases: Current management and future perspectives

The liver is the commonest site of metastatic disease for patients with colorectal cancer, with at least 25% developing colorectal liver metastases (CRLM) during the course of their illness. The management of CRLM has evolved into a complex field requiring input from experienced members of a multi-disciplinary team involving radiology (cross sectional, nuclear medicine and interventional), Oncology, Liver surgery, Colorectal surgery, and Histopathology. Patient management is based on assessment of sophisticated clinical, radiological and biomarker information. Despite incomplete evidence in this very heterogeneous patient group, maximising resection of CRLM using all available techniques remains a key objective and provides the best chance of long-term survival and cure. To this end, liver resection is maximised by the use of downsizing chemotherapy, optimisation of liver remnant by portal vein embolization, associating liver partition and portal vein ligation for staged hepatectomy, and combining resection with ablation, in the context of improvements in the functional assessment of the future remnant liver. Liver resection may safely be carried out laparoscopically or open, and synchronously with, or before, colorectal surgery in selected patients. For unresectable patients, treatment options including systemic chemotherapy, targeted biological agents, intra-arterial infusion or bead delivered chemotherapy, tumour ablation, stereotactic radiotherapy, and selective internal radiotherapy contribute to improve survival and may convert initially unresectable patients to operability. Currently evolving areas include biomarker characterisation of tumours, the development of novel systemic agents targeting specific oncogenic pathways, and the potential re-emergence of radical surgical options such as liver transplantation.

Prognostic factors differ according to KRAS mutational status: A classification and regression tree model to define prognostic groups after hepatectomy for colorectal liver metastasis

BACKGROUND

Although KRAS mutation status is known to affect the prognosis of patients with colorectal liver metastasis, the hierarchical association between other prognostic factors and KRAS status is not fully understood.

METHODS

Patients who underwent a hepatectomy for colorectal liver metastasis were identified in a multi-institutional international database. A classification and regression tree model was constructed to investigate the hierarchical association between prognostic factors and overall survival relative to KRAS status.

RESULTS

Among 1,123 patients, 29.9% (n = 336) had a KRAS mutation. Among wtKRAS patients, the classification and regression tree model identified presence of metastatic lymph nodes as the most important prognostic factor, whereas among mtKRAS patients, carcinoembryonic antigen level was identified as the most important prognostic factor. Among patients with wtKRAS, the highest 5-year overall survival (68.5%) was noted among patients with node negative primary colorectal cancer, solitary colorectal liver metastases, size <4.3 cm. In contrast, among patients with mtKRAS colorectal liver metastases, the highest 5-year overall survival (57.5%) was observed among patients with carcinoembryonic antigen <6 mg/mL. The classification and regression tree model had higher prognostic accuracy than the Fong score (wtKRAS [Akaike's Information Criterion]: classification and regression tree model 3334 vs Fong score 3341; mtKRAS [Akaike's Information Criterion]: classification and regression tree model 1356 vs Fong score 1396).

CONCLUSION

Machine learning methodology outperformed the traditional Fong clinical risk score and identified different factors, based on KRAS mutational status, as predictors of long-term prognosis.

Impact of resection margins for colorectal liver metastases in laparoscopic and open liver resection: a propensity score analysis

BACKGROUND

There is no clear consensus over the optimal width of resection margin for colorectal liver metastases (CRLM), with evolving definitions alongside the advances on the management of the disease. In addition, data on the impact of resection margin after laparoscopic liver resection are still scarce.

METHODS

Prospectively maintained databases of patients undergoing open or laparoscopic CRLM resection in 7 European tertiary hepatobiliary referral centres were reviewed. After propensity score matching (PSM), the influence of 1 mm and wider margins on OS and DFS were evaluated in open and laparoscopic cohorts.

RESULTS

After PSM, 648 patients were comparable in each group. The incidence of positive margins (< 1 mm) was similar in open and laparoscopic groups (17% vs 13%, p = 0,142). Margins < 1 mm were associated with shorter RFS in open (12 vs 26 months, p = 0.042) and in laparoscopic group (13 vs 23, p = 0,002). Margins < 1 mm were associated with shorter OS in open (36 vs 57 months, p = 0.027), but not in laparoscopic group (49 vs 60, p = 0,177). Subgroups with margins ≥ 1 mm (1-4 mm, 5-9 mm, ≥ 10 mm) presented similar RFS in open (p = 0,251) or laparoscopic cohorts (p = 0.117), as well as similar OS in open (p = 0.295) or laparoscopic cohorts (p = 0.908). In the presence of liver recurrence, repeat liver resection was performed in 70 (30%) patients in the open group and 88 (48%) in the laparoscopic group (p < 0.001).

CONCLUSIONS

Our study suggests that a positive resection margin (less than 1 mm) width does not impact OS after laparoscopic resection of CRLMs as it does in open liver resection. However, a positive margin continues to affect RFS in open and laparoscopic resection. Wider margins than 1 mm do not seem to improve oncological results in open or laparoscopic surgery.

Does KRAS mutation status impact the risk of local recurrence after R1 vascular resection for colorectal liver metastasis? An observational cohort study

INTRODUCTION

R0 margin is the standard in the surgical treatment of colorectal liver metastases (CLM). Recently R1 surgery, at least that enabling CLM vessel-detachment (R1vasc), seems comparable to R0. As a possible background of that biologic factors could play some role. Among them, KRAS has been investigated in the present study.

METHODS

Patients who underwent curative surgery for CLM between 2008 and 2016 were identified. R0, R1vasc and parenchymal R1 (R1par; tumor exposure once dissected from the parenchyma) resections with known KRAS status were analyzed.

RESULTS

Of 1000 resection areas in 340 patients, 654 (65%) R0, 98 (10%) R1vasc and 248 (25%) R1par. In mutated KRAS (mKRAS), local recurrence (LR) was similar between R0 and R1vasc (per-patient 4,8% vs. 2%, p = 0.628; per-area 2,1% vs. 1,9%, p = 0.940), while higher in R1par (per-patient 25,4% and per-area 19,5%; p < 0.001 for both). In wild-type KRAS (wtKRAS), R0 had less LR compared to R1vasc (per-patient 7,6% vs 14,6%, p = 0.335; per-area 3,1% vs 13,3%, p = 0.012) and R1par (per-patient 18,3%, p = 0.060; per-area 9,9%, p = 0.013). KRAS did not impact LR in R0 (per-patient 7,6% vs. 4,8%, p = 0.491; per-area 3,1% vs. 2,1%, p = 0.555), while wtKRAS R1par had less LR compared to mKRAS R1par (per-patient 18,3% vs 25,4%, p = 0.404; per-area 9,9% vs 19,5%, p = 0.048). Inversely, LR was increased in wtKRAS R1vasc compared to mKRAS R1vasc (per-patient 14,6% vs 2%, p = 0.043; per-area 13,3% vs 1,9%, p = 0.046).

CONCLUSION

KRAS status does not impact LR risk in R0 resection. Inversely, R1vasc vs R1par LR risk is reduced in mKRAS, and increased in wtKRAS. If confirmed these results are of note.

The impact of resection margin on overall survival for patients with colon cancer liver metastasis varied according to the primary cancer location

INTRODUCTION

Investigation into right and left-sided primary colon liver metastasis (CLM) has revealed differences in the tumor biology and prognosis. This indicates that preoperative and operative factors may affect outcomes of right-sided primary CLM differently than left. This retrospective analysis investigated the effects of resection margin stratified by left and right-sided primary CLM on overall survival (OS) for patients undergoing hepatectomy.

METHODS

A total of 732 patients undergoing hepatic resection for CLM at the Cleveland Clinic and Johns Hopkins were identified between 2002 and 2016. Clinically significant variables were analyzed using Cox proportional hazard regression. The cohort was then divided into patients with right and left-sided CLM and analyzed separately using Kaplan Meier analysis and Cox proportional hazard regression.

RESULTS

Cox proportional hazard regression showed that left-sided CLM with an R0 margin was a statistically significant predictor of OS even after controlling for other important factors (HR = 0.629, P = 0.024) but right-sided CLM with R0 margin was not (HR = 0.788, P = 0.245). Kaplan-Meier analysis demonstrated that patients with a left-sided CLM and R0 margin had the best prognosis (P = 0.037).

CONCLUSION

Surgical margin is an important prognostic factor for left-sided primary CLM but tumor biology may override surgical technique for right-sided CLM.

R1 resection of colorectal liver metastasis - What is the cost of marginal resection?

BACKGROUND AND OBJECTIVES

The impact of resection margins on the outcome of patients with colorectal liver metastasis (CRLM) remains controversial. We evaluated the short and long-term results of R1 resection.

METHODS

Between 2006 and 2016, 202 patients underwent liver resection for CRLM. R1 resection was defined as a distance of less than 1 mm between tumor cells and the transection plain. Patient and tumor characteristics, perioperative, and long-term outcomes were assessed.

RESULTS

In 161 (79.7%) and 41 (20.3%) patients, an R0 and R1 resections were achieved, respectively. Patients that underwent an R1 resection had higher rates of disease progression while on chemotherapy (12.1% vs 5.5%, P = 0.001), need for second-line chemotherapy (17% vs 6.2%, P < 0.001), increased use of preoperative volume manipulation (14.6% vs 5.5%, P = 0.001), and inferior vena-cava involvement (21.9% vs 8.7%, P < 0.001). These patients had higher rates of major postoperative complications (19.5% vs 6.8%, P < 0.001) and reoperations (7.3% vs 2.4%, P < 0.001). Multivariate analysis demonstrated that R1 resections were not associated with decreased recurrence-free survival or overall survival.

CONCLUSIONS

Although R1 resection is associated with worse disease behavior and postoperative complications, the long-term outcome of patients following an R1 resection is non-inferior to those who underwent an R0 resection.

Higher Tumor Burden Neutralizes Negative Margin Status in Hepatectomy for Colorectal Cancer Liver Metastasis

OBJECTIVE

The aim of this study was to examine if the prognostic significance of margin status in hepatectomy for colorectal cancer liver metastasis (CRLM) varies for different levels of tumor burden because hepatectomy indications for CRLM have been recently expanded to include patients with a higher tumor burden in whom achieving an R0 resection is difficult.

METHODS

Clinicopathological variables in an exploration cohort of 290 patients receiving hepatectomy in Japan for CRLM were investigated. R0 resection was defined as a margin width > 0 mm. Tumor burden was assessed using the recently introduced Tumor Burden Score (TBS), which was calculated as TBS² = (maximum tumor diameter in cm)² + (number of lesions)². The principal findings were validated using a cohort from the United States.

RESULTS

R1 resection rates significantly increased as TBS increased: 4/86 (4.7%) in patients with TBS < 3, 29/171 (17.0%) in patients with TBS ≥ 3 and < 9, and 9/33 (27.3%) in patients with TBS ≥ 9 (p < 0.001). R0 resection was significantly superior to R1 resection in patients with TBS ≥ 5; however, this was not the case for TBS ≥ 6, as confirmed by both univariate and multivariate analyses. Furthermore, prehepatectomy chemotherapy was associated with significantly improved survival for patients with TBS ≥ 8. Analysis of the validation cohort yielded similar results.

CONCLUSIONS

R0 resection appeared to have a positive impact on prognosis among patients with low tumor burden; however, this was not the case for patients with high tumor burden. As such, systemic treatment, in addition to surgery, may be central to achieving satisfactory outcomes in the latter patient population.

Current status of surgical treatment of colorectal liver metastases

Liver metastasis (LM) is one of the major causes of death in patients with colorectal cancer (CRC). Approximately 60% of CRC patients develop LM during the course of their illness. About 85% of these patients have unresectable disease at the time of presentation. Surgical resection is currently the only curative treatment for patients with colorectal LM (CRLM). In recent years, with the help of modern multimodality therapy including systemic chemotherapy, radiation therapy, and surgery, the outcomes of CRLM treatment have significantly improved. This article summarizes the current status of surgical treatment of CRLM including evaluation of resectability, treatment for resectable LM, conversion therapy and liver transplantation for unresectable cases, liver resection for recurrent CRLM and elderly patients, and surgery for concomitant hepatic and extra-hepatic metastatic disease (EHMD). We believe that with the help of modern multimodality therapy, an aggressive oncosurgical approach should be implemented as it has the possibility of achieving a cure, even when EHMD is present in patients with CRLM.

The impact of R1 resection for colorectal liver metastases on local recurrence and overall survival in the era of modern chemotherapy: An analysis of 1,428 resection areas

BACKGROUND

It is still unclear whether a positive surgical margin after resection of colorectal liver metastases remains a poor prognostic factor in the era of modern perioperative chemotherapy. The aim of this study was to evaluate whether preoperative chemotherapy has an impact on reducing local recurrence after R1 resection, and the impact of local recurrence on overall survival.

METHODS

Between 2000 and 2014, a total of 421 patients underwent resection for colorectal liver metastases at our unit after preoperative chemotherapy. The overall number of analyzed resection areas was 1,428.

RESULTS

The local recurrence rate was 12.8%, significantly higher after R1 resection than after R0 (24.5% vs 8.7%; P < .001). These results were also confirmed in patients with response to preoperative chemotherapy (23.1% after R1 vs 11.2% after R0; P < .001). At multivariate analysis, R1 resection was the only independent risk factor for local recurrence (P < .001). At the analysis of the 1,428 resection areas, local recurrence significantly decreased according to the increase of the surgical margin width (from 19.1% in 0 mm margin to 2.4% in ≥10 mm). At multivariable logistic regression analysis for overall survival, the presence of local recurrence showed a significant negative impact on 5-year overall survival (P < .001).

CONCLUSION

Surgical margin recurrence after modern preoperative chemotherapy for colorectal liver metastases was still significantly higher after R1 resection than it was after R0 resection. Local recurrence showed a negative prognostic impact on overall survival. R0 resection should be recommended whenever technically achievable, as well as in patients treated by modern preoperative chemotherapy.

Serum tumor markers enhance the predictive power of the AJCC and LCSGJ staging systems in resectable intrahepatic cholangiocarcinoma

BACKGROUND

While several prognostic models have been developed to predict long-term outcomes in resectable intrahepatic cholangiocarcinoma (ICC), their prognostic discrimination remains limited. The addition of tumor markers might improve the prognostic power of the classification schemas proposed by the AJCC 8th edition and the Liver Cancer Study Group of Japan (LCSGJ).

METHODS

The prognostic discrimination of the AJCC and the LCSGJ were compared before and after the addition of CA 19-9 and CEA, using Harrell's C-index, net reclassification improvement (NRI) and the integrated discrimination improvement (IDI) in an international, multi-institutional cohort.

RESULTS

Eight hundred and five surgically treated patients with ICC that met the inclusion criteria were identified. On multivariable analysis, CEA5 ng/mL, 100IU/mL CA 19-9< 500IU/mL and CA 19-9500 IU/mL were associated with worse overall survival. The C-index of the AJCC and the LCSGJ improved from 0.540 to 0.626 and 0.553 to 0.626, respectively following incorporation of CA 19-9 and CEA. The NRI and IDI metrics confirmed the superiority of the modified AJCC and LCSGJ, compared to the original versions.

CONCLUSION

The inclusion of preoperative CA 19-9 and CEA in the AJCC and LCSGJ staging schemas may improve prognostic discrimination among surgically treated patients with ICC.

The Prognostic Value of Varying Definitions of Positive Resection Margin in Patients with Colorectal Cancer Liver Metastases

BACKGROUND

Varying definitions of resection margin clearance are currently employed among patients with colorectal cancer liver metastases (CRLM). Specifically, a microscopically positive margin (R1) has alternatively been equated with an involved margin (margin width = 0 mm) or a margin width < 1 mm. Consequently, patients with a margin width of 0-1 mm (sub-mm) are inconsistently classified in either the R0 or R1 categories, thus obscuring the prognostic implications of sub-mm margins.

METHODS

Six hundred thirty-three patients who underwent resection of CRLM were identified. Both R1 definitions were alternatively employed and multivariable analysis was used to determine the predictive power of each definition, as well as the prognostic implications of a sub-mm margin.

RESULTS

Five hundred thirty-nine (85.2%) patients had a margin width ≥ 1 mm, 42 had a sub-mm margin width, and 52 had an involved margin (0 mm). A margin width ≥ 1 mm was associated with improved survival vs. a sub-mm margin (65 vs. 36 months; P = 0.03) or an involved margin (65 vs. 33 months; P < 0.001). No significant difference in survival was detected between patients with involved vs. sub-mm margins (P = 0.31). A sub-mm margin and an involved margin were both independent predictors of worse OS (HR 1.66, 1.04-2.67; P = 0.04, and HR 2.14, 1.46-3.16; P < 0.001, respectively) in multivariable analysis. Importantly, after combining the two definitions, patients with either an involved margin or a sub-mm margin were associated with worse OS in multivariable analysis (HR 1.94, 1.41-2.65; P < 0.001).

CONCLUSIONS

Patients with involved or sub-mm margins demonstrated a similar inferior OS vs. patients with a margin width > 1 mm. Consequently, a uniform definition of R1 as a margin width < 1 mm should perhaps be employed by future studies.

Colorectal Liver Metastases: Does the Future of Precision Medicine Lie in Genetic Testing?

Colorectal liver metastases (CRLM) present an important clinical challenge in both surgical and medical oncology. Despite improvements in management, survival among patients undergoing resection of CRLM is still very variable and there is a paucity of clinical trial data and reliable biomarkers that could guide prognostic forecasts, treatment selection, and follow-up. Fortunately, recent advances in molecular biology and tumor sequencing have identified a number of critical genetic loci and proliferation markers that may hold the key to understanding the biologic behavior of CRLM; specifically, mutations of KRAS, BRAF, TP53, PIK3CA, APC, expression of Ki-67, and the presence of microsatellite instability appear to have a decisive impact on prognosis and response to treatment in patients with CRLM. While the applicability of genetic biomarkers in everyday clinical practice remains conditional on the development of inexpensive bedside sequencing, targeted therapies, and the conduct of appropriate clinical trials, the promise of personalized treatment may be closer to realization than ever before.

Genetic And Morphological Evaluation (GAME) score for patients with colorectal liver metastases

BACKGROUND

This study sought to develop a clinical risk score for resectable colorectal liver metastasis (CRLM) by combining clinicopathological and clinically available biological indicators, including KRAS.

METHODS

A cohort of patients who underwent resection for CRLM at the Johns Hopkins Hospital (JHH) was analysed to identify independent predictors of overall survival (OS) that can be assessed before operation; these factors were combined into the Genetic And Morphological Evaluation (GAME) score. The score was compared with the current standard (Fong score) and validated in an external cohort of patients from the Memorial Sloan Kettering Cancer Center (MSKCC).

RESULTS

Six preoperative predictors of worse OS were identified on multivariable Cox regression analysis in the JHH cohort (502 patients). The GAME score was calculated by allocating points to each patient according to the presence of these predictive factors: KRAS-mutated tumours (1 point); carcinoembryonic antigen level 20 ng/ml or more (1 point), primary tumour lymph node metastasis (1 point); Tumour Burden Score between 3 and 8 (1 point) or 9 and over (2 points); and extrahepatic disease (2 points). The high-risk group in the JHH cohort (GAME score at least 4 points) had a 5-year OS rate of 11 per cent, compared with 73·4 per cent for those in the low-risk group (score 0-1 point). Importantly, in cohorts from both the JHH and MSKCC (747 patients), the discriminatory capacity of the GAME score was superior to that of the Fong score, as demonstrated by the C-index and the Akaike information criterion.

CONCLUSION

The GAME score is a preoperative prognostic tool that can be used to inform treatment selection.

Histopathologic patterns as markers of prognosis in patients undergoing hepatectomy for colorectal cancer liver metastases - Pushing growth as an independent risk factor for decreased survival

INTRODUCTION

Liver resection combined with neoadjuvant chemotherapy (NAC) has reported notable results in patients with colorectal liver metastases (CRLM). Tumoral response to NAC is associated with specific histopathologic patterns with prognostic implications. The main objective of this study was to evaluate the influence of pathological findings on overall survival (OS), disease-free survival (DFS) and liver recurrence-free survival (LRFS).

PATIENTS AND METHODS

Analysis of clinical and outcome data from 110 patients who underwent first CRLM resection between January 2010 and July 2013. Blinded pathological review of histological material of several parameters: resection margin, tumor regression grade (TRG), tumor thickness at the tumor-normal interface (TTNI) and the growth pattern (GP).

RESULTS

The median survival following hepatic resection was 52 months and 3- and 5- year Kaplan-Meier estimates were 69 and 48%, respectively. Seventy-four patients developed recurrent disease. Oxaliplatin-based chemotherapy was significantly associated with a pushing GP. A positive resection margin was an independent predictor of decreased DFS (p = 0.018) but not of decreased OS. LRFS was strongly reduced by the absence of histologic tumor response (p = 0.018). The pushing pattern had an adverse impact on both OS (p = 0.007) and DFS (p = 0.004) on multivariate analysis.

CONCLUSION

The prognostic value of histopathological features in patients who underwent CRLM's resection is undeniable. The pushing GP was related with worse prognosis. Further studies are required to clarify the biological mechanisms underlying these findings in order to enhance a more personalized and efficient treatment of these patients.

Associating Liver Partition and Portal Vein Ligation for Staged Hepatectomy in the Treatment of Colorectal Liver Metastases: Current Scenario

Associating Liver Partition and Portal vein ligation for Staged hepatectomy (ALPPS) has expanded the surgical armamentarium for patients with advanced and bilateral colorectal liver metastases. However, the enthusiasm that the medical fraternity had about ALPPS was hampered by a high mortality rate and early and frequent tumor recurrence. While surgical safety has improved, mainly due to technical refinements and a better patient selection, the oncological value in the face of early tumor recurrence remains unclear. The only randomized controlled trial on ALPPS versus two-stage hepatectomy (TSH) so far confirmed that ALPPS led to higher resectability with comparable perioperative complication rate, but oncological outcome was not measured. Robust data regarding long-term outcome are still missing. TSH and ALPPS might be complementary strategies for the resection of colorectal liver metatsases (CRLM) with ALPPS being reserved for patients with no other surgical option, that is, after failed portal vein embolization or those with an extremely small future liver remnant. In other words, ALPPS can be considered a supplementary tool and a last resort in the liver surgeon's hand to offer resectability in otherwise nonresectable CRLM. In these individual cases, and always embedded into a multimodal treatment setting, ALPPS may offer a chance of complete tumor removal and prolonged survival and even a chance for cure.

Liver resection is justified for patients with bilateral multiple colorectal liver metastases: A propensity-score-matched analysis

BACKGROUND

Increasingly, patients with multiple colorectal liver metastases (CLM) are surgically treated. Some studies have shown that patients with bilobar and unilobar multiple CLM have similar outcomes, but other have shown that patients with bilobar CLM have worse outcomes after resection. We aimed to compare clinical outcomes of surgical treatment of bilobar and unilobar CLM using propensity score matching.

METHODS

The single-institution study included patients who underwent hepatectomy for ≥3 histologically confirmed CLM during 1998-2014. Clinicopathologic characteristics and long-term outcomes were compared between patients with bilobar and unilobar CLM in a propensity-score-adjusted cohort.

RESULTS

A total of 473 patients met the inclusion criteria, 271 (57%) with bilobar and 202 (43%) with unilobar CLM. In the propensity-score-matched population (bilobar, 170; unilobar, 170), no differences were observed according to the distribution of CLM except for a greater frequency of concomitant ablation, and R1 resection in the bilobar group. There was no difference between the bilobar and unilobar groups in 5-year overall survival rates (46% and 49%, respectively; P = 0.740) or 3-year recurrence-free survival rates (21% and 24%, respectively; P = 0.674).

CONCLUSIONS

Tumor distribution may not affect the curability of surgery for multiple CLM. Liver resection would be justified for selected patients with bilobar CLM.

Anatomical Resections Improve Disease-free Survival in Patients With KRAS-mutated Colorectal Liver Metastases

OBJECTIVE

To investigate the potential clinical advantage of anatomical resection versus nonanatomical resection for colorectal liver metastases, according to KRAS mutational status.

BACKGROUND

KRAS-mutated colorectal liver metastases (CRLM) are known to be more aggressive than KRAS wild-type tumors. Although nonanatomical liver resections have been demonstrated as a viable approach for CRLM patients with similar oncologic outcomes to anatomical resections, this may not be the case for the subset of KRAS-mutated CRLM.

METHODS

389 patients who underwent hepatic resection of CRLM with known KRAS mutational status were identified. Survival estimates were calculated using the Kaplan-Meier method, and multivariable analysis was conducted using the Cox proportional hazards regression model.

RESULTS

In this study, 165 patients (42.4%) underwent nonanatomical resections and 140 (36.0%) presented with KRAS-mutated CRLM. Median disease-free survival (DFS) in the entire cohort was 21.3 months, whereas 1-, 3-, and 5-year DFS was 67.3%, 34.9%, and 31.5% respectively. Although there was no difference in DFS between anatomical and nonanatomical resections in patients with KRAS wild-type tumors (P = 0.142), a significant difference in favor of anatomical resection was observed in patients with a KRAS mutation (10.5 vs. 33.8 months; P < 0.001). Five-year DFS was only 14.4% in the nonanatomically resected group, versus 46.4% in the anatomically resected group. This observation persisted in multivariable analysis (hazard ratio: 0.45; 95% confidence interval: 0.27-0.74; P = 0.002), when corrected for number of tumors, bilobar disease, and intraoperative ablations.

CONCLUSIONS

Nonanatomical tissue-sparing hepatectomies are associated with worse DFS in patients with KRAS-mutated tumors. Because of the aggressive nature of KRAS-mutated CRLM, more extensive anatomical hepatectomies may be warranted.

The Prognostic Impact of Determining Resection Margin Status for Multiple Colorectal Metastases According to the Margin of the Largest Lesion

BACKGROUND

Although the prognostic role of surgical margin status after resection of colorectal liver metastasis (CRLM) has been previously examined, controversy still surrounds the importance of surgical margin status in patients with multiple tumors.

METHODS

Patients who underwent curative-intent surgery for CRLM from 2000 to 2015 and who presented with multiple tumors were identified. Patients with R1 resection status determined by the closest resection margin of the non-largest tumor were classified as R1-Type 1; patients with R1 status determined by the resection margin of the largest tumor were defined as R1-Type 2. Data regarding surgical margin status, size of tumors, and overall survival (OS) were collected and assessed.

RESULTS

A total of 251 patients met inclusion criteria; 156 patients (62.2%) had a negative margin (R0), 50 had an R1-type 1 (19.9%), and 45 had an R1-type 2 (17.9%) margin. Median and 5-year OS in the entire cohort was 56.4 months and 48.0%, respectively. When all R1 (Type 1 + Type 2) patients were compared with R0 patients, an R1 was not associated with worse prognosis (P = 0.05). In contrast, when R1-type 2 patients were compared with R0 patients, an R1 was strongly associated with worse OS (P = 0.009). On multivariate analysis, although the prognostic impact of all R1 was not associated with OS (hazard ratio [HR] 1.56; P = 0.08), R1-Type 2 margin status independently predicted a poor outcome (HR 1.93; P = 0.03).

CONCLUSIONS

The impact of margin status varied according to the size of the tumor assessed. While R1 margin status defined according to the non-largest tumor was not associated with OS, R1 margin status relative to the largest index lesion was associated with prognosis.