Prognostic impact of intrahepatic lymphatic and microvascular involvement in cases of colorectal liver metastases

Anatomical resection improves relapse-free survival in colorectal liver metastases in patients with KRAS/NRAS/BRAF mutations or right-sided colon cancer: a retrospective cohort study

BACKGROUND

The type of liver resection (anatomical resection, AR or non-anatomical resection, NAR) for colorectal liver metastases (CRLM) is subject to debate. The debate may persist because some prognostic factors, associated with aggressive tumor biological behavior, have been overlooked.

OBJECTIVE

Our study aimed to investigate the characteristics of patients who would benefit more from anatomical resection for CRLM.

METHODS

Seven hundred twenty-nine patients who underwent hepatic resection of CRLM were retrospectively collected from June 2012 to May 2019. Treatment effects between AR and NAR were compared in full subgroup analyses. Tumor relapse-free survival (RFS) was evaluated by a stratified log-rank test and summarized with the use of Kaplan-Meier and Cox proportional hazards methods.

RESULTS

Among 729 patients, 235 (32.2%) underwent AR and 494 (67.8%) underwent NAR. We showed favorable trends in RFS for AR compared with NAR in the patients with KRAS/NRAS/BRAF mutation (interaction P <0.001) or right-sidedness (interaction P <0.05). Patients who underwent AR had a markedly improved RFS compared with NAR in the cohorts of RAS/NRAS/BRAF mutation (median RFS 23.2 vs. 11.1 months, P <0.001) or right-sidedness (median RFS 31.6 vs. 11.5 months, P <0.001); upon the multivariable analyses, AR [gene mutation: hazard ratio (HR)=0.506, 95% CI=0.371-0.690, P <0.001; right-sidedness: HR=0.426, 95% CI=0.261-0.695, P =0.001) remained prognostic independently. In contrast, patients who underwent AR had a similar RFS compared with those who underwent NAR, in the cohorts of patients with gene wild-type tumors (median RFS 20.5 vs. 21.6 months, P =0.333). or left-sidedness (median RFS 15.8 vs. 19.5 months, P =0.294).

CONCLUSIONS

CRLM patients with gene mutation or right-sidedness can benefit more from AR rather than from NAR.

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.

Histopathological and Immune Prognostic Factors in Colo-Rectal Liver Metastases

Prognostic studies are increasingly providing new tools to stratify colo-rectal liver metastasis patients into clinical subgroups, with remarkable implications in terms of clinical management and therapeutic choice. Here, the strengths and hurdles of current prognostic tools in colo-rectal liver metastasis are discussed. Alongside more classic histopathological parameters, which capture features related to the tumor component, such as tumor invasion, tumor growth pattern and regression score, we will discuss immune mediators, which are starting to be considered important features. Their objective quantification has shown significant results in prognostication studies, with most of the work focused on adaptive immune cells, namely T cells. As for macrophages, they are only starting to be appreciated and we will present recent advances in evaluation of macrophage morphological features. Deeper knowledge acquired by multiparametric analyses is rapidly uncovering the variety of immune players that should be assessed. The future projection is to implement deep-learning histopathological tools and to integrate histopathological and immune metrics in multiparametric scores, with the ultimate objective to achieve a deeper resolution of the tumor features and their relevance for colo-rectal liver metastasis.

Histopathological prognostic factors for colorectal liver metastases: A systematic review and meta-analysis of observational studies

INTRODUCTION

Resection is the mainstay of treatment for colorectal liver metastases (CRLMs). Many different histopathological factors related to the primary colorectal tumour have been well studied; however, histopathological prognostic factors related to CRLMs are still under evaluation.

OBJECTIVE

To identify histopathological factors related to overall survival (OS) and disease-free survival (DFS) in patients with resected CRLMs.

METHODS

A systematic review was performed with the following databases up to August 2020: PubMed, EMBASE, Web of Science, SciELO, and LILACS. The GRADE approach was used to rate the overall certainty of evidence by outcome.

RESULTS

Thirty-three studies including 4,641 patients were eligible. We found very low certainty evidence that the following histopathological prognostic factors are associated with a statistically significant decrease in OS: presence of portal vein invasion (HR, 0,50 [95% CI, 0,37 to 0,68]; I²=0%), presence of perineural invasion (HR, 0,55 [95% CI, 0,36 to 0,83]; I²=0%), absence of pseudocapsule (HR, 0,41 [CI 95%, 0,29 to 0,57], p<0,00001; I²=0%), presence of satellite nodules (OR, 0,45 [95% CI, 0,26 to 0,80]; I²=0%), and the absence of peritumoural inflammatory infiltrate (OR, 0,20 [95% CI, 0,08 to 0,54]; I²=0%). Outcome data on DFS were scarce, except for tumour borders, which did not present a significant impact, precluding the meta-analysis.

CONCLUSION

Of the histopathological prognostic factors studied, low- to moderate-certainty evidence shows that vascular invasion, perineural invasion, absence of pseudocapsule, presence of satellite nodules, and absence of peritumoral inflammatory infiltrate are associated with shorter overall survival in CRLMs.

Propensity score analysis of non-anatomical versus anatomical resection of colorectal liver metastases

Background

There are concerns that non‐anatomical resection (NAR) worsens perioperative and oncological outcomes compared with those following anatomical resection (AR) for colorectal liver metastases (CRLM). Most previous studies have been biased by the effect of tumour size. The aim of this study was to compare oncological outcomes after NAR versus AR.

Methods

This was a retrospective study of consecutive patients who underwent CRLM resection with curative intent from 1999 to 2016. Data were retrieved from a prospectively developed database. Survival and perioperative outcomes for NAR and AR were compared using propensity score analyses.

Results

Some 358 patients were included in the study. Median follow‐up was 34 (i.q.r. 16–68) months. NAR was associated with significantly less morbidity compared with AR (31·1 versus 44·4 per cent respectively; P = 0·037). Larger (hazard ratio (HR) for lesions 5 cm or greater 1·81, 95 per cent c.i. 1·13 to 2·90; P = 0·035) or multiple (HR 1·48, 1·03 to 2·12; P = 0·035) metastases were associated with poor overall survival (OS). Synchronous (HR 1·33, 1·01 to 1·77; P = 0·045) and multiple (HR 1·51, 1·14 to 2·00; P = 0·004) liver metastases, major complications after liver resection (HR 1·49, 1·05 to 2·11; P = 0·026) or complications after resection of the primary colorectal tumour (HR 1·51, 1·01 to 2·26; P = 0·045) were associated with poor disease‐free survival (DFS). AR was prognostic for poor OS only in tumours smaller than 30 mm, and R1 margin status was not prognostic for either OS or DFS. NAR was associated with a higher rate of salvage resection than AR following intrahepatic recurrence.

Conclusions

NAR has at least equivalent oncological outcomes to AR while proving to be safer. NAR should therefore be the primary surgical approach to CRLM, especially for lesions smaller than 30 mm.

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.

Lymphatic Invasion is an Independent Adverse Prognostic Factor in Patients with Colorectal Liver Metastasis

BACKGROUND

For a selection of patients with colorectal liver metastases (CRLM), liver resection is a curative option. In order to predict long-term survival, clinicopathologic risk scores have been developed, but little is known about histologic factors and their prognostic value for disease-free and overall survival. The objective of the present study was to assess possible prognostic histologic factors in patients with solitary CRLM treated with liver resection who did not receive neoadjuvant treatment.

METHODS

Patients with solitary CRLM who underwent liver resection between 1992 and 2011 were evaluated for clinical prognostic factors. Histologic analyses on tumor thickness at the tumor-normal interface, presence of a fibrotic capsule, intrahepatic vascular invasion, lymphatic invasion, or bile duct invasion and perineural growth were performed, using immunohistochemistry.

RESULTS

A total of 124 patients were analyzed with a median follow-up of 41 months (range 1-232 months). There was no association between histologic factors and disease-free survival in multivariate analysis. In multivariate analysis, intrahepatic lymphatic invasion was associated with a decreased overall survival (41.9 vs. 61.0 months; p = 0.041), especially in combination with vascular invasion (n = 15) (28.1 vs. 62.2 months; p < 0.0001). In addition, size over 50 mm (29.2 vs. 65.9 months; p = 0.004) and interval less than 12 months between resection of the primary tumor and diagnosis of liver metastasis (49.0 vs. 91.5 months: p = 0.019) were also independent adverse prognostic factors.

CONCLUSIONS

Intrahepatic lymphatic invasion, especially in combination with vascular invasion, is an important adverse prognostic factor for overall survival in patients with solitary CRLM after liver resection.

Critical review of the prognostic significance of pathological variables in patients undergoing resection for colorectal liver metastases

OBJECTIVE

The aim of this study was to identify prognostic factors, particularly pathological variables, that influence disease-free and overall survival following resection for colorectal liver metastases (CRLM).

METHODS

Patients undergoing CRLM resection from January 2005 to December 2011 were included. Data analysed included information on demographics, laboratory results, operative findings, histopathological features and survival.

RESULTS

A total of 259 patients were included. Of these, 138 (53.3%) patients developed recurrent disease, of which 95 died. The median length of follow-up in the remaining patients was 28 months (range: 12-96 months). There were significant associations between recurrence and higher tumour number (P = 0.002), presence of perineural invasion (P = 0.009) and positive margin (R1) resection (P = 0.002). Multivariate analysis showed all three prognostic factors to be independent predictors of disease-free survival. Significantly poorer overall survival after hepatic resection for CRLM was observed in patients undergoing hemi-hepatectomy or more radical resection (P = 0.021), patients with a higher number of tumours (P = 0.024) and patients with perineural invasion (P < 0.001). Multivariate analysis showed perineural invasion to be the only independent predictor of overall survival.

CONCLUSIONS

The presence of perineural invasion, multiple tumours and an R1 margin were associated with recurrent disease. Perineural invasion was also an independent prognostic factor with respect to overall survival.

Lymphatic drainage of the liver and its implications in the management of colorectal cancer liver metastases

The liver is the most common site of distant metastases in patients with colorectal cancer. Surgery represents the mainstream for curative treatment of colorectal cancer liver metastases (CRCLM) with long-term survival up to 58 and 36 % at 5 and 10 years, respectively. Despite advances on diagnosis, staging and surgical strategies, 60-70 % of patients will develop recurrence of the disease even after R0 resection of CRCLM. Tumor staging, prognosis, and therapeutic approaches for cancer are most often based on the extent of involvement of regional lymph nodes (LNs) and, to a lesser extent, on the invasion of regional lymphatic vessels draining the primary tumor. For CRCLM, the presence of intra hepatic lymphatic and blood vascular dissemination has been associated with an increased risk of intra hepatic recurrence, poorer disease-free and overall survival after liver resection. Also, several studies have reviewed the role of surgery in the patient with concomitant CRCLM and liver pedicle LN metastasis. Although pedicle LN involvement is related to worst survival rates, it does not differentiate patients that will relapse from those that will not. This review aims to briefly describe the anatomy of the liver's lymphatic drainage, the incidence of intrahepatic lymphatic invasion and hilar lymph node involvement, as well as their clinical impact in CRCLM. A better understanding of the role of liver lymphatic metastasis might, in the near future, impact the strategy of systemic therapies after liver resection as for primary colorectal tumors.

Intrahepatic lymphatic invasion but not vascular invasion is a major prognostic factor after resection of colorectal cancer liver metastases

BACKGROUND

Despite advances in diagnosis and surgical strategies, up to 70% of patients will develop recurrence of the disease after resection of colorectal cancer liver metastases (CRCLM). The purpose of our study was to determine the frequency of four different mechanisms of intrahepatic dissemination, and to evaluate the impact of each mechanism on patient outcomes.

METHODS

The medical records of 118 patients who underwent a first resection of CRCLM during the period between 2000 and 2010 were reviewed. Clinicopathologic variables and outcome parameters were examined. Resected specimens were submitted to routine histological evaluation, and immunohistochemical staining with D2-40 (lymphatic vessels), CD34 (blood vessels), CK-7 (biliary epithelium), and CK-20 (CRC cells).

RESULTS

The mean follow-up after resection was 38 months. Tumor recurrence was observed in 76 patients, with a median interval of 13 months after resection. Overall survival and disease-free survival (DFS) rates after hepatectomy were 62 and 56%, and 26 and 24% at 3 and 5 years, respectively. Intrahepatic microscopic invasion included portal venous in 49 patients, sinusoidal in 43 patients, biliary in 20 patients, and lymphatic in 33 patients. Intra-hepatic lymphatic invasion was the only mechanism of dissemination independently associated with the risk of hepatic recurrence (odds ratio 2.75) and shorter DFS (p = 0.006).

CONCLUSION

Intrahepatic lymphatic invasion is a significant prognostic factor. Other mechanisms of invasion, although frequently observed, are not related to recurrence or survival, suggesting that the lymphatic system is the main route for dissemination of CRCLM. Furthermore, immunohistochemical detection of intrahepatic lymphatic invasion might be of value in clinical practice.

Management of colorectal cancer patients after resection of liver metastases: can we offer a tailored treatment?

Surgical resection remains the only option of cure for patients with colorectal liver metastases, and no patient should be precluded from surgery. There is much controversy not only regarding the most appropriate therapeutic approach in the neoadjuvant setting but also after surgery is performed. Many patients will experience early relapses but others will be long survivors. We need to establish reliable prognostic and predictive factors to offer a tailored treatment. Several prognostic factors after metastasectomy have been identified: high C-reactive protein levels, a high neutrophil-lymphocyte ratio, elevated neutrophil count and low serum albumin are related to a worst outcome. Elevated CEA and Ki 67 levels, intrahepatic and perihepatic lymph node invasion are also some of the markers related to a worst outcome. In contrast, the administration of preoperative chemotherapy has been associated with a better prognosis after hepatectomy. The administration of adjuvant chemotherapy should be done taking in consideration these factors. Regarding predictive factors, determination of ERCC1, TS, TP and DPD and UGT1 polymorphisms assessment could be considered prior to chemotherapy administration. This would avoid treatment related toxicities and increase this population quality of life.