Resection of Colorectal Liver Metastasis: Prognostic Impact of Tumor Burden vs KRAS Mutational Status

A Glimpse into the Role and Effectiveness of Splenectomy for Isolated Metachronous Spleen Metastasis of Colorectal Cancer Origin: Long-Term Survivals Can Be Achieved

Background: Many papers exploring the role of resectioning metastases in colorectal cancer (CRC) have focused mainly on liver and lung sites, showing improved survival compared with non-resectional therapies. However, data about exceptional metastatic sites such as splenic metastases (SMs) are scarce. This paper aims to assess the role and effectiveness of splenectomy in the case of isolated metachronous SM of CRC origin. Methods: The patients' data were extracted after a comprehensive literature search through public databases for articles reporting patients with splenectomies for isolated metachronous SM of CRC origin. Potential predictors of survival were explored, along with demographic, diagnostic, pathology, and treatment data for each patient. Results: A total of 83 patients with splenectomies for isolated metachronous SM of CRC origin were identified. The primary CRC was at an advanced stage (Duke's C-70.3%) and on the left colon (45.5%) for most patients, while the median interval between CRC resection and SM was 24 months. The median overall survival after splenectomy was 84 months, and patients younger than 62 years presented statistically significantly worse overall survival rates than those ≥62 years old (p = 0.011). There was no significant impact on the long-term outcomes for factors including primary tumor location or adjuvant chemotherapy (p values ≥ 0.070, ns). Laparoscopic splenectomy was increasingly used in the last 20 years from 2002 (33.3% vs. 0%, p < 0.001). Conclusions: Splenectomy is the optimal treatment for patients with isolated metachronous SM of CRC, with the laparoscopic approach being increasingly used and having the potential to become a standard of care. Encouraging long-term survival rates were reported in the context of a multidisciplinary approach. Younger ages are associated with worse survival. Perioperative chemotherapy in the context of a patient diagnosed with SM of CRC origin appears to be a reasonable option, although the present study failed to show any significant impact on long-term survival.

Exosomes promote pre-metastatic niche formation in colorectal cancer

It is well known that colorectal cancer (CRC) has a high morbidity rate, a poor prognosis when metastasized, and a greatly shortened 5-year survival rate. Therefore, understanding the mechanism of tumor metastasis is still important. Based on the "seed and soil" theory, the concept of " premetastatic niche (PMN)" was introduced by Kaplan et al. The complex interaction between primary tumors and the metastatic organ provides a beneficial microenvironment for tumor cells to colonize at a distance. With further exploration of the PMN, exosomes have gradually attracted interest from researchers. Exosomes are extracellular vesicles secreted from cells that include various biological information and are involved in communication between cells. As a key molecule in the PMN, exosomes are closely related to tumor metastasis. In this article, we obtained information by conducting a comprehensive search across academic databases including PubMed and Web of Science using relevant keywords. Only recent, peer-reviewed articles published in the English language were considered for inclusion. This study aims to explore in depth how exosomes promote the formation of pre-metastatic microenvironment (PMN) in colorectal cancer and its related mechanisms.

Current landscape of preoperative neoadjuvant therapies for initial resectable colorectal cancer liver metastasis

Colorectal cancer liver metastasis (CRLM) presents a clinical challenge, and optimizing treatment strategies is crucial for improving patient outcomes. Surgical resection, a key element in achieving prolonged survival, is often linked to a heightened risk of recurrence. Acknowledging the potential benefits of preoperative neoadjuvant chemotherapy in managing resectable liver metastases, this approach has gained attention for its role in tumor downsizing, assessing biological behavior, and reducing the risk of postoperative recurrence. However, the use of neoadjuvant chemotherapy in initially resectable CRLM sparks ongoing debates. The balance between tumor reduction and the risk of hepatic injury, coupled with concerns about delaying surgery, necessitates a nuanced approach. This article explores recent research insights and draws upon the practical experiences at our center to address critical issues regarding considerations for initially resectable cases. Examining the criteria for patient selection and the judicious choice of neoadjuvant regimens are pivotal areas of discussion. Striking the right balance between maximizing treatment efficacy and minimizing adverse effects is imperative. The dynamic landscape of precision medicine is also reflected in the evolving role of gene testing, such as RAS/BRAF and PIK3CA, in tailoring neoadjuvant regimens. Furthermore, the review emphasizes the need for a multidisciplinary approach to navigate the complexities of CRLM. Integrating technical expertise and biological insights is crucial in refining neoadjuvant strategies. The management of progression following neoadjuvant chemotherapy requires a tailored approach, acknowledging the diverse biological behaviors that may emerge. In conclusion, this review aims to provide a comprehensive perspective on the considerations, challenges, and advancements in the use of neoadjuvant chemotherapy for initially resectable CRLM. By combining evidence-based insights with practical experiences, we aspire to contribute to the ongoing discourse on refining treatment paradigms for improved outcomes in patients with CRLM.

Molecular Mechanisms of Colorectal Liver Metastases

The liver is the most frequently target for metastasis among patients with colorectal cancer mainly because of the portal vein circulation that directly connects the colon and rectum with the liver. The liver tumor microenvironment consists of different cell types each with unique characteristics and functions that modulate the antigen recognition and immune system activation. Primary tumors from other sites "prime" the liver prior to the seeding of cancer cells, creating a pre-metastatic niche. Following invasion into the liver, four different phases are key to the development of liver metastases: a microvascular phase in which cancer cells infiltrate and become trapped in sinusoidal vessels; an extravascular, pre-angiogenic phase; an angiogenic phase that supplies oxygen and nutrients to cancer cells; and a growth phase in which metastatic cells multiply and enlarge to form detectable tumors. Exosomes carry proteins, lipids, as well as genetic information that can create a pre-metastatic niche in distant sites, including the liver. The complexity of angiogenic mechanisms and the exploitation of the vasculature in situ by cancer cells have limited the efficacy of currently available anti-angiogenic therapies. Delineating the molecular mechanisms implicated in colorectal liver metastases is crucial to understand and predict tumor progression; the development of distant metastases; and resistance to chemotherapy, immunotherapy, and targeted treatment.

Combined Tumor Burden Score and Carbohydrate Antigen 19-9 Grading System to Predict Outcomes Among Patients with Intrahepatic Cholangiocarcinoma

BACKGROUND

The interplay of carbohydrate antigen 19-9 (CA19-9) and tumor burden score (TBS) within intrahepatic cholangiocarcinoma remains ill-defined. We evaluated the roles of TBS and CA19-9 relative to overall survival (OS) and recurrence, as well as the predictive ability of the combined TBS and CA19-9 (CTC) grading system.

STUDY DESIGN

Patients undergoing liver resection for intrahepatic cholangiocarcinoma between 2000 and 2020 were identified using a multi-institutional database. The impact of CA19-9 and TBS on 5-year OS and 3-year recurrence was assessed, along with the prognostic accuracy of the CTC grading system (ie the composite score of CA19-9 level and TBS).

RESULTS

Among 831 patients, the median age was 58.2 years and 482 (58.0%) were male. The median [IQR] CA19-9 level was 49.7 [17.0, 221.0] U/mL and TBS was 6.1 [4.1, 8.3]. Median [IQR] and 5-year OS were 36.9 [32.3, 43.1] months and 38.9%, respectively; 3-year recurrence was 68.9%. Five-year survival varied relative to CA19-9 (low vs high, 49.0% vs 19.7%) and TBS (low vs high, 53.6% vs 26.9%) (p < 0.001 for both). On multivariable analysis, high CA19-9 (hazard ratio [HR] 2.02, 95% CI 1.64 to 2.49) and high TBS (HR 1.64, 95% CI 1.32 to 2.06) remained independently associated with OS. In turn, the CTC grading score stratified 5-year OS (low vs intermediate vs high CTC, 57.7% vs 39.9% vs 12.6%; p < 0.001) and remained an independent prognostic factor (referent, low CTC; [intermediate CTC] HR 1.54, 95% CI 1.18 to 2.01; [high CTC] HR 3.28, 95% CI 2.47 to 4.36).

CONCLUSIONS

The interplay between tumor morphology and biology dictates long-term prognosis after liver resection for intrahepatic cholangiocarcinoma. Prognostic models such as the CTC grading system may inform discussions around prognosis, as well as help identify which patients with ICC may benefit more from neoadjuvant chemotherapy rather than up-front surgery.

Optimizing the selection of technically unresectable colorectal liver metastases

BACKGROUND

The prediction of conversion surgery in patients with technically unresectable colorectal liver metastases has not been generalized or well-established. We developed a predictive model for conversion surgery and assessed the long-term outcomes of patients with technically unresectable colorectal liver metastases.

METHODS

In this single-center, retrospective study, we analyzed the perioperative parameters and outcomes of 892 consecutive patients (2014-2021). Conversion surgery was indicated when the chemotherapy response allowed the complete resection of colorectal liver metastases with negative margins and adequate remnant liver volume.

RESULTS

Of the 892 patients, 122 had technically unresectable colorectal liver metastases; 61 underwent conversion surgery (conversion surgery group) and 61 did not (nonconversion surgery group). The median overall survival was significantly higher in the conversion surgery group than in the nonconversion surgery group (5.6 vs 1.8 years, P < .001). After univariate and multivariate analyses, the predictive model for conversion surgery was constructed using 4 predictive factors: Rat sarcoma viral oncogene homolog status (mutant, +2 points), tumor number (≥15, +1), hepatic vein contact (≥2 hepatic veins, +1), and the presence of preservable sections (absence of preservable sections, +2). The area under the curve for conversion surgery was 0.889. Patients were graded according to the scores (A [0-2], B [3-4], and C [5-6]), and the conversion rates were 91.5% (A), 32.6% (B), and 10.3% (C) (P < .001). Grade A patients (median survival time, 5.7 years) had significantly better overall survival than grade B and C patients (median survival time, 2.2 and 1.6 years, respectively; P < .001).

CONCLUSION

Patients who underwent conversion surgery for technically unresectable colorectal liver metastases had better prognoses, and our novel predictive model was useful in predicting conversion surgery and prognosis.

Long-Term Outcomes of Perioperative Versus Neoadjuvant Chemotherapy for Resectable Colorectal Liver Metastases: An International Multicentre Propensity-Score Matched Analysis with Stratification by Contemporary Risk-Scoring

BACKGROUND

There is still debate regarding the principal role and ideal timing of perioperative chemotherapy (CTx) for patients with upfront resectable colorectal liver metastases (CRLM). This study assesses long-term oncological outcomes in patients receiving neoadjuvant CTx only versus those receiving neoadjuvant combined with adjuvant therapy (perioperative CTx).

METHODS

International multicentre retrospective analysis of patients with CRLM undergoing liver resection between 2010 and 2015. Characteristics and outcomes were compared before and after propensity score matching (PSM). Primary endpoints were long-term oncological outcomes, such as recurrence-free survival (RFS) and overall survival (OS). Furthermore, stratification by the tumour burden score (TBS) was applied.

RESULTS

Of 967 patients undergoing hepatectomy, 252 were analysed, with a median follow-up of 45 months. The unmatched comparison revealed a bias towards patients with neoadjuvant CTx presenting with more high-risk patients (p = 0.045) and experiencing increased postoperative complications ≥Clavien-Dindo III (20.9% vs. 8%, p = 0.003). Multivariable analysis showed that perioperative CTx was associated with significantly improved RFS (hazard ratio [HR] 0.579, 95% confidence interval [CI] 0.420-0.800, p = 0.001) and OS (HR 0.579, 95% CI 0.403-0.834, p = 0.003). After PSM (n = 180 patients), the two groups were comparable regarding baseline characteristics. The perioperative CTx group presented with a significantly prolonged RFS (HR 0.53, 95% CI 0.37-0.76, p = 0.007) and OS (HR 0.58, 95% CI 0.38-0.87, p = 0.010) in both low and high TBS patients.

CONCLUSIONS

When patients after resection of CRLM are able to tolerate additional postoperative CTx, a perioperative strategy demonstrates increased RFS and OS in comparison with neoadjuvant CTx only in both low and high-risk situations.

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.

KRAS Assessment Following ESMO Recommendations for Colorectal Liver Metastases. Is It Always Worth It?

Background: Genetic evaluation is essential in assessing colorectal cancer (CRC) and colorectal liver metastasis (CRLM). The aim of this study was to determine the pragmatic value of KRAS on oncological outcomes after CRLM according to the ESMO recommendations and to query whether it is necessary to request KRAS testing in each situation. Methods: A retrospective cohort of 126 patients who underwent surgery for hepatic resection for CRLM between 2009 and 2020 were reviewed. The patients were divided into three categories: wild-type KRAS, mutated KRAS and impractical KRAS according to their oncological variables. The impractical (not tested) KRAS group included patients with metachronous tumours and negative lymph nodes harvested. Disease-free survival (DFS), overall survival (OS) and hepatic recurrence-free survival (HRFS) were calculated by the Kaplan–Meier method, and a multivariable analysis was conducted using the Cox proportional hazards regression model. Results: Of the 108 patients identified, 35 cases had KRAS wild-type, 50 cases had a KRAS mutation and the remaining 23 were classified as impractical KRAS. Significantly longer medians for OS, HRFS and DFS were found in the impractical KRAS group. In the multivariable analyses, the KRAS mutational gene was the only variable that was maintained through OS, HRFS and DFS. For HRFS (HR: 13.63; 95% confidence interval (CI): 1.35–100.62; p = 0.010 for KRAS), for DFS (HR: 10.06; 95% CI: 2.40–42.17; p = 0.002 for KRAS) and for OS (HR: 4.55%; 95% CI: 1.37–15.10; p = 0.013). Conclusion: Our study considers the possibility of unnecessary KRAS testing in patients with metachronous tumours and negative lymph nodes harvested. Combining the genetic mutational profile (i.e., KRAS in specific cases) with tumour characteristics helps patient selection and achieves the best prognosis after CRLM resection.

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 [...].

Total tumor burden in lymphoma - an evolving strong prognostic parameter

Total metabolic tumor volume (TMTV), a new parameter extracted from baseline FDG-PET/CT, has been recently proposed by several groups as a prognosticator in lymphomas before first-line treatment. TMTV, the sum of the metabolic volume of each lesion, is an index of the metabolically most active part of the tumor and highly correlates with the total tumor burden. TMTV measurement is obtained from PET images processed with different software and techniques, many being now freely available. In the various lymphoma subtypes where it has been measured, such as diffuse large B-cell lymphoma, Hodgkin lymphoma, Follicular Lymphoma, and Peripheral T-cell lymphoma, TMTV has been reported as a strong predictor of outcome (progression-free survival and overall survival) often outperforming the clinical scores, molecular predictors, and results of interim PET. Combined with these scores, TMTV improves the stratification of the populations into risk groups with different outcomes. TMTV cut-off separating the high-risk from the low-risk population impacts the outcome whatever the technique used for its measurement and an international harmonization is ongoing. TMTV is a unique and easy tool that could replace the surrogate of tumor burden included in the prognostic indexes used in lymphoma and help tailor therapy. Other parameters extracted from the baseline PET may give an information on the dissemination of this total tumor volume such as the maximum distance between the lesions. Trials based on TMTV would probably demonstrate its predictive value.