Prognostic and Therapeutic Implications of Tumor Biology, Including Gene Alterations, in Colorectal Liver Metastases

The role of living donor liver transplantation in colorectal cancer liver metastases

PURPOSE OF REVIEW

Despite technical and therapeutic advances, only 20-40% of patients with colorectal liver metastases (CRLM) have resectable disease. Historically, the remaining patients with unresectable, liver-only CRLM would receive palliative chemotherapy, with a median survival of 8 months.

RECENT FINDINGS

Liver transplantation has emerged as a viable option for selected patients with CRLM. This advancement stems from improved understanding of tumour genomics and biology and better patient selection criteria. The results of recent prospective clinical trials have further ignited enthusiasm for liver transplantation as a viable therapeutic option. Living donor liver transplantation (LDLT) offers several advantages over deceased donor liver transplantation (DDLT) for this disease, including reduced wait-time and optimized timing and coordination of oncologic therapy. On-going LDLT clinical trials have demonstrated favourable outcomes as compared with other liver transplantation indications. However, there is no established consensus or standardization in the implementation of LDLT for CRLM, beyond trials and centre-specific protocols.

SUMMARY

LDLT is an excellent therapeutic option in highly selected patients with CRLM. Refining prognostic factors and selection criteria will help to further optimize the utility and broaden the acceptance and implementation of LDLT for patients with CRLM.

Neoadjuvant chemotherapy for borderline resectable colorectal cancer liver metastases: a single-institution retrospective study

INTRODUCTION

This study aimed to extract prognostic factors in patients undergoing neoadjuvant chemotherapy (NAC) for borderline resectable colorectal liver metastasis (BR-CRLM) (tumor size ≥5 cm, number of tumors ≥4, or resectable extrahepatic diseases) and assess validity of this strategy.

MATERIALS AND METHODS

Since 2010, patients with BR-CRLM were treated with hepatectomy after six cycles of NAC. Prognostic factors of these patients were evaluated using clinicopathological data.

RESULTS

Of 650 patients who underwent initial hepatectomy for CRLM from 2010 to 2018, 246 BR-CRLM cases underwent hepatectomy after NAC (BR-NAC). The 5-year recurrence-free survival rate was 16.7% and the 5-year overall survival rate (5y-OS) was 52.9%. Number of tumors ≥6, carcinoembryonic antigen (CEA) level ≥25 ng/mL, tumor diameter ≥5 cm, and progressive disease (PD) after NAC were identified as independent poor prognostic factors for OS. Patients were divided into four groups according to the number of risk factors, and prognoses of the four groups were well stratified.

CONCLUSION

In patients with BR-NAC, number of tumors ≥6, CEA ≥25 ng/mL, tumor diameter ≥5 cm, and PD after NAC were independent poor prognostic factors. Patients with three or four risk factors showed poor prognosis and may need to switch chemotherapy.

Incidence of and Risk Factors for Incisional Hernia After Hepatectomy for Colorectal Liver Metastases

BACKGROUND

Incisional hernia (IH) is common after major abdominal surgery; however, the incidence after hepatectomy for cancer has not been described. We analyzed incidence of and risk factors for IH after hepatectomy for colorectal liver metastases (CLM).

METHODS

Patients who underwent open hepatectomy with midline or reverse-L incision for CLM at a single institution between 2010 and 2018 were retrospectively analyzed. Postoperative CT scans were reviewed to identify IH and the time from hepatectomy to hernia. Cumulative IH incidence was calculated using competing risk analysis. Risk factors were assessed using Cox proportional hazards model analysis. The relationship between IH incidence and preoperative body mass index (BMI) was estimated using a generalized additive model.

RESULTS

Among 470 patients (median follow-up: 16.9 months), IH rates at 12, 24, and 60 months were 41.5%, 51.0%, and 59.2%, respectively. Factors independently associated with IH were surgical site infection (HR: 1.54, 95% CI 1.16-2.06, P = 0.003) and BMI > 25 kg/m2 (HR: 1.94, 95% CI 1.45-2.61, P < 0.001). IH incidence was similar in patients undergoing midline and reverse-L incisions and patients who received and did not receive a bevacizumab-containing regimen. The 1-year IH rate increased with increasing number of risk factors (zero: 22.2%; one: 46.8%; two: 60.3%; P < 0.001). Estimated IH incidence was 10% for BMI of 15 kg/m2 and 80% for BMI of 40 kg/m2.

CONCLUSION

IH is common after open hepatectomy for CLM, particularly in obese patients and patients with surgical site infection. Surgeons should consider risk-mitigation strategies, including alternative fascial closure techniques.

Construction of a co-expression network and prediction of metastasis markers in colorectal cancer patients with liver metastasis

BACKGROUND

Colorectal cancer (CRC) is a common global malignancy associated with high invasiveness, high metastasis, and poor prognosis. CRC commonly metastasizes to the liver, where the treatment of metastasis is both difficult and an important topic in current CRC management.

METHODS

Microarrays data of human CRC with liver metastasis (CRCLM) were downloaded from the National Center for Biotechnology Information (NCBI) Gene Expression Omnibus (GEO) database to identify potential key genes. Differentially expressed (DE) genes (DEGs) and DEmiRNAs of primary CRC tumor tissues and metastatic liver tissues were identified. Microenvironment Cell Populations (MCP)-counter was used to estimate the abundance of immune cells in the tumor micro-environment (TME), and weighted gene correlation network analysis (WGCNA) was used to construct the co-expression network analysis. Gene Ontology and Kyoto Encyclopaedia of Gene and Genome (KEGG) pathway enrichment analyses were conducted, and the protein-protein interaction (PPI) network for the DEGs were constructed and gene modules were screened.

RESULTS

Thirty-five pairs of matched colorectal primary cancer and liver metastatic gene expression profiles were screened, and 610 DEGs (265 up-regulated and 345 down-regulated) and 284 DEmiRNAs were identified. The DEGs were mainly enriched in the complement and coagulation cascade pathways and renin secretion. Immune infiltrating cells including neutrophils, monocytic lineage, and cancer-associated fibroblasts (CAFs) differed significantly between primary tumor tissues and metastatic liver tissues. WGCN analysis obtained 12 modules and identified 62 genes with significant interactions which were mainly related to complement and coagulation cascade and the focal adhesion pathway. The best subset regression analysis and backward stepwise regression analysis were performed, and eight genes were determined, including F10, FGG, KNG1, MBL2, PROC, SERPINA1, CAV1, and SPP1. Further analysis showed four genes, including FGG, KNG1, CAV1, and SPP1 were significantly associated with CRCLM.

CONCLUSIONS

Our study implies complement and coagulation cascade and the focal adhesion pathway play a significant role in the development and progression of CRCLM, and FGG, KNG1, CAV1, and SPP1 may be metastatic markers for its early diagnosis.