Lymphatics and colorectal liver metastases: the case for sentinel node mapping

VEGF-C propagates 'onward' colorectal cancer metastasis from liver to lung

BACKGROUND

The formation of lung metastasis as part of the progression of colon cancer is a poorly understood process. Theoretically, liver metastases could seed lung metastases.

METHODS

To assess the contribution of the liver lymphatic vasculature to metastatic spread to the lungs, we generated murine liver-metastasis-derived organoids overexpressing vascular endothelial growth factor (VEGF)-C. The organoids were reimplanted into the mouse liver for tumour generation and onward metastasis.

RESULTS

Liver metastases from patients with concomitant lung metastases showed higher expression of VEGF-C, lymphatic vessel hyperplasia, and tumour cell invasion into lymphatic vessels when compared to those without lung metastases. Reimplantation of VEGF-C overexpressing organoids into the mouse liver showed that VEGF-C caused peritumoral lymphatic vessel hyperplasia, lymphatic tumour cell invasion, and lung metastasis formation. This change in metastatic organotropism was accompanied by reduced expression of WNT-driven adult stem cell markers, and increased expression of fetal stem cell markers and NOTCH pathway genes. Further NOTCH pathway inhibition with γ-secretase inhibitor (DAPT) in vivo results in a slight reduction in lung metastases and a decrease in lymphatic hyperplasia and invasion in VEGF-C-overexpressing tumours.

CONCLUSION

Collectively, these data indicate that VEGF-C can drive onward metastasis from the liver to the lung and suggest that targeting VEGF-C/NOTCH pathways may impair the progression of colorectal cancer.

Lymph node metastasis of intrahepatic cholangiocarcinoma: the present and prospect of detection and dissection

Intrahepatic cholangiocarcinoma (ICC) ranks as the second most primary liver cancer that often goes unnoticed with a high mortality rate. Hepatectomy is the main treatment for ICC, but only 15% of patients are suitable for surgery. Despite advancements in therapeutic approaches, ICC has an unfavorable prognosis, largely due to lymph node metastasis (LNM) that is closely linked to the elevated recurrence rates. Consequently, the identification of precise and suitable techniques for the detection and staging of LNM assumes paramount importance for ICC therapy. While preoperative imaging plays a crucial role in ICC diagnosis, its efficacy in accurately diagnosing LNM remains unsatisfactory. The inclusion of lymph node dissection as part of the hepatectomy procedures is significant for the accurate pathological diagnosis of LNM, although it continues to be a topic of debate. The concept of sentinel lymph node in ICC has presented a novel and potentially valuable approach for diagnosing LNM. This review aims to explore the current state and prospects of LNM in ICC, offering a promising avenue for enhancing the clinical diagnosis and treatment of ICC to improve patient prognosis.

Impact of Positive Lymph Nodes after Systematic Perihilar Lymphadenectomy in Colorectal Liver Metastases

Background: 25 to 50% of patients suffering from colorectal cancer develop liver metastases. The incidence of regional lymph node (LN) metastases within the liver is up to 14%. The need for perihilar lymph node dissection (LND) is still a controversial topic in patients with colorectal liver metastases (CRLM). This study investigates the role of perihilar LND in patients with CRLM. Methods: For this retrospective study, patients undergoing surgery for CRLM at the University Hospital Basel between May 2009 and December 2021 were included. In patients with perihilar LND, LN were stained for CK22 and examined for single tumour cells (<0.2 mm), micro- (0.2-2 mm), and macro-metastases (>2 mm). Results: 112 patients undergoing surgery for CRLM were included. 54 patients underwent LND, 58/112 underwent liver resection only (LR). 3/54 (5.6%) showed perihilar LN metastases in preoperative imaging, and in 10/54 (18.5%), micro-metastases could be proven after CK22 staining. Overall complications were similar in both groups (LND: 46, 85.2%; LR: 48, 79.3%; p = 0.800). The rate of major complications was higher in the LND group (LND: 22, 40.7%; LR: 18, 31%, p = 0.002). Median recurrence-free survival (RFS) (LND: 10 months; LR: 15 months, p = 0.076) and overall survival (OS) were similar (LND: 49 months; LR: 60 months, p = 0.959). Conclusion: Preoperative imaging is not sensitive enough to detect perihilar LN metastases. Perihilar LND enables precise tumour staging by detecting more lymph node metastases, especially through CK22 staining. However, perihilar LND does not influence oncologic outcomes in patients with CRLM.

Surgical resectability of multisite metastatic colorectal cancer: Pushing the limits while appropriately selecting patients

Management of multisite colorectal metastases is expanding to make curative resection possible for more patients who present with advanced disease. Patient selection, tumor biology, meticulous surgical technique, and thoughtful perioperative care are essential to extending the benefit to patients previously treated with palliative goals of care.

Prognostic impact of perihepatic lymph node metastases in patients with resectable colorectal liver metastases

BACKGROUND

Although perihepatic lymph node metastases (PLNMs) are known to be a poor prognosticator for patients with colorectal liver metastases (CRLMs), optimal management remains unclear. This study aimed to determine the risk factors for PLNMs, and the survival impact of their number and location in patients with resectable CRLMs.

METHODS

Data on patients with CRLM who underwent hepatectomy during 2003-2014 were analysed retrospectively. Recurrence-free (RFS) and overall (OS) survival were calculated according to presence, number and location of PLNMs. Risk factors for PLNM were evaluated by logistic regression analysis.

RESULTS

Of 1485 patients, 174 underwent lymphadenectomy, and 54 (31·0 per cent) had PLNM. Ten patients (5·7 per cent) who had lymphadenectomy and 176 (13·4 per cent) who did not underwent repeat hepatectomy. Survival of patients with PLNM was significantly poorer than that of patients without (RFS: 5·3 versus 13·8 months, P < 0·001; OS: 20·5 versus 71·3 months; P < 0·001). Median OS was significantly better in patients with para-aortic versus hepatoduodenal ligament PLNMs (58·2 versus 15·5 months; P = 0·011). Patients with three or more PLNMs had significantly worse median OS than those with one or two (16·3 versus 25·4 months; P = 0·039). The presence of primary tumour lymph node metastases (odds ratio 2·35; P = 0·037) and intrahepatic recurrence requiring repeat hepatectomy (odds ratio 5·61; P = 0·012) were significant risk factors for PLNM on multivariable analysis.

CONCLUSION

Patients undergoing repeat hepatectomy and those with primary tumour lymph node metastases are at significant risk of PLNM. Although PLNM is a poor prognostic factor independent of perihepatic lymph node station, patients with one or two PLNMs have a more favourable outcome than those with more PLNMs.